Turtle LakeTurtle LakeWater Quality IndexWater Quality Index

Turtle Lake Watershed Inc.

June 13, 2005

Water Quality MonitoringWater Quality Monitoring Gathers and collects

data Provides information

on current conditions Can show trends in

water quality over time Provides information

on which to make decisions

Water Quality MonitoringWater Quality Monitoring Monitoring programs can be

established for a variety of different reasons

The parameters monitored can tell us different things about the water quality

Parameters can be related to one another

Each piece of information can be used to provide an overall assessment of the water quality

Water Quality DataWater Quality Data

Individual parameters are compared to some form of standard/objective (Saskatchewan Surface Water Quality Objectives)

Usually based on intended use of the water (protection of aquatic life, irrigation, recreation, livestock watering)

Water Quality DataWater Quality Data

Parameters that are within the Surface Water Quality Objectives would be considered suitable for a particular intended use.

Monitoring dataMonitoring data

Dissolved Oxygen (DO)Dissolved Oxygen (DO)

All Aquatic organisms require oxygen to live– Fish, invertebrates, plants, and aerobic

bacteria Objectives set DO levels at 5 mg/L

for the protection of fish and aquatic life

Levels below 3 mg/L can be stressful for most aquatic organisms;

Levels below 1 mg/L are considered to be anoxic (no oxygen present)

Total PhosphorousTotal Phosphorous Is an essential nutrient for plant

and animal growth Occurs naturally in the

environment Enters water bodies as a result of

surface run-off, soil erosion, decay of organic matter, and waste

High phosphorous levels can stimulate algal and weed growth (TP greater than 0.1 mg/L)

NitrogenNitrogen

Occurs in several forms in water– Ammonia, nitrate, nitrite, and organically bound

It is an important plant nutrient Ammonia nitrogen is used as an indicator of the

quality of the water for aquatic life– High ammonia concentrations can be toxic to fish

Nitrate levels are typically less that 1 mg/L in healthy surface water systems

Total Dissolved Solids (TDS)Total Dissolved Solids (TDS)

Is a measure of the amount of dissolved material in water– Bicarbonate, sulphate, chloride, calcium, magnesium,

sodium, and potassium Concentration of TDS depends on:

– The amount of precipitation a water body receives– The type of solid and rock the water passes over– Human activities

TDS levels for irrigation should not exceed 700 mg/L Turtle Lake TDS values range between 576-750 mg/L

TurbidityTurbidity

Indicates the amount of suspended material in water– Soil particles, algae, or other

microscopic organisms High turbidity reduces light

penetration, productivity and habitat quality

Suspended sediment can carry nutrients, metals, and pesticides

Heavy MetalsHeavy Metals

Can be toxic to the aquatic environment at elevated levels

Some metals can bio-accumulate, e.g. mercury Occurs naturally in the environment Enters water bodies as a result of surface run-off,

soil erosion, or improper waste disposal Can restrict water use

Algal BloomsAlgal Blooms Common in nutrient-rich surface

waters Main types include:

– Green algae, diatoms, and blue-green algae (cyanobacteria)

Green algae and diatoms = nuisance organisms– Plug irrigation equipment, affect

recreation, treatment plant operations, and can produce taste and odour compounds

Blue-green algae = toxic organisms– Produce neuro- and hepato-toxins

Fecal ColiformsFecal Coliforms

Used as an indicator of the sanitary quality of water

Found in the intestinal tract of human and other warm blooded animals

A high fecal coliform count indicates water contamination

For recreational use of a water body, levels should not exceed mean density of 200 organisms per 100 mL, must be absent in drinking water

Water Quality IndexWater Quality Index

Water Quality IndexWater Quality Index

The WQI is a simple tool that can be used to summarize and report on complex water quality monitoring data

What is the Water Quality Index?What is the Water Quality Index?

It is a mathematically calculation that combines a number of water quality factors and then ranks the water quality in a simple and easily understood way

It can be used to report on the overall and on-going condition of a water body in a way that can be used by technical and non technical people

Development of the Water Development of the Water Quality IndexQuality Index

The Canadian Water Quality Index was developed by a Federal/Provincial Taskforce for the Canadian Council of Ministers of the Environment

It was based on an index developed by British Columbia - Ministry Environment, Land and Parks

CWQICWQI

The Water Quality Index is based on a combination of three factors:

the number of variables whose objectives are not met (scope)

The frequency with which the objectives are not met (frequency) and

The amount by which the objective is not met (amplitude)

Water Quality IndexWater Quality Index

Combining all water quality parameters the water quality index produces a number between 0 and 100, where 0 represents the “worst” water quality and 100 represents the “best” water quality.

CWQICWQI

Excellent: (CWQI Value 95-100) – water quality is protected with a virtual absence of threat or impairment; conditions very close to natural or pristine levels.

Good: (CWQI Value 80-94) – water quality is protected with only a minor degree of threat or impairment; conditions rarely depart from natural or desirable levels.

CWQICWQI

Fair: (CWQI Value 65-79) – water quality is usually protected but occasionally threatened or impaired; conditions sometimes depart from natural or desirable levels.

Marginal: (CWQI Value 45-64) – water quality is frequently threatened or impaired; conditions often depart from natural or desirable levels.

CWQICWQI

Poor: (CWQI Value 0-44) – water quality is usually threatened or impaired; conditions usually depart from natural or desirable levels.

Saskatchewan Water Quality Index Saskatchewan Water Quality Index for use in Watershed Protectionfor use in Watershed Protection

Parameters used in the SWA Water Quality Index

– Total Dissolved Solids– Sulphate– Chloride– Sodium– Nitrate/nitrite– Ammonia– Total Phosphorous– Chromium

– Mercury– Aluminum– Arsenic– pH– Dissolved oxygen– Chlorophyll a– MCPA– 2, 4-D– Fecal coliforms

Turtle LakeTurtle Lake Water Quality Index Water Quality Index

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90.1

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CWQI Score

2001 2003 2004

Year

Water Quality Index Water Quality Index Turtle LakeTurtle Lake

Turtle Lake water quality rated as Good (WQI value 90.1)

– water quality is protected with only a minor degree of threat or impairment; conditions rarely depart from natural or desirable levels.

Turtle LakeTurtle Lake Summary Summary

Water Quality Index rating was good

Parameters that exceeded the WQI objectives the most were pH and TDS

In 2004: pH 8.83 – 9.38 TDS 576-583, 750

WQI Summary WQI Summary

Provides a simple ranking system to evaluate water quality - although some interpretation is still required.

Can be used to assess overall watershed health and assess changes in water quality over time

Questions?