an overview on the critical impact of ...metro cebumetro cebu, philippines source: nwrb-jica, 1998...

AN OVERVIEW ON THE CRITICAL IMPACT OF

GROUNDWATER DEVELOPMENT AND EFFECTS ON METRO CEBU

COASTAL AQUIFERS AND QECOSYSTEMS

Dr. SEVILLO D. DAVID Jr. and

LUTGARDO S. LARAÑODepartment of Environment and Natural Resources

Mines and Geosciences BureauManila, Philippines

1. INTRODUCTION

Regional Dynamic Settingeg o y c Se g

• Western Pacific Domain

Pacific PlatePacific Plate

Eurasian Plate

Indo-Australian Platesdo ust a a ates

• Southeast Asian Tectonic Region

Philippine Sea Plate

Southeast Asian Margin

SOURCE: DENR-MGB

1. INTRODUCTION (cont’d)

• Surrounded by opposing subduction zones

GEOTECTONIC FRAMEWORK

LUZON PHILIPPINE SEA

Man

ila

• Characterized by several volcanic arc chains

• Volcanism and plutonism since Pre-

• Igneous rock-related ore depositsSTUDY AREACEBU ISLAND

WESTPHILIPPINE

SEA

M

pTertiary (> 60 Ma)

• Philippine Fault and related structures control localization of many important d it

CEBU ISLAND

SEA

nch

deposits

• The Manila and Negros trenches on the eastern boundary of the belt were created from the

lli i f th P l i ti t l bl k

VISAYAS

MINDANAOSULU SEA

Tre

ncollision of the Palawan microcontinental block with the Philippine Mobile Belt

• The western border of the Philippine plate is a convergent boundary; however it is an ocean-continent convergent plate boundary where the Philippine plate is subducting beneath northern Asia on the Eurasian Plate.

CELEBES SEA

Asia on the Eurasian Plate.

SOURCE: DENR-MGB


SIMPLIFIED GEOLOGY PHILIPPINE SEA

Limestone

SIMPLIFIED GEOLOGY

WEST

STUDY AREACEBU ISLAND

I t i k

Volcanic rocks

WESTPHILIPPINE

SEA

Ultramafic rocks

Intrusive rocks

SULU SEA

CELEBES SEA

SOURCE: DENR-MGB


CASE STUDY:

METRO CEBUMETRO CEBU, PHILIPPINES

SOURCE: NWRB-JICA, 1998


Social and Economics

2nd largest Urban CenterSTUDY AREA

g3 Cities and 5 Municipalities

Premier Island Vessel Operation – 80%70% industrial output in Central Visayas (B i e P e i I d t(Business Processing IndustryExport Industry / Mining / Tourism)60% country’s export productsStrongest Economic Gainer (2010-2011)g ( )Highly UrbanizedPopulation – 4.17M (2010) 6.01M (2015)

Ave. GR – 2.5%Cebu City 1 42MCebu City -1.42M

Total Land Area – 4,932km²

GW Resources Development and Management78% GW78% GW22% SW (Dams) Cuurent Total Demand – 506,755 cumd (2005)Future Demand – 577,173 cumd (2015), ( )

2. Physical Background

BASEMENT ROCKRegional Geology

Lutopan Diorite – Paleocene

Pandan Formation/Cansi Volcanics –Cretaceous

Tunlob Schist – Jurassic

TERTIARY ROCKS

Carcar Formation – Pliocene

Maingit Formation – Late Miocene

Serpentinized Peridotite – Late Miocene

ToledoFormation - Middle Miocene

Bulacao Formation - Middle Miocene

Uling Formation - Middle Miocene

Talamban Diorite - Middle Miocene

Malubog Formation – Early Miocene

Cebu Orbitoidal Lst Formation – Late Oligocene

Lutak Hill Formation – Early Oligocene

QUATERNARY ROCKS

Quaternary Alluvium - RecentSOURCE: MGB--JICA, 1984

GEOMORPHOLOGY

2. Physical Background (cont’d)

1180000

Cebu Island MorphologyMountainous and Hillslopes – 75%Coastal Area – 15%

Max Ground Elevation – 600masl1160000

Max Ground Elevation – 600masl

Karstic Topography exist under most Limestone/Carbonated rock

1140000

Types

Matamorphic and Tertiary Rocktends to be more resistant 1140000tends to be more resistant developing Rugged terrain and slopes

1120000

Box pattern river drainage formson old limestone areas, while younger imestone outcrop and older basement rocks shows

TOPOGRAPHIC MAP OF METRO CEBU

580000 600000

older basement rocks shows dentritic and Irregular pattern.

SOURCE: NWRB-CEST Consultant, 2004

GEOMORPHOLOGY2. Physical Background (cont’d)

3D VIEW OF STUDY AREA3D-VIEW OF STUDY AREA

Metro Cebu-North

Metro Cebu-Central

Metro Cebu-South SOURCE: NWRB-CEST Consultant, 2004

HYDROLOGIC FEATURES


CLIMATE DATA

Type III-IV Climate Class on the Western Pacific Monsoon Climate Zone

Dry season – Nov to Aprily p

Wet Season – Rest of the Year

Ave. Annual Precipitation - 1,519mm

Monthly Temp - 27°C - 29°Cy p

Annual Evaporation - 900mm

Annual Humidity - 79%

SOURCE: PAGASA

2. Physical BackgroundHydrological Features

MEAN ANNUAL ISOHYTAL MAPMEAN ANNUAL ISOHYTAL MAP FOR METRO CEBU

SOURCE: NWRB, CEST Concultant, 2004

2. Physical BackgroundHydrogeology

SOURCE ; DENR-MGB

2. Physical Background (cont’d)Hydrogeology


HYDROGEOLOGY


• MCN, MCC & MCS (Sub-Area 1)

AQUIFER TYPES

( )

unconfined aquifers to semi-confined near the coast (limestone is overlain by unconsolidated and alternatingby unconsolidated and alternating sediments)

• Mactan Island (Sub-Area 2)

Unconfined Aquifers

AQUIFER GEOMETRYAQUIFER GEOMETRY

Transmissivity – 2,000 to 3,000m²/day

Storage Coefficient – 0.01 to 0.05

S ifi Yi ld 3% 27%Specific Yield – 3% to 27%

Earth Resistivity – 360 to 640ohm-m

HYDROGEOLOGY2. Physical Background (cont’d)

GW FLOW THROUGH UNCONFINED AQUIFER

Hydrology2. Physical Background (cont’d)

Present and Future Surface Water Source

Metro Cebu South (MCS)Daanlunsod RiverP d Ri ePandan River

Metro Cebu Central (MCC)Butuanon RiverMaghaway RiverMandaue RiverKotkot River

Metro Cebu North (MCN)Danao RiverLuyang Rivery gNaghalin RiverBoso River

22% (349lps) SW from the22% (349lps) SW from the total1,593lps produced by MCWD through dam

2. Physical Background Hydrology (cont’d)


3. Legal and Institutional Framework

SOURCE : Phil Environment Monitor (PEM) on Water Quality, 2003

3. Legal and Institutional Framework (cont’d)

SOURCE : Phil Environment Monitor (PEM) on Water Quality, 2003

3. Legal and Institutional Framework (cont’d)

Functional Chart of Water Related Agencies in the Philippines

SOURCE : NWRB

1979 Groundwater Level

4. Problem Descriptions - GW Depletions

1979 Groundwater Level1979 Groundwater Level

1. Not so Intense and almost parallel to the Coastal Line

2. Talisay and Cebu City

3. Level decline measured,-2mbsl to -8mbsl

SOURCE : Kampsax Kruger, 1979

2004 Groundwater Level

4. Problem Descriptions - GW Depletions (cont’d)

2004 G2004 Groundwater LevelTwo major Cone of Depression recognized

Liloan at -20mbslMandaue -20mbslMandaue 20mbsl

Two Minor Cone of Depression ObservedCebu City -10mbslMactan Island -10mbsl

SOURCE : NWRB, 2004

4. Problem Descriptions - GW Depletions (cont’d)

1979-2004 Groundwater Level Decline

MCWD abstract 110,000m3/d from 80-100DW i 70% 30% l ld HH dserving 70% to 30% volume sold to HH and

Industrial, commercial etc (PIDS-DENR, 1998)

20,000-250,000 wells current GW extraction set at 280,000-340,000ms/d

Aquifer area 180sq km providing 150,000m3/d. while SY estimated at 120,000m3/d.

3.4cm-5.5cm/ year land subsidence due to

overpumping (Lagmay, UP NIGS, 2011)

Greatest GW Decline 1979-2004

Liloan Wellfied - >-16m

Cebu City – 8my

Mandaue City – 8m

Consolacion – 8mSOURCE : NWRB, 2004

4. Problem Descriptions- GW Pollution

GROUNDWATER POLLLUTION

Major Sources of SW and GW Pollution

P i t S PEM EMB R t St tPoint Sources: PEM EMB Report Status

Domestic Wastewater 48% 33%

Agricultural Wastewater 37% 29%

Note:Point Source are define as those which emit harmfull substances directly into a particular water body

Industrial Wastewater 15% 27%

Non-point sources Not included 11%

Point Source are define as those which emit harmfull substances directly into a particular water bodyNon-point source are classified as no identifiable source but scattered with pollutants indirectly.

Rivers and lakes in cebu are considered satisfactory based on DO and BOD parameters set by DENR WQ Standard while bays and coastal waters are slightly below.

GW quality is very high in TDS.

58% of groundwater sampled contaminated with coliform bacteria, and needs treatment. PEM, NWRB, LWUA, Feasibility Studies-1997

Source : PEM, NWRB, LWUA, Feasibility Studies-1997

4. Problem Descriptions- GW Pollution (con’t)

pH LevelpH Level

<6.5 Acidic Water (WQ problem on disinfection corrosiondisinfection, corrosion control, water softening and higher treatment cost

6.5-8.5 dominates the study area.

SOURCE : NWRB, 2004


Hardness levelHardness level

26% - industrial/industrial (924.86lps out of 3,532lps)

Mandaue City, Cebu City,Talisay Liloan and Campostela >300mgl

SOURCE : NWRB, 2004


Nitrate levelNitrate level

Organic decomposing process through bacterial action – human/animalaction human/animal waste, plant debris and fertilizer

>30mgl – Cebu City (11 30 g Cebu C y (wells, Campostela-4wells, Liloan – 4wells, Concepsion-3wells, M d T li LMandaue, Talisay, Lapu-Lapu-Lapu City -1well each)

10 l PNSDW All bl10mgl PNSDW Allowable Limit

SOURCE : NWRB, 2004


Description of Saltwater IntrusionDescription of Saltwater Intrusion

Cebu Island5 kilometers inshore

abandonment of several wells andabandonment of several wells and economic loss of US30M/yr (Manila Standard).

Critical to GW extraction.

Escalating water prices

Exceesive GW extraction (82,000 private wells and Metropolitan Cebu Water pDistrict’s 108 wells, Walag 2007). 90% of the wells are saline in other areas (RUcore Resources,2010)

li d i i (W l 2007)water quality deterioration (Walag 2007).

SOURCE : NWRB, 2004


Regional Pollution Hotspots

No. of Domestic No. of Mfg. Industrial Agriculture Agricultural

Households BOD Establishments BOD Land Area BOD

Region Generation Generation (in km2) Generation

NCR Metro Manila 2,132,989 17.60% 7,774 42.50% 0 0

CAR 263,816 1.70% 88 0.60% 190,235 2.30%

I Il 831 549 5 20% 344 3 30% 415 434 11 50%I Ilocos 831,549 5.20% 344 3.30% 415,434 11.50%

II Cagayan Valley 554,004 3.50% 146 0.20% 709,964 6.10%

III Central Luzon 1,632,047 9.90% 1,840 9.00% 653,607 9.10%

IV Southern Tagalog 2,410,972 14.60% 3,806 14.10% 1,410,315 13.30%

V Bicol 891,541 5.80% 234 3.10% 1,004,425 5.40%

VI Western Visayas 1,211,547 7.70% 580 5.10% 889,549 8.10%

VII Central Visayas 1,129,317 7.10% 1,432 7.40% 665,446 10.60%

VIII Eastern Visayas 715 025 4 50% 169 1 10% 957 329 2 60%VIII Eastern Visayas 715,025 4.50% 169 1.10% 957,329 2.60%

IX Western Mindanao 595,728 3.80% 238 3.30% 763,796 5.20%

X Northern Mindanao 542,075 3.40% 311 2.20% 828,515 9.10%

XI Southern. Mindanao 1,066,199 6.40% 727 6.60% 1,103,297 8.60%

XII Central Mindanao 501,915 3.20% 186 0.50% 706,472 3.90%

ARMM 393,269 3.00% 13 0.00% - 3.00%

CARAGA 393,362 2.60% 144 0.90% - 1.20%

(Source: Philippines Environment Monitor 2003

5. Research Questions and Objectives

A. Research Questions for Groundwater Depletion, Pollution Over-extraction and Saltwater Intrusion

A th till ti l l ti th t d t t th d t i ti

B Obj ti f G d t C t l P bl

Are there still practical solutions that we can adapt to reverse the deteriorating environmental status in order to balance and sustain nature resources relative with man’s progress and survival?

B. Objective for Groundwater Coastal Problems

To be able to formulate and implement practical measures towards sustainable water security for economic progress, conservation and water resource management.

To acquire state-of-the-art, knowledge-based products and services that meet the practical needs on various water domain and improve the water sector’s performance by promoting effective solution under a given diverse situation.

To establish an effective knowledge partnership for information sharing utilizing available experiences and expertise that could readily be applied and customized considering various geographical condition.

To develop better stewardship and governance in managing coastal groundwater resources and resource sustainability that could be used as reference in prioritizing uses, minimizing risk associated with GW problems and identifies areas requiring immediate

i f fi i h l f d i d lsupport in terms of financing, technology transfer and capacity development.

6. Data Availability

Department of Environment and Natural Resources, DENR

Programs and projects that help protect, preserves and enhance natural resources

Environmental Management Bureau (EMB) Focuses on environmental laws, for various environmental media, standards and environmental quality status of the countrystandards and environmental quality status of the country

National Water Resources Board (NWRB) Water resources region and water quality and availability

Metropolitan Waterworks and Sewerage System (MWSS)

provides potable water and sewerage services to Metro Manila. It is one of the oldest waterworks systems in Asia, as well as one of the oldest

t d d t ll d ti i th Phili igovernment-owned and controlled corporations in the Philippines.

Local Water Utilities Administration (LWUA)

Government Ownrd and Control corporation that provides water supply and distribution systems for domestic, industrial, municipal and agricultural uses for water resources development, utilization and disposaldisposal.

Mines and Geosciences Bureau (MGB) It is responsible for the conservation, management, development and proper use of the country’s mineral resources including those in reservations and lands of public domains.

Metro Cebu Water District MCWD envisions itself to be a progressive and economically viable utility firm that provides adequate, safe, potable and affordable water and an effective sewerage system for Metro Cebu.

National Mapping and Resources I f ti A th it (NMABRIA)

Provides mapmaking services as well as geographic and resource i f tiInformation Authority (NMABRIA) information.

National Irrigation Administration (NIA) a Government-Owned and Controlled Corporation (GOCC) tasked with the development and operation of irrigation systems all over the country."

None -Government Organization (NGO)g ( )

7. Training Needs and Capacity Development7. Training Needs and Capacity Development

NUMBERS OF EXPERTS, EXPERIENCES AND TRAINING REQUIREDREQUIRED

20 personnel on-the-job training and upgrading GW data and assessment (NWRB, Water Resources Assessment for Prioritized Critical Areas (Ph-I, 2004)

Georesistivity survey and interpretationPumping test and data analysisWatershed and Water Balance aided thru GW modeling forWatershed and Water Balance aided thru GW modeling for groundwater assessment and management studies

Instruments for Groundwater MonitoringGeophysical Survey (Resistivity, GPR, seismic, magnetometer etc.)Monitoring and Water Quality Devices (Automated data Well loggers and probes etc.)Hydrographic and Sedimentation Instruments (current price meterHydrographic and Sedimentation Instruments (current price meter, water samplers etc.)

7. Training Needs and Capacity Development (cont’d)

SOFTWARES FOR GW MODELING1. Groundwater Availability Assessment

MODFLOW software(Developed by McDonald and Harbaugh 1988 USGS(Developed by McDonald and Harbaugh, 1988, USGS

2. Water Balance and Hydrograph ModelingHEC-1, Flood Hydrograph Package (Ver. 4) (Developed by :USACE hydrologic Eng’g Center)DR3M Disttributed Routing Rainfall Run off Model (Ver II 1991)DR3M – Disttributed Routing Rainfall-Run-off Model (Ver. II-1991)Developed by USGSHSPF – Hydrologic Simulation Program – FortranDeveloped by USGS/USEPAPRMS precipitation-Run-off Modeling System (!991 Version)PRMS – precipitation-Run-off Modeling System (!991 Version)Developed by USGS

3. Watershed ModellingSWATCH Software Developed by Dr. Morel-Seytour/Alhassoun, Colorado State UniversityColorado State University

MITIGATING MEASURES ON GW PROBLEMSDeclaring identified GW areas as “Critical Areas” for exploitationConjuctive use of surface and GroundwaterConjuctive use of surface and GroundwaterEnforcing Design Standard for New Wells and Submission of Monitored DataProtection of GW Quality – finance and construction of Sewerage facilites and mapping of geologically unstable areasProtection of Watershed Areas and ManagementProtection of Watershed Areas and ManagementEnhancement of GW Data CollectionSustainability of GW Modeling Studies

8. Expectations from the Project

H h ld j t i d k h b i d?How should project seminars and workshops be organized?Workshops, training and seminar must be participated by all stakeholders consisting of consumers, scientists, medical practitioners, engineers, politician and educators. Presentation shall provide information on the current state and f t i d h t t t b t t t i / l b l idfuture scenario and what steps must be execute to prevent region/global wide calamity.

What assistances are required from the project?Fi i l i t d t h l i l d t t l iti tFinancial assistance and new technological advances to control or mitigate GW problems, assess GW availability through field studies, digital modeling, geophysical instrumentation and installation of monitoring network system.

Wh t lt t d f th j t?What results are expected from the project?At the end of the project, I expect to infuses or integrate in our system the lesson learn from this project through participating in local conferences, forum and intra-agency seminars or training.

What do you want to learn from other countries?Comparative similarities and differences in term of geographical condition, diverse geological affiliation and solutions adaptation to existing problems.

What experiences do you want to share with other countries?Our state or conditions of our country’s water resources what we have done so

far.

Thank you!ywww mgb gov phwww.mgb.gov.ph

Mines and Geosciences BureauNorth Ave Diliman Quezon CityNorth Ave., Diliman, Quezon City

Tel. 9209120/9288642 Fax. 9201635E-mail: central@mgb gov phE-mail: [email protected]

an overview on the critical impact of ...metro cebumetro cebu, philippines source: nwrb-jica, 1998...

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