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Mapping of Shallow Coastal Groundwaters, Their Hydrology and Environmental Geochemistry: Pumicestone Catchment, Southeast Queensland Ha Thi Thu Phan

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Page 1: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

Mapping of Shallow Coastal Groundwaters,

Their Hydrology and Environmental

Geochemistry: Pumicestone Catchment,

Southeast Queensland

Ha Thi Thu Phan

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Mapping of Shallow Coastal Groundwaters,

Their Hydrology and Environmental

Geochemistry: Pumicestone Catchment,

Southeast Queensland

Ha Thi Thu Phan

Supervisors

Associate Professor Malcolm E Cox - Discipline of Biogeosciences, QUT

Dr. Mauricio Taulis - Lecturer, Discipline of Biogeosciences, QUT

Dr. Craig Sloss - Lecturer, Discipline of Biogeosciences, QUT

A thesis submitted in partial fulfilment of the requirements for the Degree

of Master of Applied Sciences at the Queensland University of Technology.

2011

Discipline of Biogeosciences

Queensland University of Technology

Brisbane, Queensland, Australia

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Abstract

Blooms of the toxic cyanobacterium majuscula Lyngbya in the coastal waters of southeast

Queensland have caused adverse impacts on both environmental health and human health, and

on local economies such as fishing and tourism. A number of studies have confirmed that the

main limiting nutrients (“nutrients of concern”) that contribute to these blooms area Fe, DOC,

N, P and also pH. This study is conducted to establish the distribution of these parameters in a

typical southeast Queensland coastal setting. The study maps the geochemistry of shallow

groundwater in the mainland Pumicestone catchment with an emphasis on the nutrients of

concern to understand how these nutrients relate to aquifer materials, landuse and

anthropogenic activities. The results of the study form a GIS information layer which will be

incorporated into a larger GIS model being produced by Queensland Department of

Environment and Resource Management (DERM) to support landuse management to

avoid/minimize blooms of Lyngbya in Moreton Bay, southeast Queensland, and other similar

settings.

A total of 38 boreholes were established in the mainland Pumicestone region and four

sampling rounds of groundwater carried out in both dry and wet conditions. These

groundwater samples were measured in the field for physico-chemical parameters, and in the

laboratory analyses for the nutrients of concern, and other major and minor ions. Aquifer

materials were confirmed using the Geological Survey of Queensland digital geology map,

and geomaterials were assigned to seven categories which are A (sands), B (silts, sandy silts),

C (estuarine mud, silts), D (humid soils), E (alluvium), F (sandstone) and G (other bedrock).

The results of the water chemistry were examined by use of the software package

AquaChem/AqQA, and divided into six groundwater groups, based on groundwater chemical

types and location of boreholes. The type of aquifer material and location, and proximity to

waterways was found to be important because they affected physico-chemical properties and

concentrations of nutrients of concern and dissolved ions.

The analytical results showed that iron concentrations of shallow groundwaters were high due

to acid sulfate soils, and also mud and silt, but were lower in sand materials. DOC

concentrations of these shallow groundwaters in the sand material were high probably due to

rapid infiltration. In addition, DOC concentrations in some boreholes were high because they

were installed in organic rich wetlands. The pH values of boreholes were from acidic to near

neutral; some boreholes with pH values were low (< 4), showing acid sulfate soils in these

boreholes. Concentrations of total nitrogen and total phosphorus of groundwaters were

generally low, and the main causes of elevated concentrations of total nitrogen and total

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phosphorus are largely due to animal and human wastes and tend to be found in localized

source areas. Comparison of the relative percentage of nitrogen species (NH3/NH4+, Org-N,

NO3-N and NO2-N) demonstrated that they could be related to sources such as animal waste,

residential and agricultural fertilizers, forest and vegetation, mixed residents and farms, and

variable setting and vegetation covers. Total concentrations of dissolved ions in sampling

round 3 (dry period) were higher than those in sampling round 2 (wet period) due to both

evaporation of groundwater in the dry period and the dilution of rainfall in the wet period.

This showed that the highest concentrations of nutrients of concern were due to acid sulfate

soils, aquifer materials, landuse and anthropogenic activities and were typically in aquifer

materials of E (alluvium) and C (estuarine muds) and locations of Burpengary, Caboolture,

and Glass Mountain catchments.

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TABLE OF CONTENTS

Abstract.............................................................................................................................

Table of Contents.............................................................................................................

List of Figures...................................................................................................................

List of Tables....................................................................................................................

List of Abbreviations.......................................................................................................

Statement of Original Authorship..................................................................................

Acknowledgements...........................................................................................................

1. INTRODUCTION........................................................................................................

1.1. Introduction...................................................................................................

1.2. Aims and Objectives.....................................................................................

1.2.1. Aims.................................................................................................

1.2.2. Objectives.........................................................................................

1.3. Significance of Study.....................................................................................

2. DESCRIPTION OF THE STUDY AREA.................................................................

2.1. Location of Study Area.................................................................................

2.2. Climate...........................................................................................................

2.3. Geomorphology and Elevation....................................................................

2.4. Drainage Systems..........................................................................................

2.5. Landuse..........................................................................................................

2.6. General Geology...........................................................................................

2.7. Hydrogeology................................................................................................

3. BACKGROUND..........................................................................................................

3.1. Introduction..................................................................................................

3.2. Previous and Current Studies......................................................................

3.2.1. Previous Studies...............................................................................

3.2.2. Current Studies.................................................................................

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3.3. Features of Groundwater in Coastal Settings…………………………....

3.3.1. Surface Water Systems....................................................................

3.3.2. Coastal Groundwater Systems.........................................................

3.4. Concerns with Coastal Groundwater.........................................................

3.3.1. Coastal Groundwater Quality...........................................................

a) Lyngbya Majuscula...................................................................

b) Hydrogeochemistry...................................................................

c) Nitrogen.....................................................................................

d) Phosphorus................................................................................

e) Iron............................................................................................

f) Dissolved Organic Carbon........................................................

3.3.2. Saline Intrusion................................................................................

4. METHODS...................................................................................................................

4.1. Location of Boreholes ..................................................................................

4.2. Sampling Periods and Conditions...............................................................

4.3. Field Measurements and Sample Collection..............................................

4.3.1. Water Level Monitoring..................................................................

4.3.2. Physico-Chemical Analysis.............................................................

4.3.3. Groundwater Sample Collection......................................................

4.3.4. Groundwater Collection for Cations Analysis…………………….

4.3.5. Groundwater Collection for Anions and DOC Analysis………….

4.3.6. Groundwater Collection for Nutrient Analysis……………………

4.4. Laboratory Analyses.....................................................................................

4.4.1. Cations.............................................................................................

4.4.2. Anions and Nutrients.......................................................................

4.4.3. DOC.................................................................................................

4.5. Data Collection..............................................................................................

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4.6. Data Assessment Methods...........................................................................

4.6.1. Nutrients of Concern........................................................................

4.6.2. Ions...................................................................................................

5. RESULTS.....................................................................................................................

5.1. Boreholes in the field ...................................................................................

5.2. Aquifer Material Map..................................................................................

5.3. Location of Boreholes in the Aquifer Material Map.................................

5.4. Field Investigations.......................................................................................

5.4.1. Groundwater Monitoring Program..................................................

5.4.2. Physico-Chemical Measurements....................................................

5.5. Laboratory Analyses.....................................................................................

5.5.1. Charge Balance................................................................................

5.5.2. Major and Minor Ions.....................................................................

5.5.3. Seawater Intrusion...........................................................................

5.5.4. Forms of Nitrogen and Phosphorus.................................................

5.6. Nutrients of Concern....................................................................................

5.6.1. pH Measurements............................................................................

5.6.2. Total Iron.........................................................................................

5.6.3. Dissolved Organic Carbon...............................................................

5.6.4. Total Nitrogen..................................................................................

5.6.5. Total Phosphorus.............................................................................

6. DISCUSSION...............................................................................................................

6.1. Nutrients of Concern....................................................................................

6.1.1. Total Iron and pH.............................................................................

6.1.2. DOC.................................................................................................

6.1.3. Total Nitrogen and Total Phosphorus..............................................

6.2. Forms of Nitrogen.........................................................................................

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6.3. Comparing Ions in the Wet and Dry Periods.............................................

6.4. Groundwater Chemistry..............................................................................

6.4.1. Hydrochemical Groups....................................................................

6.3.2. Correlation Coefficient....................................................................

7. CONCLUSION.............................................................................................................

REFERENCES.................................................................................................................

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APPENDICES

Appendix 1: Analysis Manual of Cation Parameters

Appendix 2: Summary of Analysis Manual of Anions, Nutrients and DOC Parameters

Appendix 3: Cation Concentrations with Minimum, Maximum, Median and Average

Concentrations for All Boreholes

Appendix 4: Anion Concentrations with Minimum, Maximum, Median and Average

Concentrations for All Boreholes

Appendix 5: Minimum, Maximum, Median and Average Concentrations of Forms of

Nitrogen and Phosphorus for All Boreholes

Appendix 6: Concentration of Nutrients of Concern with Minimum, Maximum, Median

Concentrations for All Boreholes

Appendix 7: Percentage of Forms of Nitrogen and Phosphorus for All Boreholes

Appendix 8: Complete Data Sets of Four Sampling Rounds

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LIST OF FIGURES

Figure 2.1: Regional location of the study area in southeast Queensland, showing its

location relative to Brisbane

Figure 2.2: Location of the mainland Pumicestone study area - southeast Queensland

Figure 2.3: Monthly rainfall diagram (January 2008 - August 2010) in the study area

Figure 2.4: Elevation distribution in the mainland Pumicestone study area

Figure 2.5: Drainage systems in the mainland Pumicestone study area

Figure 2.6: Landuse map of the mainland Pumicestone study area

Figure 2.7: Different landuse in the mainland Pumicestone study area (a) Strawberry farm,

(b) Pineapple farm and (c) Exotic pine plantation

Figure 2.8: Geological map in the mainland Pumicestone study area

Figure 3.1: Warning of blue green algae bloom the mainland Pumicestone region

Figure 3.2: Bloom of Lyngbya in some locations in Southeast, Queensland

Figure 4.1: Location established in this area and their locations

Figure 4.2: Shallow groundwater borehole Sea 1110 near Ningi area

Figure 4.3: Shallow groundwater borehole Cab 208 near the sea and the Ningi residence

area

Figure 4.4: Water level measurement of borehole LYN 181 in the Bullock catchment (in the

forest near the Pumicestone Passage)

Figure 4.5: A TPS 90-FLMV field lab analyser

Figure 4.6: Groundwater collection in borehole LYN 181 in the Bullock catchment, this

borehole is installed in the forest near the Pumicestone Passage

Figure 4.7: Filtering of groundwater sample for cations analysis in the field

Figure 5.1: Location of 38 boreholes for collecting groundwater samples. Colours refer to

the different subcatchments

Figure 5.2: The aquifer material map developed for the mainland Pumicestone area

Figure 5.3: Distribution of boreholes on the aquifer material map for the mainland

Pumicestone study area, showing the surface drainage system catchment and aquifer

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materials

Figure 5.4: Groundwater level for all the boreholes throughout the different sampling

rounds. Water levels above 0 m reflect flooding

Figure 5.5: Variation of pH among sampling rounds and for different boreholes

Figure 5.6: Variation in EC values (less than 10000 µS/cm) among sampling rounds and for

boreholes

Figure 5.7: Variation in EC values (higher than 10000µS/cm) for sampling rounds and for

boreholes

Figure 5.8: EC values show the salinity of groundwater under wet conditions in sampling

round 2, June - July 2009

Figure 5.9: EC values show the salinity of groundwater under dry conditions in sampling

round 3, November 2009

Figure 5.10: Variation in Eh for sampling rounds and for different boreholes

Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for

different periods

Figure 5.12: Piper diagram for identifying groundwater types. Water types based on

dominant cations (left ternary) and anions (right ternary)

Figure 5.13: Plots of groundwater types in the wet period in the study area

Figure 5.14: Values of Cl/HCO3 ratio based on laboratory analysis of groundwater samples

collected in sampling round 2 during the wet period (June to July 2009)

Figure 5.15: Values of Cl/HCO3 ratio based on laboratory analysis of groundwater samples

collected in sampling round 3 during the dry period (November 2009)

Figure 5.16: Map of the median pH for all periods relating to the aquifer material layer in

the study area

Figure 5.17: Variation in total iron concentrations (mg/L) among sampling rounds and for

different boreholes

Figure 5.18: Map of the median iron concentration for all periods relating to the aquifer

material layer in the study area

Figure 5.19: Variation in DOC concentration (mg/L) between sampling rounds and for

different boreholes

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Figure 5.20: Map of the median DOC concentration for all periods relating to the aquifer

material layer in the study area

Figure 5.21: Variation in total nitrogen (mg/L) among sampling rounds and for different

boreholes

Figure 5.22: Map of the median total nitrogen concentration for all periods relating to the

aquifer material layer in the study area

Figure 5.23: Variation in total phosphorus between sampling rounds and for different

boreholes in aquifer materials in the study area

Figure 5.24: Map of total phosphorus concentration relating to the aquifer material layer in

the study area

Figure 6.1: Relationship of Fe and pH in four sampling rounds

Figure 6.2: Ternary diagram of the main forms of nitrogen in groundwater samples

Figure 6.3: Boreholes in the diagram showing the approximate stability fields of dissolved

nitrogen species as a function of Eh and pH at 25 °C and 1 atmosphere nitrogen pressure

Figure 6.4: Landuse and other factors influencing the percentage of nitrogen species in

groundwater samples

Figure 6.5: Total units and scales of each parameter in sampling rounds 2 and 3 (in the wet

and dry periods)

Figure 6.6: Logarithmic scatter plots of the median concentration of sodium and sulfate in

each groundwater group, comparing the wet and dry periods

Figure 6.7: Dominant groundwater groups and chemistry in the region shown by trilinear

diagram classifying groundwater into hydrochemical groups. This plot is for sampling round

2 (wet period)

Figure 6.8: Plot of pH and HCO3- in sampling round 2 (in the wet period)

Figure 6.9: Plot of EC and Cl- in sampling round 2 (in the wet period) showing the strong

relation between EC and Cl-

Figure 6.10: Plot of EC and SO4 in sampling round 2 (in the wet period) which shows the

strong relation between EC and SO4

Figure 6.11: Plot of NH3/NH4+ and TKN in sampling round 2 (in the wet period)

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LIST OF TABLES

Table 2.1: Monthly average rainfall (January 2008 - August 2010) for five stations in the

mainland Pumicestone study area

Table 4.1: Location of boreholes and their coordinates

Table 4.2:Sampling Periods and Conditions

Table 4.3: Sample analysis, measurement and methods

Table 4.4: Ranking of nutrients of concern to cause blooms

Table 5.1: 38 boreholes in subcatchments in the mainland Pumicestone study area

Table 5.2: Summary of the Aquifer Material Map

Table 5.3: Summary of boreholes, aquifer material, elevation and depth to water level

Table 5.4: Physico-chemical parameters for groundwaters

Table 5.5: Groundwater types based on electrical conductivity ranges

Table 5.6: Comparison of groundwater salinity variations in sampling rounds 2 and 3 (wet

and dry periods)

Table 5.7: Cation concentrations with minimum, maximum, median and average

concentrations for representative boreholes

Table 5.8: Anion concentrations with minimum, maximum, median and average

concentrations for representative boreholes

Table 5.9: Groundwater chemical types of boreholes in sampling round 2 (wet period)

relating to aquifer material

Table 5.10: Minimum, maximum, median and average concentrations forms of nitrogen and

phosphorus of several representative boreholes

Table 5.11: Concentration of nutrients of concern with median, minimum and maximum

concentrations for representative boreholes

Table 5.12: Median, minimum and maximum pH values for borehole samples in aquifer

materials in the study area

Table 5.13: Median, minimum and maximum iron concentrations for borehole samples in

aquifer materials in the study area

Table 5.14: Median, minimum and maximum DOC concentrations for borehole samples in

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aquifer materials in the study area

Table 5.15: Median, minimum and maximum total nitrogen concentrations for borehole

samples in aquifer materials in the study area

Table 5.16: Median, minimum and maximum total phosphorus concentrations for borehole

samples

Table 5.17: Summary of nutrients of concern in aquifer materials

Table 6.1: Percentage of forms of nitrogen for some boreholes

Table 6.2: Groundwater chemical type and relation to aquifers for sampling round 2 (wet

period)

Table 6.3: Spearman correlation of cations (A) and physico-chemistry, anions and nutrients

(B) for groundwater samples in sampling round 2 (in the wet period) in the mainland

Pumicestone region

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LIST OF ABBREVIATIONS

ASL Above Sea Level

ASS Acid Sulfate Soil

DERM Department of Environment and Resource Management

DOC Dissolved Organic Carbon

EC Electrical Conductivity

Eh Redox Potential

GIS Geographic Information System

GPS Global Positioning System

GSQ Geological Survey of Queensland

IC Inorganic Carbon

ICP-OES Inductively Coupled Plasma - Optical Emission Spectroscopy

NoC Nutrients of Concern

PASSCON Passage Conference

PVC Polyvinyl Chloride

QASSIT Queensland Acid Sulfate Soils Investigation Team

QUT Queensland University of Technology

TC Total Carbon

TDS Total Dissolved Solids

TKN Total Kjeldahl Nitrogen

TKP Total Kjeldahl Phosphorus

TN Total Nitrogen

TOC Total Organic Carbon

TP Total Phosphorus

WD Wheel Drive

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STATEMENT OF ORIGINAL WORK

All work contained within this thesis has not previously been submitted for any degree at any

other higher education institution and to the best of my knowledge, this thesis contains no

material previously unpublished or written by any other person except where due reference

has been made.

Signed………………………

Date…………………………

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ACKNOWLEDGMENTS

I would like to thank my principal supervisor Assoc.Prof. Malcolm Cox for giving me this

opportunity to undertake the study and his assistance and encouragement throughout the term

of this research project. I wish to thank to two associate supervisors Dr. Mauricio Taulis and

Dr. Craig Sloss.

I would like to thank to the Queensland University of Technology for giving me the tuition

fee and the Department of Environment and Resource Management, Queensland Government

for giving me the living scholarship to me having conditions to implement this study.

I would like to say a special thank to staff of DERM, Shane Pointon for his enthusiastic

assistance in my project.

I would like to thank to laboratory technician of QUT Shane Russell for his fair assistance in

working in the lab.

I wish to thank to my colleagues Genevieve Larsen and Martin Labadz for their assistance in

my study.

I wish to thank to staff and students of QUT (Rachael, Nate, Eloise and Peter) for their

assistance in collecting samples.

I have to make a special thank to my family for their support and love.

Thank you very much!

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1. INTRODUCTION

1.1. Introduction

The coastal zone is the transition area from land to sea and from fresh water to salt water and

within it there can be complex processes, especially in relation to the coastal groundwater

resource and its condition (Custodio & Bruggeman, 1987). Use of and impacts on coastal

groundwater have increased because populations and activities have become concentrated

along coastal regions and as a result, groundwater quality has deteriorated in recent years

(Newton et al., 2003). Many coastal areas have experienced an increase in blooms of the toxic

cyanobacteria Lyngbya majuscula in coastal zones (Albert et al., 2005). A number of studies

indicate that the main limiting nutrients for these outbreaks are pH, iron (Fe), dissolved

organic carbon (DOC), nitrogen (N), and phosphorus (P) (Ahern et al., 2008; Albert et al.,

2005; Johnson et al., 2009a). These main controlling nutrients for bloom of Lyngbya can be

related to the physical setting and also to landuse (Cox & Preda, 2005; Johnson et al., 2009b).

The Queensland Department of Environment and Resource Management (DERM) has

collaborated with universities and other organizations in the project “Implementing Algal

Blooms Policy” to create a hazard map which includes GIS coverage (acid sulfate soils,

landuse, soils, groundwater, pre-cleaning vegetation and remnant vegetation) and a proximity

to coast and stream coverage. The main purpose of this project is to identify the areas most

likely to produce and export “nutrients of concern” for coastal algal blooms in Moreton Bay,

southeast Queensland.

1.2. Aims and Objectives

1.2.1. Aims

This study forms part of the project “Implementing Algal Blooms Policy”. The aim of this

study is to mapping/characterize the geochemistry of shallow groundwater in the Pumicestone

catchment with an emphasize on the nutrients of concern in shallow groundwater to help the

parental project to identify the nutrient hazardous areas in order to avoid/minimize blooms of

Lyngbya majuscula in Moreton Bay, southeast Queensland, Australia

1.2.2. Objectives

To achieve the aim of the project, the following objectives will be addressed:

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Characterize the aquifer material based on previously published map of DERM

Produce maps (GIS layers) of shallow coastal groundwater showing the distribution

of nutrients of concern (pH, Fe, DOC, N and P) from new data in the mainland

Pumicestone area

Consider concentrations of nutrients of concern in each aquifer material to define

which aquifer materials export and produce mostly nutrients of concern into Moreton

Bay, southeast Queensland

Define species of nutrients of concern relating to aquifer materials and landuse in the

area

Assess the chemical characteristics and concentration of sampling rounds and

consider changes their concentrations in the wet and dry conditions in the area

1.3. Significance of Study

Blooms of Lyngbya are a significant problem in the coastal area in southeast Queensland,

Australia. Therefore, this study and its outcome will support the project “Implementing Algal

Blooms Policy” of DERM to define which areas export and produce mostly nutrients of

concerns into Moreton Bay, southeast Queensland to avoid/minimize blooms of the toxic

cyanobacteria Lyngbya majuscula in coastal zones.

Nutrients of concern is a term used for the parameters, pH, Fe, DOC, N and P as the

presence of these parameters in water is likely to promote the blooms of Lyngbya majuscula.

Acidity or pH is not a nutrient but a property of groundwater and always determines

conditions and setting of acidic groundwater can be related to acid sulfate soils (Buddhima et

al., 2010). Acid sulfate soil is the common name given to soils and sediments containing iron

sulfides, with pyrite being the most common. When exposed to air due to drainage or

disturbance, these soils produce sulfuric acid, often releasing toxic quantities of iron,

aluminum and heavy metals. Acid sulfate soils underlie much of the coastal zone in this

region, notably in areas at less than 5 m above sea level (Queensland Government, 2010).

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2. DESCRIPTION OF THE STUDY AREA

2.1. Location of Study Area

The Pumicestone region is a unique catchment in northern Moreton Bay, southeast

Queensland. The Pumicestone Region Catchment stretches from Golden Beach, Caloundra, in

the north to the Redcliffe Peninsula in the south. It is bounded by the D‟Aguilar Range in the

west and the Coral Sea in the east. The Catchment covers an area of 1,184 km2

including sub-

catchments. Bribie Island is a part of the drainage system which discharges into Pumicestone

Passage and Deception Bay. The region supports a diverse range of landuse activities

including forestry, aquaculture, extractive industries and also several National Parks and

nature conservation areas (Cox et al., 2000). This current study only focuses on the mainland

area in the Pumicestone region which includes the subcatchments of Burpengary, Caboolture,

Ningi, Elimbah; Bullock and Glass Mountain areas. The study site is located 80 km north of

Brisbane as shown in Figures 2.1 and 2.2.

Figure 2.1: Regional location of the study area in southeast Queensland, showing

its location relative to Brisbane

Moreton Bay

Brisbane River

Mainland

Pumicestone

Caboolture River

Pine River

0 10 20 30 kilometres

Bribie Island

Moreton Island

North Stradbroke Island

Redcliffe

153 0 00 ‟ 153 0 30 ‟ 152 0 30 ‟

27 0

Brisbane City

N

Deception Bay

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Figure 2.2: Location of the mainland Pumicestone study area - southeast Queensland

(Google Earth, 2009)

The Pumicestone Passage is a narrow waterway between Bribie Island and the mainland

Pumicestone region in southeast Queensland. The Pumicestone Passage is estuarine in nature,

with the northern passage entrance opening to the Pacific Ocean via a shallow unstable sand

bar, and the southern entrance joining Moreton Bay through a wide unobstructed opening

(Larsen, 2007). Bribie Island is separated from the mainland. Around 80% of the Passage is

less than two meters deep and is a low energy environment with a large input of suspended

material carried by the ten creek systems which drain directly into the Passage (Cox et al.,

2000; Larsen, 2007). The Pumicestone region is very important ecologically, economically

and especially the condition of the catchment. This is because it drains into the Pumicestone

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Passage and can influence the health of the Passage itself. The catchment area of 571 km2

drains directly into the Pumicestone Passage.

2.2. Climate

The mainland Pumicestone region is located in the sub-tropical region of Australia. The

climate is characterized by warm wet summers and mild, relative dry winters with the mean

temperature of 15 to 29 0C in the summer and from 9 to 20

oC in the winter.

The rainfall is higher in the summer which provides 65% to 70% of the annual average

rainfall. Yearly rainfall depends on the EI Niño/La Niña cycle, topography and vegetation

cover (Preda et al., 2000). Rainfall in the study area is recorded in five stations and listed

below and the monthly average rainfall (from January 2008 to August 2010) for these five

stations in the study area is shown in Table 2.1.

- Beerburrum Forest Station; Site number: 040284; Latitude: 26.96 °S; Longitude:

152.96 °E; Elevation: 48 m; Commenced: 1898.

- Peachester; Site number: 40169; Latitude: 26.84° S; Longitude: 152.88° E;

Elevation: 175 m; Commenced: 1915.

- Morayfield Mark St; Site number: 40774; Latitude: 27.10° S; Longitude: 152.95° E;

Elevation: 7 m; Commenced: 1989.

- Wamuran; Site number: 40343; Latitude: 27.04° S; Longitude: 152.87° E; Elevation:

33 m; Commenced: 1915.

- Godwin Beach; Site number: 40969; Latitude: 27.07° S; Longitude: 153.11° E;

Elevation: 7 m; Commenced: 2005.

Table 2.1: Monthly average rainfall (January 2008- August 2010) for five stations in the

mainland Pumicestone study area (BOM, 2010)

Monthly Godwin Beach Morayfield

Mark St

Beerburrum

Forest Station Wamuran Peachester

Jan 113.5 139.5 163.7 206.0 214.9

Feb 223.8 195.7 306.8 268.5 413.5

Mar 164.1 156.7 177.5 147.6 242.2

Apr 210.1 236.8 159.0 170.2 169.6

May 209.8 135.6 230.9 164.5 134.3

Jun 135.8 106.4 113.1 70.1 103.1

Jul 66.0 17.6 57.1 47.4 64.3

Aug 37.9 31.6 29.8 31.3 30.4

Sep 78.8 97.0 56.9 65.4 84.9

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Oct 89.2 85.8 102.4 67.0 73.4

Nov 140.2 174.3 119.7 147.9 119.8

Dec 100.1 121.7 147.8 166.6 138.0

Minimum 37.9 17.6 29.8 31.3 30.4

Maximum 223.8 236.8 306.8 268.5 413.5

Average 130.8 124.9 138.7 129.4 149.0

Annual rainfall in 2008 was 1528 mm, 1755 mm in 2009 and for the eight months (January -

August) in 2010 was 1146 mm in the study area. The lowest monthly rainfall recorded was

6.7 mm in August 2008 and the highest monthly rainfall was 414.6 mm from January 2008 to

August 2010 in the study. The yearly and monthly rainfall in the area was not equal. The

rainfall changed in months and years. Monthly rainfall diagram from January 2008 to August

2010 in the study area is shown in Figure 2.3.

Figure 2.3: Monthly rainfall diagram (January 2008 - August 2010) in the study area

(BOM, 2010)

2.3. Geomorphology and Elevation

The geomorphology of the mainland Pumicestone study area reflects a long history between

weathering and more recent estuarine sedimentation. The Landsborough Sandstone forms

topographic highs on the western boundary of the study area and reaching an elevation of 275

m above sea level. The morphology of the Landsborough Sandstone and variations in sea

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level were important in controlling the location and geometry of the younger deposits such as

sediment accumulation in the coastal plains. Along the southern and northern boundaries of

the study area are a series of ridges that form the catchment divide, and also mark the

groundwater and surface water divides. Shape of the study area shoreline is determined by a

combination of influences such as relative resistance to weathering of different rock units, sea

level variations and the related balance between sediment deposition and erosion, ocean and

bay currents and variations in tidal and wave energy (Cox et al., 2000; Ezzy, 2000).

Figure 2.4: Elevation distribution in the mainland Pumicestone study area (DERM,

2008)

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Land surface elevation in the region ranges from 0 to 275 m above sea level. The high

elevation is in the west around the catchment boundaries and the low elevation is towards the

coastline in the east. The majority of the study area consists of coastal plains with elevation

values of less than 20 m ASL. Therefore, these coastal plains were inundated annually in the

wet season (Larsen, 2007). The elevation distribution in the region is represented in Figure

2.4.

2.4. Drainage Systems

Topography of the study area is distributed from high in the west to low in the east.

Therefore, the drainage systems of the area have headwaters in the west which discharge into

the Passage and Deception Bay in the east. The water bodies of the area include river,

estuaries, freshwater wetlands and tidal lagoons. The drainage systems have formed a

complex series of catchments and sub-catchments such as the Caboolture River and the five

creeks of Burpengary, Ningi, Elimbah, Bullock and Glasshouse Mountain as shown in Figure

2.5. The streams flow through tidal estuarine sections on the low relief coastal plains. This is

particularly the case in the lower 5 - 10 km of many creeks where they adopt a meandering

form and traverse the coastal plain (Alletson, 2000; Cox et al., 2000; Preda & Cox, 2002).

Burpengary Creek is located about 40 kilometres north of Brisbane, and has a total catchment

area of 7960 ha, occupying 6.5% of the Shire of Caboolture. The Burpengary Creek

catchment includes two creeks; Little Burpengary Creek of 1600 ha and Burpengary Creek of

6360 ha. These creeks flow into Deception Bay just south of the Caboolture River mouth.

Burpengary Creek begins in the D‟Aguilar Ranges at a height of 340 m above sea level. It

then flows through Morayfield, around the township of Burpengary to discharge into southern

Deception Bay (Caboolture Shire Council, 2007).

The Caboolture River catchment is approximately 32700 ha, with headwaters in the D'Aguilar

Ranges, near Mount Mee, an elevation of about 500 m above sea level. The river flows past

the town of Caboolture and meanders through mangrove-lined estuaries to northern Deception

Bay near Beachmere. Increased urbanisation threatens the environment in the Caboolture

River catchment and has resulted in reduced vegetation along river banks particularly in the

lower sections of the river, increased soil erosion and sediment, and nutrients entering

waterways (Caboolture Shire Council, 2008).

The Ningi Catchment is a meandering tidal creek flowing from west to east. The mouth of

Ningi Creek flows into the southern section of Pumicestone Passage and eventually through

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the southern tidal inlet into Moreton Bay via Deception Bay. Mangrove ecosystems dominate

this catchment with an elevation of less than 3 m ASL. These form the majority of the coastal

plains located within 4 km of the Pumicestone Passage (Pavlik, 2005).

Elimbah Creek is a large meandering creek flowing from west to east through the centre of

the catchment. Much of the Elimbah Creek catchment is located in a flat coastal plain area an

elevation of 0 to 50 m ASL. Bullock Creek and Ningi Creek are peripheral to this area, and

both these tidal inlets are shorter and shallower drainage systems than Elimbah Creek (Ezzy,

2000; Labadz, 2007).

Bullock and Glasshouse Mountain Creeks in the north of the study area are meandering tidal

creeks, flowing from west to east. A large part of the Bullock and Glasshouse Mountain

Creek catchments is located in a flat coastal plain area with an elevation from 0 to 50 m ASL.

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Figure 2.5: Drainage systems in the mainland Pumicestone study area (DERM, 2008)

2.5. Landuse

The mainland Pumicestone study area hosts the four major landuse categories of

agricultural/horticultural, urban/residential, plantation forestry and natural vegetation (Pointon

et al., 2003). The landuse map in the mainland Pumicestone study area is shown in Figure 2.6.

GLASSHOUSE MT CREEK

BURPENGARY CREEK

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Figure 2.6: Landuse map of the mainland Pumicestone study area (Summary from the

Geological Survey of Queensland (GSQ) date 4 October 2009)

Small livestock and produce farms have existed over the last 100 years in the study area.

Recently, a number of commercial activities have started to use and depend on local surface

and groundwater. These activities include cattle and horse grazing, strawberry and pineapple

farms, aquaculture (including oyster), worm and prawn farms, nursery development.

Additionally, several large scale chicken farms have been recently developed in the area.

Pineapples have been grown in the region from the early 1990s. It is a major local rural

industry with 60% of the total Australia production and a net area of some 2000 hectares.

Therefore, development of these activities will impact on ground and surface water.

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Urban areas in the region are a combination of residential, business services, commercial and

small-scale industrial uses and mining. The key urban areas include Ningi, Toorbul, Toorbul

Point, Donnybrook and Meldale. Urban-residential areas are mostly centred in western inland

areas on the railway towns west of Caloundra, west of Toorbul, close to Calboolture and

along the D‟Aguilar Range.

Pine plantations are the major landuse of the higher ground on the northern and western sides

of the study area. The exotic pine species, Pinus ellioti was successfully established in 1949

after trial runs by the Department of Forestry, Queensland. The different landuse in the

mainland Pumicestone study area are shown in Figure 2.7.

(a)

(b)

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Figure 2.7: Different landuse in the mainland Pumicestone study area (a) Strawberry

farm, (b) Pineapple farm and (c) Exotic pine plantation

2.6. General Geology

The geological setting of the Pumicestone region has a major influence on the coastal plain,

the form of the drainage systems and the chemical character of surface water and groundwater

in the region (Cox et al., 2000).

The mainland Pumicestone study area is part of the regional Mesozoic Nambour Basin which

was formed in a stable continental interior. The Nambour Basin includes continental fluviatile

sediments of the Triassic-Jurassic Landsborough Sandstone, Tertiary volcanoes, Quaternary

alluvium, Pleistocene alluvium and Holocene unconsolidated sediments (McKellar, 1993).

The Landsborough Sandstone is a dominant unit and covers most of the Pumicestone region

(Cox et al., 2000; Pavlik, 2005); the Sandstone units comprise brown to light grey, fine to

coarse grains (Ezzy, 2000). The Landsborough Sandstone is composed of abundant quartz

with about 50% occurring mainly as individual grains but also as microcrystalline quartz;

about 20% of feldspars including plagioclase (Na-Ca feldspars) and K-feldspar; abundant

lithic fragments form about 30% with volcanic minerals such as cryptocrystalline quartz,

mafic minerals, tuff and glass fragments, scattered patches of titaniferous minerals and small

amounts of metamorphic fragments (Cox et al., 2000; Hawkins, 1983; Pavlik, 2005). The

sedimentary sequences of the Landsborough Sandstone were deposited as thick fluviatile and

swampy sheets in the Nambour Basin. The Landsborough Sandstone has a total thickness

greater than 450 m and a thick laterite weathering profile with a thickness of 10 to 20 m on

top (Ezzy et al., 2006; Labadz, 2006).

(c)

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Tertiary volcanoes which occupy a small part in the Pumicestone region were created as

follows: freshwater sediments were deposited and basaltic volcanism occurred in the Early

Tertiary period; akali rhyolite and trachyte volcanism occurred along lines of structural

weakness in the underlying basement in the Mid-Tertiary and subsequent erosion of these

volcanoes has produced the remnant volcanoes in the Glass House Mountains in the

Pumicestone region (Cox et al., 2000).

Coastal areas in the Pumicestone region have evolved with the deposition of Quaternary

sediments, unconformable on bedrock (Oberhardt & Huftile, 2000). Quaternary alluvium is

composed of weathered material derived from the exposed surfaces of outcrops to the west is

the main part of the Quaternary sediments. There are also areas of the Quaternary

unconsolidated material including „coffee rock‟ or indurated sand layers which are generally

sand, partly or completely cemented by organic complexes or iron oxides (Pavlik, 2005).

The estuarine flats of the Pumicestone region have been developed since the last Quaternary

because of aggregation of Pleistocene and Holocene sediments on top of the bedrock (Ezzy et

al., 2006). Sediment was deposited in the Ice Ages of the Pleistocene period when sea levels

reached minimums of more than 120 m below the present level and the continental shelf was

exposed, weathered, and incised by river systems (Williams et al., 1998).

Holocene unconsolidated sediments were formed overlying the Pleistocene older alluvial

sediments during the periods of rising sea levels due to melting ice. The existing creek lines,

flood plains, and lagoons in-filled with estuarine sediment deposition were created during this

time. Bribie Island was formed due to the sea level changes and coastal progradation and the

Pumicestone Passage which separates the island from the mainland is a mesotidal, elongate,

backbarrier lagoon estuary with tidal inlets at either end (Cox et al., 2000). The geological

map in the mainland Pumicestone study area based on the Geological Survey of Queensland

is shown in Figure 2.8.

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Figure 2.8: Geological map in the mainland Pumicestonestudy area (The Geological

Survey of Queensland (GSQ))

2.7. Hydrogeology

Geologic materials in the Pumicestone region can be divided into consolidated rock and

unconsolidated sediments from a hydrogeological point of view. Consolidated rock in the

region consists of Triassic-Jurassic Landsborough Sandstone, basalt and unconsolidated

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sediment which contains granular materials such as sand, gravel, silt and clay is the major

aquifer in the Quaternary plain in the Pumicestone region (Ezzy et al., 2006).

Confined, semi-confined and unconfined aquifers are present in the Pumicestone region

(Bean, 2000; Ezzy et al., 2006; Hodgkinson, 2008). The confined aquifer which is recharged

at some distance is in the western hills and central plain regions. Groundwater in the confined

aquifer is under sub-artesian conditions. On the other hand, semi-confined aquifer has been

defined toward the east where it is overlain by Holocene coastal units and Late Pleistocene

clays. Additionally, this unconfined aquifer was found in oceanic island settings where tidal

water mixing occurs in low lying areas (Bean, 2000; Ezzy et al., 2006).

This study installed boreholes in the shallow unconfined aquifers influenced by the interaction

of multiple processes such as seasonal rainfall variations, fluvial discharge, tidal and wave

energy flux and near shore currents. The differences of density between saline ocean waters

and fresh shallow groundwaters formed an interface or transition zone between the two water

bodies (Hodgkinson, 2008). All of these processes play an important role in including

groundwater quality variations and different groundwater types.

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3. BACKGROUND

3.1. Introduction

The mainland Pumicestone study area in southeast Queensland extends along the coast from

Glasshouse Mountain Creek in the north to Burpengary Creek in the south. This area is bound

by the D‟Aguilar Range in the west. The western side is protected from the direct oceanic

influence by a sand barrier, Bribie Island (McKellar, 1993). The shape of shoreline in the

study area is determined by a combination of influences such as relative resistance to

weathering of different rock units, sea level variations and the related balance between

sediment deposition and erosion, ocean and bay currents and variations in tidal and wave

energy (Cox et al., 2000; Ezzy, 2000).

The chemical characteristics of coastal groundwater in the area are different from

groundwaters of other areas (Ezzy, 2000). Shallow groundwater found in the area is strongly

influenced by the shallow lithostratigraphy, topography, seasonal rainfall, tidal fluctuations

and landuse.

The particular concern in the area is the changing landuse related to rapid population growth

(EPA/DERM, 2004). Agricultural/horticultural, urban/residential, plantation forestry and

natural vegetation are major landuse categories in the area. These various landuses have the

potential to place considerable pressure on coastal groundwater resources through pollution or

over abstraction (Pavlik, 2005). Sources of coastal groundwater pollution in the area rise from

fertilizers used in intensive agriculture, manures of animals from farms and residential area

sewage near to coast areas. In addition, coastal groundwaters in this area are affected by saline

intrusion and acid sulfate soils. Therefore, the study area has seen an increase in blooms of the

toxic cyanobacteria Lyngbya majuscula due to nutrients of concern. These main controlling

nutrients for bloom of Lyngbya can be reflected in the physical setting and also to landuse

(Cox & Preda, 2005).

3.2. Previous and Current Studies

3.2.1. Previous Studies

There have been numerous studies of groundwater systems and hydrogeology in the mainland

Pumicestone region but in small areas. This current study will be implemented in the whole

mainland Pumicestone region. In addition, this study also analyses all parameters of nutrients

of concern, major and minor ions and measurement of depth to water level of boreholes.

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Hodgkinson (2008) studied the groundwater and its setting on Toorbul island and showed that

back-barrier island in Toorbul was evaluated as discrete hydrogeological entity. Back-barrier

islands have complex groundwater systems which exist in a delicate state of equilibrium. Poor

groundwater quality is not necessarily derived from intrusion of the surrounding estuarine

surface water and can instead be attributed to the influence of continentally derived

groundwater.

Labadz (2006) studied the hydrogeological conceptual model on Beachmere area which

revealed a complex stratification of Quaternary sediments in the area. Heterogeneity within

these sediments formed a complex hydrological system with a broad range of hydraulic

conductivities affecting groundwater levels, groundwater flow paths and groundwater

chemistry. Labadz also measured the macronutrients nitrogen (NO3-) and phosphorus (PO4

3-)

and the micronutrient iron (Fe) at the monitoring wells to integrate into the results of the flow

budget of the study area to determine discharge loads of nutrients of concern into Deception

Bay.

Brewster (2006) studied the hydrogeological conceptual model and analyses of water table

fluctuation on Meldale island and he identified three separate aquifers in the alluvial sands

existing on eastern Meldale. The astronomical tide has a major influence on water levels in

aquifer 1 in the north of the island. Aquifer 2 in the middle of the island and aquifer 3 in the

south of the island are affected by diurnal fluctuations. The groundwater of eastern Meldale is

fresh to brackish and neutral to slightly acidic from 5 to 7, with salinity increasing and pH

decreasing towards the eastern margins of the island. The high acidity of the groundwater on

the periphery of the island is caused by acid sulfate soils. Humic sands are not extensive over

the island. In addition, he identified that the atmospheric pressure affects the water table on

the island.

Pavlik (2005) studied distribution and chemistry of groundwater on the Ningi catchment.

Pavlik found that groundwater is almost entirely recharged by rainfall because of high

bicarbonate enrichment. A low-lying swamp area exists in the northern part of the central

catchment with flow paths from both east and west directed towards this area, resulting in a

zone of fresh water/seawater mixing. Pavlik defined four distinct hydrochemical groups in the

catchment in which the sodium chloride water type is the most common (75%). Through

cation exchange processes of aquifer materials, seawater was the dominant source of ions

with groundwater enrichment of calcium and magnesium. The high concentration of calcium

in groundwater is due to shell carbonate material dissolution. The acidic groundwater is due to

acid sulfate soils. In addition, elevated nutrient levels in the form of NO3 were found to be

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originating from farmland in the west of the catchment, and groundwater at one site

surrounded by pineapple plantations contained low TDS with NO3 as the dominant anion.

Ezzy (2000) studied distribution and chemistry of the groundwater on the Meldate coastal

plain. Ezzy defined that groundwater in the Meldale coastal plain exhibits a complex

distribution and the chemical character of the groundwater is quite diverse. There were seven

major groups of groundwater in the area. Groups 1 to 3 are hosted in coastal sands and

shallow bedrock and are predominantly fresh waters, with a neutral pH, low EC values and

high Eh values. The significant concentrations of Ca and HCO3 are attributed to fresh water

flushing and the dissolution of shelly carbonate material. Groups 4 to 7 are situated in alluvial

sand, fluvial sand, weathered bedrock and deeper sandstone bedrock. These waters have a low

pH, high EC and low Eh. Elevated Na and Cl are indicative of the influence of seawater and

rainwater inputs. Anomalous SO4 concentrations in those groundwaters are attributed to

sulfuric sediments in the shallow coastal plain. Hypersaline groundwater in fluvial sand

deposits is characterized by Mg-enrichment which is possibly a consequence of seawater

intrusion and cation exchange reactions with Mg-smectite in the sediment. The cause of those

characteristics was the plain‟s variable sedimentary succession, which has been primarily

influenced by Late Pleistocene sea level fluctuations. Ezzy also found there was a

discontinuous nature of the groundwater bodies because of a high proportion of low

permeability silts and clays and the occurrence of sandrock in the sedimentary succession.

The study identified the five groundwater bodies in the Meldale coastal plain:

1. Alluvial sand and silt

2. Coastal sand and silt

3. Fluvial sand and gravel associated with the Elimbah Creek

4. Mottled silty clay layer in the weathered bedrock and

5. Landsborough Sandstone bedrock

In addition, a compilation of work was made at PASSCON 2000, the Pumicestone Passage

and Deception Bay Catchment Conference which was developed around the concept of

Science Informing Catchment Management covering a substantial area of Moreton Bay in

southeast Queensland. The conference identified the environmental settings in this region

such as shallow marine, estuaries, freshwater, and the headwaters of the many streams

draining towards the coastline and Bribie Island. This conference provided knowledge for

environmental managers, scientists and political groups involved in decision making of the

region. The conference focused on four themes such as geo setting, water systems, biological

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processes and towards sustainability. These themes of PASSCON covered many researches

from universities, government and industries. In which many researches were useful reference

for this study such as General Features of the Geo Setting of the Pumicestone Region (Cox et

al., 2000); Surface Water Quality in Response to Rainfall, Pumicestone Passage and

Tributaries (Preda et al., 2000); General Features of Groundwater Occurrence and

Implications for Management - Beachmere Coastal Plain, Northern Deception Bay (Lee,

2000) and Groundwater Chemical Character; Migration, Donnybrook Township, Pumicestone

Passage (Buck & Cox, 2000) and Surface water quality of the freshwater section of Elimbah

Creek, Pumicestone Passage (Cullen, 2000).

Other investigation, research and conference which were implemented such as the

Queensland Acid Sulphate Soils Investigation Team has conducted investigations about acid

sulphate soils in coastal plain in Queensland; trace metals in acid sediments and waters,

Pimpama catchment, southeast Queensland, Australia (Preda & Cox, 2001); hazard mapping

of land-based "nutrients of concern" for coastal algal blooms in Southeast Queensland

(Pointon et al., 2008) and trace metal occurrence and distribution in sediments and

mangroves, Pumicestone region, southeast Queensland, Australia (Preda & Cox, 2002).

3.2.2. Current Studies

A current PhD study of Labadz (2011) in the Elimbah Creek is:

- To understand the nutrient cycle within Elimbah Creek catchment and identify nutrient

sources, their concentrations, forms, controls on release, distribution and fixing, and

specifically the association with current landuse

- To understand the complex interaction between nitrogen and phosphorus, both natural and

anthropogenic, within surface water and shallow groundwater of the study area

- To determine whether nitrogen and phosphorus from the catchment are subject to transport

into the estuary and adjoining marine environments, and will identify the associated controls.

3.3. Features of Groundwater in Coastal Settings

The coastal zone is the interface between the land and seawater and is continually changing

because of the dynamic interaction. These zones are important and include many of the fastest

growing countries and coastal communities will continue to expand in the future. Coastal

communities and industries require many natural resources to sustain them and the most

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important resource is freshwater so groundwater use has increased in mostly coastal areas

(Barlow, 2003; Nelson, 2009).

3.3.1. Surface Water Systems

Surface water systems include rivers, creeks, estuaries, lakes, freshwater wetlands and tidal

lagoons. Surface water in the coastal plains in the region is limited due to the highly

permeable surface sediments and the low-relief morphology (Armstrong, 2006). The surface

water systems are distributed variously and complexly because of various morphology in the

area (Alletson, 2000; Cox et al., 2000; Preda & Cox, 2002).

3.3.2. Coastal Groundwater Systems

Rising sea levels inundated many areas, land and saline water occupied many contemporary

freshwater coastal plain aquifers in the area during the Late Quaternary (Fetter, 1994). The

mixing of freshwater with saltwater causes the development of a salinity gradient. Saline

water has a far greater content of dissolved salts than fresh water therefore, it has a greater

density. Therefore, more saline water in inland aquifers could be either trapped from the time

of formation or occur due to mineralization and stagnant flow conditions owing to density

contracts (Fetter, 1994).

Coastal groundwater in the mainland Pumicestone study area occurs in a variety of aquifer

material such as confined, semi-confined and unconfined aquifers (Ezzy et al., 2006;

Hodgkinson, 2008). Known impacts on the aquifer and the groundwater include changes in

landuse from agricultural to residential; rising water tables as a result of decreasing of

extraction for irrigation; declining water tables in areas where extraction has increased;

decline in water quality due to increasing use of nutrients (fertilizers and sewage); and an

increased number of private bores on some bay islands. Restrictions of the development of

groundwater resources do not exist on the mainland, hence a further decline in water quality

and availability is assumed (Cox et al., 1996; Labadz, 2006). Water management plans only

exist on the barrier islands such as Bribie, North Stradbroke and Moreton.

The coastal groundwater systems have chemical characters which distinguish them from

groundwaters of other settings. The coastal groundwater systems in the study area have the

important characteristics such as mixing of freshwater and seawater, variations in aquifer

material and variations in groundwater types (Ezzy, 2000). Coastal groundwater in the study

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area is variable in groundwater types. Groundwater type Na(Ca,Mg)-Cl is typical in coastal

groundwater in the area. Groundwater type with two ions Cl and HCO3 would define the

mixing of waters from different sources, called saline intrusion. Groundwater type with ion

SO4 is probably related either to sediments of marine origin or to sulfide minerals in

carbonaceous layers (Cox et al., 1996; Labadz, 2006). Groundwater type with two dissolved

components Ca and HCO3 in coastal groundwater is related to the occurrence of shell

fragments in the Holocene sediments (Ezzy, 2000; Pavlik, 2005).

3.4. Concerns with Coastal Groundwater

3.4.1. Coastal Groundwater Quality

Groundwater quality in many cases is better and more stable than surface water, and can

sometimes be used without treatment as a domestic water source. The quality and chemical

character of groundwater depends on local geological settings, land use and human activities

(Katayama, 2008).

However, the quality of coastal groundwater in many regions of the world has deteriorated in

recent years because human population and activities have increased along coastal regions

(Newton et al., 2003). Many of the environmental issues related to coastal ecosystems such as

red tides, fish kills, loss of seagrass habitats, and destruction of coral reefs can be attributed to

the introduction of excess nutrients from freshwater discharges (Barlow, 2003). Coastal zones

often have the greatest population worldwide because of flat land, easy sea transportation,

good soils and high productivity of organic matter. Therefore, the demand for freshwater

often exceeds available resources in these areas with anthropogenic activities often interfering

with the natural processes of coastal zones (Custodio & Bruggeman, 1987).

The groundwater quality in many coastal areas of the Pumicestone region is effected by

saline intrusion due to its low elevation (Ezzy, 2000; Kleindienst, 2000) and is also severely

affected by acid sulfate soils (ASS) and the leaching of trace metals (Dear et al., 2002).

Contaminant discharge via groundwater into the ocean may have contributed to the

degradation of coastal marine systems around the world including water quality and ecology

(Li et al., 1999). In addition, the use of nitrogen fertilizers and organic manures has increased

significantly with intensive agriculture. However, their utilization efficiency is generally low

and the unutilized nitrogen may accumulate in the soil profile potentially causing pollution in

streams or groundwater (Ferreira et al., 2003).

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Acidic groundwater is an environmental problem in many coastal areas of Australia

(Buddhima et al., 2010). Acid sulfate soils typically has ≤ 4, high concentrations of SO42-

and

mobile toxic metals. Environmental problems occur such as acidification and metal loadings

of surface waters, extensive hydrobiological damage, weathering of concrete, and depletion or

enrichment of metals in biota arise where these soils are widespread (Åström et al., 2007).

ASS causes environmental and social impacts on coastal zones such as fish kills, corrosion,

loss of biodiversity, subsidence and loss in agricultural productivity due to acidic and metal-

rich drainage. Change in the soil chemical environment can increase leaching of trace metals

bound in soils (Green et al., 2008; Klepper et al., 1992; Linde et al., 2007). Among these trace

metals, iron is an important biological and geochemical elements of concern due to

biogeochemical recycling and ecological risks and it has been identified as an important

limiting nutrient together the other nutrients of concern (N, P, DOC and pH) to cause bloom

of Lyngbya (Liaghati et al., 2005).

a) Lyngbya Majuscula

International

In recent years, the blooms of toxic cyanobacteria Lyngbya have been increasing in frequency

and severity in some marine places in the world. Three major Lyngbya species,

Lyngbyapolychroa, Lyngbya confervoides and Lyngbya majuscula, have been identified as

„nuisance‟ blooms. For examples, Lyngbya polychroa and Lyngbya confervoides are often

found co-existing on coral reefs in Broward County, the northern Florida Keys and they

bloom in the spring-fall (Matthew et al., 2008). The occurrence and distribution of

cyanobacterial toxins from 1989 to 2006 in several Italian lakes of different characteristics

and human uses have been reported including drinking water abstraction and recreation

(Messineo et al., 2008). Other examples are the occurrence of toxic cyanobacteria in drinking

and recreational waters in Abha city, Saudi Arabia (Mohamed & Al Shehri, 2007), the blue

green bloom in the near shore waters of Cukai Bay facing the South China Sea (Shamsudin,

1999) the blue green algal communities formed an extensive cover on soils in Bangladesh

(Rother & Whitton, 1989). Lyngbya majuscula which blooms sporadically during the summer

months in the Indian River Lagoon has been found throughout tropical and subtropical

oceans. It is commonly found in inshore benthic habitats at depths up to 30 m and often forms

cosmopolitan assemblages with other filamentous organisms.

At present, there is a poor understanding of the temporal and spatial variation of Lyngbya‟s

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24

species. Physico-chemical and biological parameters including temperature, light attenuation,

nutrient availability and grazer preference are the likely cause of the bloom (Arthur et al.,

2008; Capper & Paul, 2008; Paul et al., 2005).

Nutrients such as phosphorus, nitrogen, iron and dissolved organic carbon are identified to

cause the Lyngbya blooms within Moreton Bay (Ahern et al., 2006; Albert et al., 2005;

Pointon et al., 2008). The nitrogen and phosphorus content of water has sharply increased as a

result of the changes in landuse. Nutrients mostly nitrogen and phosphorus for agriculture

have led to runoff and transportation of nutrients from non-point pollution sources into rivers

and lakes which threaten water quality (Leone et al., 2008) so urban stormwater runoff is

relative with deterioration of water quality in estuaries or lake bodies (Jeng et al., 2005).

Australia and Local Area

Lyngbya majuscula which is a toxic, filamentous marine blue-green cyanobacterium of the

family of Oscillatoriaceae Lyngbya inhabits tropical and sub-tropical estuarine and coastal

waters (Albert et al., 2005; Gross & Martin, 1996; Osborne et al., 2001; Watkinson, 2000).

Lyngbya majuscula which is a common component of many marine ecosystems grows on

solid or sandy substrates or epiphytically on seagrass, macroalgae and corals in the coastal

zones of many sub-tropical and tropical oceans.

The blooms of the toxic cyanobacterium Lyngbya in Australia have been documented for over

100 years (Watkinson et al., 2005). The nuisance blooms of Lyngbya had been observed

seasonally in the Moreton Bay, Queensland, Australia since the early 1990‟s (Albert et al.,

2005). From the mid 1990s, Lyngbya was reported in periodic bloom in the northern

Deception Bay and from the late 1990s on the eastern banks of Moreton Bay. In 2002, bloom

occurrences continued on the eastern banks of Moreton Bay, extending to Peel Island,

Fishermens Island, Thompsons Beach Redland Bay and extended further into the southern

Bay (Moreton Bay Waterways and Catchments Partnership, 2002). Bloom of Lyngbya in

some locations in southeast, Queensland is shown in Figure 3.2.

Recent research shows that the growth and development of Lyngbya is related to iron,

phosphorus and nitrogen (Gross & Martin, 1996; Pointon et al., 2008). The bloom of Lyngbya

on the coastal areas of Southeast Queensland causes adverse impacts on environmental health,

human health and economics such as fishing and tourism (Garcia & Johnstone, 2006;

Queensland Government, 2008). Lyngbya has been identified in the northern Deception Bay

since 2000 and had affected about 1 km2 of seagrass habitat. Figure 3.1 shows the warning of

the blue green algae bloom in the region.

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Figure 3.1: Warning of blue green algae bloom in the mainland Pumicestone region

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Figure 3.2: Bloom of Lyngbya in some locations in southeast, Queensland (Pointon et al.,

2004)

b) Hydrogeochemistry

Hydrogeochemistry in the natural environment is controlled by multiple processes and is

inherently complex. Chemical equilibrium between groundwater and the aquifer host material

is largely dependent on residence time, the presence of reactive minerals in the system and

climatic variation (Deutsch, 1997). Hydrogeochemical investigations were conducted to

assess the chemical composition of groundwater, identify its quality, as well as develop a tool

to understand groundwater processes. Major ions (Na+, K

+, Ca

2+, Mg

2+, Cl

-, SO4

2- and HCO3

-)

Reported bloom sites

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are used to check analyses, total dissolved solids and show groundwater types and mixing

surface water and groundwater.

Groundwater can be a mixture of waters of different chemical composition due to natural or

anthropogenic processes. Groundwater in an unconfined aquifer shows a characteristic

response to rainfall. The major dissolved ions provide different information about chemical

facies (Hodgkinson et al., 2007; Ramos-Leal et al., 2007). The hydrochemistry of

groundwater has been influenced by factors such as the aquifer mineralogical composition,

longitude and depth of the flow systems, underground temperatures, residence time and

evaporation processes (Ramos-Leal et al., 2007).

c) Nitrogen

Importance of Nitrogen

Nitrogen is an essential element to all life. It is an important component of proteins, genetic

material, chlorophyll and other organic molecules and is the fourth most common element in

living tissues (after oxygen, carbon and hydrogen) (River Science, 2005). The growth and

development of all organisms depends on the availability of mineral nutrients in which

nitrogen (N2) is the most important (Ahern et al., 2004; Deacon, 2008; Postgate, 1987).

Forms of Nitrogen

There are many forms of nitrogen which exist in the natural environment and they play an

important role as indicators in environmental studies. To determine nitrogen concentration in

groundwater in this study, different species of nitrogen such as nitrate (NO3-), nitrite (NO2

-),

ammonia (NH3/NH4+) and a total of ammonia and organic nitrogen were analyzed in the

laboratory. The different forms of nitrogen measured in this study are listed as follows:

- NO3- = NO3-N x 4.4

- Total Inorganic nitrogen (Ninorg) = NO3- + NO2

- + NH3/NH4

+

- TN (Total nitrogen) = Org-N + NO3- + NO2

- + NH3/NH4

+

Sources of Nitrogen

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Nitrogen gas forms about 78% of the earth‟s atmosphere. However, most organisms cannot

use the available nitrogen gas because of a triple bond between the two nitrogen atoms,

making the molecule almost inert. Nitrogen can be used for growth and development and all

organisms can fix N2 in the form of ammonium (NH4+) or nitrate (NO3

-) or it can take up

NH4+ and NO3

- from the water for metabolism (Ahern et al., 2004; Deacon, 2008; Harrison,

2008). The weathering of rocks releases NH4+ and NO3

- at a low rate. Therefore, nitrogen has

been identified as a limiting factor for the growth and development of organisms and has a

competitive advantage with other non-nitrogen fixing organisms in areas with limited

nitrogen (Ahern et al., 2008; Deacon, 2008; Jones, 1990).

Globally, human activities have the potential to increase the amount of nitrogen in the

environment though the use of synthetic fertilizers for intensive agriculture. Nitrogen in these

fertilizers leaks into groundwater, rivers, and streams, gradually seeping into coastal waters.

Animal wastes, wastewater treatment plants, and the combustion of fossil fuels are other

sources of nitrogen. These fuels release nitrogen compounds into the atmosphere which fall in

acid rain, adding significant amounts of nitrogen to some coastal waters (Newton et al., 2003).

d) Phosphorus

Importance of Phosphorus

Phosphorus is also an indispensable element to life. It is a component of important biological

molecules including RNA, DNA, ATP and phospholiquids. Phosphorus also helps to maintain

normal acid-base balance (pH) (Ahern et al., 2004; Gillooly et al., 2005). Phosphorus is one

of the required nutrients of Lyngbya and one of the major limiting nutrients for the Lyngbya‟s

growth. The increase of phosphorus loadings or concentration in the water ecosystem can

contribute to bloom of Lyngbya (Gillooly et al., 2005; Labadz, 2007; Ryther & Dunstan,

1971).

Forms of Phosphorus

Phosphorus usually exists as phosphate in natural systems, in which each phosphorus atom is

surrounded by 4 atoms of oxygen. The simplest phosphate is orthophosphate (PO43-

) (River

Science, 2005). In this study, orthophosphate (PO43-

) and total phosphorus (TP) were

analyzed in the laboratory. Total phosphorus (TP) is sum of orthophosphate (PO43-

) and

organic phosphorus.

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Orthophosphate is the major form of biologically available phosphorus found in water. It is

usually present as a combination of HPO42-

and H2PO4-, depending on pH, but for simplicity it

will be referred to here in this study as PO43-

. The sum of all forms of phosphorus in water is

known as total phosphorus (TP). Phosphorus is usually in a particulate form in waterways.

Some of this phosphorus can readily become available through mineralisation or desorption.

However, most of the sediment phosphorus pool remains unavailable most of the time. This

component includes inorganic phosphate compounds that are highly insoluble and organic

phosphate compounds that are resistant to mineralisation (River Science, 2005).

Source of Phosphorus

Phosphorus is one of the 20 most abundant elements in the solar system, and the 11th

most

abundant in the earth‟s crust (Minnesota Pollution Control Agency, 2007). Phosphorus is

found in soils, rock minerals, living organisms and water, but unlike nitrogen it is not present

in the atmosphere (River Science, 2005). Phosphorus-bearing minerals, the most abundant

source of phosphorus occurs in soils and sediments and goes into solution when in contact

with ground and surface water bodies. Phosphorus can exist in particulate or soluble forms

with the soluble phase such as inorganic or organic compounds. Phosphate is the most

common form of phosphorus in water ecosystems (Ahern et al., 2004; Labadz, 2007).

As with nitrogen, phosphorus too is an important fertilizer used in the Australian agricultural

sector for many years. Surface runoff and permeability will transfer fertilizer nitrogen and

phosphorus into water ecosystem which is also one of the causes of Lyngbya bloom and

eutrophication of water sources (Gross & Martin, 1996; Labadz, 2007).

Under natural conditions, phosphorus is scarce in water. However, human activities have

resulted in an excessive load of phosphorus into freshwater systems which can cause water

pollution in the form of eutrophication, algal bloom, and fish poisoning(Minnesota Pollution

Control Agency, 2007; Nieder & Benbi, 2008).

e) Iron

Importance of Iron

Iron is an important bioelement and its percent contents in the living matter are up to 1x10-2

%

(Verkhovtseva et al., 2001). Iron is an essential nutrient for the growth and metabolism of

aquatic organisms and its bioavailability has a profound influence on the productivity,

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30

composition and trophic structure of marine planktonic communities (Filgueiras & Prego,

2007). It is a critical element in all aerobic organisms as it participates in a variety of

metabolic networks. It is a major component of ferredoxin, an essential component of

photosynthetic and respirator electron transport chains (Ahern et al., 2004; Ahern et al., 2006;

Albert et al., 2005; Chenier et al., 2008). Recent studies show that iron is one of the main

elements supporting the growth of Lyngbya in the Pumicestone region, southeast Queensland

(Ahern et al., 2006; Albert et al., 2005; Liaghati et al., 2005; Pointon et al., 2003).

Forms of Iron

Iron is a very reactive element because it exists in three oxidation states such as metallic iron

(Fe0), ferrous iron or iron (II) (Fe

2+) and ferric iron or iron (III) (Fe

3+). The pH and redox

potential is important in dictating the form in which iron occurs in the environment (Ehrlich,

2002). In this study, total iron (Fetot

) was analyzed in the laboratory by using ICP-OES.

Source of Iron

Iron (Fe) is the fourth most abundant element and makes up 5% in the Earth‟s crust. A

number of minerals in rocks, soil and sediments contain iron. The primary source of iron on

the Earth‟s surface is accumulated from volcanic activity and the weathering of iron-

containing rocks and minerals is often an important phase in the formation of local iron

accumulation including sedimentary ore deposits (Ehrlich, 2002). Weathering and erosion of

geological formations and human activities will result in a major input of iron and metals to

coastal lowlands. Iron and other metals with dissolved and particulate forms from acid sulfate

soils (Queensland Government, 2010) are transported by streams or rivers and are deposited

on coastal floodplains, estuaries and bays (Preda & Cox, 2001).

The most important pathway for transportation of iron to the land–sea margins is the riverine

input and the mass-balance in the land–sea boundaries in seven of the largest rivers in the

world have been obtained. Therefore, the interest in this matter has been reconsidered and

extended recently to small rivers and tributaries (Filgueiras & Prego, 2007). The iron

concentration of seawater is quite low. Dissolved iron can exist in seawater in two oxidation

states Fe (II) and Fe (III) (Ahern et al., 2004). Generally, the dissolved iron concentrations in

mid-depth and deep water layers is higher than those in the surface mixed layer (Kenshi,

2008).

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f) Dissolved Organic Carbon

Importance of DOC

Dissolved organic carbon (DOC) which is an important component of the carbon cycle is a

parameter normally used to quantify organic pollution of water and wastewater. The fraction

of organics that passes through a 0.45 µm pore size membrane is called DOC (Katsoyiannis &

Samara, 2007).

Terrestrial-derived dissolved organic carbon contributes significantly to the energetic basis of

many aquatic food webs (Tittel et al., 2009). DOC is a food supplement which promotes the

growth of microorganisms and is one of the nutrient sources to cause Lyngbya bloom (Ahern

et al., 2004; Albert et al., 2005).

Source of DOC

Dissolved organic carbon (DOC) is found in water deriving from organic materials. DOC is

organic material broken down from plants and animals. Some DOC molecules have a

recognizable chemical structure easily identified such as fats, carbohydrates and proteins.

However most of them have no readily identifiable structure and are lumped under the term

“humic” or “tannin” substances.

3.3.2. Saline Intrusion

Under natural conditions, a balance exists between seawater and freshwater but as the density

of groundwater is less than that of seawater, seawater intrusion can occur. The interface

between the seawater and groundwater acquires a complicated shape (Khublaryan et al.,

2008). A coastal aquifer has at least one side of its perimeter in direct contact with the sea;

other sides can be affected by possible urban, industrial or agricultural pollution rising from

the mainland. Seawater intrusion and deterioration of its quality are two subjects of coastal

groundwater (Moujabber et al., 2006). Saline intrusion is often related to over pumping in

coastal regions. Therefore, seawater intrusion can take place with a drop in water levels in

unconfined aquifers or with the lowering of piezometric surfaces in confined aquifers causing

a detrimental effect on groundwater quality (Moujabber et al., 2006; Terzić et al., 2008). To

identify whether coastal groundwaters have potentially been intruded by seawater, the

Cl/HCO3 ratio is often used as an evaluation criteria. For example, if the ratio is greater than

1.5 EPM (equivalent parts per million), it is likely that the aquifer has been intruded by sea

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32

water. If the ratio is less than 1.5 EPM, it is likely that the aquifer has not been intruded by

sea water (Ezzy, 2000; Pavlik, 2005).

Saline intrusion has occurred in the mainland Pumicestone study area because a number of

commercial activities such as nurseries and aquaculture in the study area extract groundwater.

Residents in this area also use groundwater for gardening watering. These extractions enhance

the potential for saline intrusion in the area (Ezzy, 2000; Pavlik, 2005).

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4. METHODS

This study is a part of the project “Implementing Algal Bloom Policy” of the Department of

Environment and Resource Management (DERM). The goal of this investigation is to support

the Algal Bloom Nutrient Hazard Maps/models developed for DERM. The current study

addresses the coastal groundwater component and chemical characteristics of groundwater.

The activities conducted in this study include surveying the location of boreholes; sampling

events; field measurement and sample collection; laboratory analyses; data collection and data

assessment methods.

4.1. Location of Boreholes

Locating the boreholes was conducted in collaboration with the Queensland Acid Sulfate

Soils Investigation Team – Department of Environment and Resource Management

(QASSIT-DERM). New boreholes were designed to provide core samples for characterizing

the soils and for their subsequent development as shallow groundwater piezometers. The aim

was to collect cores from representative areas in the subcatchments and to establish a network

of bores with the areas of unconfined groundwater, and so aid in defining groundwater

character. The location of these boreholes was set up at selected locations and determined

using a Global Positioning System (GPS).

Elevation of these borehole locations is relatively low and mostly less than 5 m ASL. Only

three boreholes were installed at an elevation from 10 to 15 m ASL. A total of 39 new

shallow groundwater boreholes in the study area are shown in Figure 4.1, the location of

boreholes and their coordinates is shown in Table 4.1 and shallow groundwater boreholes in

the field are shown in Figures 4.2 and 4.3.

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34

Figure 4.1: Boreholes established in this area, and their locations

Table 4.1: Location of boreholes and their coordinates

Subcatchments RN Easting Northing RN Easting Northing

Burpengary

LYN 32 501438 6997716 SEA 1035 502745 6997259

LYN54 497745 6996721 SEA 1042 499800 6997218

SEA 1030 500418 6995239

Caboolture

BM5 508451 7003158 SEA 1047 504105 6999716

LYN 26 511193 7004210 SEA 1054 504728 7002116

LYN 34 506379 7001372 SEA 1063 502279 7001227

LYN 38 500849 7005123 SEA 1073 502660 7003587

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LYN 73 500840 7002498 SEA 1089 498981 7002083

SEA 1046 505272 6999569 SEA 1092 500758 7006225

Elimbah_Bullock

CAB 231 506595 7013480 LYN 48 497869 7013963

LYN 181 505203 7013974 SEA 1101 507332 7010766

LYN 36 504280 7011525 SEA 1108 503299 7010541

LYN 37 507558 7009724

Glass Mountain

LYN 183 501763 7015908 LYN 65 506127 7015994

LYN 184 501450 7016663 LYN 66 504299 7015634

LYN 39 501135 7017392

Ningi_Toorbul

CAB 208 509247 7010514 LYN 44 500112 7008539

CAB 214 509981 7009437 LYN 9 510671 7006204

CAB 216 510590 7008414 SEA 1109 508505 7009348

CAB 219 509510 7007885 SEA 1110 505718 7008782

LYN 4 513598 7005243 SEA 1156 503304 7009227

Figure 4.2: Shallow groundwater borehole Sea 1110 near Ningi Creek

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Figure 4.3: Shallow groundwater borehole Cab 208 near the sea and the Ningi

residential area

4.2. Sampling Periods and Conditions

Four sampling rounds were conducted (2 rounds in the dry periods and 2 rounds in the wet

periods). Sampling periods and conditions (amounts of rainfall, mm) are shown in Table 4.2.

Table 4.2: Sampling Periods and Conditions

Rounds Number of

Samples

Sampling

Location

Date of Sampling Conditions

Round 1 5 Glasshouse

Mountains

12/2008 - 01/2009

(mid summer)

Very dry

Round 2 37 All areas 06 - 07/2009

(winter)

Very wet

Round 3 37 All areas 11/2009

(early summer)

Very dry

Round 4 38 All areas 03/2010

(late summer)

Very wet

Only five groundwater samples in the Glasshouse Mountains were collected in sampling

round 1 (the dry period). Groundwater samples were collected using an electrical pump

during this sampling round. However, the groundwater level in each of the boreholes was

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37

very low so a hand pump was used to collect the groundwater samples. In this sampling

round, various difficulties were encountered including not being able to find the boreholes

and problems using a new analyzer and equipment. Therefore only five groundwater samples

were collected.

A total of 37 boreholes in all subcatchments were collected in sampling round 2 (wet period).

Borehole LYN 38 in the Caboolture catchment was marine and therefore difficult to collect.

Borehole SEA 1030 in the Burpengary catchment was destroyed by flood and possibly

vandalized.

A total of 37 boreholes in all subcatchments was collected in sampling round 3 (dry period)

because Borehole LYN 4 in the Ningi catchment had no water. Many boreholes were fired

and no water in the dry season. Therefore they were reinstalled and replaced.

A total of 38 boreholes in all subcatchments was collected and analyzed completely in

sampling round 4 (wet period). Generally, the southeast Queensland wet period was in winter,

starting in June and finishing in August. However, the 2009 wet period in Queensland

occurred earlier, from February to April, in late summer.

4.3. Field Measurement and Sample Collection

Groundwater parameters measured and methods are summarized in Table 4.3.

Table 4.3: Sample analysis, measurement and methods

Measurement and Analysis Parameters Analytical

Methods

Water Level Monitoring Depth to water level (m) Solinst Model 101

Water Level Meter

Physico-chemistry (in-situ) EC, Eh, pH, Temp Field meter

TPS 90-FLMV

Major and minor cations Na+, K

+, Mg

2+, Ca

2+, Al

3+, Mn

4+, Fe

tot,

Cu2+

, Zn2+

, Sr2+

ICP-OES

Major anions Cl-, SO4

2-, HCO3

- Colorimetry

Nitrogen (N) and

Phosphorus (P)

NO3-, NO2

-, NH3/NH4

+, TKN, PO4

3-,

TP

TN = NO3- + NO2

- + TKN

TKN = NH3/NH4++ Org-N

Colorimetry

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38

Dissolved organic carbon

(DOC)

DOC TOC analyzer

4.3.1. Water Level Monitoring

A Solinst Model 101 Water Level Meter was used to measure the depth to water level of

boreholes. The meter has a probe connected to a marked polyethylene tape fitted on a reel.

When the probe contacts the water, a light is switched on and the buzzer sounds. The water

level is measured by reading directly from the tape at the top of borehole concrete pad (i.e.

groundwater).

Measurement of water level was implemented to consider the change of water level with in

periods. A photo of a water level measurement is shown in Figure 4.4.

Figure 4.4: Water level measurement of borehole LYN 181 in the Bullock catchment (in

the forest near the Pumicestone Passage)

4.3.2. Physico-Chemical Analysis

Physico-chemical parameters were measured at the end of the sampling round. After purging

the borehole, physico-chemical parameters were measured either in-situ or collected into a

plastic bottle using a TPS 90-FLMV field lab analyser (Figure 4.5), depending on the depth of

groundwater level and the length of probe cables. Physico-chemical parameters were tested

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39

including hydrogen ion activity (pH), electrical conductivity (EC; µS/cm), reduction-

oxidation potential (Eh; mV) and temperature (T; 0C).

The meter was calibrated using known standards. Redox potential was pre-calibrated in the

laboratory due to the hazardous nature of the calibration standard. The pH was calibrated

against two known solutions of pH 6.88 and 4.00. Eh was calibrated using a Zobell solution

with a known value of 186 mV. Temperature was calibrated using an alcohol thermometer.

The conductivity probe was calibrated by a known solution of KCl 0.01mol and 0.001mol.

Figure 4.5: A TPS 90-FLMV field lab analyser

4.3.3. Groundwater Sample Collection

Groundwater samples were collected by a transparent perspex bailer (handpump) of about 50

cm or 1 m in length. Groundwater collection is shown in Figure 4.6. The amount of water in

the boreholes varied greatly with periods. In the wet period, the water level was high therefore

groundwater samples were easy to collect. However, problems were encounted in the dry

period when boreholes often had little water. Groundwater samples were collected in100 mL

and 200 mL polyethylene screw cap bottles.

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Figure 4.6: Groundwater collection in borehole LYN 181 in the Bullock catchment, this

borehole is installed in the forest near the Pumicestone Passage

4.3.4. Groundwater Collection for Cation Analyses

Plastic 100 mL bottles were used to collect water samples for major (Na+, K

+, Mg

2+ and Ca

2+)

and minor (Al3+

, Sr2+

, Mn2+

, Fetot

, Zn2+

and Cu2+

) cation analyses. These bottles were cleaned,

and rinsed with nitric acid with a 1:1 ratio (1 mL of nitric acid to 1 mL of distilled water) by

transferring approximately 20 mL of 1:1 nitric acid to each bottle, shaking it vigorously for

about 30 seconds, and transferring it to the next bottle. After rinsing these bottles 3 times with

distilled water, all traces of nitric acid were removed and then they were dried in the oven at

65 0C.

Each water sample was filtered using 0.45 µm syringe filters, and then acidified with nitric

acid to pH < 2. Samples were preserved by cooling to 4°C in a cooler box. Figure 4.7 is a

photo of the on-site sample filtering procedure for cation analysis.

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Figure 4.7: Filtering of groundwater sample for cation analyses in the field

4.3.5. Groundwater Collection for Anions and DOC Analyses

Plastic bottles 200 mL were used to collect groundwater samples for anions (HCO3-, Cl

-,

SO42, NO2

-, PO4

3- and DOC) analysis. These bottles were washed, and then soaked in Decon

solution for 24 hours. After rinsing with tap water 3 times, then with distilled water 3 times,

they were dried in the oven at 65 0C. Groundwater samples for anion analyses were collected

in the field and preserved by cooling to 4°C in a cooler box.

4.3.6. Groundwater Collection for Nutrient Analyses

Plastic 200 mL bottles were used to collect groundwater samples for nutrient analysis (NO3-,

NH4+, TKN and TKP). These bottles were cleaned using tap water, then rinsed with a sulfuric

acid solution with a ratio of 1:4 (1 mL of sulfuric acid and 4 mL of distilled water). This was

achieved by transferring about 20 mL of sulfuric acid solution in a bottle, shaking vigorously

for 30 seconds, and then transferring to the next bottle. After rinsing these bottles 3 times with

distilled water to remove all traces of sulfuric acid, they were then dried in the oven at 65 0C.

Groundwater samples were collected, acidified by sulfuric acid to pH < 2 and preserving it by

cooling to 4°C in the cooler box.

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4.4. Laboratory Analyses

The laboratory analysis of water samples involved the determination of cations and major

anions, nutrients (N, P) and dissolved organic carbon (DOC).

4.4.1. Cations

Inductively Coupled Plasma – Optical Emissions Spectrometer (ICP-OES) was used to

analyze major cations (Na+, K

+, Mg

2+ and Ca

2+) and minor cations (Fe

tot, Al

3+, Sr

2+, Mn

2+,

Zn2+

and Cu2+

). Before analysis, groundwater samples with high electrical conductivity (EC)

were diluted to less than 4000 µS/cm. Four water standards of known cationic concentrations

were used to test calibration and repeated after analysis of eight or ten water samples. The

analytical manuals for cations are attached in Appendix 1.

4.4.2. Anions and Nutrients

The AQ2+ Discrete Analyzer was used to analyze anions (HCO3

-, Cl

- and SO4

2-) and nutrient

(NO2-, NO3

-, NH4

+, NH4

+ + Org-N, PO4

3- and TP). NO2

- and PO4

3- must be analyzed within 48

hours after collection, while HCO3- must be analyzed within 14 days after collection. Other

parameters must be analyzed within 28 days after collection.

Groundwater samples were filtered using a 0.45 µm syringe filter before pouring them into a

2 mL vial. Standard solutions and reagents were prepared for analysis of parameters and

contained in plastic and glass bottles. The summary of analysis manuals of these parameters is

attached in Appendix 3. Higher standard solution and diluted standard solution of known

chemical concentrations had to be used to test calibration and concentration of standard

solutions to guarantee the precision of cation concentrations. After sample analysis was

finished, samples of high concentration were diluted automatically for continuous analysis.

4.4.3. DOC

The TOC-VCPH/TOC-VCPN (hereinafter referred to as TOC-V) instrument was used to

measure the amount of total carbon (TC), inorganic carbon (IC) and total organic carbon

(TOC) in water. In this study, water samples were filtered using a 0.45 µm filter therefore,

total organic carbon (TOC) will be as dissolved organic carbon (DOC).

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After groundwater samples were filtered, they were poured into 25 mL vials for analysis. TC

and IC standard solutions of known chemical concentrations, and distilled water were used to

test calibration and standard solutions. TC and IC standard solutions were prepared for DOC

analysis and contained in glass bottles. The summary of analysis manuals of anions,nutrients

and DOC is attached in Appendix 2.

4.5. Data Collection

This study had collected the regional data of the mainland Pumiestone region, southeast

Queensland from the Department of Environmental and Resource Management (DERM)

such as rainfall, elevation (DEM) and digital geology maps, landuse, drainage system, roads,

forestry compartments and road to create maps of the area.

4.6. Data Assessment Methods

4.6.1. Nutrients of concern

The methods used in this part of the study are for the purpose of assisting DERM in creating

the Algal Bloom Nutrient Hazard Maps/models. These maps define which aquifer materials

export and produce mostly nutrients of concern into Moreton Bay. To meet demand of the

project, each map of nutrients of concern was divided into nutrients hazard categories: low,

median, high and very high.

Based on the results of sampling rounds, mean values of all sampling rounds, references of

the Australia and New Zealand Guidelines for Fresh and Marine Water Quality 2000 and after

meetings with staff of DERM about the progresses of the project, ranks of nutrients of

concern (1, 2, 3 and 4) were divided. These ranks are equal to low, median, high and very

high levels of nutrient hazard. Ranks of nutrients of concern according to nutrient hazard are

shown in Table 4.4.

Table 4.4: Ranking of nutrients of concern to cause blooms

Rank pH Fe

(mg/L) DOC

(mg/L) TN

(mg/L) TP

(mg/L) Nutrients

Hazard

1 6.0 - 7.5 < 5.0 < 5.0 < 1.0 < 0.25 Low

2 5.1 - 6.0 5 - 14.9 5.0 - 9.9 1.0 - 4.9 0.25 - 0.49 Median

3 4.1 - 5.0 15 - 49.9 10 - 49.9 5.0 - 9.9 0.5 - 0.75 High

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4 <= 4.0 >= 50 >= 50 >= 10 > 0.75 Very high

An aquifer material map of the mainland Pumicestone study area was also created based on

the Geological Survey of Queensland (GSQ) digital geology map using the following seven

categories. These divisions were based on grouping the lithological units of the GSQ geology

into each category with similar characteristics.

1. A - sands

2. B - silts, sandy silts

3. C - estuarine mud, silts

4. D - humid soils

5. E - alluvium

6. F - sandstone

7. G - other bedrock

One map layer of 38 boreholes was created and defined the number of boreholes in each

aquifer material. After that the median, minimum and maximum values of each aquifer

material were defined to compare which aquifer material obtains the nutrient hazard such as

low, median, high and very high.

4.6.2. Ions

The cation and anion analytical results of sampling rounds were entered into the software

package AquaChem/AqQA to identify groundwater types and calculate charge balance errors

of groundwater samples in sampling rounds. After considering the results of sampling rounds,

a hydrochemical classification system for groundwater in sampling round 2 (wet period) was

implemented using a trilinear Piper plot. This identified the dominant groundwater groups.

Additionally, the Spearman correlation of cations (A) and physico-chemistry, anions and

nutrients (B) were calculated to identify possible associations. Bivariate graphs of major

cations and anions also identified trends, grouping and mixing of different groundwater

groups and the percentage of species of nitrogen was calculated.

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5. RESULTS

This chapter presents the results obtained from field and laboratory work and includes data

sections such as drilling and installing boreholes; aquifer material map; field investigations,

laboratory results and analytical precision.

Drilling and installing shallow groundwater boreholes was conducted before collection of

groundwater samples. However, some boreholes were shallow and not located in optimum

positions, and had no water in the dry season; other boreholes were burnt in a fire, or flooded

after heavy rain. These boreholes were reinstalled during the study to guarantee collection of

samples. The aquifer material map is a summary based on the GSQ (Geological Survey of

Queensland) digital geology map. The field investigation section presents measurement

results of depth to water and physico-chemical parameters (pH, EC, Eh and T0) of

groundwater in the sampling rounds. The section on laboratory analysis and precision

presents analytical results of major and minor cations, anions, dissolved organic carbon,

nutrients of concern and forms of nitrogen and phosphorus.

5.1. Boreholes in the field

There were 39 boreholes drilled and installed in the mainland Pumicestone study area.

Borehole SEA 1030 in the Burpengary catchment was vandalized and a total of 38 boreholes

were used for collecting groundwater samples. Boreholes and their subcatchments are shown

in Table 5.1 and Figure 5.1.

Table 5.1: The 38 boreholes in subcatchmentsin the mainland Pumicestonestudy area

No Subcatchments Number of boreholes

1 Burpengary 4

2 Caboolture 12

3 Ningi-Toorbul 10

4 Elimbah-Bullock 7

5 Glasshouse Mountain 5

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46

Figure 5.1: Locations of the 38 boreholes for collecting groundwater samples. Colours

refer to the different subcatchments

5.2. Aquifer Material Map

To provide a generalized hydrogeological map, an aquifer material map (Figure 5.2) was

produced by summarizing from the digital geology map produced by GSQ and by discussion

with staff of DERM in the progresses of the projects. To adequately represent materials in the

study area, seven material categories were established on this map (Table 5.2): A (sands); B

(silts, sandy silts); C (estuarine muds); D (humic soils); E (alluvium); F (sandstone) and G

(other bedrock).

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Table 5.2: Summary of the Aquifer Material Map

Generalised

Aquifer

Material

Age Lithology

From GSQ Digital Geology Map Symbol

(GSQ)

A. Sands

Holocene Quartz sand in Holocene beach ridge and berm Qhcb/1

Holocene Quartz sand in Holocene beach ridge and berm Qhcb/2

Holocene Quartz sand in Holocene beach ridge and berm Qhcb/4

Holocene Quartz sand in Holocene beach ridge and berm Qhcb/5

Holocene Sand, shelly sand in beach ridges Qhcb

Pleistocene Sand and shelly sand in beach ridges Qpcb

B. Silts, sandy

silts

Holocene Mud and sand in undifferentiated coastal plains Qhc

Holocene Quartz sand and peaty quartz sand in Holocene

coastal swamp Qhcw

Quaternary Quartz sand in tidal delta Qmt

Pleistocene Clay, silt, sand and gravel in stranded river

terrace (above floodplain) Qpa/1

Pleistocene Silt, clay, sand and gravel in high level alluvium Qpa,Qhc

Pleistocene Silt, clay, sand and gravel in high level alluvium Qpa

Quaternary Sand, soil, clay, rock debris in residual soil and

colluvium Qr

C. Estuarine

muds

Holocene Sand, mud, grades in tidal flats Qhct

Holocene Sandy mud, muddy sand and minor gravel in

estuarine channels and banks Qhe

Holocene Lithofeldspathicsublabile sand and muddy sand

in fluvial delta Qhmd

Holocene Lithofeldspathicsublabile sand, muddy sand and

sandy mud in shoreface/fringing coral reef Qhms

D. Humic soils Holocene Mud, silt and peat in swampy basins Qhaw

E. Alluvium

Holocene Gravel, sand, silt, clay in the lowest river terrace Qha/1

Holocene Sand, silt, clay gravel in the second river terrace Qha/2

Holocene Clay, silt and sand in active stream channels and

low terraces Qha

Quaternary Clay, silt, sand and gravel in flood plain

alluvium Qa

Quaternary Alluvial clay, silt, sand in estuarine Qe

F. Sandstone

(bedrock)

Triassic -

Jurassic

Siltstone, shale, minor coal and ferruginous

iolite marker in lithofeldspathic labile and

quartzose sandstone

RJl

Quaternary Residual soil, colluvium; sand, soil, clay and

minor rock debris over Landsborough Sandstone Qr>RJl

G. Other

bedrock Tertiary Rhyolite Ti

Reference for GSQ (Geological Survey of Queensland) digital geological maps for symbols

Aquifer material A (sands) is grouped from six lithological units which include quartz

sand in Holocene beach ridge and berm (Qhcb/1); quartz sand in Holocene beach ridge

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and berm (Qhcb/2); quartz sand in Holocene beach ridge and berm (Qhcb/4); quartz

sand in Holocene beach ridge and berm (Qhcb/5); sand and shelly sand in Holocene

beach ridges (Qhcb); and sand and shelly sand in Pleistoncene beach ridges (Qpcb).

These types of “sand” were grouped because they have similar characteristics. Sand

materials (A) are along and often parallel to the coast from the Caboolture River to

Elimbah Creek. These deposits mostly occur on active beach zones or sand dune

systems behind the beaches.

Aquifer material B (silts, sandy silts) is grouped from seven lithological units which

include mud and sand in Holocene undifferentiated coastal plains (Qhc); quartz sand

and peaty quartz sand in Holocene coastal swamp (Qhcw); quartz sand in Quaternary

tidal delta (Qmt); clay, silt, sand and gravel in Pleistocene stranded river terrace (above

floodplain) (Qpa/1); silt, clay, sand and gravel in Pleistocene high level alluvium (Qpa,

Qhc); silt, clay, sand and gravel in Pleistocene high level alluvium (Qpa); sand, soil,

clay and rock debris in Quaternary residual soil and colluviums (Qr). These lithological

units are grouped because they mix of silt, sand, gravel and soil. Silt and sandy silt

material (B) is distributed near the coast, in the middle of the sand material, near

estuarine mud material and in the Caboolture area. These deposits occur behind the

dunes.

Aquifer material C (estuarine muds) is grouped from four lithological units which

include sand and mud from Holocene tidal flats (Qhct); sandy mud, muddy sand and

minor gravel in Holocene estuarine channels and banks (Qhe); lithofeldspathicsublabile

sand, muddy sand in Holocene fluvial delta (Qhmd); lithofeldspathicsublabile sand,

muddy sand, sandy mud in Holocene fringing coral reef (Qhms). These lithological

units are grouped because they area mix of mud and sandy mud from estuaries.

Estuarine mud material (C) is distributed near seven estuaries in the study area with an

elevation less than 5 m above sea level.

Aquifer material D (humic soils) consists of mud, silt and peat in a Holocene swampy

basin (Qhaw). This aquifer material is based on one original group, humic soil material

(D), which is distributed near the silt and sandy silt material occupies the small area

Aquifer material E (alluvium)was grouped from four lithological units with similar

characters and morphological setting and include gravel, sand, silt and clay in

Holocene lowest river terrace (Qha/1); sand, silt and clay gravel in Holocene second

river terrace (Qha/2); clay, silt and sand in Holocene active stream channels and low

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49

terraces (Qha); clay, silt, sand and gravel in Quaternary flood plain alluvium (Qa) and

estuarine and alluvial clay, silt, sand in Quaternary estuarine (Qe). Alluvium material

(E) is the connected part of estuarine mud material which is distributed over a large

area in the study area.

Aquifer material F (sandstone (bedrock) is based on two lithological units which

include siltstone, shale, minor coal, ferruginous iolite marker in Triassic-Jurassic

lithofeldspathic labile and quartzose sandstone (RJI); and sand, soil, clay, minor rock

debris over Landsborough Sandstone in Quaternary residual soil and colluviums

(Qr>RJI). These lithological units were grouped into one aquifer material because they

are mixed siltstone, shale, minor coal, ferruginous iolite marker, sand, soil, clay and

minor rock debris. This group forms the bedrock underlying unconsolidated material

and is not considered an aquifer in this study. Sandstone bedrock material (F) is

distributed over the largest extension of land in the study area. This material is

intermixed with other materials.

Aquifer material G (other bedrock) consists of rhyolite in Tertiary (Ti) aged material

which occupies one small portion in the northwest area in the study area. This is

intrusive volcanic material in the Glasshouse Mountains region. Other bedrock material

(G) is distributed in the Glasshouse Mountains creek area and includes volcanic

material. These materials are not significant in this study.

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Figure 5.2: The aquifer material map developed for the mainland Pumicestone area

5.3. Location of Boreholes in the Aquifer Material Map

The 38 boreholes installed in the Pumicestone area were distributed in representative aquifer

materials (A, B, C and E) as follows: aquifer A with 5 boreholes; aquifer B with 12 boreholes;

aquifer C with 4 boreholes and aquifer E with 17 boreholes. The distribution of boreholes in

the aquifer material map in the study area is shown in Figure 5.3 and sites boreholes in

unconsolidated aquifer materials for which there would be some hydrological connections to

the drainage systems. The importance of this is the potential of groundwater to enter the

active drainage systems. Therefore, these boreholes were often installed near the drainage

systems at a lower relative elevation in subcatchments and commonly in locations that have a

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51

hydrological connection to drainage systems. Groundwater in these boreholes was called the

shallow unconfined groundwater.

Figure 5.3: Distribution of boreholes on the aquifer material map for the mainland Pumicestone

study area, showing the surface drainage system catchments and summarized aquifer materials

5.4. Field Investigations

5.4.1. Groundwater Monitoring Program

All boreholes were installed in areas of low elevation, mostly less than 5 m ASL. Only two

boreholes (LYN 48 and LYN 39) were installed at around 10 m ASL and another (LYN 44) at

an elevation of 16 m ASL. The boreholes were installed close to waterways and within

unconfined aquifers. Additionally, the depth to water level in all boreholes is relatively

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52

shallow. Table 5.3 presents a summary of water level measurements for the different

boreholes throughout the different catchments and for each aquifer material.

Table 5.3: Summary of boreholes, aquifer material, elevation and depth to water level

Aquifer

Material RN Catchments

Elevation

(m ASL)

Depth to Water Level (m) min-max

(median/aver)

A

LYN 26 Caboolture 2.0 0.3 - 0.93

(0.4/0.54)

LYN 34 Caboolture 1.5 0.4 - 1.27

(0.75/0.81)

BM5 Caboolture 2.5 0.8 - 1.3

(0.96/1.02)

SEA 1046 Caboolture 3.0 0.5 - 1.1

(0.8/0.8)

LYN 9 Ningi_Toorbul 2.0 0.22 - 0.64

(0.3/0.39)

B

SEA 1047 Caboolture 2.0 0.6 - 0.9

(0.84/0.78)

LYN 4 Ningi_Toorbul 3.0 0.44 - 0.6

(0.52/0.52)

LYN 44 Ningi_Toorbul 16.0 0.45 - 0.65

(0.5/0.53)

CAB 219 Ningi_Toorbul 2.0 1.06 - 2.38

(1.6/1.68)

SEA 1109 Ningi_Toorbul 1.0 0.03 - 1.27

(0.1/0.47)

CAB 216 Ningi_Toorbul 0.5 0.16 - 1.73

(0.2/0.7)

CAB 214 Ningi_Toorbul 0.5 0.13 - 1.49

(0.79/0.8)

CAB 208 Ningi_Toorbul 0.5 0.63 - 0.87

(0.63/0.71)

LYN 36 Elimbah_Bullock 2.0 0.78 - 2.58

(2.24/1.87)

LYN 37 Elimbah_Bullock 1.0 0.39 - 0.67

(0.6/0.55)

SEA 1101 Elimbah_Bullock 1.0 0.24 - 1.08

(0.35/0.56)

SEA 1108 Elimbah_Bullock 4.0 0.13 - 1.36

(0.25/0.58)

C

SEA 1035 Burpengary 1.5 0.04 - 0.67

(0.5/0.4)

SEA 1110 Ningi_Toorbul 1.0 0.07 - 0.46

(0.14/0.22)

LYN 65 Glass Mountain 0.5 0 - 0.67

(0.45/0.39)

LYN 66 Glass Mountain 2.5 0 - 0.9

(0.19/0.32)

LYN 32 Burpengary 2.0 0 - 0.2

(0/0.07)

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E

LYN54 Burpengary 2.0 _0.1 - 0.05

(-0.1/-0.05)

SEA 1042 Burpengary 3.0 1.4 - 2.35

(1.78/1.84)

LYN 48 Elimbah_Bullock 10.0 _0.08 - 0.49

(-0.3/0.04)

LYN 181 Elimbah_Bullock 5.0 0.05 - 1.21

(0.76/0.67)

CAB 231 Elimbah_Bullock 2.0 0.49 - 1.96

(0.8/1.08)

LYN 39 Glass Mountain 10.0 _0.1 - 0.27

(0.12/0.1)

LYN 183 Glass Mountain 2.5 _0.35 - 0.6

(0.31/0.218)

LYN 184 Glass Mountain 5.0 0.1 - 1.06

(0.56/0.57)

LYN 38 Caboolture 1.0 0 - 0.3

(0.15/0.02)

LYN 73 Caboolture 1.5 0.23 - 1.15

(0.5/0.63)

SEA 1054 Caboolture 2.0 0.24 - 1.84

(0.66/0.91)

SEA 1063 Caboolture 1.0 0.08 - 1.14

(0.15/0.46)

SEA 1073 Caboolture 3.0 0 - 0.82

(0.02/0.28)

SEA 1089 Caboolture 3.0 1.3 - 1.8

(1.56/1.55)

SEA 1092 Caboolture 2.0 0.08 - 0.2

(0.15/0.14)

SEA 1156 Ningi_Toorbul 2.0 0.07 - 1.39

(0.73/0.73)

Measurement of the depth to water level was conducted on all boreholes throughout the

different sampling rounds. The depth to groundwater level changed throughout the different

rounds because of rainfall variations, although some of these were not typical of seasonal

norms for the wet and dry periods. Figure 5.4 shows the groundwater level variations for the

monitored boreholes throughout the different sampling rounds.

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Figure 5.4: Groundwater level for all boreholes throughout the different sampling

rounds. Water levels above 0 m reflect flooding.

The groundwater levels of boreholes clearly respond to rainfall. For example, it is noted that

groundwater levels in the dry periods occurred at a lower depth than in the wet periods. The

water level for all boreholes was typically 0 to 2.58 m below ground level. However, the

water level was above ground level for some boreholes located in the Glasshouse Mountains,

Burpengary and Elimbah-Bullock. For borehole Lyn 54, the water levels in Rounds 2 and 3

(dry and wet periods) were identical. The water levels for this borehole were above ground

level because this borehole was installed in the creek. Also, the water level for borehole Lyn

48 was above ground level in rounds 2 and 4 (wet periods). The water levels in round 4 (wet

period) were identical and higher than ground level for some boreholes in the Glasshouse

Mountains area because of flooding near these boreholes.

Burpen Caboolture Ningi_Toorbul Elimbah_Bullock GlassMt

SouthNorth South

North

Flood

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5.4.2. Physico-Chemical Measurements

Physico-chemical parameters include pH, Eh, EC and T were measured in the field for two

dry and two wet periods. The minimum, maximum, median and average values of each

parameter in these physico-chemical parameters are shown in Table 5.4.

Table 5.4: Physico-chemical parameters for groundwaters

Aquifer

Material RN

pH min-max

(median/aver)

EC (µS/cm) min-max

(median/aver)

Eh (mV) min-max

(median/aver)

T0 (

0C)

min-max (median/aver)

A

LYN 26 5.4 - 6.2

(6.1/5.9) 160.3 - 281

(270/237.1) 86 - 174

(148/136) 20.3 - 23.7

(22.4/22.1)

LYN 34 5.1 - 7.8

(6.1/6.3) 505 - 6530

(3050/3361.7) 33 - 132

(42/69) 19.4 - 24.1

(23.6/22.4)

BM5 4.2 - 5.9

(5.5/5.2) 171.1 - 692

(272/378.4) 63 - 250

(188/167) 21.3 - 26.2

(22.5/23.3)

SEA 1046 5.4 - 5.9

(5.4/5.6) 134.3 - 215

(148.5/166) 34 - 122

(96/84) 19.1 - 25.9

(23.1/22.7)

LYN 9 5.8 - 6.0

(5.9/5.9) 225 - 254

(232/237) _216 - 76

(58/-27.3) 21.7 - 24

(22.3/22.7)

B

SEA 1047 5.7 - 6.3

(5.7/5.9) 19630 - 24900

(19630/22453.3) 115 - 168

(160/147.7) 19.4 - 24.7

(21.6/21.9)

LYN 4 4.3 - 5.3

(4.8/4.8) 254 - 425

(339.5/339.5) 67 - 179

(123/123) 20.4 - 24.7

(22.6//22.6)

LYN 44 5 - 5.5

(5.1/5.2) 151.7 - 245.5

(194/197.1) 158 - 205

(160/174.3) 17 - 25

(23.3/21.8)

CAB 219 5.0 - 5.8

(5.5/5.4) 75.8 - 783

(120.5/326.4) 209 - 273

(223/235) 18.9 - 25.1

(24.8/22.9)

SEA 1109 3.7 - 5.5

(3.7/4.3) 326 - 6090

(540/2318.7) 226 - 349

(327/300.7) 19.3 - 26.5

(23.6/23.1)

CAB 216 5 - 5.7

(5.7/5.5) 95.8 - 167.3

(97/120) 189 - 268

(204/220.3) 17.4 - 24.4

(23.6/21.8)

CAB 214 5.5 - 7.2

(6.6/6.4) 251 - 1522

(487/753.3) _53 - 155

(104/68.7) 16.9 - 26.2

(25/22.7)

CAB 208 4.9 - 5.7

(5.1/5.2) 12560 - 26000

(16300/18286.7) _60 - 201

(-50/30.3) 19.9 - 25.1

(22.9/22.6)

LYN 36 4.4 - 5.2

(4.6/4.8) 69.3 - 882

(322/424.4) 172 - 210

(183/188.3) 18.6 - 23.9

(22.7/21.7)

LYN 37 4.6 - 6.8

(5.8/5.7) 4460 - 29800

(10920/15060) 45 - 167

(101/104.3) 20 - 25.4

(25.4/23.6)

SEA 1101 4.4 - 5.7

(5.1/5.0) 439.6 - 6560

(1107/2702.2) 106 - 284

(112/167.3) 20.8 - 24.4

(23.8/23)

SEA 1108 3.7 - 4.7

(3.9/4.1) 731 - 1567

(1358/1227.7) 287 - 340

(330/319) 21.7 - 27.1

(24.5/24.4)

C

SEA 1035 5.1 - 6.4

(5.7/5.7) 52200 - 60600

(55800/56200) 50 - 144

(110/101.3) 17.8 - 25.9

(25.4/23)

SEA 1110 4.9 - 5.6

(5.3/5.3) 17260 - 55100

(53900/42086.7) 61 - 150

(127/112.7) 19.5 - 26.2

(23.8/23.2)

LYN 65 3.2 - 5.3

(4.9/4.58) 32000 - 40900

(38950/32000) 69 - 324

(147.5/172) 18.3 - 25.7

(24.2/23.1)

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LYN 66 3.1 - 5.4

(3.6/3.9) 35600 - 44300

(42350/41150) 225 - 260

(252.5/247.5) 17.9 - 25.7

(24.9/23.4)

E

LYN 32 2.9 - 3.8

(3.2/3.3) 14450 - 15570

(15400/15140) 320 - 402

(320/347.3) 18.6 - 25

(24.5/22.7)

LYN 54 4.5 - 5.8

(5.6/5.3 219 - 393

(312/308) _534 - 203

(203/-80) 21.3 - 25

(22.7/23)

SEA 1042 5.1 - 6.2

(5.7/5.7) 11180 - 15200

(13520/13300) 180 - 304

(230/238) 20.4 - 25.8

(24.4/23.5)

LYN 48 5.1 - 5.6

(5.4/5.4) 192.6 - 359

(246/265.9) 52 - 251

(167/156.7) 20.7 -23.6

(22.4/22.2)

LYN 181 4.8 - 6.3

(5.8/5.6) 654 - 2249

(2033/1645.3) 161 - 189

(174/174.7) 19.3 - 26.1

(25.7/23.7)

CAB 231 5.8 - 6.5

(6.5/6.3) 497 - 675

(594/588.7) 19 - 214

(187/140) 19.4 - 24.8

(24/22.7)

LYN 39 5.2 - 6.0

(5.6/5.6) 147 - 173.8

(160/160.1) 28 - 65

(46.5/46.5) 16.2 - 26

(22.2/21.7)

LYN 183 3.6 - 5.5

(4.8/4.7) 131.2 - 323

(164.2/195.6) 24 - 195

(102/105.8) 16.2 - 26

(21.9/21.5)

LYN 184 4.9 - 7.1

(6.0/6.0) 98.6 - 370

(129.4/181.8) 62 - 139

(102.5/101.5) 16.2 - 28.1

(23.9/23)

LYN 38 5.3 - 5.8

(5.5/5.5) 251 - 526

(388.5/388.5) 89 - 170

(129.5/129.5) 22 - 25.9

(24/24)

LYN 73 4.3 - 5.9

(4.8/5.0) 2190 - 16250

(3220/7220) 86 - 195

(175/152) 20.5 - 23.6

(21.9/22)

SEA 1054 2.7 - 3.6

(3.2/3.2) 4680 - 13800

(9760/9413.3) 126 - 370

(278/258) 20.8 - 23.9

(22.5/22.4)

SEA 1063 3.8 - 4.9

(4.7/4.4) 2112 - 8840

(6650/5867.3) 229 - 311

(263/267.7) 19.7 - 25

(24/22.9)

SEA 1073 4.1 - 5.7

(4.8/4.9) 850 - 1293

(873/1005.3) 52 - 239

(187/159.3) 21.4 - 27.6

(24.2/24.4)

SEA 1089 5.4 - 7.0

(6.7/6.4) 1488 - 2560

(1758/1935.3) _410 - 146

(102/-54) 19.5 - 25

(23.6/22.7)

SEA 1092 5.4 - 5.9

(5.7/5.7) 648 - 831

(822/767) 3. - 88

(70/53.7) 18.5 - 24.8

(24.6/22.6)

SEA 1156 5.2 - 6.2

(5.6/5.7) 243 - 1997

(1120/1120) 12 - 162

(98/90.7) 19.6 - 25

(24.9/23.2)

pH Measurements

pH variations throughout the different sampling rounds were:

pH ranged from 3.2 to 5.5in sampling round 1 (dry period).

pH ranged from 3.2 to 6.8 in sampling round 2 (wet period).

pH ranged from 3.2 to 7.8 in sampling round 3 (dry period).

pH ranged from 2.7 to 6.5 in sampling round 4 (wet period).

These show acidic shallow groundwater dominating in subcatchments. Most boreholes had

pH values of 4.0 to 6.0; some boreholes with pH higher than 6.0; boreholes LYN 32, SEA

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1054, SEA 1109 and five boreholes in the Glasshouse Mountain Creek had a pH less than 4,

showing the strongly acidic shallow groundwater in some boreholes. The pH values in the dry

and wet periods were different and pH values were different in the two dry periods in 2008

and 2009 and in the two wet periods in 2009 and 2010. Figure 5.5 shows the pH variation

among sampling rounds and for different boreholes.

Figure 5.5: Variation of pH among sampling rounds and for different boreholes

Electrical Conductivity

Electrical conductivity (EC) values for borehole samples showed some variation over time.

EC values changed in the wet and dry periods and EC values in the wet period had the larger

range that in the dry period.

EC values ranged from 131 to 35600 µS/cm in sampling round 1 (dry period).

EC values ranged from 69 to 60600 µS/cm in sampling round 2 (wet period).

EC values ranged from 149 to 55100 µS/cm in sampling round 3 (dry period).

EC values ranged from 96 to 55800 µS/cm in sampling round 4 (wet period).

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Borehole samples with EC values less than 10000 µS/cm are shown in Figure 5.6.Eleven

borehole samples with EC values were higher than 10000 µS/cm and are shown in Figure 5.7.

The four borehole samples with the highest EC values are located near the estuaries; SEA

1035 in Burpengary, SEA 1110 in Ningi-Toorbul, LYN 65 and 66 in Glasshouse Mountains.

Figure 5.7 shows the borehole samples with EC values higher than 10000 µS/cm in sampling

rounds and for different boreholes.

Figure 5.6: Variation in EC values (less than 10000 µS/cm) among sampling rounds and

for boreholes

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Figure 5.7: Variation in EC values (higher than 10000 µS/cm) for sampling rounds and

for boreholes

The salinity of coastal groundwater can be represented by electrical conductivity which is an

important parameter in coastal settings. Electrical conductivity values can be used to represent

and display the characters of groundwater. However, the divisions of groundwater types are

only relative. Table 5.5 shows some broad electrical conductivity ranges which indicate four

groupings of groundwater in the mainland Pumicestone study area which can be used for

comparison of the general water character and setting.

Table 5.5: Groundwater types based on electrical conductivity ranges

(Australian Government, 2004; Podschun et al., 2001)

Groundwater type Electrical conductivity (µS/cm)

Fresh water < 1500

Brackish water 1500 - 15000

Saline water 15000 - 50000

Seawater Approx. 55000

Seawater

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Four sampling rounds were completed between December 2008 and March 2010. After

evaluating the results for samples collected during these rounds, rounds 2 and 3 were chosen

to compare the wet and dry conditions. Additionally, the charge balance errors of the

boreholes in these sampling rounds were the lowest and more acceptable, compared with

other sampling rounds.

Based on the EC grouping in Table 5.5, groundwater categories for sampling rounds 2 and 3

are shown in Figures 5.8 and 5.9. These indicate the hydrological processes and connection to

marine or estuarine environments. In sampling round 2, there were 21 boreholes with fresh

water, 10 boreholes with brackish water, 5 boreholes with saline water and 1 borehole with

seawater. In sampling round 3, there were 18 boreholes with fresh water, 10 boreholes with

brackish water, 8 boreholes with saline water and 1 borehole with seawater.

Figure 5.8: EC values show the salinity of groundwater under wet conditions in

sampling round 2, June - July 2009

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61

Figure 5.9: EC values show the salinity of groundwater under dry conditions in

sampling round 3, November 2009

Boreholes intersecting fresh groundwater were installed in aquifer materials A, B and E.

Aquifer material A was almost entirely dominated by fresh water. Boreholes accessing

brackish water were installed in the aquifer materials such as A, B and E. Boreholes with

saline water were typically installed in the aquifer materials such as B, C and E. Boreholes

accessing seawater were in aquifer material C which is typically estuarine mud. Table 5.6

shows a comparison of changes in nature between water in the wet and dry periods.

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Table 5.6: Comparison of groundwater salinity variations in sampling rounds 2 and 3

(wet and dry periods)

RN EC2

(µS/cm)

Nature of water

(wet period)

RN EC3

(µS/cm)

Nature of water

(wet period)

LYN 36 (B) 69.3

Fresh water

SEA 1046 (A) 148.5

Fresh water

CAB 219 (B) 75.8 LYN 39 (E) 154.4

CAB 216 (B) 97 LYN 184 (E) 156.3

LYN 184 (E) 102.5 LYN 26 (A) 160.3

SEA 1046 (A) 134.3 LYN 183 (E) 166.8

LYN 39 (E) 173.8 CAB 216 (B) 167.3

LYN54 (E) 219 BM5 (A) 171.1

LYN 9 (A) 225 LYN 48 (E) 192.6

LYN 44 (B) 245.5 LYN 44 (B) 194

LYN 48 (E) 246 LYN 9 (A) 254

LYN 4 (B) 254 LYN54 (E) 393

LYN 26 (A) 281 CAB 231 (E) 497

LYN 183 (E) 323 LYN 38 (E) 526

CAB 214 (B) 487 SEA 1092 (E) 648

SEA 1109 (B) 540 CAB 219 (B) 783

CAB 231 (E) 675 LYN 36 (B) 882

BM5 (A) 692 SEA 1156 (E) 1120

SEA 1092 (E) 822 SEA 1073 (E) 1293

SEA 1073 (E) 873 CAB 214 (B) 1522

Brackish water

SEA 1101 (B) 1107 SEA 1108 (B) 1567

SEA 1108 (B) 1385 SEA 1089 (E) 1758

SEA 1156 (E) 1997

Brackish water

LYN 181 (E) 2033

LYN 73 (E) 2190 SEA 1109 (B) 6090

LYN 181 (E) 2249 LYN 34 (A) 6530

SEA 1089 (E) 2560 SEA 1101 (B) 6560

LYN 34 (A) 3050 SEA 1063 (E) 8840

LYN 37 (B) 4460

SEA 1042 (E) 13520

SEA 1063 (E) 6650 SEA 1054 (E) 13800

SEA 1054 (E) 9760 LYN 32 (E) 15570

CAB 208 (B) 12560 LYN 73 (E) 16250

LYN 32 (E) 14450 CAB 208 (B) 16300

SEA 1042 (E) 15200

Saline water

SEA 1047 (B) 24900 Saline water

SEA 1047 (B) 22830 LYN 37 (B) 29800

LYN 65 (C) 37400

LYN 65 (C) 40900

LYN 66 (C) 43400 LYN 66 (C) 44300

SEA 1110 (C) 53900 SEA 1035 (C) 52200

SEA 1035 (C) 60600 Seawater SEA 1110 (C) 55100 Seawater

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63

Comparison of EC values and ranges between sampling rounds 2 and 3 reflected a number of

both spatial and temporal variations as follows:

There were 4 boreholes with saline water in the wet period and 7 boreholes with saline water

in the dry period; there were 4 boreholes of brackish water in the wet period shifted to the dry

period and one borehole from saline water shifted to brackish water in the dry period and one

borehole SEA 1042 belonging to aquifer material E with saline water in the wet period shifted

to a borehole with brackish water in the dry period.

There were ten boreholes with brackish water in the wet and dry period; some boreholes with

fresh water in the wet period shifted to boreholes with brackish water in the dry period. Only

borehole SEA 1156 belonging to aquifer material E with brackish water in the wet period

shifted to a borehole with fresh water in the dry period. Therefore, there were 21 boreholes

with fresh water in the wet period and 18 boreholes with fresh water in the dry period.

Numbers and locations of boreholes with groundwater of seawater concentration were the

same in the wet and dry periods, only the EC values of these boreholes changed between the

wet and dry periods.

The change of these EC values was due to the changes of chemical composition and

concentration of groundwater in boreholes caused by physical processes such as location of

boreholes, rainfall, runoff, evaporation, temperature, interaction of fresh water and seawater,

geology of the study area, input of chemicals deriving from anthropogenic activities (Ezzy,

2000; Hem, 1992).

Redox Potential (Eh)

Redox potential (Eh) values among sampling rounds of boreholes had changes as follows:

Eh values ranged from 24 to 324 mV in sampling round 1 (dry period).

Eh values ranged from -53 to 370 mV in sampling round 2 (wet period).

Eh values ranged from -534 to 320 mV in sampling round 3 (dry period).

Eh values ranged from -216 to 402 mV in sampling round 4 (wet period).

Most boreholes with Eh values were positive and range from 0 to 400 mV. Five other

boreholes with Eh values were negative (from -534 to 0) in boreholes LYN 54, SEA 1089,

LYN 8, CAB 214 and CAB 208. Figure 5.10 shows the variation in Eh among sampling

rounds, and for different boreholes.

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64

Figure 5.10: Variation in Eh for sampling rounds and for different boreholes

Temperature (T

0)

Temperature of groundwater samples of sampling rounds shows minor variations between

periods.

Temperature ranged from 22.4 to 28.1 0C in sampling round 1 (dry period).

Temperature ranged from 16.2 to 21.7 0C in sampling round 2 (wet period).

Temperature ranged from 21.4 to 27.1 0C in sampling round 3 (dry period).

Temperature ranged from 22.6 to 27.6 0C in sampling round 4 (wet period).

Temperature of groundwater samples in sampling rounds 1, 3 and 4 was nearly the same.

Temperature of groundwater samples in sampling round 2 was obviously lowest by 4 - 5 0C

because it was in winter (June – July 2009). The northern subcatchments also had cooler

groundwaters. Sampling round 4 was the wet period but in summer (March 2010) due to

Burpen Caboolture Ningi_Toorbul Elimbah_Bullock GlassMountta

South North

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65

climate change. Figure 5.11 shows the variation in temperature between sampling rounds and

for different boreholes.

Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for

different periods

5.5. Laboratory Analyses

Four periods of sampling were conducted for major and minor ions, and nutrients of concern

from December 2008 to March 2010. Cation concentrations with minimum, maximum,

median and average concentrations are shown in Table 5.7 for some boreholes, all boreholes

and the data for all boreholes is shown in Appendix 3. Anion concentrations with minimum,

maximum, median and average concentrations for some boreholes are shown in Table 5.8 and

all boreholes in Appendix 4.

Burpen Caboolture Ningi_Toorbul Elimbah_Bullock GlassMounta

South North

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66

Table 5.7: Cation concentrations with minimum, maximum, median and average concentrations for some boreholes

Aquifer

Material RN

K+ (mg/L)

min-max

(median/aver)

Al3+(mg/L)

min-max

(median/aver)

Ca2+ (mg/L)

min-max

(median/aver)

Cu2+ (mg/L)

min-max

(median/aver)

Fetot (mg/L)

min-max

(median/aver)

Mg2+ (mg/L)

min-max

(median/aver)

Mn2+ (mg/L)

min-max

(median/aver)

Na+(mg/L)

min-max

(median/aver)

Sr2+ (mg/L)

min-max

(median/aver)

Zn2+ (mg/L)

min-max

(median/aver)

A

LYN 26 2.8 - 5.3

(2.8/3.6)

0 - 0.098

(0/0.033)

13 - 20

(16/16.3)

0

(0/0)

0 - 3.6

(0.064/1.22)

3.7 - 5.7

(4.8/4.7)

0.01 - 0.02

(0.02/0.01)

11. - 34

(23/22.7)

0.05 - 0.09

(0.07/0.07)

0

(0/0)

LYN 34 7.8 - 45

(10.7/21.2)

0.11 - 2

(0.234/0.781)

4.2 - 108

(27/46.4)

0.009 - 0.03

(0.02/0.02)

3.78 - 10

(6.2/6.66)

19 - 300

(98/139)

0.03 - 1.08

(0.22/0.45)

100 - 1200

(460/586.7)

0.05 - 0.84

(0.45/0.45)

0 - 0.168

(0.084/0.084)

B

SEA 1047 84.4 - 93.3

(85.1/87.6)

0.035 - 0.416

(0.189/0.213)

432 - 500

(462/464.7)

0 - 0.032

(0.016/0.016)

0.33 - 2.31

(0.576/1.072)

1152 - 1239

(1200/1197)

0.37 - 0.97

(0.4/0.58)

3840 - 3990

(3900/3910)

3.8 - 3.84

(3.82/3.82)

0 - 0.069

(0.035/0.035)

LYN 4 0.8 - 2.4

(1.6/1.6)

0.74 - 1.8

(1.27/1.27)

1.8 - 2.3

(2.1/2.1)

0.007

(0.007/0.007)

1.9 - 2.3

(2.1/2.1)

8.4 - 19

(13.7/13.7)

0

(0/0)

40 - 56

(48/48)

0.03

(0.03/0.03)

0

(0/0)

C SEA 1035

312.5 - 404

(344/353.5)

0

(0/0)

650

(650/650)

0

(0/0)

35 - 105

(44.5 - 61.5)

3400 - 3800

(3400/3533.3)

0.6 - 1.1

(0.7/0.8)

12000 - 13500

(12500/12666.7)

7.5 - 8.5

(8/8)

0

(0/0)

SEA 1110 109.9 - 343.8

(282.1/245.2)

0

(0/0)

56.1 - 357

(332.1/248.4)

0

(0/0)

10.25 - 29.4

(27.5/22.383)

539 - 2624

(2500/1887.7)

0.07 - 0.16

(0.07/0.1)

2860 - 10710

(9020/7530)

0.97 - 5.33

(3.15/3.15)

0

(0/0)

E

LYN 183 0.9 - 4.75

(4.2/3.3)

0 - 0.32

(0.041/0.12)

1 - 1.3

(1.1/1.1)

0 - 0.008

(0.004/0.004)

1.8 - 12

(6.3/6.7)

3 - 6.1

(3.9/4.3)

0.04 - 0.06

(0.05/0.05)

20 - 53

(20/31)

0.01 - 0.02

(0.02/0.02)

0 - 0.01

(0.005/0.005)

LYN 184 0.9 - 5.2

(4.9/3.7)

0.051 - 0.88

(0.67/0.534)

0.6 - 0.8

(0.7/0.7)

0.005 - 0.007

(0.006/0.006)

1.8 - 9.4

(3/4.73)

2.9 - 4.3

(3.4/3.5)

0.03 - 0.04

(0.04/0.04)

13 - 18

(14/15)

0.01

(0.01/0.01)

0 - 0.069

(0.035/0.035)

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Table 5.8: Anion concentrations with minimum, maximum, median and average

concentrations for some boreholes

Aquifer

Material RN

HCO3- (mg/L)

min-max (median/aver)

Cl- (mg/L)

min-max (median/aver)

SO42-

(mg/L)

min-max (median/aver)

Charge Balance (%)

min-max (median/aver)

A

LYN 26 55.6 – 100.6

(72.2/76.6)

11.4 - 42.7

(26.5/26.9)

16.421 - 21.1

(20.6/19.4)

-3.6 to 0.8

(-0.9/-1.2)

LYN 34 28 – 129.2

(76.6/78)

194.6 - 1887.1

(992.9/1024.9)

20.5 - 795.2

(51.1/289)

-0.1 to -7.8

(1.6/3.1)

B

SEA 1047 129.7 - 138

(133.5/133.8)

7519 - 8610

(7550.9/7893.5)

1502.4 - 2543.4

(1673.6/1906.5)

3.7 to 7.4

(5.1/5.4)

LYN 4 0 – 14.9

(7.4/7.4)

63.8 - 162.2

(123/123)

49.6 - 70.1

(59.8/59.8)

-17.3to -7.2

(-12.3/-12.3)

C

SEA 1035 25.4 - 63

(46.8/45)

24372.6 - 27992.3

(26143.6/26169.5)

4574.4 - 5638.6

(5375 - 5196)

-2.4 to 5.1

(4/2.2)

SEA 1110 9.6 - 87

(50/48.8)

6338 - 22800

(17100.8/15413)

1003.9 - 4389.8

(3000.7/2798.2)

-6.8 to 4.9

(-0.5/-0.8)

E

LYN 183 7.4–57.5

(11/25.4)

13 - 75.7

(31.2/40)

20.3 - 44.2

(20.7/28.4)

-3.1 to 8.3

(-2.7/0.8)

LYN 184 12–21.7

(12.2/15.4)

24.2 - 39

(25.3/29.5)

5.8 - 18.6

(15.6/13.3)

-7.3 to -0.7

(-2.7/-3.6)

5.5.1. Charge Balance

Calculation of charge balance errors is standard practice in determining the accuracy of water

sample analyses. Solution electroneutrality means that the sum of cations in solution

(expressed in meq/L) should be equal to the sum of anions. In this study there are some high

charge balance errors (from -15% to 15%). However, they are considered acceptable within

this study as (a) the volume of shallow groundwater that was available for collection in some

boreholes was minimal in the dry period, and (b) in these coastal settings dissolved and

suspended organic matter can affect analytical procedures.

Charge balance errors of groundwaters are shown in Table 5.8. Eight water samples had

charge balance error exceeding the acceptable range from -15% to 15%. Although these

samples were all recollected and reanalyzed, their charge balance errors still exceeded the

acceptable range. Seven groundwater samples of boreholes such as LYN 4; CAB 219; CAB

208; LYN 65; SEA 1156 and SEA 1046 had negative charge balance errors ranging from -

27.4% to -15.2%, and are shown to be cation deficient. The causes of cation deficiency in

these boreholes were groundwaters containing humic fulvic acid and acid sulphate soils.

These are exceptionally high for typical groundwater and these errors did not affect the study.

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5.5.2. Major and Minor Ions

Classification of Groundwater Types

The Piper classification system of water summarized by Davies and De Weist (1966) has been

utilized to identify the hydrochemical groups for shallow groundwater in the mainland

Pumicestone study area. According to this classification, the relative concentration of ions in

% meq/L is plotted on a trilinear diagram (Figure 5.12) which is used for identifying water

types based on dominant cations (left ternary) and anions (right ternary).

Figure 5.12: Piper diagram for identifying groundwater types. Water types based on

dominant cations (left ternary) and anions (right ternary)

Sampling round 2 (in the wet period) of the various catchments and groundwater samples of

this sampling round had the lowest charge balance errors, therefore, it was used to create the

Piper plot as shown in Figure 5.13. Using AquaChem/AqQA software and the plots in Figure

5.13, groundwater types of boreholes in the wet period are shown in Table 5.9.

80 60 40 20 20 40 60 80

20

40

60

80 80

60

40

20

20

40

60

80

20

40

60

80

Ca Na HCO3 Cl

Mg SO4

Groundwater in the Black Swamp Plantation

Legend:

groundwater bores in

Figure 15: Piper diagram for identifying groundwater types in the Black Swamp

Plantation.

Figure 14: Piper diagram utilising the Davies and De Wiest (1966) classification system

for identifying groundwater types. The left ternary shows the dominant cations, the right

indicates dominant anions.

E3

A2

Legend:

groundwater bores

under dry condition

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Figure 5.13: Plots of groundwater types in sampling round 2 (wet period) in the study

area

Table 5.9: Groundwater chemical types of boreholes in sampling round 2 (wet period),

relating to aquifer material

RN2 Groundwater Type

BM5 (A) Mg-Ca-SO4

SEA 1046 (A) Mg-Na-Fe-Cl-SO4-HCO3

LYN 183 (E) Na-Cl-HCO3

LYN 39 (E) Na-Fe-Cl-HCO3

CAB 216 (B) Na-SO4-Cl-HCO3

CAB 219 (B) Na-Mg-Cl-SO4-HCO3

SEA 1109 (B) Mg-Na-Fe-SO4-Cl

LYN 44 (B); SEA 1156 (E) Na-Cl-SO4

CAB 231 (E); LYN 26 (A) Na-Ca-HCO3-Cl

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CAB 214 (B); LYN 9 (A) Na-Ca-Mg-HCO3-Cl

LYN 37 (B); SEA 1073 (E); SEA 1101 (B); SEA 1108 (B) Na-Cl

LYN 32 (E); LYN 54 (E); SEA 1042 (E); LYN 36 (B); LYN

4 (B); LYN 73 (E); SEA 1054 (E); SEA 1089 (E) Na-Mg-Cl-SO4

SEA 1035 (C); LYN 65 (C); LYN 66 (C); SEA 1110 (C);

CAB 208 (B); LYN 181 (E); LYN 184 (E); LYN 34 (A);

LYN 48 (E); SEA 1047 (B); SEA 1063 (E); SEA 1092 (E);

Na-Mg-Cl

5.5.3. Seawater Intrusion

The Cl/HCO3 ratio is useful as a criterion to evaluate seawater intrusion. Chloride is the

dominant anion in seawater and available in much smaller quantities in groundwater. In

contrast, bicarbonate is available in larger quantities in groundwater and very small

concentrations in seawater. A ratio of more than or equal to 1.5 EPM (equivalent parts per

million) in groundwater is indicative of seawater intrusion. A ratio of less than 1.5 EPM in

groundwater is generally indicative of fresh water (Ezzy, 2000; Pavlik, 2005). Values of

Cl/HCO3 ratio based on laboratory analysis of groundwater samples collected in sampling

rounds 2 and 3 are presented in Figure 5.14 and Figure 5.15. Seawater intrusion was different

in the wet and dry seasons as follows:

Seven boreholes in the wet period and 10 boreholes (7 boreholes in the same wet period and 3

additional boreholes (LYN 38, LYN 73 and SEA 1073) in the dry period contained no

bicarbonate or bicarbonate concentrations were below. Therefore, Cl/HCO3 ratios were not

calculated.

Nine boreholes in the wet season and 4 boreholes in the dry period with a ratio of 1.5 in

groundwater are indicative of no intrusion.

Three boreholes (LYN 37, LYN 65 and SEA 1110) with a ratio of seawater intrusion were

highest in the dry period. Additionally, there were changes in the ratio of seawater intrusion in

other boreholes in the wet and dry periods.

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Figure 5.14: Values of Cl/HCO3 ratio based on laboratory analysis of groundwater

samples collected in sampling round 2 during the wet period (June to July 2009)

e Denotes the absence of detectable HCO3 in the groundwater

samples, due to low pH, therefore, ratios were not calculated.

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Figure 5.15: Values of Cl/HCO3 ratio based on laboratory analysis of groundwater

samples collected in sampling round 3 during the dry period (November 2009)

e Denotes the absence of detectable HCO3 in the groundwater

samples, due to low pH, therefore, ratios were not calculated.

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5.5.4. Forms of Nitrogen and Phosphorus

Four forms of nitrogen (NO3-, NO2

-, NH3 and NH3 + Org-N) and two forms of phosphorus (PO4

3- and TP) were analyzed in this study. The minimum,

maximum, median and average concentrations of forms of nitrogen and phosphorus of several representative boreholes are shown in Table 5.10.A

complete list showing all borehole samples is presented in Appendix 5.

Table 5.10: The minimum, maximum, median and average concentrations of forms of nitrogen and phosphorus for several representative

boreholes

Aquifer

Material RN

NO3-N (mg/L)

min-max

(median/aver)

NO2- (mg/L)

min-max

(median/aver)

NH3/NH4+ (mg/L)

min-max

(median/aver)

NH3/NH4++ Org-N (mg/L)

min-max

(median/aver)

PO43-

(mg/L)

min-max

(median/aver)

TP (mg/L)

min-max

(median/aver)

A

LYN 26 0.231 - 2.071

(1.354/1.22)

0 - 0.099

(0.023/0.041)

0.299 - 0.815

(0.435/0.516)

0.782 - 3.03

(0.818/1.543)

0.015 - 0.052

(0.036/0.034)

0.028 - 0.64

(0.282/0.316)

LYN 34 0.086 - 0.596

(0.104/0.262)

0 - 0.1

(0.025/0.041)

0.661 - 0.945

(0.686/0.764)

1.435 - 2.002

(1.718/1.718)

0

(0/0)

0 - 0.17

(0.059/0.076)

B

SEA 1047 0 - 0.069

(0.059/0.042)

0

(0/0)

0.691 - 1.301

(0.867/0.953)

0.695 - 1.084

(0.928/0.902)

0 - 0.035

(0.013/0.016)

0.122 - 0.377

(0.156/0.219)

LYN 4 0 - 0.137

(0.069/0.069)

0

(0/0)

0.024 - 0.209

(0.116/0.116)

1.112 - 1.757

(1.435/1.435)

0

(0/0)

0 - 0.143

(0.071/0.071)

C

SEA 1035 0.142 - 0.164

(0.154/0.154)

0

(0/0)

1.153 - 1.916

(1.552 - 1.54)

1.582 - 3.937

(3.589 - 3.036)

0 - 0.005

(0/0.002)

0 - 0.339

(0.23/0.19)

SEA 1110 0.081 - 0.286

(0.092/0.153)

0

(0/0)

0.755 -1.793

(1.082/1.21)

1.407 - 5.157

(2.927/3.164)

0 - 0.155

(0.143/0.1)

0 - 0.617

(0.158/0.258)

E

LYN 183 0.177 - 0.221

(0.204/0.201)

0

(0/0)

0.240 - 0.63

(0.603/0.49)

0.4937 - 0.854

(0.828/0.7254)

0 - 0.129

(0.009/0.046)

0.213 - 0.891

(0.464/0.046)

LYN 184 0.037 - 0.155

(0.11/0.101)

0

(0/0)

0.095 - 1.364

(0.472/0.644)

0.540 - 1.548

(1.370/1.153)

0

(0/0)

0 - 0.087

(0.013/0.033)

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Forms of Nitrogen

Samples collected throughout the different sampling rounds were analyzed in the laboratory

for four forms of nitrogen; NO2-, NO3-N, NH3/NH4

+and NH3/NH4

++ Org-N. Other forms of

nitrogen were calculated from these measured forms. For example, total nitrogen (TN), total

inorganic nitrogen (Tinorg). The groundwater samples collected during this study presented a

nitrogen speciation having NH3 as the dominant species followed by NO3-N and having low

NO2- concentrations.

Forms of Phosphorus

Two forms of phosphorus: PO43-

and TP were analyzed for sampling rounds in the laboratory.

PO43-

is representative of inorganic phosphorus whereas TP represents total phosphorus (PO43-

and organic phosphorus). Concentration of TP in groundwater samples was higher or equal

concentration of PO43-

.

5.6. Nutrients of Concern

Groundwater samples collected throughout the different sampling rounds were tested for the

nutrients of concern (pH, DOC, Fe, TN and TP). The median, minimum and maximum

concentrations of nutrients of concern for representative boreholes are presented in Table 5.11

and for all boreholes in Appendix 6.

Table 5.11: Concentration of nutrients of concern with median, minimum and

maximum concentrations for representative boreholes

Aquifer

Material

RN

median

(min-max)

pH

median

(min-max)

Fetot

(mg/L)

median

(min-max)

DOC (mg/L)

median

(min-max)

TN (mg/L)

median

(min-max)

TP (mg/L)

median

(min-max)

A

BM5 5.5

(4.2 - 5.9)

0.58

(0.48 - 15)

8.81

(5.11 - 17.5)

5.641

(2.154 - 8.343)

0.61

(0.16 - 0.9)

LYN 26 6.1

(5.4 - 6.2)

0.064

(0 - 3.6)

7.84

(6.8 - 9.43)

2.952

(1.049 - 4.407)

0.282

(0.028 - 0.64)

B

CAB 208 5.1

(4.9 - 5.7)

9.3

(0.957 - 17.6)

95.64

(75.18 - 116.1)

7.842

(3.491 - 7.920)

0.52

(0.304 - 0.736)

CAB 214 6.6

(5.5 - 7.2)

3.9

(2 - 21.055)

16.01

(15.24 - 26.3)

1.544

(1.078 - 4.544)

0.663

(0.246 - 1.661)

C

LYN 65 4.9

(3.2 - 5.3)

49.4

(32.8 - 50)

15.74

(7.116 - 22.32)

1.823

(0.230 - 3.755)

0.072

(0 - 0.215)

LYN 66 3.6

(3.1 - 5.4)

74.5

(26 - 105)

10.96

(9.698 - 15.4)

2.638

(2.547 - 3.809)

0.022

(0 - 0.113)

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E

LYN 38 5.5

5.3 - 5.8

11.053

(8.8 - 13.306)

10.59

(7.73 - 13.44)

1.180

(1.082 - 1.277)

0.164

(0.135 - 0.192)

LYN 73 4.8

(4.3 - 5.9)

34.248

(31 - 418)

17.25

(7.49 - 18.45)

4.309

(2.244 - 4.917)

0.147

(0.125 - 0.695)

5.6.1. pH Measurements

Although pH is not a “nutrient” it is a significant physico-chemical parameter related to

Lyngbya blooms. The median pH values for all sampling periods ranged from 3.2 to 6.8,

showing acidic to near neutral groundwater in all boreholes in the area: 5 boreholes had the

lowest pH values ≤ 4.0; 7 boreholes had pH values from 4.1 to 5.0; 21 boreholes had pH

values from 5.1 to 6.0 and 5 boreholes had pH values from 6.1 to 6.8. The variations of pH

values were distributed in all subcatchments and did not focus on any specific subcatchments.

The median pH for groundwater samples collected from boreholes located in the different

aquifer materials in the study area are shown in Figure 5.16.

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Figure 5.16: Map of the median pH concentration for all periods relating to the aquifer

material layer in the study area

The median, minimum and maximum values of pH in aquifer materials in the area are shown

in Table 5.12. The median pH value in aquifer material A (sands) was 5.9 and the minimum

and maximum pH values ranged from 5.5 to 6.1. The minimum and maximum range values

were small at 0.6 mg/L.

The median pH value in aquifer material B (silts, sandy silts) was 5.1 and the minimum and

maximum pH values ranged from 3.7 to 6.6. The minimum and maximum range value was

2.9 mg/L which is large in these boreholes. It shows that there were high differences of pH

values in this aquifer material due to inequity of materials.

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The median pH value in aquifer material C (estuarine muds) was 5.1 and the minimum and

maximum pH values ranged from 3.6 to 5.7. This range of 2.1 mg/L is also large.

The median pH value in aquifer material E (alluvium) was 5.6 and the minimum and

maximum pH values ranged from 3.2 to 6.8. This range of pH values was 3.6 mg/L, the

largest distance, compared with other aquifer materials.

Table 5.12: Median, minimum and maximum pH values for borehole samples in aquifer

materials in the study area

Aquifer Material pH

(median)

(min – max)

A. Sands 5.9

5.5 - 6.1

B. Silts, sandy silts 5.1

3.7 - 6.6

C. Estuarine muds 5.1

3.6 - 5.7

E. Alluvium 5.6

3.2 - 6.8

5.6.2. Total Iron

Most borehole samples had total iron concentration values less than 40 mg/L. Several

borehole samples had total iron concentration in the range of 41 to 78 mg/L. Three boreholes

(LYN 32, SEA 1035 and LYN 66) had very high total iron concentrations from 105 mg/L to

594 mg/L. Iron concentration variations throughout the different sampling rounds are shown

in Figure 5.17.

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Figure 5.17: Variation intotal iron concentrations (mg/L) among sampling rounds and

for different boreholes

Map of Median Iron Concentration for All Periods

The median iron concentration from all samples ranged from 0 to 524.2 mg/L and two

boreholes were very high; the median iron concentrations from boreholes LYN 32 and LYN

66 were 524.2 mg/L and 104 mg/L respectively; 10 boreholes had median iron concentrations

of 15 to 49.9 mg/L; 9 boreholes were from 5 to 9.9 mg/L and 16 boreholes were from 0 to 4.9

mg/L. The range of the median iron concentration was distributed in all subcatchments and

did not focus on the specific subcatchments. Figure 5.18 shows the median iron concentration

for all periods of the aquifer material layer in the study area.

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Figure 5.18: Map of the median iron concentration for all periods relating to the aquifer

material layer in the study area

Median, minimum and maximum iron concentrations for borehole samples in aquifer

materials in the study area are shown in Table 5.13. The median iron concentration in aquifer

material A (sands) was 6.2 mg/L. The range of the minimum and maximum iron

concentrations was from 0.06 mg/L to 10 mg/L (spread of 9.9 mg/L) which was the narrowest

range of iron concentrations for borehole samples throughout the different aquifer materials.

The median iron concentration in the aquifer material B (silts, sandy silts) was 3 mg/L. The

range in this aquifer was from 0.47 mg/L to 30 mg/L, a difference of 29.5 mg/L.

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The median iron concentration in the aquifer material C (estuarine muds) was 47 mg/L. The

range in this aquifer was from 27.5 mg/L to 104 mg/L, a difference of 76.5 mg/L.

The median iron concentration in the aquifer material E (alluvium) was 7.8 mg/L. The range

was from 0 to 524.2 mg/L and was the largest range. It shows that groundwater in the aquifer

material E (alluvium) to be the worst and groundwater in the aquifer material A (sands) was

considered to be the best compared with the other aquifer materials in the area.

Two boreholes LYN 32 and LYN 66 had the highest iron concentrations (104 mg/L and 524.2

mg/L, respectively) and pH values less than 4. These show that acid sulfate soils exist in these

boreholes.

Table 5.13: Median, minimum and maximum iron concentrations for borehole samples

in aquifer materials in the study area

Aquifer Material Fe (mg/L)

(median)

(min – max)

A. Sands 6.2

0.06 - 10

B. Silts, sandy silts 3

0.47 - 30

C. Estuarine muds 46.95

27.5 - 104

E. Alluvium 7.8

0 - 524.2

5.6.3. Dissolved Organic Carbon

Dissolved organic carbon (DOC) was analyzed for all samples in rounds 2, 3 and 4. Most

boreholes with DOC values ranged from 2.0 to 20 mg/L. Some boreholes had DOC values

were from 20 mg/L to 40 mg/L. The highest concentration of DOC (116 mg/L) occurred in

borehole CAB 208 in sampling round 4. DOC concentration in Borehole SEA 1046 was 67.75

mg/L (sampling rounds 3) and 75.25 mg/L in sampling rounds 4. Figure 5.19 shows DOC

variations for different samples.

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Figure 5.19: Variation in DOC concentration (mg/L) between sampling rounds and for

different boreholes

Map of Median Dissolved Organic Carbon Concentration for All Periods

The median DOC concentration of each borehole was from 2.9 mg/L to 95.6 mg/L in which 3

boreholes ranged from 2.9 mg/L to 4.9 mg/L; 12 boreholes ranged from 5.0 mg/L to 9.9

mg/L; 20 boreholes ranged 10 mg/L to 49.9 mg/L and 3 boreholes ranged from 50 mg/L to

95.6 mg/L. The median DOC concentration of each borehole compared with the aquifer

material layer in the study area is shown in Figure 5.20.

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Figure 5.20: Map of the median DOC concentration for all periods relating to the

aquifer material layer in the study area

The median, minimum and maximum DOC concentration for borehole samples in aquifer

materials in the study area are shown in Table 6.14. The median DOC concentration in the

aquifer material A (sands) was 20.2 mg/L. The range for minimum and maximum DOC

concentration in this aquifer material was from 7.8 mg/L to 67.8 mg/L, a difference of 60

mg/L. This is the second largest range compared with the range of other aquifer materials.

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The median DOC concentration in the aquifer material B (silts, sandy silts) was 9.3 mg/L.

The minimum and maximum DOC concentration was from 2.9 mg/L to 95.6 mg/L, a

difference of 92.7 mg/L. This is the largest range of DOC concentration compared with other

aquifer materials in this study.

The median DOC concentration in the aquifer material C (estuarine muds) was 16.3 mg/L.

The minimum and maximum DOC concentration was from 11 mg/L to 17.8 mg/L. The range

is only 6.8 mg/L and as such is the smallest.

The median DOC concentration in the aquifer material E (alluvium) was 10.6 mg/L. The

minimum and maximum DOC concentration was from 3.5 mg/L to 38.4 mg/L with a range of

34.9 mg/L.

Table 5.14: The median, minimum and maximum DOC concentration for borehole

samples in aquifer materials in the study area

Aquifer Material DOC (mg/L)

(median)

(min – max)

A. Sands 20.2

7.8 - 67.8

B. Silts, sandy silts 9.3

2.9 - 95.6

C. Estuarine muds 16.3

11 - 17.8

E. Alluvium 10.6

3.5 - 38.4

5.6.4. Total Nitrogen

Most boreholes with total nitrogen concentration ranged from 0.38 mg/L to 4.0 mg/L. Four

boreholes (BM5, CAB 208 and SEA 1110) with the highest total nitrogen concentration

ranged from 5.4 mg/L to 8.3 mg/L. Variations in total nitrogen between sampling rounds and

for different boreholes are shown in Figure 5.21.

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84

Figure 5.21: Variation in total nitrogen (mg/L) among sampling rounds and for different

boreholes

Map of Median Total Nitrogen Concentration for All Periods

The median total nitrogen concentration of boreholes in the area ranged from 0.6 to 7.8 mg/L:

3 boreholes had a range of 0.6 to 0.9 mg/L; 33 boreholes ranged from 1 to 4.9 mg/L and two

boreholes had the highest total nitrogen concentration CAB 208 (7.8 mg/L) and BM5 (5.6

mg/L). Borehole BM5 was installed near a chicken farm and so the results are likely to reflect

seepage of soluble nitrogen from waste products. Borehole CAB 208 was installed near the

shoreline, included a residential area and public toilets which could include leaked wastewater

from both these areas. Three boreholes had a small total nitrogen concentration of less than 1

mg/L and other boreholes had the total nitrogen concentration ranging from 1 mg/L to 4.9

mg/L. Figure 5.22 shows the median total nitrogen concentration for all periods compared

with the aquifer material layer in the study area.

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Figure 5.22: Map of the median total nitrogen concentration for all periods relating to

the aquifer material layer in the study area

Median, minimum and maximum total nitrogen concentrations for borehole samples in

aquifer materials in the study area are shown in Table 5.15. The median total nitrogen

concentration in the aquifer material A (sands) was 3.0 mg/L and the minimum and maximum

total nitrogen concentration ranged from 2.1 mg/L to 5.6 mg/L, a difference of 3.5 mg/L.

Borehole BM5 (5.6 mg/L) was included in this aquifer material.

The median total nitrogen concentration in the aquifer material B (silts, sandy silts) was 1.4

mg/L and the minimum and maximum total nitrogen concentration ranged from 0.8 mg/L to

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86

7.8 mg/L with a difference of 7.0 mg/L. Borehole CAB 208 (7.8 mg/L) was included in this

aquifer material.

The median total nitrogen concentration in the aquifer material C (estuarine muds) was 2.9

mg/L and the minimum and maximum total nitrogen concentration ranged from 2.6 mg/L to

3.0 mg/L. This difference was only 0.4 mg/L.

The median total nitrogen concentration in the aquifer material E (alluvium) was 1.3 mg/L

and the minimum and maximum total nitrogen concentration was from 0.6 mg/L to 4.3 mg/L.

The difference in these values was only 3.7 mg/L.

Table 5.15: Median, minimum and maximum total nitrogen concentration for borehole

samples in aquifer materials in the study area

Aquifer Material TN (mg/L)

(median)

(min – max)

A. Sands 3.0

2.1 - 5.6

B. Silts, sandy silts 1.4

0.8 – 7.8

C. Estuarine muds 2.9

2.6 – 3.0

E. Alluvium 1.3

0.6 - 4.3

5.6.5. Total Phosphorus

Most boreholes with total phosphorus concentration ranged from 0 mg/L to 1 mg/L.

Boreholes (BM5, SEA 1046 and CAB 214) had a total phosphorus concentration higher than

1 mg/L. Borehole LYN 9 had the highest total phosphorus concentration at 2.36 mg/L. The

variation in total phosphorus, between sampling rounds, and for different boreholes is shown

in Figure 5.23.

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87

Figure 5.23: Variation in total phosphorus between sampling rounds and for different

boreholes

Map of Median Total Phosphorus Concentration for All Periods

The median TP concentration of each borehole in the study area ranged from 0 to 1.03 mg/L.

Boreholes SEA 1042 (1.03 mg/L) and LYN 9 (0.8 mg/L) had high TP concentrations.

Borehole SEA 1042 was installed in farm land with cattle and horse grazing and the high

probability of waste runoff. Borehole LYN 9 was installed near the sea and the residential

area. Wastewater from the residential area leaked into this borehole.

Three boreholes (BM5, CAB 208 and CAB 214) had a TP concentration ranging from 0.5

mg/L to 0.75 mg/L. Borehole BM5 was installed near a chicken farm therefore groundwater

of this borehole was likely to be influenced by waste discharge. Boreholes CAB 208 and CAB

214 were installed near the residential area and the public toilets, and could be influenced by

waste runoff from septic systems.

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The median TP concentration of the other boreholes was less than 0.49 mg/L. The median,

minimum and maximum values of total phosphorus concentration in aquifer materials in the

study area are shown in Table 5.16.

Figure 5.24: Map of total phosphorus concentration relating to the aquifer material

layer in the study area

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Table 5.16: The median, minimum and maximum total phosphorus concentration for

borehole samples in aquifer materials in the study area

Aquifer Material TP (mg/L)

(median)

(min – max)

A. Sands 0.46

0.06 - 0.8

B. Silts, sandy silts 0.16

0 - 0.66

C. Estuarine muds 0.08

0 - 0.23

E. Alluvium 0.15

0 - 1.03

The summary of nutrients of concern in four aquifer materials is shown in Table 5.17.

Table 5.17: Summary of nutrients of concern in aquifer materials

Aquifer A (sands):

- Slightly acidic pH

- RelativelyDOC

- Fe

- Some Nitrogen

- P

Aquifer B (silts, sandy silts):

- Slightly acidic but sometimes pH

- Relatively but sometimes DOC

- Fe

- Nitrogen

- P

Aquifer C (estuarine muds):

- Slightly acidic but sometimes pH

- Relatively DOC

- Fe

- Some Nitrogen

- P

Aquifer E (alluvium):

- Slightly acidic but sometimes pH

- Relatively but sometimes DOC

- Fe except for 1 particular borehole with Fe

- Some Nitrogen

- P

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Other data

This chapter presents the tables which summarise data from field measurements and

laboratory analyses. The complete data sets are presented in Appendix 8.

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6. DISCUSSION

Here the analytical results of the groundwater sampling, the variations in water levels, and the

character and distribution of the different aquifer materials are considered together. The

influence of the amount of rainfall (wet versus dry conditions) is also considered in respect to

water levels and chemical character of groundwater. A goal is to be able to establish

representative values (ranges and medians) for the various nutrients within each of the groups

of aquifer materials.

6.1. Nutrients of Concern

A number of studies indicate that the main limiting nutrients for out breaks of Lyngbya are

pH, iron (Fe), dissolved organic carbon (DOC), nitrogen (N), and phosphorus (P) (Ahern et

al., 2008; Albert et al., 2005; Johnson et al., 2009a). These main controlling nutrients for

Lyngbya blooms can be related to the physical setting and also to landuse (Cox & Preda,

2005; Johnson et al., 2009b). This section will identify the relationships between nutrients of

concern with both aquifer materials (physical setting) and with landuse and human activities.

6.1.1. Total Iron and pH

Iron exists in three oxidation states such as metallic iron (Fe0), ferrous iron or iron (II) (Fe

2+)

and ferric iron or iron (III) (Fe3+

) because it is a very reactive element. The pH and redox

potential is important in dictating the form in which iron occurs in the environment (Ehrlich,

2002; Nature, 2004). In this study, total iron (Fetot

), the main form in groundwater was

analyzed in the laboratory.

Iron and pH are two nutrients of concern causing the Lyngbya blooms in southeast

Queensland. The relationship between Fe and pH is shown in Figure 6.1. Four main groups of

iron and pH were identified in this study.

Group 1: Four boreholes (SEA 1109, SEA 1054, LYN 66 and LYN 32) were in this group.

The median pH values of these boreholes for all sampling rounds ranged from 3.2 to 3.8. The

median iron concentrations of these boreholes were also high, from 30 mg/L to 524.15 mg/L.

They show that there are relationships between pH values and iron concentrations in those

boreholes because of acid sulfate soils (Queensland Government, 2010).

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93

Figure 6.1: Relationship of Fe and pH in four sampling rounds

Group 2: Seven boreholes (SEA 1073, SEA 1110, LYN 73, SEA 1092, SEA 1035, SEA

1063 and LYN 65) were in this group. The median pH values of these boreholes ranged from

4.7 to 5.7 and their median iron concentration ranged from 22 mg/L to 49 mg/L in which

three boreholes (SEA 1110, SEA 1035 and LYN 65) are in aquifer material C (estuarine

muds) and four boreholes (LYN 73, SEA 1073, SEA 1092 and SEA 1063) are in aquifer

material E (alluvium). In addition, Borehole LYN 66 is in aquifer material C with the median

iron concentrations of 104 mg/L. This shows that groundwater within aquifer material C tend

to have a high iron concentration.

Four boreholes (LYN 73, SEA 1073, SEA 1092 and SEA 1063) and two boreholes (SEA

1054 and LYN 32) are in aquifer material E with median iron concentrations ranging 34.2

mg/L to 524.2 mg/L. These six boreholes were installed in the Burpengary and Caboolture

areas and show that aquifer material E in the Burpengary and Caboolture areas also caused the

high iron concentration. The cause of high iron concentration in aquifer material C and E in

these areas was due to the boreholes were installed in areas with more mud and silt.

Group 3: Eighteen boreholes are in this group with their pH values from 4.6 to 6.0 and Eh

values from 0 mV to 223 mV. With the control of these Eh and pH values, iron was dissolved

1 2

3

4

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94

in groundwater with the low amount (< 15 mg/L). In addition, these boreholes were installed

on the higher coastal areas in aquifer material A (sands), in aquifer material B (silts and sandy

silts) and mostly in aquifer material E (alluvium). Most boreholes of this group were in Group

IV, V and VI. Ca2+

and HCO3- ions existed in groundwater chemical types of these boreholes,

therefore iron concentrations were low because these boreholes were installed in the areas

with more sand material.

Group 4: Three boreholes (CAB 231, LYN 26 and SEA 1089) are in this group in which

CAB 231 was in aquifer material A; LYN 26 and SEA 1089 were in aquifer material E. Their

iron median concentrations were very low (< 0.25 mg/L) and their median pH values were

slightly high, from 6.1 to 6.75. This shows a decrease in dissolved iron due to higher pH

values (i.e. less acidic conditions). This is a general trend of inverse correlation, decrease in

Fe and increase in pH.

6.1.2. DOC

The median DOC concentrations of most boreholes were less than 20 mg/L. Only seven

boreholes with the median DOC concentrations were higher than 20 mg/L in which three

boreholes in aquifer material A (sands) with the median DOC concentration were higher than

20 mg/L. This shows that aquifer material A (sands) allow water to move rapidly down to

groundwater compared with the other materials (Muller & Helsel, 1996), so the organic

molecules of various composition infiltrated fast into groundwater sources.

Three boreholes (LYN 37, LYN 4 and CAB 208) in aquifer material B (Silts, sandy silts) and

two boreholes (LYN 181 and SEA 1054) in aquifer material E (Alluvium) with the median

DOC concentration were higher than 25 mg/L in which borehole CAB 208 was installed near

the beach and under the pig trees, borehole LYN 4 was installed in the forest, borehole LYN

37 was installed in the wet plant cover and two boreholes (LYN 181 and SEA 1054) were

installed near drainage system in the forest. Therefore, the mean DOC concentration of three

boreholes was high because leaves and other vegetation had broken down and dissolved in

groundwater.

6.1.3. Total Nitrogen and Total Phosphorus

Median concentrations of total nitrogen and total phosphorus of boreholes for four sampling

rounds were generally low, comparing with water quality standards for groundwaters of the

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95

state of Washington, USA (NO3-N = 10 mg/L) and Australian and New Zealand Guidelines

for Fresh and Marine Water Quality (2000), (NO3-N = 10 mg/L).

There were two boreholes (BM5 and CAB 208) with a high total nitrogen concentration and

four boreholes (SEA 1042, BM5, LYN 9 and CAB 208) with a high total phosphorus

concentration. The reasons for the high concentration of total nitrogen and total phosphorus

were: Borehole BM5 was installed near the chicken farm and Borehole SEA 1042 was

installed in the horse and cow farm. These two boreholes were affected by chicken, horse and

cow manure; therefore, the concentrations of total nitrogen and total phosphorus in these

boreholes were high.

Boreholes CAB 208 and LYN 9 were installed near the public toilets and residential areas.

Therefore, the high concentrations of total nitrogen and total phosphorus in the two boreholes

were likely to be caused by septic tank.

Elevated concentrations of total nitrogen and total phosphorus are largely due to animal and

human wastes and tend to be found in localized source areas.

6.2. Forms of Nitrogen

This study determined the main forms of nitrogen as NO3-N, NO2-, NH3/NH4

+ and

NH3/NH4++Org-N. Nitrate nitrogen (NO3-N) which occurs in groundwater with an oxidation

state of +5 is the most oxidized form of nitrogen. Ammonia (NH3/NH4+) occurred in

groundwater with an oxidation state of -3, however, the weathering of rocks releases ammonia

and nitrate very slowly (Ahern et al., 2008; Deacon, 2008; Jones, 1990). Typical sources of

nitrogen in groundwater result from human activities such as using fertilizers for intensive

agriculture and wastes from poultry and animal grazing farms such as in two boreholes BM5

and CAB 208. The nitrogen in these fertilizers leaks into coastal groundwater in the area. The

percentage of forms of nitrogen for some boreholes is shown in Table 6.1 and all boreholes in

Appendix 7.

Table 6.1: Percentage of forms of nitrogen for some boreholes

Aquifer RN

NO3-N

(median)

(mg/L)

NO3-N

(median)

%

NO2-

(median)

(mg/L)

NO2-

(median)

%

NH3/NH4+

(median)

(mg/L)

NH3/NH4+

(median)

%

Org-N

(median)

(mg/L)

Org-N

(median)

%

A

BM5 3.447 63.6 0.0 0.0 0.520 9.6 1.449 26.7

LYN 26 1.354 61.7 0.023 1.1 0.435 19.8 0.383 17.4

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96

B

LYN 36 0.173 17.8 0.0 0.0 0.000 0.0 0.799 82.2

LYN 37 0.141 9.0 0.0 0.0 0.727 46.1 0.708 44.9

C

LYN 65 0.230 8.2 0.0 0.0 2.409 86.3 0.152 5.5

LYN 66 0.193 7.5 0.0 0.0 2.141 83.6 0.228 8.9

E

SEA 1063 0.152 11.7 0.0 0.0 0.799 61.6 0.346 26.7

SEA 1073 0.335 11.2 0.0 0.0 1.493 49.9 1.165 38.9

% 13.7 0.1 46.2 40.0

Median ammonia (NH3/NH4+) concentration in four sampling rounds formed the highest

percentage with 46.2%; median organic nitrogen concentration in four sampling rounds was

40%; NO3-N was 13.7%, and NO2-

with the lowest percentage was 0.1%. In general, the

median concentrations of forms of nitrogen in groundwater samples were low.

Ammonia (NH3/NH4+), organic nitrogen and NO3-N are three main forms of nitrogen in this

study. In many reported studies and earlier studies in the region, nitrogen is presented as NO3-

which is useful as an indicator but only reflects the small percentage of available dissolved

nitrogen.

In an attempt to display the landuse associations of the main species of nitrogen a ternary

diagram of the groundwater samples is shown in Figure 6.2. The main forms of nitrogen are

NH3/NH4+, NO3-N and NO2

- and fall into five groups, which depended on the percentage of

forms of nitrogen. These groups were considered to relate to aquifer material in the area,

character of groundwater, the character of the setting, and importantly landuse.

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97

Figure 6.2: Ternary diagram of the main forms of nitrogen in groundwater samples

Group a: Two boreholes (BM5 and LYN 26) belong to this group and both were in aquifer

material A (sands). The percentage of NO3-N in these boreholes was very high with 63.6% in

BM5 and 62.8% in LYN 26. The percentage of organic nitrogen and NH3/NH4+

was lower,

from 9.6 % to 26.7% because these boreholes were installed near the chicken farms.

Therefore, the groundwater samples of the boreholes were affected by chicken mature causing

the high concentration of nitrate nitrogen.

Group b: Three boreholes (SEA 1101, SEA 1109 and LYN 39) were in this group. The

percentage of nitrogen species is similar in which two boreholes (SEA 1101 and SEA 1109)

were installed in aquifer material B (silts, sandy silts) with each borehole in the each bank of

Elimbah Creek. In addition, they were installed near the residential areas and in the forest near

the sea. Therefore, the groundwater of two boreholes was affected by these factors.

Group c: Five boreholes (LYN 4, LYN 36, LYN 181, SEA 1046 and SEA 1156) were in this

group. The percentage of Org-N in these boreholes was very high from 66.4% to 87.7%, in

which four boreholes (LYN 4, LYN 36, LYN 181 and SEA 1046) were installed in the forest

NH3 /NH4+

Org-N NO3-N

a

b

e

d

c

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98

and Borehole SEA 1046 was installed in a grass cover. Therefore, the groundwater of these

boreholes was affected by vegetation cover and trees in the forest, causing the high percentage

of organic nitrogen.

Group d: Five boreholes (CAB 219, SEA 1047, LYN 32, LYN 65 and LYN 66) were in this

group. The percentage of NH3/NH4+

in these boreholes was very high from 77.9% to 91% in

which the percentage of NO3-N and Org-N was low. The high percentage of NH3/NH4+

of

three boreholes (CAB 219, SEA 1047 and LYN 32) was due to their installation near the

residential areas. Therefore, their groundwater was affected by the household‟s wastewater

and septic tank.

Two boreholes (LYN 65 and LYN 66) were installed near a household‟s big pineapple farm.

Therefore, the groundwater in these boreholes was affected by the fertilizer used for the

pineapples.

In addition, three boreholes (LYN 32, LYN 65 and LYN 66) were installed in aquifer material

C (estuarine muds). The elevation of this aquifer material is low: the groundwater is from a

high elevation moving to a low elevation and this can also be a cause of the percentage of

NH3/NH4+

in the boreholes near aquifer material C.

Group e: The dominant distribution for all subcatchments and aquifer materials is in this

grouping. The percentage of NH3/NH4+

and the organic nitrogen of these boreholes were high,

in which the percentage of NH3/NH4+

ranged from 32% to 62.6% and the organic nitrogen

percentage was from 22% to 61%. The NO3-N percentage was low, from 3.1% to 20%.

All boreholes had pH values from 4.2 to 6.8 and the Eh values were from -50 mV to 263 mV.

With these pH and Eh values of most boreholes, in natural, NH3/NH4+ existed mostly in

groundwater due to variable settings and vegetation covers.

Boreholes in Figure 6.3 show the approximate stability fields of dissolved nitrogen species as

a function of Eh and pH at 25 °C and 1 atmosphere nitrogen pressure. It shows the

environments of groundwater samples in these sampling rounds (e.g. pH range and

groupings). Most Eh values of groundwater samples were higher than 50 mV but some near 0

mV or even negative values. From that, landuse and other factors influencing the percentage

of nitrogen species in groundwater samples are summarized and shown in Figure 6.4.

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99

Figure 6.3: Boreholes in the diagram showing the approximate stability fields of

dissolved nitrogen species as a function of Eh and pH at 25 °C and 1 atmosphere

nitrogen pressure (Feder, 1986).

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100

Figure 6.4: Landuse and other factors influencing the percentage of nitrogen species in

groundwater samples

6.3. Comparing Ions in the Wet and Dry Periods

The chemical composition of groundwater in the mainland Pumicestone study area is

determined by factors such as physical aspects, location of boreholes, rainfall, runoff,

evaporation, temperature, the interaction of fresh water and seawater, the geology of the study

area, and the input of chemicals deriving from anthropogenic activities. Anthropogenic

influences in the study area can also affect chemical characters of groundwater due to the

presence of features such as septic tanks, landfill leachate, domestic or industrial effluents and

fertilizers (Ezzy, 2000; Hem, 1992).

To define differences about concentrations of parameters in groundwater of the study area,

total concentrations of each parameter in sampling rounds 2 and 3 (in the wet and dry periods)

are shown in Figure 6.5 (a, b and c). This figure shows that all total units or scales of each

parameter in sampling round 3 (dry period) were higher than those in sampling round 2 (wet

period), except total Eh values in sampling round 2 was higher than that in sampling round 3.

NH3 /NH4+

Org-N NO3-N

Manure of

animals

Mixed

residents

& farms

Variable

settings &

vegetation

covers

Residential &

agricultural

fertilizers

Forests &

vegetation

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101

The cause of the higher concentrations of parameters in the dry period was due to the

evaporation of water in the dry period and the dilution of rainfall in the wet period.

Total Eh values in sampling round 2 was higher than that in sampling round 3 because in the

wet periods, the rainfall causes stronger reactions among ions in groundwater.

0

500

1000

1500

2000

2500

3000

3500

4000

Depth pH To K Al Ca Fe Mn

(m, 0C

, m

g/L

)

Round 2 (w et period)

Round 3 (dry period)

0

50000

100000

150000

200000

250000

300000

350000

400000

EC Eh Akalinity Cl SO4 Na Mg

(µS

/cm

, m

V, m

g/L

)

Round 2 (w et period)

Round 3 (dry period)

a)

b)

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102

0

100

200

300

400

500

600

NO3-N NO3 NO2 NH3/NH4 TKN PO4 TP DOC

(mg

/L)

Round 2 (w et period)

Round 3 (dry period)

Figure 6.5: Total units and scales of each parameter in sampling rounds 2 and 3 (in the

wet and dry periods)

Sodium and Sulfate

Bivariate graphs are also used to identify the ranges and distribution of selected major ions in

natural groundwaters and compare the relationship in the wet and dry periods. These

comparisons are to show that there is connectivity of groundwater groups. The concentrations

of certain ions are dependent upon the mineralogy of rocks and sediments in the study area

and the chemical composition of recharge waters as well as ionic concentrations of adjacent

water bodies in zones of groundwater mixing.

Sulfate was the third most common anion in shallow groundwater in the mainland

Pumicestone study area and best represented in seven groundwater types in the wet period.

Logarithmic scatter plots of sodium and sulfate show the comparison between the two ions in

the wet and dry periods in Figure 6.6. Median concentrations of sulfate in the groups of

groundwater show that the median concentration of sulfate in the dry period was higher than

that in the wet period, because of the evaporation of water in the dry period and the dilution of

rainwater in the wet period. Therefore, the concentration of sulfate was higher in the dry

period. The sulfate concentration in the wet and dry periods is shown in Appendix 8.

c)

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103

Figure 6.6: Logarithmic scatter plots of the median

concentration of sodium and sulfate in each groundwater group,

comparing the wet and dry periods

Stream water

Freshwater

Brackish water

Saline water

Seawater

Sulfate shifted

Dry

SO4 Na

Wet

SO4

Na

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104

6.4. Groundwater Chemistry

6.4.1. Hydrochemical Groups

Four sampling rounds of groundwater were collected and analysed. However, only sampling

round 2 (in the wet period) was used to plot the Piper diagram of groundwater and correlation

coefficient because the charge balance errors of groundwater samples in boreholes obtained

the lower levels than those of the other sampling rounds. A total of 37 boreholes were

collected and analysed in which many groundwater samples were collected and analysed two

or three times because their charge balance errors were higher than ± 10% to define whether

collection and analysis processes were accurate. In addition, as above mentioned, the higher

concentrations of parameters in the dry period was due to the evaporation of water in the dry

period and the dilution of rainfall in the wet period.

The major chemistry of the groundwater is considered as it can help understand the

characteristics of aquifer material setting and processes involved. Plotting groundwaters on

the Piper diagram for sampling round 2 by use of Aquachem/AqQA software, six dominant

groundwater groups have been identified in the mainland Pumicestone study area. These

groundwater types and groups in sampling round 2 (wet period) are shown in Figure 6.7 and

Table 6.2 where they are related to the different aquifer material types and the number of

boreholes per aquifer material type. Although Na-Cl may be expected to be the dominant

cation-anion in this low-lying coastal setting, variation of other ions reflecting different

settings.

Two mixing trends were identified in this sampling round. Mg enrichment trend was from

Group I to Group IV and Ca-HCO3 enrichment trend was from Group I through Group V &

VI.

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105

Figure 6.7: Dominant groundwater groups and chemistry in the region shown by

trilinear diagram classifying groundwater into hydrochemical groups. This plot is for

sampling round 2 (wet period)

Table 6.2: Groundwater chemical type and relation to aquifers for sampling round 2

(wet period)

Groundwater

Groups and

Chemistry

Groundwater

Types Wet Period (RN2)

Number of

Boreholes

and Aquifer

Material

I Na-Cl

LYN 37 (B); SEA 1073 (E); SEA

1101 (B); SEA 1108 (B)

3B, 1E

Na-Cl-SO4 LYN 44 (B); SEA 1156 (E) 1B, 1E

II

I

III

V VI

IV

LEGEND

Stream water

Fresh water

Brackish water

Saline water

Sea water

Mg enrichment

Ca-HCO3 enrichment

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106

II

Na-Mg-Cl

SEA 1035 (C); LYN 65 (C); LYN

66 (C); SEA 1110 (C); CAB 208

(B); LYN 181 (E); LYN 184 (E);

LYN 34 (A); LYN 48 (E); SEA

1047 (B); SEA 1063 (E); SEA

1092 (E);

5E, 4C, 2B;

1A

Na-Mg-Cl-SO4

LYN 54 (E); SEA 1042 (E); LYN

36 (B); LYN 4 (B); LYN 73 (E);

SEA 1054 (E); SEA 1089 (E)

5E, 2B

III Mg-Na-Fe-Cl-SO4 LYN 32 (E); SEA 1109 (B) 1E, 1B

IV Mg-Ca-SO4 BM5 (A) 1A

V

Na-Cl-HCO3 LYN 183 (E)

2E, 2B

Na-Fe-Cl-HCO3 LYN 39 (E)

Na-SO4-Cl-HCO3 CAB 216 (B)

Na-Mg-Cl-SO4-

HCO3 CAB 219 (B)

VI

Na-Ca-HCO3-Cl CAB 231 (E); LYN 26 (A)

3A, 1B, 1E Na-Ca-Mg-Cl-HCO3 CAB 214 (B); LYN 9 (A)

Mg-Na-Fe-Cl-SO4-

HCO3 SEA 1046 (A)

Group I: Six boreholes in sampling round 2 fell into this group. Two groundwater types in

this group were Na-Cl with four boreholes (LYN 37; SEA 1073; SEA 1101 and SEA 1108)

and Na-Cl-SO4 with two boreholes (LYN 44 and SEA 1156). These boreholes were in aquifer

material B (silts, sandy silts) and E (estuarine muds). Groundwater samples in these boreholes

were mostly fresh and brackish.

The boreholes were installed in the low-lying floodplain and coastal area, commonly less than

5 m ASL, so there was seawater intrusion because Cl/HCO3 ratios are more than 1.5, and

electrical conductivity values of these boreholes are higher than 1500 µS/cm. The low level of

pH values in Appendix 8 shows acidic groundwater in these boreholes.

Group II: This chemical group was dominated in sampling round 2 with 19 boreholes. The

two groundwater types in this group were Na-Mg-Cl and Na-Mg-Cl-SO4. These boreholes

were in aquifer materials C (estuarine muds), E (alluvium), B (silts, sandy silts) and A

(sands). Four boreholes (SEA 1035; LYN 65; LYN 66; SEA 1110) are in aquifer material C,

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107

only one borehole is in aquifer material A, 10 boreholes are in aquifer material E and 4

boreholes are in aquifer material B.

Thirteen groundwater samples of boreholes in this group with high EC values were brackish,

saline and sea waters. Only six groundwater samples of boreholes in this group were fresh

water with low EC values. These various aquifers reflect dynamic hydrology with quite a bit

of mixing between waters of different types often with a tidal influence.

Boreholes with high EC values were located in the floodplain as well as the estuaries with

seawater as the major source of dissolved sodium and chloride in addition to weathering Na-

feldspar of the sandstone bedrock. The pH values of these boreholes were from 3.8 to 6.8,

showing acidic groundwater dominates in most of these boreholes, only one borehole (pH =

6.8) was neutral. Elevated Mg was also present in these groundwater groups as cations

exchange possibly took place between the groundwater and the common Mg-smectite (Ezzy,

2000; Pavlik, 2005).

Group III: There were two boreholes (LYN 32 and SEA 1109) in this group with

groundwater type Mg-Na-Fe-Cl-SO4. Iron concentrations in these two boreholes were very

high with Borehole LYN 32 of 524 mg/L and Borehole SEA 1109 of 30 mg/L, therefore iron

was present in groundwater type. Two boreholes were in aquifer materials B (silts, sandy

silts) and E (alluvium), near creeks and coastal zone. There was sea water intrusion because

Cl/HCO3 ratios are more than 1.5, and electrical conductivity values of these boreholes are

higher than 1500 µS/cm.

The pH values of these boreholes were very low (3.2 and 3.7), showing acid in groundwater

because the presence of acid sulfate soil (Dear et al., 2002). The cause of the higher

concentration of sulfate is coastal sediments containing iron sulfides. When exposed to air,

this soil produces sulfuric acid, often releasing quantities of iron (Queensland Government,

2010). Mg was also present in groundwater due to derived from the dissolution of Mg-

smectite (Ezzy, 2000; Pavlik, 2005).

Group IV: This group was only one borehole BM5 with groundwater type Mg-Ca-SO4. The

borehole was fresh water (EC values of 692 µS/cm) and had a pH value of 5.5, being slightly

acidic groundwater. It was in aquifer material A (sands) in the Caboolture area, installed near

the coastal area. Ca is more likely to be derived from the dissolution of calcite due to the

presence of shell material (Ezzy, 2000; Pavlik, 2005). Mg was present in groundwater,

probably derived from the dissolution of Mg-smectite.

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Group V: This group included four boreholes which were in aquifer material B (silts, sandy

silts) and E (alluvium). These boreholes typically had increasing HCO3-and they were

representative of four groundwater types such as Na-Cl-HCO3, Na-Fe-Cl-HCO3, Na-SO4-Cl-

HCO3 and Na-Mg-Cl-SO4-HCO3. They were fresh water with low EC values, in which two

boreholes (CAB 216 and CAB 219) in aquifer material B in Ningi-Toorbul areas were fresh

water with no intrusion. The other two boreholes (Lyn 183 and LYN 39) in aquifer material E

in the Glasshouse Mountain area were fresh water with sea water intrusion. Na and Cl ions

were present in these groundwater boreholes due to sea water intrusion and weathering Na-

feldspar (Cox et al., 2000; Pavlik, 2005).

The pH ranges in these boreholes ranged from 5.4 to 6.0 which indicate the presence of

slightly acidic groundwater. The dominant ion pairing of Ca and HCO3 is more likely to be

derived from the dissolution of calcite due to the presence of shell material. However, the

groundwater types of this group only had HCO3 ion, which shows that there was mixing of

fresh groundwater and seawater in these boreholes and Ca ion had low concentration

therefore, it was not present in these groundwater types. Mg ion was present in one

groundwater borehole due to the dissolution of Mg-smectite (Ezzy, 2000; Pavlik, 2005).

Group VI: This group includes five boreholes which were installed in aquifer material A

(sands), B (silts, sandy silts) and E (alluvium). Five boreholes were representative of three

groundwater types Na-Ca-HCO3-Cl, Na-Ca-Mg-Cl-HCO3 and Mg-Na-Fe-Cl-SO4-HCO3.

These boreholes were fresh water with very low EC values. They were installed in high-lying

coastal area so no sea water intrusion. The pH values ranged from 5.9 to 6.5. This group

obtained the best groundwater quality compared to the other groups.

These boreholes were installed dominantly in aquifer material A (sands) with three boreholes.

The dominant ion pairing of Ca and HCO3 is more likely to be derived from the dissolution of

calcite due to the presence of shell material. The parameters (Na and Cl) in these boreholes

were not seawater intrusion; these showed direct discharge from rainfall and from weathering

Na-Ca feldspars. Mg ion was present in groundwater boreholes due to the dissolution of Mg-

smectite.

6.3.2. Correlation Coefficient

The chemical reactions that take place in groundwater are mainly represented by the

concentrations of major ions, and to a lesser extent minor ions that are present in groundwater.

The proportions of individual ions in groundwater are dependent upon the mineral

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109

composition of the rocks and sediments that the water comes in contact with. This

relationship may be simple, such as if the aquifer receives recharge directly by rainfall, or

where water is discharged without contacting any other aquifer or other water (Hem, 1992).

Complexities arise when there is more than one interconnected aquifer of different

compositions, the mixing of unlike waters, chemical reactions such as cation exchange, the

adsorption of dissolved ions, and biological and anthropogenic influences (Hem, 1992). These

mixing can occur in these coastal setting where the aquifer systems can be locally complex.

To determine a potential relationship and its degree between two ions in groundwater

samples, two correlation matrixes were established. The values in these matrixes are the

results of calculation of the Spearman coefficient of correlation (r). These r values are based

on the strength of correlation between each individual ion correlation, and vary from -1 (a

strong negative correlation) to +1 (a strong positive correlation). In this and several previous

studies (Harbison, 1998; Labadz, 2006) strong correlations for r values were defined greater

than or equal to 0.6 because these values reflects probably groundwater near to equilibrium

and corresponds to an increasing monotonic trend between two ions. Spearman correlations of

cations (A) and physico-chemistry, anions and nutrients (B) for groundwater samples in

sampling round 2 (in the wet period) in the mainland Pumicestone region are shown in Table

6.3.

There are strong relationships between Na+ and K

+, Na

+ and Ca

2+, Na

+ and Mg

2+; K

+ and

Ca2+

; K+ and Mg

2+; Ca

2+ and Mg

2+ and Ca

2+ and Mn

2+ in Table 6.3A. The high correlation

between the major cations reflects probably groundwater near to equilibrium. There is the

generally poor correlation of Fe and Al.

A Spearman correlation was also attempted for nutrients of concern and anions, however, few

of these parameters displayed significant correlations. In this later case, the parameters that

showed this correlation were pH and HCO3-, EC and Cl

-, EC and SO4

2-, Cl

- and SO4

2-,

NH3/NH4++Org-N and NH3/NH4

+ in Table 6.3B.

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110

Table 6.3: Spearman correlation of cations (A) and physico-chemistry, anions and

nutrients (B) for groundwater samples in sampling round 2 (in the wet period) in the

mainland Pumicestone region

Na+ 1.00 A

K+

0.783 1.00

Ca2+

0.756 0.790 1.00

Mg2+

0.928 0.864 0.815 1.00

Fe(tot) 0.383 0.551 0.463 0.487 1.00

Mn2+ 0.488 0.903 0.608 0.648 0.568 1.00

Al3+ 0.167 0.242 0.243 0.294 0.451 0.298 1.00

Na+

K+

Ca2+

Mg2+

Fe(tot)

Mn2+

Al3+

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111

pH 1.00 B

EC -0.195 1.00

DOC 0.086 0.242 1.00

HCO3-

0.834 -0.056 0.083 1.00

Cl- -0.263 0.942 0.224 -0.007 1.00

SO42-

-0.361 0.872 0.181 -0.190 0.827 1.00

NO3-N -0.189 0.033 -0.096 -0.032 -0.051 -0.095 1.00

NO2- 0.290 0.008 0.114 0.344 -0.059 -0.058 -0.084 1.00

NH3/NH4+

-0.031 0.472 0.025 0.093 0.374 0.046 -0.028 0.223 1.00

NH3/NH4++Org-N -0.053 0.287 0.532 -0.031 0.215 0.345 -0.009 0.238 0.689 1.00

PO43-

0.262 -0.02 0.154 0.339 -0.229 -0.234 0.221 0.466 0.118 0.240 1.00

TP 0.336 -0.085 -0.235 0.414 -0.177 -0.159 0.137 0.343 0.158 0.024 0.456 1.00

pH EC DOC HCO3-

Cl-

SO42-

NO3-N NO2- NH3/NH4

+ NH3/NH4

++Org-N PO4

3- TP

Strong correlations for r values greater than or equal to 0.6 are denoted in bold.

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112

In regard to physico-chemical parameters, nitrogen and phosphorus that relate to Lyngbya

blooms, pH has been identified as strong correlation with HCO3-. It is worth nothing here that

has a low positive correlation with TP, PO43-

and NO2-, but clear negative correlation with

NO3-N, NH3/NH4+, except NH3/NH4

+ and TKN. The various forms of nitrogen have only a

low positive correlation.

a) pH and H2CO3/HCO3-

The plot of pH versus H2CO3/HCO3- in Figure 6.8 is useful as it confirms that HCO3

- is a

main component of “alkalinity” in groundwater and represents the acid-neutralizing capacity

in groundwater (Wu et al., 1997). The pH is a property of groundwater and reflects conditions

and setting such as acidic conditions (Buddhima et al., 2010). Carbonate species are carbonic

acid (H2CO3), bicarbonate ion (HCO3-) and carbonate ion (CO3

2-). The percentage of

carbonate species depends on pH (Fetter, 1994). In this study, when pH values were lower

than 5.0, H2CO3 exists in groundwater so the HCO3- concentration was 0 mg/L in group (i).

When pH values were from 5.0 to 7.0, both H2CO3 and HCO3- exists in the groundwater but

H2CO3 concentration was reduced gradually and HCO3- concentration was increased gradually

in group (ii). Therefore, pH and H2CO3/HCO3- had a strong correlation.

Figure 6.8: Plot of pH and H2CO3/HCO3- in sampling round 2 (wet period)

i

ii

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113

b) EC and Cl-

The chemical behavior of chloride in natural water is subdued compared to the other major

ions. Chloride ions do not significantly enter into oxidation or reduction reactions, form no

important solute complexes with other ions unless the chloride concentration is extremely

high, do not form salts of low solubility, and are not significantly absorbed on mineral

surfaces (Hem, 1992). Therefore, Cl- is an effective indicator of the groundwater in coastal

settings.

EC and Cl- had a very strong correlation in groundwater samples in sampling round 2 (in the

wet period), with the Spearman coefficient of correlation (r = 0.942). Plot of EC and Cl- in

sampling round 2 (in the wet period) was shown in Figure 6.9. This plot shows the relation

between EC and Cl- and demonstrates that in this setting Cl

- is a dominant ion in the

groundwater types in this area so it was present in most of the groundwater types and the EC

value indicates the total amount of dissolved ions in the water.

Figure 6.9: Plot of EC and Cl- in sampling round 2 (wet period) showing a strong relation

between EC and Cl- because of their Spearman coefficient of correlation, r = 0.942

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114

c) EC and SO42-

Sulfur occurs in oxidation states ranging from S2-

to S6+

; the chemical behavior of sulfur is

related strongly to the redox properties of aqueous systems. Sulfur occurs many

oxidation/reduction states including sulfate (SO42-

) and pyrite (FeS) (Hem, 1992). In the

groundwater samples in sampling round 2, SO42-

is also a dominant anion in the groundwater

types in this area and it was present in seven groundwater types. However, the correlation

matrix of EC and SO42-

(r = 0.872) shows that EC and SO42-

had a lower correlation than EC

and Cl-

in groundwater samples because concentration of chloride was higher than

concentration of sulfate in groundwater samples. The plot of EC and SO42-

in Figure 6.10

shows that when sulfate concentration is high, EC value is high and when sulfate

concentration is low, the EC value is also low.

Figure 6.10: Plot of EC and SO4 in sampling round 2 (wet period) showing a strong relation

between EC and SO4 because of their Spearman coefficient of correlation, r = 0.872

d) NH3/NH4+ and TKN

NH3/NH4+

and TKN are two main forms of nitrogen. NH3/NH4+

occupied 46.2% of the total

nitrogen. TKN is the total of NH3/NH4+

and organic nitrogen; it occupied the highest

percentage with 86.2% of the total nitrogen. Therefore, NH3/NH4+

and TKN had a strong

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115

correlation in groundwater samples in sampling round 2 (in the wet period) with the

Spearman coefficient of correlation (r = 0.689). The plot of NH3/NH4+

and TKN is shown in

Figure 6.11.

NH3/NH4+

and TKN concentrations of most groundwater samples reflect the setting in this

area. NH3/NH4+

and TKN concentrations of five boreholes (CAB 208, CAB 214, LYN 65,

LYN 66 and LYN 32) were high because these boreholes were installed near toilets,

residential areas and pineapple farm so their groundwater was affected by septic tanks and

fertilizer.

Figure 6.11: Plot of NH3/NH4+ and TKN in sampling round 2 (in the wet period)

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116

7. CONCLUSION

This study is a part of the project “Implementing Algal Blooms Policy” of DERM with the

main aim to map the nutrients of concern in shallow groundwater of a representative coastal

setting to support the project to identify the nutrient sources and conditions in order to

avoid/minimize blooms of Lyngbya majuscula in Moreton Bay, southeast Queensland,

Australia.

The mainland Pumicestone region which is located 80 km north of Brisbane, Queensland,

Australia supports a diverse range of landuse activities including forestry, aquaculture,

extractive industries and also several National Parks and nature conservation areas. This study

includes five subcatchments such as Burpengary, Caboolture, Ningi, Elimbah, Bullock and

Glass Mountain areas and within these settings are variable geological materials, forms of

drainage systems, landuse and vegetation cover .

The main findings of this study are:

(a) Geological materials were divided into seven material categories, as follows A (sands); B

(silts, sandy silts); C (estuarine muds); D (humic soils); E (alluvium); F (sandstone) and G

(other bedrock) based on the digital geology map (Geological Survey of Queensland) and by

discussion with DERM personnel. Boreholes were sited in selected areas which included four

aquifer materials such as A (sands), B (silts, sandy silts), C (estuarine muds) and E (alluvium)

near the drainage systems at a lower relative elevation in subcatchments and commonly in

locations that have a hydrological connection to drainage systems.

(b) Fe and pH in shallow groundwaters have a strong correlation. When pH values were low

(< 4), iron concentrations of four boreholes were high (from 30 to 524 mg/L) due to acid

sulfate soils. When pH values were from 4.4 to 5.7, iron concentrations of seven boreholes

were from 22 to 49 mg/L because these boreholes were installed in areas with finer grain

sediments (mud and silt). When pH values were 4.6 to 6.0, iron concentrations of eighteen

boreholes were less than 15 mg/L due to due to sand material in these boreholes.

(c) Aquifer material A (sands) had the highest median concentrations of DOC, possibly as

sands allow infiltrating water to move rapidly to saturated groundwater with dissolved organic

molecules. In addition, DOC concentrations in some boreholes located in aquifer materials B

(silts, sandy silts) and E (alluvium) were high because they were installed in organic rich

wetlands.

(d) Concentrations of total nitrogen and phosphorus in shallow groundwaters were generally

low, however, concentrations for some boreholes were high due to proximity to animal waste

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117

(chicken, horse and cow) on farms and near the public septic toilet of residential (recreation)

areas. Elevated concentrations of total nitrogen and phosphorus tend to be found in localized

source areas.

(e) The distribution of the main forms of nitrogen were NH3/NH4+, the highest percentage

with 46.2%; organic nitrogen was 40%; NO3-N was 13.7% and NO2-N with the lowest

percentage was 0.1%. Five groups of nitrogen species were identified in this study in which

the various percentages of nitrogen species in the area was influenced by animal waste,

residential and agricultural fertilizers, forest and vegetation, mixed residents and farms, and

variable setting and vegetation covers.

(f) Total concentrations of dissolved ions in sampling round 3 (dry period) were higher than

those in sampling round 2 (wet period) was due to the evaporation of water in the dry period

and the dilution of rainfall in the wet period.

(g) The chemical characteristics of the groundwater is diverse in the mainland Pumicestone

study area due to the variability of the settings, the natural processes and from anthropogenic

activities. Chemical analysis of groundwater samples collected in sampling round 2 (wet

period) shows that there are six groundwater groups. Two mixing trends identified in this

sampling round. Mg enrichment trend was from Group I to Group IV and Ca-HCO3

enrichment trend was from Group I through Group V & VI.

These finding results were used to produce the groundwater GIS layer of a hazard map being

produced by DERM which identifies source areas and transport of nutrients of concern into

Moreton Bay. The final GIS map will be used by DERM to develop guidelines for coastal

landuse management to avoid/minimize blooms of Lyngbya in southeast Queensland,

Australia.

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Appendix 1

Analysis Manual of Cation Parameters

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CATIONS in WATER

by INDUCTIVELY COUPLED PLASMA - OPTICAL EMISSION

SPECTROSCOPY (ICP-OES)

Cations commonly analysed in water samples by ICP-OES are:

Major Cations: Na, K, Mg and Ca

Minor Cations: Al, Si, Sr, Mn, Fe, Zn and Cu

DECTECTION LIMITS:

Element

Working Detection Limits

Na 0.015 – 1500 mg/L

K 0.20 – 150 mg/L

Mg 0.001 – 150 mg/L

Ca 0.0003 – 250 mg/L

Al 0.015 – 75 mg/L

Si 0.011 – 75 mg/L

Sr 0.0006 – 75 mg/L

Mn 0.003 – 7.5 mg/L

Fe 0.015 – 7.5 mg/L

Zn 0.009 – 7.5 mg/L

Cu 0.02 – 0.75 mg/L

THEORY OF OPERATION:

The cation and sulfur concentrations are measured using inductively coupled plasma - optical

emission spectroscopy (ICP-OES). This technique involves the water sample being aspirated

into a plasma. The intensity of characteristic wavelengths emitted by the excited analyte ions

in the plasma are measured by a spectrophotometer. The measured intensity is proportional to

concentration, thus concentration of ions in the sample can be determined.

SAMPLE PREPARATION:

Little or no sample preparation is required for analysis of aqueous samples by ICP-OES

except for highly turbid samples which must be filtered and samples of high conductivity

which must be diluted to <4000 µS before analysis. Also, concentration of elements

determined must be within the detection limits of the ICP-OES for the results to have

analytical meaning.

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Filter turbid samples through a 0.45 or 0.8 µm membrane filter, collect and analyse the

filtrate, diluting if necessary.

It is possible for cations other than those listed above to be analysed, however it may not be

feasible if the selected analyte ions are present only in trace amounts ie at levels below the

limits of ICP-OES detection.

RESULTS

All data should be within detection limits set out above. Any results out of this range should

be recorded as being out of detection limits. Data out of dectection limits has no real

meaning, inclusion this data in a report or thesis is completely inaccurate.

Interpreting ICP-OES results print-outs:

Sample Name Program File Name Date Time

Element Mean Units Standard Weight/Volume

Analysed Intensity Deviation Recalculated

concentration element Wavelength

Concentration Percent in original sample

at which of element in Relative adjusting for sample

element is solution Standard weight and dilution.

determined Deviation

The above printout shows for Sample 1 the potassium (K) concentration was measured at a

wavelenth of 769.896 nm and was found to be 3.101 ppm in the original sample.

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Appendix 2

Summary of Analysis Manual of Anions, Nutrients and DOC

Parameters

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Parameters Analyzer Max storage

of GS (days)

Preservation of GS Reagents Standard Solution

Alkalinity

(5 – 80 mg/L)

AQ2 14 Cooling to 4 0C Methyl-orange-

buffered reagent

Stock standard solution (1000 mg

CaCO3/L)

- Anhydrous sodium carbonate

Chloride

(2 – 100

mg/L)

AQ2 28 Cl color reagent Stock standard solution (1000 mg

CL/L)

- Sodium chloride (NaCl)

Sulfate

(9 – 40 mg/L)

AQ2 28 Cooling to 4 0C - SO4 conditioner

- SO4 10% BaCl2

Stock standard solution (1000 mg

SO4/L)

- Anhydrous sodium sulfate

(Na2SO4)

Nitrate-N

(0.03 – 4.5

mg/L)

AQ2 28 Acidifying to pH < 2 with

concentrated sulfuric acid and

cooling to 4 0C

- NOx Ammonium

chloride buffer

- NOx sulfanilamide -

NEDD

Stock nitrate-N standard solution

(500 mg NO3-N/L)

- Sodium nitrate

Nitrite-N

(0.014 – 1.2

mg/L)

AQ2 2 Cooling to 4 0C, no use acid for

preservation

- NOx sulfanilamide -

NEDD

- NOx ammonium

chloride buffer

Stock nitrite-N standard solution

(500 mg NO2-N/L)

- Sodium nitrite

Ammonia-N

(0.02 – 2.0

mg/L)

AQ2 28 Acidifying to pH < 2 with

concentrated sulfuric acid and

cooling to 4 0C

- NH3 EDTA buffer

- NH3 phenate

- NH3 hypochlorite

- NH3 nitroprusside

Stock standard solution (1000 mg

N/L)

- Anhydrous ammonium chloride

(NH4CL)

- Concentrated sulfuric acid

TKN-N

(0.1 – 4.0

mg/L)

AQ2 Acidifying to pH < 2 with

concentrated sulfuric acid and

cooling to 4 0C

- TKN working

buffer

- TKN salicylate

Stock standard solution (1000 mg

N/L)

- Anhydrous ammonium chloride

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- TKN hypochlor (NH4Cl)

- Concentrated sulfuric acid

Phosphate

(0.005 – 1.0

mg/L)

AQ2 2 Cooling to 4 0C, no use acid for

preservation

- Molybdate

- Ascorbic

Stock standard solution (1000 mg

P/L)

- Potassium dihydrogen

orthophosphate (KH2PO4)

TKP AQ2 28 Acidifying to pH < 2 with

concentrated sulfuric acid and

cooling to 4 0C

- TKP acid/salt with

P

- TKP molybdate

- TKP ascorbic

Stock standard solution (800 mg

P/L)

- Potassium dihydrogen

orthophosphate

DOC TOC-V 28 Cooling to 4 0C - TOC solution (potassium

hydrogen phthalate)

- IC solution (sodium hydro

carbonate and sodium carbonate)

- DI water

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Appendix 3

Cation Concentrations with Minimum, Maximum, Median and

Average Concentrations for All Boreholes

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Aquifer

Material RN

K+ (mg/L)

min-max

(median/aver)

Al3+ (mg/L)

min-max

(median/aver)

Ca2+ (mg/L)

min-max

(median/aver)

Cu2+ (mg/L)

min-max

(median/aver)

Fetot (mg/L)

min-max

(median/aver)

Mg2+ (mg/L)

min-max

(median/aver)

Mn2+ (mg/L)

min-max

(median/aver)

Na+ (mg/L)

min-max

(median/aver)

Sr2+ (mg/L)

min-max

(median/aver)

Zn2+ (mg/L)

min-max

(median/aver)

A LYN 26 2.8 - 5.3

(2.8/3.6)

0 - 0.098

(0/0.033)

13 - 20

(16/16.3)

0

(0/0)

0 - 3.6

(0.064/1.22)

3.7 - 5.7

(4.8/4.7)

0.01 - 0.02

(0.02/0.01)

11. - 34

(23/22.7)

0.05 - 0.09

(0.07/0.07)

0

(0/0)

A LYN 34 7.8 - 45

(10.7/21.2)

0.11 - 2

(0.234/0.781)

4.2 - 108

(27/46.4)

0.009 - 0.03

(0.02/0.02)

3.78 - 10

(6.2/6.66)

19 - 300

(98/139)

0.03 - 1.08

(0.22/0.45)

100 - 1200

(460/586.7)

0.05 - 0.84

(0.45/0.45)

0 - 0.168

(0.084/0.084)

A BM5 7.3 - 30.4

(12.6/16.8)

0.12 - 0.22

(0.2/0.18)

9.5 - 56

(17/27.5)

0.006 - 0.007

(0.007/0.007)

0.48 - 15

(0.58/5.35)

6.3 - 37

(11/18.1)

0.02 - 0.22

(0.05/0.09)

8.6 - 16

(9.6/11.4)

0.06 - 0.11

(0.08/0.08)

0.038 - 0.086

(0.062/0.062)

A SEA 1046 4 - 12.6

(6/7.5)

0.41 - 1.8

(1/1.07)

2.8 - 3.4

(3.1/3.1)

0

(0/0)

8.1 - 19.508

(8.2/12)

3.8 - 6.8

(3.9/4.8)

0.19 - 0.27

(0.2/0.22)

6.9 - 20

(9.6/12.17)

0.03

(0.03/0.03)

0 - 0.096

(0.048/0.048)

A LYN 9 1.4 - 2.2

(2/1.8)

0.051 - 0.27

(0.051/0.13)

11. - 16

(14/13.7)

0

(0/0)

8.6 - 10

(10/9.53)

5.8 - 8.7

(7.5/7.3)

0.08 - 0.15

(0.11/0.11)

20 - 22

(22/21.3)

0.08 - 0.09

(0.08/0.08)

0

(0/0)

B SEA 1047 84.4 - 93.3

(85.1/87.6)

0.035 - 0.416

(0.189/0.213)

432 - 500

(462/464.7)

0 - 0.032

(0.016/0.016)

0.33 - 2.31

(0.576/1.072)

1152 - 1239

(1200/1197)

0.37 - 0.97

(0.4/0.58)

3840 - 3990

(3900/3910)

3.8 - 3.84

(3.82/3.82)

0 - 0.069

(0.035/0.035)

B LYN 4 0.8 - 2.4

(1.6/1.6)

0.74 - 1.8

(1.27/1.27)

1.8 - 2.3

(2.1/2.1)

0.007

(0.007/0.007)

1.9 - 2.3

(2.1/2.1)

8.4 - 19

(13.7/13.7)

0

(0/0)

40 - 56

(48/48)

0.03

(0.03/0.03)

0

(0/0)

B LYN 44 0 - 3.9

(0.6/1.5)

0 - 2.4

(0.011/0.804)

0.5 - 1.4

(0.9/0.9)

0

(0/0)

0.087 - 3.3

(0.32/1.236)

3. - 5

(4.6/4.2)

0.04 - 0.08

(0.06/0.06)

23 - 38

(29/30)

0.01

(0.01/0.01)

0 - 0.014

(0.007/0.007)

B CAB 219 0.1 - 9.6

(2.7/4.1)

0.7 - 0.99

(0.7/0.603)

1.4 - 7

(2.9/3.8)

0 - 0.002

(0.001/0.001)

0.05 - 2.6

(0.47/1.04)

3.2 - 14

(3.3/6.8)

0 - 0.17

(0/0.06)

13 - 75

(17/35)

0.03 - 0.07

(0.05/0.05)

0 - 0.13

(0.065/0.065)

B SEA 1109 2.8 - 47.6

(3.2/17.9)

2.3 - 186

(6.6/64.97)

2.4 - 66

(5.2/24.5)

0 - 0.008

(0.004/0.004)

0.54 - 1140

(30/390.18)

11 - 372

(21/134.7)

0.09 - 5.4

(0.28/1.92)

34 - 246

(43/107.7)

0.06 - 0.96

(0.51/0.51)

0.019 - 2.1

(1.06/1.06)

B CAB 216 0.4 - 6.3

(1.2/2.6)

0 - 0.74

(0.73/0.49)

0.45 - 1.6

(1.5/1.2)

0

(0/0)

0.02 - 2.2

(0.5/0.906)

2.1 - 5.1

(2.4/3.2)

0 - 0.06

(0.03/0.03)

17 - 22

(17/17)

0.01 - 0.02

(0.01/0.01)

0 - 0.057

(0.029/0.029)

B CAB 214 3.1 - 17.8

(4.4/8.5)

0 - 0.75

(0.4/0.383)

0.78 - 26

(16/14.3)

0 - 0.004

(0.002/0.002)

2 - 21.055

(3.9/9)

8.3 - 110

(12/43.4)

0.03 - 0.22

(0.14/0.13)

25 - 190

(51/88.7)

0.01 - 0.25

(0.13/0.13)

0.042 - 0.063

(0.053/0.053)

B CAB 208 70.7 - 606.5

(198/291.7)

0.627 - 2

(1.1/1.24)

74.8 - 165.1

(74.8/105)

0 - 29.7

(14.85/14.85)

0.957 - 17.6

(9.3/9.286)

462 - 1108.5

(484/684.8)

0.07 - 0.16

(0.12/0.12)

2090 - 4720.8

(2200/3003.6)

1.05 - 2

(1.52/1.52)

0 - 0.033

(0.017/0.017)

B LYN 36 0.2 - 5.7

(3.0/3.0)

0.25 - 1.3

(0.31/0.62)

0.27 - 6.8

(0.6/2.6)

0.004 - 0.005

(0.005/0.005)

0.5 - 12

(5.6/6.033)

2.7 - 33

(12/15.9)

0 - 0.5

(0.07/0.19)

12. - 80

(43/45)

0.02 - 0.07

(0.04/0.04)

0.034 - 0.45

(0.242/0.242)

B LYN 37 36.8 - 213.6

(90.3/113.6)

0.363 - 0.72

(0.5/0.528)

12.6 - 207.5

(41.8/87.3)

0

(0/0)

2.7 - 32.5

(14.3/16.5)

84 - 1550

(363/665.7)

0 - 0.05

(0/0.02)

840 - 6500

(2310/3216.7)

0.75 - 3.5

(2.12/2.12)

0

(0/0)

B SEA 1101 3.1 - 30.8

(5.9/13.2)

0 - 0.408

(0.2/0.202)

0.4 - 13.8

(2.2/5.5)

0

(0/0)

0.26 - 78

(15/31.1)

6.9 - 168

(17/64)

0.02 - 0.6

(0.14/0.25)

73 - 1080

(170/441)

0.01 - 0.28

(0.15/0.15)

0 - 0.402

(0.201/0.201)

B SEA 1108 0.7 - 1.8

(1.2/1.2)

0.062 - 0.19

(0.13/0.127)

1.9 - 3.3

(2.7/2.6)

0

(0/0)

0.18 - 1.3

(1.1/0.86)

25 - 32

(32/29.7)

0.07 - 0.13

(0.12/0.11)

240 - 270

(260/256.7)

0.05 - 0.05

(0.05/0.05)

0.015 - 0.12

(0.068/0.068)

C SEA 1035

312.5 - 404

(344/353.5)

0

(0/0)

650

(650/650)

0

(0/0)

35 - 105

(44.5 - 61.5)

3400 - 3800

(3400/3533.3)

0.6 - 1.1

(0.7/0.8)

12000 - 13500

(12500/12666.7)

7.5 - 8.5

(8/8)

0

(0/0)

C SEA 1110 109.9 - 343.8

(282.1/245.2)

0

(0/0)

56.1 - 357

(332.1/248.4)

0

(0/0)

10.25 - 29.4

(27.5/22.383)

539 - 2624

(2500/1887.7)

0.07 - 0.16

(0.07/0.1)

2860 - 10710

(9020/7530)

0.97 - 5.33

(3.15/3.15)

0

(0/0)

C LYN 65 107.5 - 238.2

(156/167.2)

0 - 7.94

(0.5/2.81)

130 - 338

(268/245.3)

0.12 - 0.2

(0.16/0.16)

32.8 - 50

(49.4/44.07)

950 - 2158

(1840/1649.3)

0.05 - 0.32

(0.31/0.23)

3700 - 7800

(6400/5966.7)

2.25 - 4.4

(3.33/3.33)

0 - 0.16

(0.08/0.08)

C LYN 66 172 - 237.5

(217.7/211.2)

5. - 19

(10.79/11.4)

200 - 286

(255/249)

0 - 0.65

(0.325/0.325)

26 - 105

(74.5/)

2050 - 2448

(2245/2247)

0 - 0.1

(0.05/0.05)

5980 - 8840

(8250/7830)

4.3 - 4.75

(4.53/4.53)

0

(0/0)

Page 148: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

E LYN 183 0.9 - 4.75

(4.2/3.3)

0 - 0.32

(0.041/0.12)

1 - 1.3

(1.1/1.1)

0 - 0.008

(0.004/0.004)

1.8 - 12

(6.3/6.7)

3 - 6.1

(3.9/4.3)

0.04 - 0.06

(0.05/0.05)

20 - 53

(20/31)

0.01 - 0.02

(0.02/0.02)

0 - 0.01

(0.005/0.005)

E LYN 184 0.9 - 5.2

(4.9/3.7)

0.051 - 0.88

(0.67/0.534)

0.6 - 0.8

(0.7/0.7)

0.005 - 0.007

(0.006/0.006)

1.8 - 9.4

(3/4.73)

2.9 - 4.3

(3.4/3.5)

0.03 - 0.04

(0.04/0.04)

13 - 18

(14/15)

0.01

(0.01/0.01)

0 - 0.069

(0.035/0.035)

E LYN 38 4.8 - 5.4

(5.1/5.1)

0.18 - 0.23

(0.205/0.205)

3.2 - 12

(7.6/7.6)

0

(0/0)

8.8 - 13.306

(11.053/11.053)

6.2 - 22

(14.1/14.1)

0.28 - 0.51

(0.4/0.4)

20 - 52

(36/36)

0.02 - 0.1

(0.06/0.06)

0 - 0.08

(0.04/0.04)

E LYN 73 14.6 - 78.2

(20.2/37.7)

0.81 - 3.52

(2.3/2.21)

19 - 143

(31/64.3)

0 - 0.077

(0.039/0.039)

31 - 418

(34.248/161.1)

89 - 839

(165.3/363.4)

2 - 4.62

(3.4/3.34)

330 - 2750

(700/1260)

0.36 - 2.09

(1.23/1.23)

0.061 - 0.308

(0.185/0.185)

E SEA 1054 12.4 - 24.0

(17.1/17.8)

60 - 82.5

(69/70.5)

300 - 530

(341/390.3)

0.019 - 0.031

(0.025/0.025)

4.3 - 570

(48/207.43)

517 - 790

(540/615.7)

3.78 - 11

(4.4/6.4)

1540 - 2000

(1620/1720)

2.8 - 3.7

(3.25/3.25)

0.42 - 1.1

(0.76/0.76)

E SEA 1063 28.9 - 41.4

(40.7/37)

1.5 - 13.8

(10.2/8.5)

120 - 174.6

(144/146.2)

0.007 - 0.03

(0.019/0.019)

33.94 - 48

(48/43.313)

264 - 372

(321.8/319.3)

1.02 - 1.4

(1.2/1.21)

1140 - 1500

(1341.2/1327)

1.4 - 1.56

(1.48/1.48)

0.198 - 1.2

(0.7/0.7)

E SEA 1073 4.3 - 5.8

(5.2/5.13)

0 - 0.22

(0.043/0.088)

3.7 - 4

(3.9/3.9)

0 - 0.003

(0.002/0.002)

16.2 - 35.7

(22/24.63)

15 - 17

(17/16.3)

0.13 - 0.16

(0.13/0.14)

120 - 170

(140/143.3)

0.06 - 0.07

(0.07/0.07)

0.012 - 0.095

(0.054/0.054)

E SEA 1089 3.5 - 5.1

(4.4/4.4)

0 - 0.098

(0.011/0.036)

16 - 37

(20/24.3)

0.005 - 0.006

(0.006/0.006)

0 - 0.59

(0.25/0.28)

60 - 130

(85/91.7)

0.08 - 0.16

(0.11/0.12)

240 - 450

(280/323.3)

0.17 - 0.22

(0.2/0.2)

0

(0/0)

E SEA 1092 3.7 - 5.1

(4.9/4.6)

0 - 0.18

(0.09/0.09)

8.4 - 10

(8.7/9.0)

0

(0/0)

11 - 45.6

(36/30.887)

18 - 26

(24/22.7)

0.13 - 0.19

(0.13/0.15)

79 - 120

(110/103)

0.08 - 0.1

(0.09/0.09)

0 - 0.039

(0.02/0.02)

E SEA 1156 2.5 - 10

(4.9/5.8)

0.18 - 2

(0.7/0.96)

1.3 - 4.9

(2/2.7)

0.008 - 0.009

(0.085/0.085)

5. - 14

(7.8/8.93)

6.1 - 38

(14/19.4)

0.03 - 0.22

(0.09/0.11)

32 - 350

(150/177.3)

0.03

(0.03/0.03)

0 - 0.094

(0.047/0.047)

E LYN 32 25.5 - 31.5

(29.6/28.9)

82.5 - 93.5

(85.8/87.27)

231 - 253

(231/238.3)

0.044 - 0.066

(0.055/0.055)

510.28 - 594

(524.15/542.81)

1275.4 - 1434.2

(1320/1343.2)

15.4 - 16.5

(15.4/15.77)

2310 - 2640

(2420/2456.7)

0.89 - 1.02

(0.96/0.96)

0 - 0.682

(0.341/0.341)

E LYN 54 2.1 - 3.9

(3.0/3.0)

0 - 0.082

(0/0.027)

2.5 - 3.3

(2.6/2.8)

0

(0/0)

0.47 - 2.7

(1.7/1.623)

10. - 12

(12/11.3)

0.12 - 0.17

(0.15/0.15)

45 - 50

(49/48)

0.03

(0.03/0.03)

0

(0/0)

E SEA 1042

36 - 50

(48/44.6)

0 - 0.495

(0.451/0.315)

78.1 - 154

(110/114)

0

(0/0)

0 - 1.43

(0/0.477)

550 - 924

(704/726)

0.2 - 0.96

(0.68/0.61)

2200 - 2970

(2640/2603.3)

1.21 - 1.65

(1.43/1.43)

0 - 0.033

(0.017/0.017)

E LYN 48

0.5 - 2.5

(1.2/1.4)

0 - 1.9

(0/0.633)

0.2 - 0.6

(0.5/0.4)

0.004 - 0.009

(0.007/0.007)

0.013 - 0.97

(0.33/0.438)

2.9 - 8.8

(6.3/6)

0 - 0.01

(0.01/0.01)

21 - 32

(26/26.33)

0 - 0.01

(0.01/0.01)

0 - 0.008

(0.004/0.004)

E LYN 181

0.4 - 3

(0.4/1.3)

0.058 - 0.24

(0.1/0.133)

1.1 - 2.4

(1.7/1.7)

0

(0/0)

0.29 - 1.8

(1/1.03)

19 - 84.7

(74/59.2)

0.03 - 0.06

(0.05/0.05)

110 - 390

(360/286.7)

0.01 -0.03

(0.02/0.02)

0.8 - 2.4

(1.6/1.6)

E CAB 231

0.1 - 2.5

(1.6/1.4)

0 - 0.26

(0/0.087)

45 - 100

(62/69)

0

(0/0)

0 - 3.9

(0.061/1.32)

3 - 3.66

(3.2/3.3)

0 - 0.02

(0/0.01)

35 - 40.8

(40/38.6)

0.11 - 0.15

(0.13/0.13)

0 - 0.03

(0.015/0.015)

E LYN 39

0 - 2.2

(0.2/0.8)

0.15 - 0.42

(0.24/0.27)

0.5 - 1.1

(0.6/0.8)

0 - 0.015

(0.008/0.008)

19 - 24

(19.658/20.886)

2.7 - 4.6

(3/3.4)

0.03 - 0.03

(0.03/0.03)

13 - 21

(17/17)

0.01 - 0.01

(0.01/0.01)

0 - 0.008

(0.004/0.004)

Page 149: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

Appendix 4

Anion Concentrations with Minimum, Maximum, Median and

Average Concentrations for All Boreholes

Page 150: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

Aquifer

Material RN

HCO3- (mg/L)

min-max

(median/aver)

Cl- (mg/L)

min-max

(median/aver)

SO42- (mg/L)

min-max

(median/aver)

Charge Balance (%)

min-max

(median/aver)

A LYN 26 46.3 - 82.5

(59.5/62.8)

11.4 - 42.7

(26.5/26.9)

16.421 - 21.1

(20.6/19.4)

-3.6 to 0.8

(-0.9/-1.2)

A LYN 34 23.1 - 105.9

(62.8/64)

194.6 - 1887.1

(992.9/1024.9)

20.5 - 795.2

(51.1/289)

-0.1 to -7.8

(1.6/3.1)

A BM5 7.5 - 14.5

(8.5/10.2)

14.3 - 27.2

(15.12/18.9)

32.7 - 363.5

(64.8/153.7)

-8.1 to -3.8

(-6.5/-6.1)

A SEA 1046 15.5 - 19.9

(18.3/17.9)

22.2 - 58.3

(28/36.1)

20.8 - 41.4

(34.8/32.3)

-17.1 to -3.1

(-10.1/-10.1)

A LYN 9 57.2 - 76.7

(57.2/63.9)

25.3 - 34.4

(34.4/31.3)

7.7 - 16.5

(16.4/13.5)

2 to 12.2

(7.1/7.1)

B SEA 1047 106.3 - 113.2

(109.4/109.7)

7519 - 8610

(7550.9/7893.5)

1502.4 - 2543.4

(1673.6/1906.5)

3.7 to 7.4

(5.1/5.4)

B LYN 4 0 - 10

(5/5)

63.8 - 162.2

(123/123)

49.6 - 70.1

(59.8/59.8)

-17.3 to -7.2

(-12.3/-12.3)

B LYN 44 8.6 - 13.2

(9.9/10.6)

25 - 48.9

(26.9/33.6)

32 - 39

(36.3/35.7)

-4.9 to -3.7

(-4.4/-4.3)

B CAB 219 7.56 - 11.2

(10.9/9.9)

11 - 183.1

(32.7/75.6)

13.3 - 130.3

(14.5/52.7)

-22.5 to 5.8

(-4.4/-7.0)

B SEA 1109 0

(0/0)

40.1 - 427.9

(50.9/173)

93.8 - 6292.4

(188.1/2191.4)

-24.4 to -4.9

(-7.8/-12.4)

B CAB 216 7.6 - 19.7

(13.4/13.6)

12.4 - 25.4

(17.4/18.4)

5.9 - 49.7

(16.8/24.2)

-8.3 to 0

(0/-2.8)

B CAB 214 35.3 - 98.7

(45.1/59.7)

30.8 - 378.1

(68.7/159.2)

17.5 - 271.1

(30/106.2)

4.7 to 12

(4.7/7.1)

B CAB 208 7.8 - 50

(29.6/29.1)

3504.2 - 10731.7

(6377.5/6871.1)

453.6 - 1603.3

(1221.7/1092.9)

-15.2 to 12.1

(-4/-2.4)

B LYN 36 0

(0/0)

15.7 - 257.6

(106.4/126.6)

0 - 164.8

(10/58.3)

-20 to 7.8

(7.8/-3.4)

B LYN 37 11.2 - 14.2

(12.2/12.5)

1675.8 - 11801.1

(4116.4/5864.4)

249.8 - 2249.7

(722/1073.8)

-7.8 to 5.9

(1.5/-0.1)

B SEA 1101 0 - 32.3

(19.4/17.3)

115.9 - 1892.4

(327.4/778.6)

15.9 - 137

(34.2/62.4)

-2.7 to 7

(-2.1/0.7)

B SEA 1108 0

(0/0)

439.1 - 466.77

(454.9/453.6)

41.2 - 81.2

(66.1/62.8)

-6.8 to 1.5

(1.5/-1.3)

C SEA 1035 20.8 - 51.6 (38.4/37)

24372.6 - 27992.3 (26143.6/26169.5)

4574.4 - 5638.6 (5375 - 5196)

-2.4 to 5.1 (4/2.2)

C SEA 1110 7.9 - 71.3

(40.7/40)

6338 - 22800

(17100.8/15413)

1003.9 - 4389.8

(3000.7/2798.2)

-6.8 to 4.9

(-0.5/-0.8)

C LYN 65 0 - 52.1

(17/23)

11348.8 - 17298.2

(15267.7/14638.2)

2080.4 - 4276.7

(2113.7/2823.6)

-18.7 to 6.7

(-12.6/-8.2)

C LYN 66 0 - 30.1

(0/7.52)

12069.8 - 19871.1

(16011.4/15991)

2224 - 3118.8

(2908.5/2790)

-7.7 to 4.3

(1.7/-0.03)

E LYN 183 6.1 - 47.1

(9.1/20.8)

13 - 75.7

(31.2/40)

20.3 - 44.2

(20.7/28.4)

-3.1 to 8.3

(-2.7/0.8)

E LYN 184 9.9 - 17.8

(10/12.6)

24.2 - 39

(25.3/29.5)

5.8 - 18.6

(15.6/13.3)

-7.3 to -0.7

(-2.7/-3.6)

E LYN 38 0 - 6.7

(3.4/3.4)

41.4 - 54.9

(48.2/48.2)

33.2 - 209

(121.1/121.1)

-7.1 to 3.8

(-1.7/-1.7)

E LYN 73 0 - 7.4

(2.5/2.5)

599.2 - 6238.4

(1388.2/2742)

229.2 - 2156

(303/896.1)

-1.9 to 5.1

(2.1/1.8)

E SEA 1054 0

(0/0)

1867.6 - 2932.5

(1924.9/2241.7)

2923 - 5520.7

(3581.2/4008.3)

0.6 to 5.7

(1.2/2.5)

E SEA 1063 0

(0/0)

2339.6 - 3021.1

(2948.9/2768.9)

566.1 - 1180.8

(641.4/796.1)

-1.8 to 1.3

(-0.3/1.3)

E SEA 1073 0 - 53.2

(0/17.7)

177.2 - 313.1

(212.9/234.4)

49.5 - 190.1

(120.8/120.1)

-12.7 to 7.3

(-0.9/-2.1)

E SEA 1089 116.5 - 120.3

(118.2/118.4)

319.9 - 446.2

(329.4/365.2)

151.2 - 630.6

(280.4/354.1)

7 to 8.5

(7.6/7.7)

E SEA 1092 56.9 - 78.1

(63.3/66.1)

124.3 - 312.5

(247.7/228.2)

20.7 - 74

(56/50.2)

-11.5 to 5.8

(-0.9/-2.2)

E SEA 1156 11.3 - 51.6 (19.8/27.5)

54.1 - 548.7 (316.8/306.5)

35.9 - 236.4 (224.2/165.5)

-26.6 to -3.6 (-7.4/-12.5)

E LYN 32 0 - 20.8

(0/6.9)

3811.7 - 4606.8

(4475.7/4298)

3966.6 - 5891.8

(4715.1/4857.8)

-0.9 to 11

(8.2/6.1)

E LYN 54 6.0 - 17.8

(14.3/12.7)

61.1 - 69.3

(67.3/65.9)

46.2 - 64.4

(53.4/54.7)

-2.4 to 5.1

(0.7 - 1.1)

Page 151: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

E SEA 1042 48.5 - 62.6

(56.1/55.7)

4350 - 4821.5

(4715/4628.9)

1927. 8 - 2470.7

(2017.7/2138.8)

-10.2 to 10.4

(1.2/0.5)

E LYN 48

5.8 - 11.2

(7.7/8.2)

40.7 - 69.8

(58/56.2)

9.5 - 13.6

(11.6/11.6)

-9.8 to -6.2

(-6.2/-7.4)

E LYN 181

26.7 - 101

(37/54.9)

175.5 - 643

(610.2/476.2)

72.2 - 122.1

(75.8/90)

-10 to 6.5

(6 - 0.8)

E CAB 231

109.2 - 135.2

(117/120.5)

71.9 - 89.3

(71.9/76.6)

24.5 - 36.5

(31.5/30.9)

0.1 to 17.5

(0.3/6)

E LYN 39 133 - 31.8

(29/24.6)

27.8 - 41.1

(31/33.3)

16.2 - 33.8

(16.3/22.1)

-3.9 to 2.3

(0.1/-0.5)

Page 152: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

Appendix 5

Minimum, Maximum, Median and Average Concentrations of

Forms of Nitrogen and Phosphorus for All Boreholes

Page 153: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

Aquifer

Material RN

NO3-N (mg/L)

min-max

(median/aver)

NO3- (mg/L)

min-max

(median/aver)

NO2-N (mg/L)

min-max

(median/aver)

NH3/NH4+ (mg/L)

min-max

(median/aver)

TKN (mg/L)

min-max

(median/aver)

PO43- (mg/L)

min-max

(median/aver)

TP (mg/L)

min-max

(median/aver)

A LYN 26 0.231 - 2.071

(1.354/1.22)

1.017 - 9.114

(5.958/5.363)

0 - 0.099

(0.023/0.041)

0.299 - 0.815

(0.435/0.516)

0.782 - 3.03

(0.818/1.543)

0.015 - 0.052

(0.036/0.034)

0.028 - 0.64

(0.282/0.316)

A LYN 34 0.086 - 0.596

(0.104/0.262)

0.023- 0.457

(0.379/0.286)

0 - 0.1

(0.025/0.041)

0.661 - 0.945

(0.686/0.764)

1.435 - 2.002

(1.718/1.718)

0

(0/0)

0 - 0.17

(0.059/0.076)

A BM5 0.185 - 6.4

(3.447/3.341)

0.815 - 28.114

(15.167/14.7)

0

(0/0)

0.321 - 0.867

(0.520/0.57)

1.953 - 2.193

(1.969/2.038)

0 - 0.8

(0.298/0.367)

0.16 - 0.9

(0.61/0.555)

A SEA 1046 0.11 - 0.181

(0.168/0.153)

0.485 - 0.795

(0.737/0.672)

0 - 0.015

(0/0.005)

0.4705 - 1.615

(0.874/0.986)

1.792 - 3.596

(3.357/2.915)

0.158 - 0.705

(0.312/0.396)

0.325 - 1.17

(0.465/0.653)

A LYN 9 0.123 - 0.22

(0.208/0.184)

0.542 - 0.967

(0.916/0.081)

0

(0/0)

0.699 - 1.80

(1.352/1.284)

1.271 - 16.189

(2.168/6.542)

0.138 - 0.326

(0.184/0.216)

0.630 - 2.361

(0.804/1.265)

B SEA 1047 0 - 0.069

(0.059/0.042)

0 - 0.301

(0.259/0.187)

0

(0/0)

0.691 - 1.301

(0.867/0.953)

0.695 - 1.084

(0.928/0.902)

0 - 0.035

(0.013/0.016)

0.122 - 0.377

(0.156/0.219)

B LYN 4 0 - 0.137

(0.069/0.069)

0 - 0.604

(0.302/0.302)

0

(0/0)

0.024 - 0.209

(0.116/0.116)

1.112 - 1.757

(1.435/1.435)

0

(0/0)

0 - 0.143

(0.071/0.071)

B LYN 44 0.009 - 0.714

(0.08/0.268)

0.04 - 3.14

(0.349/0.04)

0 - 0.019

(0/0.007)

0.525 - 0.61

(0.562/0.566

0.869 - 1.123

(1.026/1.006)

0 - 1.331

(0.069/0.467)

0.433 - 1.331

(0.44/0.735)

B CAB 219 0.043 - 0.575

(0.198/0.272)

0 - 0.87

(0.19/0.353)

0 - 0.021

(0/0.007)

0.578 - 0.98

(0.91/0.824)

0.917 - 1.022

(0.969/0.969)

0

(0/0)

0 - 0.195

(0.155/0.117)

B SEA 1109 0.04 - 0.47

(0.406/0.305)

0.174 - 2.072

(0.483/0.91)

0 - 2.125

(0/0.708)

0.419 - 12.055

(0.54/4.338)

0.524 - 0.929

(0.726/0.726)

0 - 0.171

(0/0.057)

0.082 - 0.767

(0.112/0.32)

B CAB 216 0.055 - 0.352

(0.192/0.2)

0 - 0.844

(0.242/0.362)

0 - 0.026

(0/0.009)

0 - 0.577

(0.496/0.358)

0.756 - 2.225

(0.823/1.27)

0

(0/0)

0 - 0.1

(0.072/0.058)

B CAB 214 0.022 - 0.06

(0.044/0.042)

0.096 - 0.263

(0.194/0.184)

0 - 0.05

(0.015/0.022)

0.356 - 1.43

(0.851/0.88)

0.097 - 4.507

(1.5/2.32)

0 - 0.128

(0.015/0.048)

0.246 - 1.661

(0.663/0.857)

B CAB 208 0.061 - 0.21

(0.062/0.111)

0.267 - 0.924

(0.272/0.488)

0 - 0.07

(0.02/0.03)

3.143 - 5.153

(3.653/3.983)

3.281 - 7.788

(7.761/6.277)

0.029 - 0.194

(0.127/0.117)

0.304 - 0.736

(0.52/0.52)

B LYN 36 0.127 - 0.61

(0.173/0.304)

0.082 - 0.763

(0.557/0.467)

0 - 0.361

(0/0.12)

0 - 0.669

(0/0.223)

0.459 - 1.877

(0.798/1.045)

0

(0/0)

0 - 0.106

(0/0.035)

B LYN 37 0.097 - 0.153

(0.141/0.13)

0.426 - 0.674

(0.622/0.574)

0

(0/0)

0.151 - 1.056

(0.727/0.645)

1.148 - 2.016

(1.43/1.53)

0

(0/0)

0 - 0.131

(0/0.044)

B SEA 1101 0.173 - 0.467

(0.216/0.285)

0 - 0.949

(0.762/0.57)

0

(0/0)

0 - 0.847

(0.205/0.351)

0.331 - 0.58

(0.482/0.464)

0

(0/0)

0.142 - 0.207

(0.174/0.207)

B SEA 1108 0.052 - 0.552

(0.079/0.228)

0 - 0.349

(0.229/0.192)

0

(0/0)

0 - 0.393

(0.27/0.221)

0.333 - 3.107

(0.495/1.312)

0 - 0.688

(0/0.229)

0.157 - 0.646

(0.206/0.336)

C SEA 1035 0.142 - 0.164

(0.154/0.154)

0.626 - 0.721

(0.679 - 0.675)

0

(0/0)

1.153 - 1.916

(1.552 - 1.54)

1.582 - 3.937

(3.589 - 3.036)

0 - 0.005

(0/0.002)

0 - 0.339

(0.23/0.19)

C SEA 1110 0.081 - 0.286

(0.092/0.153)

0.357 - 1.258

(0.406/0.674)

0

(0/0)

0.755 -1.793

(1.082/1.21)

1.407 - 5.157

(2.927/3.164)

0 - 0.155

(0.143/0.1)

0 - 0.617

(0.158/0.258)

C LYN 65 0.197 - 0.258

(0.23/0.228)

0.868 - 1.136

(1.012/1.005)

0

(0/0)

1.612 - 2.801

(2.409/2.274)

1.626 - 3.497

(2.56/2.56)

0

(0/0)

0 - 0.215

(0.072/0.072)

C LYN 66 0.143 - 0.269

(0.193/0.202)

0.495 - 1.182

(0.739/0.789)

0

(0/0)

1.745 - 2.793

(2.141/2.227)

2.181 - 3.666

(2.361/2.642)

0 - 0.021

(0/0.005)

0 - 0.113

(0.022/0.039)

Page 154: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

E LYN 183 0.177 - 0.221

(0.204/0.201)

0.779 - 0.972

(0.899/0.883)

0

(0/0)

0.240 - 0.63

(0.603/0.49)

0.4937 - 0.854

(0.828/0.7254)

0 - 0.129

(0.009/0.046)

0.213 - 0.891

(0.464/0.046)

E LYN 184 0.037 - 0.155

(0.11/0.101)

0.164 - 0.681

(0.482/0.442)

0

(0/0)

0.095 - 1.364

(0.472/0.644)

0.540 - 1.548

(1.370/1.153)

0

(0/0)

0 - 0.087

(0.013/0.033)

E LYN 38 0.14 - 0.177

(0.158/0.158)

0.615 - 0.777

(0.7/0.7)

0

(0/0)

0.408 - 0.963

(0.685/0.685)

0.943 - 1.100

(1.021/1.021)

0

(0/0)

0.135 - 0.192

(0.164/0.164)

E LYN 73 0.06 - 1.47

(0.165/0.565)

0.231 - 0.725

(0.263/0.406)

0 - 1.015

(0/0.339)

0.863 - 4.128

(1.162/2.051)

2.079 - 4.249

(2.432/2.92)

0 - 0.026

(0/0.009)

0.125 - 0.695

(0.147/0.322)

E SEA 1054 0.002 - 0.213

(0.127/0.114)

0.009 - 0.936

(0.56/0.502)

0

(0/0)

0.197 - 2.308

(1.170/1.225)

1.509 - 2.333

(1.787/1.877)

0 - 0.49

(0.01/0.167)

0 - 0.705

(0.016/0.24)

E SEA 1063 0.149 - 0.943

(0.152/0.415)

0.106 - 0.669

(0.656/0.477)

0 - 0.4651

(0/0.155)

0.711 - 0.889

(0.8/0.8)

0.856 - 1.484

(1.145/1.162)

0 - 0.017

(0/0.006)

0 - 0.475

(0.177/0.217)

E SEA 1073 0.166 - 0.951

(0.951/0.484)

0.200 - 1.473

(0.731/0.801)

0 - 0.881

(0/0.294)

0.951 - 1.723

(1.4927/1.389)

1.55 - 3.400

(2.657/2.536)

0

(0/0)

0.091 - 0.849

(0.15/0.363)

E SEA 1089 0.07 - 0.218

(0.167/0.152)

0.307 - 0.961

(0.733/0.667)

0

(0/0)

0.649 - 1.483

(0.727/0.953)

0.834 - 3.819

(1/1.883)

0 - 0.54

(0.018/0.186)

0.312 - 0.543

(0.357/0.404)

E SEA 1092 0.196 - 0.308

(0.236/0.247)

0.861 - 1.355

(1.038/1.084)

0

(0/0)

0.415 - 0.795

(0.782/0.664)

1.400 - 2.011

(1.9/1.77)

0 - 0.184

(0.133/0.106)

0.151 - 0.41

(0.232/0.264)

E SEA 1156 0.126 - 0.202

(0.148/0.159)

0.556 - 0.889

(0.649/0.698)

0 - 0.02

(0/0.007)

0.075 - 0.425

(0.216/0.239)

0.241 - 1.944

(0.994/1.06)

0 - 0.031

(0/0.01)

0.028 - 0.638

(0.185/0.284)

E LYN 32 0.014 - 0.041

(0.027/0.027)

0.059 - 0.179

(0.119/0.119)

0 - 0.069

(0/0.023)

2.408 - 5.457

(3.373/3.746)

3.086 - 4.318

(3.679/3.694)

0 - 0.031

(0.018/0.016)

0 - 0.289

(0/0.096)

E LYN 54 0.053 - 0.177

(0.079/0.103)

0.233 - 0.781

(0.345/0.453)

0

(0/0)

0.44 - 0.6722

(0.536/0.549)

0.817 - 1.086

(0.979/0.961)

0.015 - 0.087

(0.061/0.054)

0.094 - 0.553

(0.218/0.288)

E SEA 1042 0.041 - 0.387

(0.129/0.186)

0.180 - 1.705

(0.566/0.817)

0 - 0.037

(0.012/0.012)

0.279 - 1.017

(0.842/0.713)

0.283 - 2.407

(1.9/1.528)

0 - 0.082

(0.04/0.041)

0.972 - 1.726

(1.027/1.241)

E LYN 48 0.012 - 0.16

(0.142/0.105)

0.055 - 0.70

(0.624/0.46)

0

(0/0)

0.093 - 0.629

(0.578/0.433)

0.297 - 0.636

(0.466/0.466)

0

(0/0)

0 - 0.038

(0/0.126)

E LYN 181 0 - 0.102

(0.026/0.043)

0 - 0.447

(0.116/0.187)

0

(0/0)

0 - 0.64

(0.349/0.33)

0.575 - 1.213

(1.093/0.961)

0

(0/0)

0.046 - 0.083

(0.063/0.064)

E CAB 231 0 - 0.118

(0.061/0.06)

0 - 0.521

(0.268/0.263)

0

(0/0)

0.183 - 0.898

(0.396/0.492)

0.591 - 3.492

(0.63/1.571)

0 - 0.253

(0.044/0.1)

0 - 0.874

(0.064/0.313)

E LYN 39 0.145 - 0.408

(0.403/0.319)

0.64 - 1.794

(1.774/1.402)

0

(0/0)

0.36 - 0.641

(0.566/0.522)

0.767 - 1.317

(0.912/1)

0 - 0.02

(0/0.007)

0.011 - 0.204

(0.1/0.105)

Page 155: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

Appendix 6

Concentration of Nutrients of Concern with Median, Minimum

and Maximum Concentrations for All Boreholes

Page 156: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

Aquifer

Material

RN

median

(min-max)

pH

median

(min-max)

Fetot (mg/L)

median

(min-max)

DOC (mg/L)

median

(min-max)

TN (mg/L)

median

(min-max)

TP (mg/L)

median

(min-max)

A BM5 5.5

(4.2 - 5.9) 0.58

(0.48 - 15) 8.81

(5.11 - 17.5) 5.641

(2.154 - 8.343) 0.61

(0.16 - 0.9)

A LYN 26 6.1

(5.4 - 6.2)

0.064

(0 - 3.6)

7.84

(6.8 - 9.43)

2.952

(1.049 - 4.407)

0.282

(0.028 - 0.64)

A LYN 34 6.1

(5.1 - 7.8)

6.2

(3.78 - 10)

20.2

(14.95 - 29.51)

3.105

(0.111 - 2.131)

0.059

(0 - 0.17)

A LYN 9 5.9

(5.8 - 6.0)

10

(8.6 - 10)

21.72

(13.18 - 30.17)

2.376

(1.490 - 16.312)

0.804

(0.630 - 2.361)

A SEA 1046 5.4

(5.4 - 5.9)

8.2

(8.1 - 19.508)

67.75

(6.56 - 75.25)

3.552

(1.960 - 3.706)

0.465

(0.325 - 1.17)

B CAB 208 5.1

(4.9 - 5.7)

9.3

(0.957 - 17.6)

95.64

(75.18 - 116.1)

7.842

(3.491 - 7.920)

0.52

(0.304 - 0.736)

B CAB 214 6.6

(5.5 - 7.2)

3.9

(2 - 21.055)

16.01

(15.24 - 26.3)

1.544

(1.078 - 4.544)

0.663

(0.246 - 1.661)

B CAB 216 5.7

(5 - 5.7)

0.5

(0.02 - 2.2)

6.69

(5.43 - 12.94)

1.108

(0.879 - 2.443)

0.072

(0 - 0.1)

B CAB 219 5.5

(5.0 - 5.8)

0.47

(0.05 - 2.6)

12.23

(8.42 - 15.69)

1.065

(0.219 - 1.492)

0.155

(0 - 0.195)

B LYN 36 4.6

(4.4 - 5.2)

5.6

(0.5 - 12)

5.28

(1.98 - 22.05)

1.431

(0.925 - 2.050)

0

(0 - 0.106)

B LYN 37 5.8

(4.6 - 6.8)

14.3

(2.7 - 32.5)

25.25

(13.16 - 43)

1.588

(1.245 - 2.157)

0

(0 - 0.131)

B LYN 4 4.8

(4.3 - 5.3)

2.1

(1.9 - 2.3)

52.26

(29.22 - 75.29)

1.503

(1.113 - 1.894)

0.071

(0 - 0.143)

B LYN 44 5.1

(5 - 5.5)

0.32

(0.087 - 3.3)

10.36

(5.04 - 13.35)

1.105

(0.897 - 1.837)

0.44

(0.433 - 1.331)

B SEA 1047 5.7

(5.7 - 6.3)

0.576

(0.33 - 2.31)

8.21

(6.65 - 8.47)

0.987

(0.764 - 1.084)

0.156

(0.122 - 0.377)

B SEA 1101 5.1

(4.4 - 5.7)

15

(0.26 - 78)

3.81

(3.56 - 8.75)

0.753

(0.547 - 0.949)

0.174

(0.142 - 0.207)

B SEA 1108 3.9

(3.7 - 4.7)

1.1

(0.18 - 1.3)

2.88

(1.79 - 3.04)

1.047

(0.385 - 3.186)

0.206

(0.157 - 0.646)

B SEA 1109 3.7

(3.7 - 5.5)

30

(0.54 - 1140)

5.33

(4.47 - 32.88)

0.994

(0.04 - 3.460)

0.112

(0.082 - 0.767)

C LYN 65 4.9

(3.2 - 5.3)

49.4

(32.8 - 50)

15.74

(7.116 - 22.32)

1.823

(0.230 - 3.755)

0.072

(0 - 0.215)

C LYN 66 3.6

(3.1 - 5.4)

74.5

(26 - 105)

10.96

(9.698 - 15.4)

2.638

(2.547 - 3.809)

0.022

(0 - 0.113)

C SEA 1035 5.7

(5.1 - 6.4)

44.5

(35 - 105)

16.89

(10.72 - 17.65)

3.731

(1.737 - 4.101)

0.23

(0 - 0.339)

C SEA 1110 5.3

(4.9 - 5.6)

27.5

(10.25 - 29.4)

15.83

(13.7 - 40.62)

3.008

(1.499 - 5.443)

0.158

(0 - 0.617)

E LYN 38 5.5

5.3 - 5.8

11.053

(8.8 - 13.306)

10.59

(7.73 - 13.44)

1.180

(1.082 - 1.277)

0.164

(0.135 - 0.192)

E LYN 73 4.8

(4.3 - 5.9)

34.248

(31 - 418)

17.25

(7.49 - 18.45)

4.309

(2.244 - 4.917)

0.147

(0.125 - 0.695)

E SEA 1054 3.2

(2.7 - 3.6)

48

(4.3 - 570)

38.45

(30.02 - 40.42)

2.0

(1.637 - 2.335)

0.016

(0 - 0.705)

E SEA 1063 4.7

(3.8 - 4.9)

48

(33.94 - 48)

6.38

(5.85 - 28.45)

1.297

(1.005 - 2.891)

0.177

(0 - 0.475)

E SEA 1073 4.8

(4.1 - 5.7)

22

(16.2 - 35.7)

6.54

(6.45 - 10.72)

3.382

(2.992 - 3.566)

0.15

(0.091 - 0.849)

E SEA 1089 6.7

(5.4 - 7.0)

0.25

(0 - 0.59)

9.60

(8.61 - 13.43)

1.066

(1.052 - 3.986)

0.357

(0.312 - 0.543)

E SEA 1092 5.7

(5.4 - 5.9)

36

(11 - 45.6)

18.53

(16.91 - 28.51)

2.096

(1.708 - 2.247)

0.232

(0.151 - 0.41)

E SEA 1156 5.6

(5.2 - 6.2)

7.8

(5. - 14)

19.4

(11.77 - 27.03)

1.142

(0.388 - 2.146)

0.185

(0.028 - 0.638)

E CAB 231 6.5

(5.8 - 6.5)

0.061

(0 - 3.9 )

6.37

(5.12 - 8.66)

0.652

(0.630 - 3.610)

0.064

(0 - 0.874)

E LYN 181 5.8

(4.8 - 6.3)

1.0

(0.29 - 1.8)

24.7

(22.39 - 27.01)

1.093

(0.677 - 1.240)

0.063

(0.046 - 0.083)

E LYN 183 4.8

(3.6 - 5.5)

6.3

(1.8 - 12)

10.38

(6.62 - 10.42)

1.031

(0.715 - 1.033)

0.464

(0.213 - 0.891)

E LYN 184 6.0 3.0 16.15 1.525 0.013

Page 157: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

(4.9 - 7.1) (1.8 - 9.4) (8.79 - 29.7) (0.578 - 1.657) (0 - 0.087)

E LYN 32 3.2

(2.9 - 3.8)

524.15

(510.28 - 594)

15.13

(13.85 - 16.93)

3.719

(3.100 - 4.387)

0

(0 - 0.289)

E LYN 39 5.6

(5.2 - 6.0)

19.7

(19 - 24)

14.15

(6.02 - 17.39)

1.315

(0.912 - 1.725)

0.1

(0.011 - 0.204)

E LYN 48 5.4

(5.1 - 5.6)

0.33

(0.013 - 0.97)

3.54

(2.47 - 10.01)

0.457

(0.012 - 0.778)

0

(0 - 0.038)

E LYN 54 5.6

(4.5 - 5.8)

1.7

0.47 - 2.7

6.29

5.51 - 8.94

1.139

(0.896 - 1.157)

0.218

(0.094 - 0.553)

E SEA 1042 5.7

(5.1 - 6.2)

0

(0 - 1.43)

6.09

(4.706 - 15.68)

2.320

(0.412 - 2.448)

1.027

(0.972 - 1.726)

Page 158: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

Appendix 7

Percentage of Forms of Nitrogen and Phosphorus for All

Boreholes

Page 159: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

Aquifer RN

NO3-N

(median)

(mg/L)

NO3-N

(med)

%

NO2_N

(median)

(mg/L)

NO2_N

(median)

%

NH3/NH4

(median)

(mg/L)

NH3/NH4

(median)

%

Org-N

(median)

(mg/L)

Org-N

(median)

%

PO4

(median)

(mg/L)

PO4

(median)

%

Org- P

(median)

(mg/L)

Org-P

(median)

(%)

TP

(median)

(mg/L)

A BM5 3.447 63.6 0 0 0.520 9.6 1.449 26.7 0.298 32.8 0.311 67.2 0.609

B CAB 208 0.062 0.8 0.02 0.26 3.653 46.6 4.108 52.4 0.127 19.6 0.393 80.4 0.520

B CAB 214 0.044 2.8 0.015 1 0.851 54.6 0.649 41.6 0.015 2.2 0.648 97.8 0.663

B CAB 216 0.192 18.9 0 0 0.496 48.9 0.327 32.2 0 0.0 0.072 100.0 0.072

B CAB 219 0.198 16.9 0 0 0.909 77.9 0.060 5.2 0 0.0 0.155 100.0 0.155

E CAB 231 0.061 8.8 0 0 0.396 57.4 0.233 33.8 0.044 40.7 0.020 59.3 0.064

A LYN 26 1.354 61.7 0.023 1.1 0.435 19.8 0.383 17.4 0.036 11.3 0.246 88.7 0.282

E LYN 181 0.026 2.4 0 0 0.349 31.2 0.744 66.4 0 0.0 0.063 100.0 0.063

E LYN 183 0.204 19.8 0 0 0.603 58.4 0.225 21.8 0.009 1.9 0.455 98.1 0.464

E LYN 184 0.110 7.4 0 0 0.472 31.9 0.899 60.7 0 0.0 0.013 100.0 0.013

E Lyn 32 0.027 0.7 0 0 3.373 91.0 0.306 8.3 0.018 100.0 -0.018

A LYN 34 0.104 5.6 0.025 1.3 0.686 37.1 1.032 55.9 0 0.0 0.059 100.0 0.059

B LYN 36 0.173 17.8 0 0 0.000 0.0 0.799 82.2 0

B Lyn 37 0.141 9.0 0 0 0.727 46.1 0.708 44.9 0

E LYN 38 0.158 13.4 0 0 0.685 58.1 0.336 28.5 0 0.0 0.164 100.0 0.164

E LYN 39 0.403 30.6 0 0 0.566 43.0 0.347 26.3 0 0.0 0.100 100.0 0.100

B LYN 4 0.069 4.6 0 0 0.116 7.7 1.319 87.7 0 0.0 0.071 100.0 0.071

B LYN 44 0.079 7.2 0 0 0.562 50.9 0.463 41.9 0.069 13.5 0.371 86.5 0.440

E LYN 54 0.079 7.4 0 0 0.536 50.6 0.444 42.0 0.061 21.8 0.157 78.2 0.218

C LYN 65 0.230 8.2 0 0 2.409 86.3 0.152 5.5

C LYN 66 0.193 7.5 0 0 2.141 83.6 0.228 8.9 0

E LYN 73 0.165 6.3 0 0 1.162 44.8 1.270 48.9 0 0.0 0.147 100.0 0.147

A LYN 9 0.208 8.8 0 0 1.352 56.9 0.816 34.3 0.184 18.6 0.620 81.4 0.804

C SEA 1035 0.154 4.1 0 0 1.552 41.5 2.037 54.4 0 0.0 0.230 100.0 0.230

E SEA 1042 0.129 6.4 0 0 0.842 41.6 1.053 52.0 0.04 3.8 0.987 96.2 1.027

A SEA 1046 0.168 4.8 0 0 0.874 24.8 2.482 70.4 0.312 40.2 0.153 59.8 0.465

B SEA 1047 0.059 6.0 0 0 0.867 87.9 0.061 6.1 0.013 7.7 0.143 92.3 0.156

E SEA 1054 0.127 6.7 0 0 1.170 61.1 0.617 32.2 0.01 39.5 0.006 60.5 0.016

E SEA 1063 0.152 11.7 0 0 0.799 61.6 0.346 26.7 0 0.0 0.177 100.0 0.177

E SEA 1073 0.335 11.2 0 0 1.493 49.9 1.165 38.9 0 0.0 0.150 100.0 0.150

E SEA 1089 0.167 14.3 0 0 0.727 62.6 0.269 23.1 0.018 4.7 0.339 95.3 0.357

E SEA 1092 0.236 11.0 0 0 0.782 36.6 1.118 52.3 0.133 36.4 0.099 63.6 0.232

B SEA 1101 0.216 30.9 0 0 0.205 29.3 0.278 39.8 0 0.0 0.174 100.0 0.174

B SEA 1108 0.079 13.8 0 0 0.270 47.0 0.225 39.2 0 0.0 0.206 100.0 0.206

B Sea 1109 0.406 35.9 0 0 0.540 47.7 0.186 16.5 0 0.0 0.112 100.0 0.112

C SEA 1110 0.092 3.1 0 0 1.082 35.9 1.845 61.1 0.143 47.7 0.015 52.3 0.158

E SEA 1156 0.148 12.9 0 0 0.216 18.9 0.778 68.1 0 0.0 0.185 100.0 0.185

% 13.7 0.1 46.2 40.0 17.6 82.4

Page 160: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

Appendix 8

Complete Data Sets of Four Sampling Rounds

Page 161: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

RN Easting Northing Student Area Time of

sampling Round 1

Depth to

water level

(m)

pH (R1)

EC

(µS/cm)

Eh

(mV) T0 (0C)

K

(mg/l)

Al

(mg/l)

Ca

(mg/l)

Cu

(mg/l)

Fe (R1)

(mg/l)

Mg

(mg/l)

Lyn 39 501135 7017392 Phan Ha Glass Mountain 20-Jan-09 R1 0.27 5.2 147 28 22.9

Lyn 65 506127 7015994 Phan Ha Glass Mountain 20-Jan-09 R1 0.63 3.22 32000 324 24.1

Lyn 66 504299 7015634 Phan Ha Glass Mountain 20-Jan-09 R1 0.14 3.33 35600 251 25.7 172 7.02 200 26 2448

Lyn 183 501763 7015908 Phan Ha Glass Mountain 20-Jan-09 R1 0.6 5.5 131.2 24 22.4

LYN 184 501450 7016663 Phan Ha Glass Mountain 20-Jan-09 R1 0.9 4.93 370 115 28.1

RN

Mn

(mg/l)

Na

(mg/l)

Sr

(mg/l)

Zn

(mg/l)

HCO3

(mg/l)

Cl

(mg/l)

SO4

(mg/l)

NO3-N

(mg/l)

NO3

(mg/l)

NO2

(mg/l)

NH4/NH3

(mg/l)

TKN

(mg/l)

PO4

(mg/l)

TP

(mg/l)

DOC

(mg/L)

Balance

(%)

Lyn 39

Lyn 65

Lyn 66 0.026 5980 30.082 13841.14 2224.029 0.49544 0 2.1805 0.0206 0.1127 4.3

Lyn 183

LYN 184

Page 162: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

RN Easting Northing Student Area Time of

sampling Round 2

Depth to

water level

(m)

pH

(R2)

EC

(µS/cm)

Eh

(mV)

T0

(0C) Water Type

K

(mg/l)

Al

(mg/l)

Ca

(mg/l)

Lyn 32 501438 6997716 Phan Ha Burpengary 24/07/2009 R2 0 3.17 14450 320 18.6 Mg-Na-Cl-SO4 25.52 85.8 231

LYN 54 497745 6996721 Phan Ha Burpengary 2/07/2009 R2 -0.1 5.77 219 91 21.3 Mg-Na-Cl-SO4 2.06 0 2.5

SEA 1035 502745 6997259 Phan Ha Burpengary 29/06/2009 R2 0.04 5.7 60600 144 17.8 Mg-Na-Cl 312.5 0 650

SEA 1042 499800 6997218 Phan Ha Burpengary 3/07/2009 R2 1.78 5.73 15200 304 20.4 Mg-Na-Cl-SO4 50 0 154

LYN 26 511193 7004210 Phan Ha Caboolture 23/07/2009 R2 0.4 6.18 281 86 20.3 Na-Ca-HCO3-Cl 2.75 0 16

LYN 34 506379 7001372 Phan Ha Caboolture 26/06/2009 R2 0.4 6.05 3050 42 19.4 Na-Mg-Cl 10.73 0.11 27

LYN 73 500840 7002498 Phan Ha Caboolture 26/06/2009 R2 0.23 4.76 2190 86 20.5 Na-Mg-Cl-SO4 14.59 0.81 19

BM5 508451 7003158 Phan Ha Caboolture 30/06/2009 R2 0.8 5.47 692 63 21.3 Mg-Ca-SO4 30.39 0.22 56

SEA 1046 505272 6999569 Phan Ha Caboolture 29/06/2009 R2 0.5 5.92 134.3 34 19.1 Mg-Na-Fe-Cl-SO4-HCO3 4 0.41 2.8

SEA 1047 504105 6999716 Phan Ha Caboolture 29/06/2009 R2 0.6 6.27 22830 115 19.4 Na-Mg-Cl 84.42 0.189 462

SEA 1054 504728 7002116 Phan Ha Caboolture 2/07/2009 R2 0.24 3.6 9760 370 20.8 Na-Mg-SO4-Cl 12.42 60 300

SEA 1063 502279 7001227 Phan Ha Caboolture 26/06/2009 R2 0.08 3.79 6650 311 19.7 Na-Mg-Cl 28.92 10.2 120

SEA 1073 502660 7003587 Phan Ha Caboolture 19/06/2009 R2 0.02 5.72 873 52 21.4 Na-Cl 4.31 0 4

SEA 1089 498981 7002083 Phan Ha Caboolture 26/06/2009 R2 1.56 6.75 2560 102 19.5 Na-Mg-SO4-Cl 4.44 0 37

SEA 1092 500758 7006225 Phan Ha Caboolture 29/06/2009 R2 0.08 5.92 822 70 18.5 Na-Mg-Cl 3.69 0 10

LYN 4 513598 7005243 Phan Ha Ningi_Toorbul 19/06/2009 R2 0.44 5.28 254 67 20.4 Na-Mg-Cl-SO4 0.8 1.8 1.8

LYN 9 510671 7006204 Phan Ha Ningi_Toorbul 23/07/2009 R2 0.22 5.9 225 76 21.7 Na-Ca-Mg-HCO3-Cl 1.36 0.068 16

LYN 44 500112 7008539 Phan Ha Ningi_Toorbul 29/06/2009 R2 0.45 5.53 245.5 205 17 Na-Cl-SO4 0.56 0 1.4

CAB 219 509510 7007885 Phan Ha Ningi_Toorbul 26/06/2009 R2 1.06 5.81 75.8 223 18.9 Na-Mg-Cl-SO4-HCO3 0.07 0.12 1.4

Sea 1109 508505 7009348 Phan Ha Ningi_Toorbul 29/06/2009 R2 0.03 3.66 540 327 19.3 Mg-Na-Fe-SO4-Cl 3.23 6.6 5.2

SEA 1110 505718 7008782 Phan Ha Ningi_Toorbul 12/06/2009 R2 0.14 5.64 53900 127 19.5 Na-Mg-Cl 343.77 0 357

SEA 1156 503304 7009227 Phan Ha Ningi_Toorbul 19/06/2009 R2 0.73 5.2 1997 162 19.6 Na-Cl-SO4 2.51 0.18 4.9

CAB 216 510590 7008414 Phan Ha Ningi_Toorbul 26/06/2009 R2 0.16 5.68 97 189 17.4 Na-SO4-Cl-HCO3 0.41 0 1.6

CAB 214 509981 7009437 Phan Ha Ningi_Toorbul 24/07/2009 R2 0.79 6.63 487 -53 16.9 Na-Ca-Mg-Cl-HCO3 3.14 0 26

CAB 208 509247 7010514 Phan Ha Ningi_Toorbul 19/06/2009 R2 0.63 5.7 12560 -50 19.9 Na-Mg-Cl 70.73 1.1 74.8

LYN 36 504280 7011525 Phan Ha Elimbah_Bullock 12/06/2009 R2 0.78 5.22 69.3 210 18.6 Na-Mg-Cl-SO4 0.2 1.3 0.27

Lyn 37 507558 7009724 Phan Ha Elimbah_Bullock 29/06/2009 R2 0.39 5.85 4460 167 20 Na-Cl 36.78 0.72 12.6

LYN 48 497869 7013963 Phan Ha Elimbah_Bullock 3/07/2009 R2 -0.08 5.38 246 251 20.7 Na-Mg-Cl 1.23 0 0.51

LYN 181 505203 7013974 Phan Ha Elimbah_Bullock 12/06/2009 R2 0.76 5.77 2249 174 19.3 Na-Mg-Cl 0.57 0.058 1.7

CAB 231 506595 7013480 Phan Ha Elimbah_Bullock 29/06/2009 R2 0.49 6.5 6.75 187 19.4 Ca-Na-HCO3-Cl 0.14 0 100

SEA 1101 507332 7010766 Phan Ha Elimbah_Bullock 19/06/2009 R2 0.35 5.66 1107 112 20.8 Na-Cl 5.9 0 2.2

SEA 1108 503299 7010541 Phan Ha Elimbah_Bullock 29/06/2009 R2 0.13 4.65 1385 340 21.7 Na-Cl 1.21 0.062 3.3

LYN 39 501135 7017392 Phan Ha Glass Mountain 3/07/2009 R2 0 5.95 173.8 31 16.2 Na-Fe-Cl-HCO3 0.23 0.15 1.1

LYN 65 506127 7015994 Phan Ha Glass Mountain 3/07/2009 R2 0.27 4.79 37400 189 18.3 Na-Mg-Cl 238.16 7.94 338

LYN 66 504299 7015634 Phan Ha Glass Mountain 24/07/2009 R2 0.23 3.83 43400 260 17.9 Na-Mg-Cl 231.4 14.56 286

LYN 183 501763 7015908 Phan Ha Glass Mountain 24/07/2009 R2 0.15 5.4 323 73 16.2 Na-Cl-HCO3 4.18 0 1

LYN 184 501450 7016663 Phan Ha Glass Mountain 3/07/2009 R2 0.22 6.12 102.5 62 16.2 Na-Mg-Cl 0.86 0.051 0.59

Page 163: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

RN Fe (R2)

(mg/l)

Mg

(mg/l)

Mn

(mg/l)

Na

(mg/l)

HCO3

(mg/L)

Cl

(mg/l)

SO4

(mg/l)

NO3-N

(mg/l)

NO3

(mg/l)

NO2

(mg/l)

NH4

(mg/l)

TKN

(mg/l)

PO4

(mg/l)

TP

(mg/l)

DOC

(mg/L)

Balance

(%)

Lyn 32 524.15 1275.406 15.4 2310 0 3811.672 3966.5 0.0135 0.0594 0 2.408 3.0861 0 0 16.93 11

LYN 54 1.7 12 0.12 45 21.3636 61.056 53.386 0.0785 0.3454 0 0.4399 0.817 0.0873 0.0938 6.293 -0.2

SEA 1035 44.5 3400 0.7 12000 46.1328 27992.3 4575.4 0.1543 0.67892 0 1.5521 1.5823 0 0.2297 10.72 -2.4

SEA 1042 0 924 0.957 2970 67.3452 4715.039 1927.897 0.1286 0.56584 0 0.2794 0.283 0 0.9715 6.093 10.3

LYN 26 3.6 4.8 0.015 34 98.9976 26.456 20.597 2.0713 9.11372 0.099 0.2991 0.7815 0.0359 0.282 9.434 -3.8

LYN 34 10 98 0.22 460 75.3876 992.891 51.103 0.1039 0.45716 0 0.6606 2.0015 0 0.0594 29.51 -0.4

LYN 73 31 89 2 330 8.8716 599.202 229.194 0.1648 0.72512 0 0.8631 2.0791 0 0.695 7.49 5.1

BM5 15 37 0.22 16 8.9904 27.152 363.49 0.1853 0.81532 0 0.8665 1.9687 0 0.1593 5.112 -4

SEA 1046 8.1 3.8 0.2 6.9 21.972 22.205 20.844 0.1675 0.737 0 0.4705 1.7922 0.3121 0.4645 6.561 -12.1

SEA 1047 2.31 1239 0.966 3990 127.5756 8610 1673.641 0.0684 0.30096 0 0.6911 0.6953 0 0.1223 6.653 3.6

SEA 1054 48 540 3.78 1620 0 1924.872 3581.2 0.2127 0.93588 0 0.1968 1.7868 0.0104 0.0159 38.45 1.2

SEA 1063 48 264 1.02 1140 0 2339.682 566.121 0.149 0.6556 0 0.7111 0.8563 0 0 6.384 1.3

SEA 1073 35.7 15 0.16 120 63.8724 177.197 49.508 0.3347 1.47268 0 1.4927 2.6573 0 0.1495 10.72 6.1

SEA 1089 0 130 0.16 450 141.852 446.194 630.561 0.0698 0.30712 0 0.7272 0.9958 0 0.3115 9.603 6.9

SEA 1092 11 26 0.19 120 75.9468 247.686 20.653 0.236 1.0384 0 0.7946 2.0109 0.1329 0.151 18.53 -2.1

LYN 4 1.9 8.4 0.002 40 12.0108 63.75 49.578 0.1373 0.60412 0 0.0239 1.7568 0 0 75.29 -7.7

LYN 9 10 8.7 0.15 20 91.9752 25.237 7.74 0.2197 0.96668 0 0.6985 1.2707 0.1835 0.8035 13.18 6.8

LYN 44 0.32 5 0.076 38 11.892 48.931 38.785 0.0794 0.34936 0 0.5248 1.0258 0 0.4402 5.04 -5.1

CAB 219 0.05 3.2 0.003 13 13.476 11.029 14.479 0.0432 0.19008 0 0.5776 1.0217 0 0.1954 12.23 3.6

Sea 1109 30 21 0.28 34 0 40.068 188.097 0.47 2.0724 0 0.4191 0.5236 0 0.1116 5.332 -4.9

SEA 1110 29.4 2500 0.069 10710 48.792 22800.569 3000.714 0.0922 0.40568 0 1.0824 1.4068 0 0 13.7 -0.5

SEA 1156 7.8 38 0.22 350 13.5252 548.742 224.213 0.1475 0.649 0 0.0748 0.9942 0 0.1847 11.77 -3.7

CAB 216 0.02 2.4 0.032 17 23.6556 12.375 16.769 0.0551 0.24244 0 0.5766 0.8234 0 0 5.426 -3

CAB 214 21.055 12 0.14 51 118.374 68.735 29.983 0.0219 0.09636 0.015 1.4323 4.5069 0.1284 1.661 16.01 8.4

CAB 208 0.957 462 0.066 2200 59.9736 3504.229 453.562 0.0607 0.26708 0.02 3.6533 7.7611 0.1271 0.3041 12.1

LYN 36 0.5 2.7 0.003 12 0 15.649 10.028 0.1266 0.55704 0 0 0.7987 0 0 22.05 7.8

Lyn 37 2.7 84 0 840 17.0004 1675.77 249.753 0.0968 0.42592 0 0.1511 1.1478 0 0 42.99 -7.8

LYN 48 0.013 8.8 0.007 32 13.4544 69.813 13.646 0.1598 0.70312 0 0.0929 0.2968 0 0 2.472 -6.9

LYN 181 1 84.7 0.056 390 31.9812 642.994 122.103 0.1015 0.4466 0 0 0.5754 0 0.0628 22.39 6.3

CAB 231 0 3.2 0 35 162.2832 71.847 24.532 0.061 0.2684 0 0.1832 0.5905 0 0 6.378 13.1

SEA 1101 15 17 0.14 170 38.8272 327.398 15.921 0.2157 0.94908 0 0.2046 0.3311 0 0.2066 3.814 -3.2

SEA 1108 0.18 25 0.13 240 0 466.766 66.12 0.052 0.2288 0 0.2698 0.3328 0 0.2055 3.035 -6.8

LYN 39 19 4.6 0.028 21 34.8216 41.091 16.333 0.4031 1.77364 0 0.3598 0.9123 0 0.204 6.02 -2.2

LYN 65 49.4 2158 0.312 7800 0 15267.7 2080.395 0.1973 0.86812 0 1.6121 1.6256 0 0 7.116 6.7

LYN 66 104 2340 0.078 8840 0 18181.6 2714.25 0.1929 0.84876 0 1.7452 2.3536 0 0 10.96 2.7

LYN 183 6.3 6.1 0.045 53 56.4924 75.7 20.289 0.2209 0.97196 0 0.2401 0.4937 0.1289 0.4638 6.616 -5

LYN 184 1.8 2.9 0.042 13 12.0504 24.175 5.806 0.0372 0.16368 0 0.0953 0.5404 0 0.0873 8.788 -4.4

Page 164: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

RN Eastin

g Northing Student Location

Time of

sampling

Round

3

Depth

(m)

pH

(R3)

EC

(µS/c

m)

Eh

(mV) To Water Type

K

(mg/l)

Al

(mg/l

)

Ca

(mg/l)

Cu

(mg/l)

Fe

(R3)

(mg

/l) Lyn 32 501438 6997716 Phan Ha Burpengary 20-Nov-09 R-3 0.2 3.77 15570 320 25 Mg-Na-Cl-SO4 31.46 82.5 231 0.044 594

LYN 54 497745 6996721 Phan Ha Burpengary 3-Nov-09 R-3 -0.1 5.56 393 -534 22.7 Mg-Na-Cl-SO4 2.96 0 3.3 0 2.7

SEA 1035 502745 6997259 Phan Ha Burpengary 20-Nov-09 R-3 0.67 6.43 52200 50 25.9 Na-Mg-Cl 344 0 650 0 35

SEA 1042 499800 6997218 Phan Ha Burpengary 20-Nov-09 R-3 1.4 6.2 13520 180 24.4 Na-Mg-Cl-SO4 47.85 0.495 110 0 1.43

LYN 26 511193 7004210 Phan Ha Caboolture 9-Nov-09 R-3 0.93 6.1 160.3 148 22.4 Ca-Na-HCO3-SO4-

Cl 2.83 0 13 0 0

LYN 34 506379 7001372 Phan Ha Caboolture 19-Nov-09 R-3 1.27 7.81 6530 33 23.6 Na-Mg-Cl-SO4 45 0.234 108 0.03 3.78

LYN 38 500849 7005123 Phan Ha Caboolture 9-Nov-09 R-3 0.3 5.28 526 170 22 Na-Mg-SO4-Cl 5.43 0.18 12 0 8.8

LYN 73 500840 7002498 Phan Ha Caboolture 19-Nov-09 R-3 1.15 5.85 16250 175 21.9 Na-Mg-Cl-SO4 78.21 3.52 143 0.077 418

BM5 508451 7003158 Phan Ha Caboolture 9-Nov-09 R-3 1.3 5.9 171.1 188 22.5 Mg-Ca-Na-SO4-NO3 7.33 0.12 9.5 0.006 0.48

SEA 1046 505272 6999569 Phan Ha Caboolture 9-Nov-09 R-3 1.1 5.45 148.5 96 23.1 Na-SO4-Cl 6 1.8 3.4 0 8.2

SEA 1047 504105 6999716 Phan Ha Caboolture 9-Nov-09 R-3 0.84 5.71 24900 160 21.6 Na-Mg-Cl 93.34 0.035 500 0 0.33

SEA 1054 504728 7002116 Phan Ha Caboolture 3-Nov-09 R-3 1.84 3.22 13800 278 22.5 Na-Mg-SO4-Cl 24.04 69 530 0.019 570

SEA 1063 502279 7001227 Phan Ha Caboolture 19-Nov-09 R-3 1.14 4.86 8840 263 24 Na-Mg-Cl-SO4 41.4 13.8 144 0.03 48

SEA 1073 502660 7003587 Phan Ha Caboolture 9-Nov-09 R-3 0.82 4.81 1293 187 24.2 Na-Cl-SO4 5.84 0.043 3.7 0 22

SEA 1089 498981 7002083 Phan Ha Caboolture 3-Nov-09 R-3 1.8 6.99 1758 -410 23.6 Na-Mg-Cl-SO4 3.49 0.011 20 0.005 0.59

SEA 1092 500758 7006225 Phan Ha Caboolture 3-Nov-09 R-3 0.2 5.67 648 3 24.6 Na-Mg-Fe-Cl-SO4 4.87 0.09 8.4 0 36

LYN 9 510671 7006204 Phan Ha Ningi_Toorbul 9-Nov-09 R-3 0.64 6 254 58 22.3 Na-Ca-Mg-Cl-HCO3 2 0.051 14 0 8.6

LYN 44 500112 7008539 Phan Ha Ningi_Toorbul 3-Nov-09 R-3 0.65 5 194 160 23.3 Na-Mg-SO4-Cl 0 0.011 0.89 0 0.08

7 Cab 219 509510 7007885 Phan Ha Ningi_Toorbul 12-Dec-09 R-3 2.38 5.01 783 209 25.1 Na-Cl-SO4 9.6 0.7 7 0.002 2.6

SEA 1110 505718 7008782 Phan Ha Ningi_Toorbul 3-Nov-09 R-3 0.46 4.92 55100 150 23.8 Na-Mg-Cl 282.08 0 332.1 0 10.2

5 SEA 1156 503304 7009227 Phan Ha Ningi_Toorbul 20-Nov-09 R-3 1.39 6.2 1120 12 24.9 Na-Cl-SO4 9.99 0.7 2 0.008 14

CAB 216 510590 7008414 Phan Ha Ningi_Toorbul 12-Dec-09 R-3 1.73 5 167.3 204 24.4 Na-Mg-SO4-Cl 6.31 0.74 1.5 0 2.2

CAB 214 509981 7009437 Phan Ha Ningi_Toorbul 20-Nov-09 R-3 1.49 7.15 1522 104 26.2 Mg-Na-Cl-SO4 17.84 0.75 16 0.004 3.9

CAB 208 509247 7010514 Phan Ha Ningi_Toorbul 10-Nov-09 R-3 0.87 4.86 16300 201 22.9 Na-Mg-Cl 606.54 0.627 74.8 29.7 17.6

LYN 36 504280 7011525 Phan Ha Elimbah_Bullock 12-Dec-09 R-3 2.58 4.61 882 172 23.9 Na-Mg-Cl-SO4 5.74 0.25 6.8 0.004 12

LYN 37 507558 7009724 Phan Ha Elimbah_Bullock 20-Nov-09 R-3 0.67 6.78 29800 45 25.4 Na-Mg-Cl 213.75 0.5 207.5 0 32.5

LYN 48 497869 7013963 Phan Ha Elimbah_Bullock 10-Nov-09 R-3 0.49 5.09 192.6 167 22.4 Na-Mg-Cl 0.46 0 0.63 0.009 0.33

LYN 181 505203 7013974 Phan Ha Elimbah_Bullock 3-Nov-09 R-3 1.21 4.8 2033 161 25.7 Na-Mg-Cl 0.38 0.1 1.1 0 1.8

CAB 231 506595 7013480 Phan Ha Elimbah_Bullock 3-Nov-09 R-3 1.96 5.83 497 19 24 Ca-Na-Cl-HCO3 2.46 0 45 0 3.9

SEA 1101 507332 7010766 Phan Ha Elimbah_Bullock 3-Nov-09 R-3 1.08 5.07 6560 106 23.8 Na-Mg-Cl 30.78 0.408 13.8 0 78

SEA 1108 503299 7010541 Phan Ha Elimbah_Bullock 3-Nov-09 R-3 1.36 3.9 1567 287 27.1 Na-Cl 0.71 0.13 2.7 0 1.1

LYN 39 501135 7017392 Phan Ha Glass Mountain 10-Nov-09 R-3 0.23 5.6 154.4 65 21.5 Fe-Na-Cl-SO4 0 0.24 0.54 0 24

LYN 65 506127 7015994 Phan Ha Glass Mountain 12-Dec-09 R-3 0.67 5.29 40900 106 25.7 Na-Mg-Cl 156 0 268 0.12 32.8

LYN 66 504299 7015634 Phan Ha Glass Mountain 20-Nov-09 R-3 0.9 5.42 44300 254 25.1 Na-Mg-Cl 204 19 245 0 45

LYN 183 501763 7015908 Phan Ha Glass Mountain 10-Nov-09 R-3 0.47 3.56 166.8 131 21.4 Na-Fe-Mg-Cl-SO4 0.9 0.041 1.1 0.008 12

LYN 184 501450 7016663 Phan Ha Glass Mountain 20-Nov-09 R-3 1.06 7.1 156.3 90 25.2 Na-Fe-Mg-Cl-SO4 4.92 0.67 0.77 0.007 9.4

Page 165: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

RN Mg

(mg/l)

Mn

(mg/l)

Na

(mg/l)

Sr

(mg/l)

Zn

(mg/l)

HCO3

(mg/L)

Cl

(mg/l)

SO4

(mg/l)

NO3-N

(mg/l)

NO3

(mg/l)

NO2

(mg/l)

NH4

(mg/l)

TKN

(mg/l)

PO4

(mg/l)

TP

(mg/l)

DOC

(mg/L)

Balance

(%)

Lyn 32 1320 15.4 2420 0.891 0.682 0 4606.798 5891.878 0.0406 0.17864 0 3.3728 3.6787 0.0306 0 13.85 -0.9

LYN 54 12 0.17 50 0.031 0 17.48504 69.277 46.169 0.0529 0.23276 0 0.6722 1.0863 0.0605 0.5527 8.942 4.3

SEA 1035 3400 0.6 12500 7.5 0 62.92516 24372.6 5375.334 0.1639 0.72116 0 1.9157 3.9366 0 0 16.89 3.9

SEA 1042 704 0.682 2640 1.65 0.033 76.32686 4350.049 2470.714 0.041 0.1804 0 0.8424 2.4072 0.0404 1.726 4.706 1.2

LYN 26 3.7 0.009 11 0.05 0 56.4494 11.424 16.421 1.3541 5.95804 0.0231 0.4348 3.0299 0.0151 0.0278 7.835 -8.5

LYN 34 300 1.08 1200 0.84 0.168 129.15896 1887.049 795.232 0.0861 0.37884 0.0245 0.9454 0 0 14.95 7.5

LYN 38 22 0.51 52 0.096 0.08 0 54.929 209.042 0.1397 0.61468 0 0.4078 0.9426 0 0.1921 7.732 -7.1

LYN 73 836 4.62 2750 2.09 0.308 0 6238.4 2156.117 0.0597 0.26268 0 4.1275 4.2494 0.0264 0.1465 17.25 -1.9

BM5 6.3 0.016 9.6 0.057 0.038 17.73026 15.133 32.684 3.4471 15.16724 0 0.5202 2.1934 0.7999 0.8962 17.5 -9.4

SEA 1046 3.9 0.27 9.6 0.034 0.096 18.88804 27.967 41.374 0.1103 0.48532 0 0.8742 3.5957 0.1578 0.3245 75.25 -18.5

SEA 1047 1200 0.4 3900 3.8 0.069 138.0918 7519.493 2543.393 0.0588 0.25872 0 0.8671 0.9277 0.013 0.1558 8.471 5.1

SEA 1054 790 11 2000 3.7 1.1 0 2932.522 5520.711 0.0021 0.00924 0 2.3081 2.3329 0.4896 0.7051 40.42 0.6

SEA 1063 372 1.2 1500 1.56 0.198 0 3021.107 1180.824 0.1521 0.66924 0 0.8886 1.1451 0.0168 0.1768 5.851 -1.8

SEA 1073 17 0.13 170 0.061 0.095 0 313.079 190.113 0.1661 0.73084 0 1.7232 3.4001 0 0.8491 6.536 -12.7

SEA 1089 85 0.076 280 0.22 0 142.18124 329.397 280.43 0.1665 0.7326 0 1.4834 3.819 0.5402 0.5433 13.43 7.3

SEA 1092 18 0.13 79 0.079 0.039 69.44606 124.308 73.972 0.1956 0.86064 0 0.4146 1.9002 0.1839 0.2323 28.51 4.1

LYN 9 7.5 0.11 22 0.087 0 70.45866 34.405 16.383 0.1231 0.54164 0 1.3524 16.189 0.1375 2.3611 21.72 2.8

LYN 44 4.6 0.041 29 0.006 0.014 10.47858 24.982 36.297 0.7144 3.14336 0 0.5624 1.1226 1.3308 1.3314 10.36 -4.6

Cab 219 14 0.17 75 0.069 0.13 13.27604 183.137 130.297 0.1977 0.86988 0.0211 0.9847 0 0 15.69 -22.7

SEA 1110 2624 0.164 9020 5.33 0 9.61238 17100.772 4389.862 0.0812 0.35728 0 0.7549 2.92692 0.1434 0.1575 15.83 4.9

SEA 1156 14 0.091 150 0.026 0.094 62.95444 316.77 236.379 0.1264 0.55616 0.0201 0.2162 0.241 0.0307 0.6377 27.03 -27.2

CAB 216 5.1 0.056 22 0.019 0.057 16.38704 25.442 49.747 0.1919 0.84436 0.0262 0.4964 2.2251 0 0.0721 12.94 -9.5

CAB 214 110 0.22 190 0.25 0.042 55.07324 378.056 271.081 0.0597 0.26268 0.0499 0.3559 0.9687 0.0149 0.663 15.24 4.2

CAB 208 484 0.121 2090 1.045 0.033 36.051 6377.48 1221.726 0.2101 0.92444 0 3.1425 3.2813 0.0293 75.18 -15.2

LYN 36 33 0.5 80 0.066 0.45 0 257.576 164.811 0.1734 0.76296 0 0.6691 1.8768 0 0 5.281 -20

LYN 37 1550 0.05 6500 3.5 0 14.884 11801.1 2249.681 0.1412 0.62128 0 1.0561 2.0159 0 0 13.16 5.9

LYN 48 6.3 0.006 26 0.008 0.008 7.05404 57.964 9.497 0.0124 0.05456 0 0.5783 0 0.0379 3.542 -6.7

LYN 181 74 0.048 360 0.025 0.8 45.08998 610.207 75.804 0.0264 0.11616 0 0.3491 1.2134 0 0.0455 5.7

CAB 231 3.66 0.018 40.8 0.114 0.03 133.18008 68.564 36.532 0.1184 0.52096 0 0.8975 3.4918 0.2534 0.8737 8.661 -4.1

SEA 1101 168 0.6 1080 0.276 0.402 23.67532 1892.357 136.997 0.1731 0.76164 0 0.8473 0.5798 0 0.1741 8.751 6.9

SEA 1108 32 0.12 270 0.046 0.12 0 439.118 81.23 0.0792 0.34848 0 0.3934 3.1068 0.6875 0.6457 2.88 1.5

LYN 39 2.7 0.03 13 0.01 0.008 15.82706 30.991 33.75 0.1454 0.63976 0 0.5657 0.7665 0.0204 0.0108 17.39 -5.2

LYN 65 1840 0.32 6400 4.4 0.16 20.66192 17298.2 4276.729 0.23 1.012 0 2.4088 0 0 17.78 -12.6

LYN 66 2050 0.1 8000 4.3 0 0 19871.1 3102.832 0.1432 0.63008 0 2.793 3.6658 0 0 9.698 -7.7

LYN 183 3.9 0.038 20 0.011 0.01 7.46396 31.198 20.673 0.2042 0.89848 0 0.6296 0.8284 0.0089 0.8905 10.42 7.5

LYN 184 4.3 0.028 18 0.011 0.069 12.08288 38.967 18.608 0.1095 0.4818 0 1.3639 1.5476 0 0 16.15 -1.8

Page 166: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

RN Easting Northing Student Location Time of

sampling Round

Depth to

water

level (m)

pH (R/4) EC

(µS/cm)

Eh

(mV) To Water Type

K

(mg/l)

Al

(mg/l)

Ca

(mg/l)

Cu

(mg/L)

Fe

(mg/l)

Lyn 32 501438 6997716 Phan Ha Burpengary 24/03/2010 R/4 0 2.92 15400 402 24.5 Mg-Na-Cl-SO4 29.59 93.5 253 0.066 510.28

LYN 54 497745 6996721 Phan Ha Burpengary 23/03/2010 R/4 0.05 4.48 312 203 25 Mg-Na-Cl-SO4 3.89 0.082 2.6 0 0.47

SEA 1035 502745 6997259 Phan Ha Burpengary 24/03/2010 R/4 0.5 5.11 55800 110 25.4 Na-Mg-Cl 404 0 650 0 105

SEA 1042 499800 6997218 Phan Ha Burpengary 23/03/2010 R/4 2.35 510 11180 230 25.8 Na-Mg-Cl-SO4 35.97 0.451 78.1 0 0

LYN 26 511193 7004210 Phan Ha Caboolture 16/03/2010 R/4 0.3 5.42 270 174 23.7 Na-Ca-Cl-HCO3 5.31 0.098 20 0 0.064

LYN 34 506379 7001372 Phan Ha Caboolture 30/03/2010 R/4 0.75 5.09 505 132 24.1 Na-Mg-Cl 7.76 2 4.2 0.009 6.2

LYN 38 500849 7005123 Phan Ha Caboolture 23/03/2010 R/4 0 5.77 251 89 25.9 Na-Mg-Fe-Cl-SO4 4.84 0.23 3.2 0 13.306

LYN 73 500840 7002498 Phan Ha Caboolture 30/03/2010 R/4 0.5 4.33 3220 195 23.6 Na-Mg-Cl 20.21 2.3 31 0 34.248

BM5 508451 7003158 Phan Ha Caboolture 17/03/2010 R/4 0.96 4.18 272 250 26.2 Mg-Ca-SO4-NO3 12.63 0.2 17 0.007 0.58

SEA 1046 505272 6999569 Phan Ha Caboolture 24/03/2010 R/4 0.8 5.45 215 122 25.9 Na-Fe-Mg-Cl-SO4 12.62 1 3.1 0 19.508

SEA 1047 504105 6999716 Phan Ha Caboolture 24/03/2010 R/4 0.9 5.67 19630 168 24.7 Na-Mg-Cl 85.12 0.416 432 0.032 0.576

SEA 1054 504728 7002116 Phan Ha Caboolture 16/03/2010 R/4 0.66 2.67 4680 126 23.9 Na-Mg-SO4-Cl 17.09 82.5 341 0.031 4.3

SEA 1063 502279 7001227 Phan Ha Caboolture 30/03/2010 R/4 0.15 4.67 2112 229 25 Na-Mg-Cl 40.74 1.5 174.6 0.007 33.939

SEA 1073 502660 7003587 Phan Ha Caboolture 23/03/2010 R/4 0 4.12 850 239 27.6 Na-Cl-SO4 5.23 0.22 3.9 0.003 16.198

SEA 1089 498981 7002083 Phan Ha Caboolture 17/03/2010 R/4 1.3 5.4 1488 146 25 Na-Mg-Cl-SO4 5.14 0.098 16 0.006 0.25

SEA 1092 500758 7006225 Phan Ha Caboolture 24/03/2010 R/4 0.15 5.41 831 88 24.8 Na-Cl 5.11 0.18 8.7 0 45.662

LYN 4 513598 7005243 Phan Ha Ningi_Toorbul 24/03/2010 R/4 0.6 4.28 425 179 24.7 Na-Ma-Cl-SO4 2.35 0.74 2.3 0.007 2.3

LYN 9 510671 7006204 Phan Ha Ningi_Toorbul 16/03/2010 R/4 0.3 5.81 232 -216 24 Na-Ca-Mg-Cl-HCO3 2.16 0.27 11 0 10

LYN 44 500112 7008539 Phan Ha Ningi_Toorbul 23/03/2010 R/4 0.5 5.08 151.7 158 25 Na-Cl-SO4 3.9 2.4 0.52 0 3.3

CAB 219 509510 7007885 Phan Ha Ningi_Toorbul 30/03/2010 R/4 1.6 5.52 120.5 273 24.8 Na-Mg-Cl-SO4 2.71 0.99 2.9 0 0.47

SEA 1109 508505 7009348 Phan Ha Ningi_Toorbul 30/03/2010 R/4 0.1 3.72 326 349 23.6 Na-Mg-SO4-Cl 2.76 2.3 2.4 0.008 0.54

SEA 1110 505718 7008782 Phan Ha Ningi_Toorbul 23/03/2010 R/4 0.07 5.29 17260 61 26.2 Na-Mg-Cl 109.89 0 56.1 0 27.5

SEA 1156 503304 7009227 Phan Ha Ningi_Toorbul 17/03/2010 R/4 0.07 5.58 243 98 25 Na-Mg-Cl-SO4 4.85 2 1.3 0.009 5

CAB 216 510590 7008414 Phan Ha Ningi_Toorbul 30/03/2010 R/4 0.2 5.72 95.8 268 23.6 Na-Mg-Cl 1.2 0.73 0.45 0 0.5

CAB 214 509981 7009437 Phan Ha Ningi_Toorbul 23/03/2010 R/4 0.13 5.5 251 155 25 Na-Mg-Cl-HCO3 4.4 0.4 0.78 0 2

CAB 208 509247 7010514 Phan Ha Ningi_Toorbul 23/03/2010 R/4 0.63 5.06 26000 -60 25.1 Na-Mg-Cl 197.9 2 165.1 0 9.3

LYN 36 504280 7011525 Phan Ha Elimbah_Bullock 30/03/2010 R/4 2.24 4.43 322 183 22.7 Na-Mg-Cl 3 0.31 0.6 0.005 5.6

LYN 37 507558 7009724 Phan Ha Elimbah_Bullock 23/03/2010 R/4 0.6 4.58 10920 101 25.4 Na-Mg-Cl 90.31 0.363 41.8 0 14.3

LYN 48 497869 7013963 Phan Ha Elimbah_Bullock 17/03/2010 R/4 -0.3 5.59 359 52 23.6 Na-Cl 2.54 1.9 0.2 0.004 0.97

LYN 181 505203 7013974 Phan Ha Elimbah_Bullock 23/03/2010 R/4 0.05 6.32 654 189 26.1 Na-Mg-Cl-HCO3 3 0.24 2.4 0 0.29

CAB 231 506595 7013480 Phan Ha Elimbah_Bullock 23/03/2010 R/4 0.8 6.46 594 214 24.8 Ca-Na-Cl-HCO3 1.58 0.26 62 0 0.061

SEA 1101 507332 7010766 Phan Ha Elimbah_Bullock 30/03/2010 R/4 0.24 4.37 439.6 284 24.4 Na-Cl 3.05 0.2 0.36 0 0.26

SEA 1108 503299 7010541 Phan Ha Elimbah_Bullock 30/03/2010 R/4 0.25 3.65 731 330 24.5 Na-Cl 1.8 0.19 1.9 0 1.3

LYN 39 501135 7017392 Phan Ha Glass Mountain 17/03/2010 R/4 -0.1 5.57 165.5 62 26 Na-Fe-Cl-HCO3 2.2 0.42 0.62 0.015 19.658

LYN 65 506127 7015994 Phan Ha Glass Mountain 17/03/2010 R/4 0 5.03 40500 69 24.3 Na-Mg-Cl 107.5 0.5 130 0.2 50

LYN 66 504299 7015634 Phan Ha Glass Mountain 17/03/2010 R/4 0 3.07 41300 225 24.7 Na-Mg-Cl 237.5 5 265 0.65 105

LYN 183 501763 7015908 Phan Ha Glass Mountain 17/03/2010 R/4 -0.35 4.22 161.5 195 26 Na-SO4-Cl 4.75 0.32 1.3 0 1.8

LYN 184 501450 7016663 Phan Ha Glass Mountain 17/03/2010 R/4 0.1 5.84 98.6 139 22.6 Na-Mg-Cl-SO4-HCO3 5.24 0.88 0.74 0.005 3

Page 167: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12:

RN Mg

(mg/l)

Mn

(mg/l)

Na

(mg/l)

Sr

(mg/L)

Zn

(mg/L)

HCO3

(mg/l)

Cl

(mg/l)

SO4

(mg/l)

NO3-N

(mg/l)

NO3

(mg/l)

NO2

(mg/l)

NH4

(mg/l)

TKN

(mg/l)

PO4

(mg/l)

TKP

(mg/l)

DOC

(mg/L)

Balance

(%)

Lyn 32 1434.2 16.5 2640 1.023 0 25.37112 4475.65 4715.078 0.0692 5.4572 4.3177 0.0184 0.2886 15.13 8.2

LYN 54 10 0.15 49 0.031 0 7.32854 67.254 64.442 0.1774 0.78056 0 0.5355 0.9793 0.0154 0.2175 5.506 -2.7

SEA 1035 3800 1.1 13500 8.5 0 25.37112 26143.55 5638.586 0.1422 0.62568 0 1.1529 3.5888 0.0051 0.3388 17.65 5.1

SEA 1042 550 0.198 2200 1.21 0 59.12608 4821.552 2017.728 0.3874 1.70456 0.037 1.0166 1.8954 0.0821 1.0267 15.68 -10.2

LYN 26 5.7 0.018 23 0.093 0 72.5961 42.714 21.111 0.2312 1.01728 0 0.8146 0.8175 0.0523 0.6395 6.801 -4.8

LYN 34 19 0.034 100 0.053 0 28.17834 194.637 20.523 0.5955 0.0227 0.09988 0.6859 1.4352 0 0.1698 20.2 1

LYN 38 6.2 0.28 20 0.023 0 8.17156 41.368 33.168 0.1766 0.77704 0 0.9631 1.1002 0 0.1353 13.44 3.2

LYN 73 165.311 3.4 700 0.36 0.061 0 1388.217 303.001 1.4701 0.2307 1.01508 1.1621 2.4319 0 0.1246 18.45 2.1

BM5 11 0.045 8.6 0.11 0.086 10.31754 14.287 64.789 6.3895 28.1138 0 0.3213 1.953 0.298 0.6093 8.811 -7

SEA 1046 6.8 0.19 20 0.034 0 24.21334 58.263 34.81 0.1806 0.79464 0.015 1.6147 3.3565 0.7048 1.1697 67.75 -4.3

SEA 1047 1152 0.368 3840 3.84 0 133.50826 7550.85 1502.433 0 0 0 1.3005 1.0838 0.0347 0.3774 8.213 7.4

SEA 1054 517 4.4 1540 2.8 0.42 0 1867.619 2923.113 0.1273 0.56012 0 1.1703 1.5093 0 0 30.02 5.7

SEA 1063 321.826 1.4 1341.257 1.4 1.2 0 2945.881 641.379 0.9428 0.1057 0.46508 0.7989 1.4835 0 0.4754 28.45 -0.3

SEA 1073 17 0.13 140 0.073 0.012 0 212.897 120.816 0.9511 0.2003 0.88132 0.9511 1.5497 0 0.0909 6.449 -0.9

SEA 1089 60 0.11 240 0.17 0 146.79894 319.897 151.189 0.2184 0.96096 0 0.649 0.8339 0.0178 0.3571 8.611 5.5

SEA 1092 24 0.13 110 0.098 0 95.2515 312.532 55.967 0.3079 1.35476 0 0.782 1.4003 0 0.4094 16.91 -12.7

LYN 4 19 0.001 56 0.026 0 0 162.231 70.062 0 0 0 0.2083 1.1125 0 0.1428 29.22 -17.3

LYN 9 5.8 0.081 22 0.079 0 69.78156 34.349 16.505 0.2081 0.91564 0 1.7998 2.1679 0.3264 0.6303 30.17 -2.3

LYN 44 3 0.057 23 0.006 0 16.12474 26.899 31.969 0.0091 0.04004 0.0185 0.61 0.8694 0.0687 0.4328 13.35 -6.4

CAB 219 3.3 0.004 17 0.026 0 9.22076 32.734 13.279 0.575 0 0 0.9089 0.9169 0 0.1546 8.417 -4.2

SEA 1109 11 0.087 43 0.059 0.019 0 50.862 93.827 0.4063 0.483 2.1252 0.5397 0.9286 0 0.0821 4.465 -7.8

SEA 1110 539 0.066 2860 0.968 0 87.03602 6337.9 1003.926 0.286 1.2584 0 1.7928 5.1571 0.1554 0.6171 40.62 -6.8

SEA 1156 6.1 0.03 32 0.025 0 24.1072 54.071 35.935 0.202 0.8888 0 0.425 1.9441 0 0.0281 -8.7

CAB 216 2.1 0.004 12 0.007 0 9.22076 17.405 5.944 0.3522 0 0 0 0.7559 0 0.1003 6.692 -1.7

CAB 214 8.3 0.026 25 0.014 0.063 43.0416 30.809 17.523 0.044 0.1936 0 0.8508 1.5001 0 0.2461 26.3 1.3

CAB 208 1108.526 0.16 4720.791 2 0 9.48428 10731.65 1603.297 0.0618 0.27192 0.0699 5.1526 7.7879 0.1943 0.7364 116.1 -4

LYN 36 12 0.074 43 0.016 0.034 0 106.437 0 0.6107 0.0821 0.36124 0 0.4594 0 0.1062 1.979 2

LYN 37 363 0 2310 0.748 0 13.62862 4116.4 721.969 0.1531 0.67364 0 0.7267 1.4346 0 0.1306 25.25 1.5

LYN 48 2.9 0.004 21 0.004 0 9.43182 40.669 11.576 0.1418 0.62392 0 0.6289 0.6361 0 0 10.01 -10.6

LYN 181 19 0.031 110 0.014 2.4 123.21756 175.471 72.227 0 0 0 0.6395 1.0927 0 0.083 27.01 -12.2

CAB 231 3 0 40 0.15 0 142.74488 89.276 31.5 0 0 0 0.3964 0.6298 0.0438 0.0639 5.122 -3.7

SEA 1101 6.9 0.021 73 0.014 0 0 115.935 34.215 0.4666 0 0 0 0.4823 0 0.1418 3.564 -2.1

SEA 1108 32 0.067 260 0.045 0.015 0 454.853 41.157 0.5519 0 0 0 0.4949 0 0.1571 1.79 1.5

LYN 39 3 0.027 17 0.013 0 38.74476 27.772 16.227 0.4077 1.79388 0 0.6408 1.3169 0 0.1003 14.15 -1

LYN 65 950 0.05 3700 2.25 0 63.56932 11348.8 2113.721 0.2581 1.13564 0 2.8012 3.4967 0 0.2147 22.32 -18.7

LYN 66 2150 0 8500 4.75 0 0 12069.8 3118.787 0.2687 1.18228 0 2.1413 2.3693 0 0.0442 15.4 0.6

LYN 183 3 0.061 20 0.018 0 11.07394 12.953 44.165 0.177 0.7788 0 0.6034 0.8542 0 0.2126 10.38 -4.2

LYN 184 3.4 0.036 14 0.01 0 21.7038 25.314 15.592 0.1547 0.68068 0 0.4716 1.3704 0 0.0129 29.7 -9.6

Page 168: Mapping of Shallow Coastal Groundwaters, Their Hydrology ... · Figure 5.11: Variation in groundwater temperature (0C) for different boreholes and for different periods Figure 5.12: