Initial Environmental Examination
July 2014
Philippines: Angat Water Transmission Improvement
Project
Prepared by Metropolitan Waterworks and Sewerage System for the Asian Development Bank.
CURRENCY EQUIVALENTS (as of 6 June 2014)
Currency unit – peso (Php)
Php1.00 = $.0228076 $1.00 = Php43.85
ABBREVIATIONS
AAS Atomic Absorption Spectrometry ADB Asian Development Bank
ADSDPP
Ancestral Domain Sustainable Development and Protection Plan
AFP Armed Forces of the Philippines AQ Aqueduct AP Affected Person D&B Design and Build Contractor
Brgy Barangay BH Borehole BOD5 Biological Oxygen Demand (5 Days) CADT Certificate of Ancestral Land Domain Title CBFM Community-based Forest Management CEMP Contractor’s Environmental Management Plan CITES Convention on International Trade on Endangered Species of
Wild Fauna and Flora CNC Certificate of Non-coverage COD Chemical Oxygen Demand CLUP Comprehensive Land Use Plan CPDO City Planning and Development Office CPF Common Purpose Facility CWA Contractor’s Work Area DAO Department Administrative Order D&B DBH Design and Build Diameter at Breast Height DED Detailed Engineering Design DENR CO DENR Central Office DENR MO DENR Memorandum Order DPWH Department of Public Works and Highways DOST DS Department of Science and Technology Downstream DQP Design Quality Plan ECA Environmental Critical Area ECC Environmental Compliance Certificate ECP Environmental Critical Project EMB Environmental Management Bureau EMP Environmental Management Plan EO Executive Order EU Environmental Unit FED Fire and Explosives Division FGD Focus Group Discussion FIDIC Fédération Internationale Des Ingénieurs-Conseils
(International Federation Of Consulting Engineers) FVR Friendship Village Resources
GOP HH Government of the Philippines Household IEC IEE Information, Education and Communication Initial
Environmental Examination IP Indigenous People (Dumagat) IUCN International Union for Conservation of Nature IRA IV Internal Revenue Alignment Importance Value LGU Local Government Unit LWUA Local Water Utilities Administration Mbg Meters Below Ground MENRO MMT
Municipal Environmental and Natural Resources Office Multipartite Monitoring Team
MOA Memorandum of Agreement MWCI Manila Water Company Inc. MWSI Maynilad Water Services Inc. MWSS Metropolitan Waterworks and Sewerage System NCIP National Commission on Indigenous Peoples NCSO National Census and Statistics Office NGA NIPAS
National Government Agencies National Integrated Protected Area System
NPC National Power Corporation NVH North Village Housing NWRB National Water Resources Board O&M Operation and Maintenance OSP-AWTIP
Office of Special Project for Angat Water Transmission Improvement Project
PA Protected Area PAGASA PAMB Protected Area Management Board PAWB Protected Areas and Wildlife Bureau PCR Physical Cultural Resources PD Presidential Decree PGA Peak Ground Acceleration PNP PO Philippine National Police People’s Organization PPTA Project Preparation Technical Assistance QMP RA Quality Management Plan Republic Act RCE Riparian Channel Evaluation REA Rapid Environmental Assessment ROW Right of Way SAPA Special Use Agreement in the Protected Areas SPS 2009 ADB Safeguard Policy Statement, June 2009 SPSC TA Scoping/Procedural Screening Checklist Technical Assistance US Upstream WHO World Health Organization WVF West Valley Fault
NOTE
In this report, "$" refers to US dollars. This Initial Environmental Examination is a document of the borrower. The views
expressed herein do not necessarily represent those of ADB's Board of Directors, Management, or staff, and may be preliminary in nature. Your attention is directed to the “terms of use” section of this website. In preparing any country program or strategy, financing any project, or by making any designation of or reference to a particular territory or geographic area in this document, the Asian Development Bank does not intend to make any judgments as to the legal or other status of any territory or area.
Initial Environmental Examination – Output 2
Document history
Initial Environmental Examination
Angat Water Transmission
Improvement ADB/MWSS
This document has been issued and amended as follows:
Version Date Description Created by Verified by Approved by
1 Draft Rustica Romero Maynard Delfin Marissa De Guzman
2 2 Feb 2014 Draft Final Rustica Romero / Delfa Uy
Marissa De Guzman
Marissa De Guzman
3 14 Feb 2014 Final Rustica Romero Delfa Uy Marissa De Guzman
4 1 Mar 2014 Revised Final Rustica Romero Delfa Uy Marissa De Guzman
Initial Environmental Examination – Output 2
Contents
Executive Summary i
1 Introduction 1 1.2 IEE Report 1
1.2 IEE Approach and Methodology 2
2 Policy, Legal and Administrative Framework 5 2.1 National Policy and Regulatory Framework 5
2. 2 Administrative Framework 9
3 Project Description 11 3.1 Project Rationale 11
3.2 Proposed Scheme 13
3.3 Contracting Method 18
4 Environment Description 21 4.1 Climate 21
4.2 Air Quality and Noise Level 22
4.3 Topography and Soils 25
4.4 Geology 27
4.5 Seismology 28
4.6 Ecological Resources 36
4.7 Economic Development 57
4.8 Social and Cultural Resources 58
5 Anticipated Environmental Impacts and Mitigation Measures 63
5.1 Approach 63
5.2 Issues and Concerns Relative to Siting, Planning and Design 63
5.3 Issues and Concerns Prior to Construction 68
5.4 Impacts during Construction 68
5.5 Impacts during Operation 75
5.6 Project Benefit, Positive Impact and Outcome 78
6 Environmental Management Plan 79 6.1 Introduction 79
6.2 Environmental Mitigation Plan 79
6.3 Institutional Arrangement 94
Initial Environmental Examination – Output 2
6.4 Environmental Monitoring Plan 101
6.5 Performance Indicators 104
6.6 Reporting 111
7 Public Consultation, Information Disclosure and Grievance Redress Mechanism 113
7.1 Public Consultation 113
7.2 Information Disclosure 114
7.3 Additional Public Consultation and Information Campaign 114
7.4 Grievance Redress Mechanisms 114
8 Findings 118
9 Conclusions and Recommendations 120
References 122
Initial Environmental Examination – Output 2
List of Figures
Figure 1: Project Location .................................................................................................................................. 1
Figure 2: Segments of Tunnel 4 Project Component ......................................................................................... 3
Figure 3: Timeline for Securing Required Clearance/ Agreement/ Permit/ License ........................................... 9
Figure 4: Manila Water Demand with and without 15% Buffer......................................................................... 11
Figure 5: Ipo-La Mesa Transmission System Schematic ................................................................................. 12
Figure 6: Inlet Structure including Coffer Dam ................................................................................................. 14
Figure 7: Outlet Structure and Temporary Spoil Disposal Area ....................................................................... 16
Figure 8: Projected Tunnel Geology and Ground Elevation ............................................................................. 26
Figure 9: Geology in the Study Area ................................................................................................................ 28
Figure 10: Surface Water Quality and River Ecology Sampling Stations at Ipo Watershed ............................ 29
Figure 11: Average Turbidity Level at Ipo Dam................................................................................................ 29
Figure 12: Surface Water and Groundwater Sampling Stations along Tunnel Segments ............................... 33
Figure 13: Raintree and Mahogany-Dominated Vegetation in Bigte Proposed as Contractor’s Work Area ... 38
Figure 14: Tree-Dominated Vegetation (Raintree and Balete) in Bigte Tunnel Outlet ..................................... 39
Figure 15: Brushland Vegetation in Segment 2 ............................................................................................... 39
Figure 16: Residential Subdivision and Cultivated Area cum Brushland in Segment 3 ................................... 39
Figure 17: Brushland Vegetation in Segment 7 above the Tunnel Outlet in Bigte ........................................... 40
Figure 18: Open-type Vegetation in Bigte Proposed for Disposal Area ........................................................... 40
Figure 19: Angat River Mollusc Dendogram .................................................................................................... 48
Figure 20: Angat River Fish Dendogram .......................................................................................................... 49
Figure 21: Project Segments ............................................................................................................................... 49
Figure 22: Location of the Inlet and Associated Works ....................................................................................... 50
Figure 23: Location of the Outlet Structure. ..................................................................................................... 53
Figure 24: Defective Housing Unit of AFP Subdivision in Segment 3 .............................................................. 57
Figure 25: MWSS Organizational Structure ..................................................................................................... 95
Figure 26: MWSS Office of Special Projects .................................................................................................... 96
Figure 27: Grievance Redress Mechanism Diagram ..................................................................................... 117
Initial Environmental Examination – Output 2
List of Tables
Table 1: Other Relevant Laws, Regulations and Guidelines ............................................................................. 6
Table 2: Document Requirements for Foreman Blaster and Purchaser Licenses ............................................ 8
Table 3: The Philippines’ Environmental Impact Assessment Process ............................................................10
Table 4: Water Available to MWSS from Angat Reservoir ...............................................................................11
Table 5: Associated Facilities of Tunnel 4. ........................................................................................................... 17
Table 6: Projected Temperature and Rainfall Change in Bulacan Province. ...................................................... 21
Table 7: Ambient Air Quality Results .................................................................................................................. 23
Table 8: Noise Level Monitoring Results at Brgy. Hall San Mateo. ..................................................................... 24
Table 9: Noise Level Monitoring Results at Brgy. Hall San Mateo ...................................................................24
Table 10: Noise Level Monitoring Results at Ipo Dam Site ............................................................................. 25
Table 11: Borehole Sediment Quality ............................................................................................................. 27
Table 12: Surface Water Quality in Angat River (Upstream and Downstream of Ipo Dam) .............................30
Table 13: Surface Water Quality in Bigte River and Sta. Maria River ................................................................ 34
Table 14: 2013 Borehole and Water Table. .................................................................................................... 34
Table 15: Groundwater Quality along the Tunnel Segments .......................................................................... 35
Table 16: Different Segments of the Study Site .............................................................................................. 40
Table 17: River Ecology Sampling Stations .................................................................................................... 45
Table 18: Mollusc Diversity Index ....................................................................................................................47
Table 19: Fish Diversity Index ..........................................................................................................................48
Table 20: Heavy Metals in Fish ........................................................................................................................49
Table 21: Summary Description of Tunnel Segments ..................................................................................... 54
Table 22: Municipal Profile of Norzagaray, Bulacan ....................................................................................... 58
Table 23: Population/Growth Rate of Norzagaray, Bulacan .............................................................................59
Table 24: Percent Households by Type of Water Facility Used (San Mateo) ..................................................60
Table 25: Sectoral Distribution of Employment ............................................................................................... 61
Table 26: Extent and Average Yields of Agriculture Land Use: Norzagaray ...................................................... 61
Table 27: Interaction Matrix during Construction Phase ................................................................................. 69
Table 28: Interaction Matrix during Operation Phase ...................................................................................... 75
Table 29: EMP prior to Construction Phase .................................................................................................... 80
Table 30: EMP for the Construction Phase ..................................................................................................... 81
Table 31: EMP for the Operations Phase ....................................................................................................... 93
Initial Environmental Examination – Output 2
Table 32: Institutional Requirements ................................................................................................................95
Table 33: Institutional Responsibilities..............................................................................................................97
Table 34: Environmental Management Implementation Schedule ....................................................................99
Table 35: Performance Indicator ....................................................................................................................104
Table 36: Performance Monitoring Indicator ...................................................................................................108
Table 37: Summary Matrix of Issues Raised at Public Consultation ............................................................... 113
Initial Environmental Examination – Output 2
List of Abbreviations
AAS Atomic Absorption Spectrometry
ADB Asian Development Bank
ADSDPP Ancestral Domain Sustainable Development and Protection Plan
AFP Armed Forces of the Philippines
AQ Aqueduct
AP Affected Person
D&B Design and Build Contractor
Brgy Barangay
BH Borehole
BOD5 Biological Oxygen Demand (5 Days)
CADT Certificate of Ancestral Land Domain Title
CBFM Community-based Forest Management
C-E MP Contractor’s Environmental Management Plan
CITES Convention on International Trade on Endangered Species of Wild Fauna and Flora
CNC
COD
CLUP
CPDO
Certificate of Non-coverage
Chemical Oxygen Demand
Comprehensive Land Use Plan
City Planning and Development Office
CPF Common Purpose Facility
CWA Contractor’s Work Area
DAO Department Administrative Order
D&B
DBH
Design and Build
Diameter at Breast Height
DED Detailed Engineering Design
DENR CO DENR Central Office
DENR MO DENR Memorandum Order
DPWH Department of Public Works and Highways
DOST
DS
DQP
ECA
ECC
ECP
EMB
Department of Science and Technology
Downstream
Design Quality Plan
Environmental Critical Area
Environmental Compliance Certificate
Environmental Critical Project
DENR Environmental Management Bureau
EMP Environmental Management Plan
EO Executive Order
EU Environmental Unit
Initial Environmental Examination – Output 2
FED
FGD
Fire and Explosives Division
Focus Group Discussion
FIDIC Fédération Internationale Des Ingénieurs-Conseils (International Federation Of Consulting Engineers)
FVR Friendship Village Resources
GOP
HH
IEC
IEE
Government of the Philippines
Household
Information, Education and Communication
Initial Environmental Examination
IP Indigenous People (Dumagat)
IUCN International Union for Conservation of Nature
IRA
IV
LGU
Internal Revenue Alignment
Importance Value
Local Government Unit
LWUA Local Water Utilities Administration
Mbg Meters Below Ground
MENRO
MMT
Municipal Environmental and Natural Resources Office
Multipartite Monitoring Team
MOA Memorandum of Agreement
MWCI Manila Water Company Inc.
MWSI Maynilad Water Services Inc.
MWSS Metropolitan Waterworks and Sewerage System
NCIP National Commission on Indigenous Peoples
NCSO National Census and Statistics Office
NGA
NIPAS
National Government Agencies
National Integrated Protected Area System
NPC National Power Corporation
NVH North Village Housing
NWRB National Water Resources Board
O&M
OSP-AWTIP
Operation and Maintenance
Office of Special Project for Angat Water Transmission Improvement Project
PA Protected Area
PAGASA
PAMB
PAWB
Protected Area Management Board
Protected Areas and Wildlife Bureau
PCR Physical Cultural Resources
PD Presidential Decree
PGA Peak Ground Acceleration
PNP
PO
Philippine National Police
People’s Organization
TA 8196-PHI: Angat Water Transmission Improvement Project
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PPTA Project Preparation Technical Assistance
QMP
RA
Quality Management Plan
Republic Act
RCE Riparian Channel Evaluation
REA Rapid Environmental Assessment
ROW Right of Way
SAPA Special Use Agreement in the Protected Areas
SPS 2009 ADB Safeguard Policy Statement, June 2009
SPSC
TA
Scoping/Procedural Screening Checklist
Technical Assistance
US Upstream
WHO World Health Organization
WVF West Valley Fault
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Initial Environmental Examination – Output 2
Executive Summary
Introduction
The bulk of the water supply for Metro Manilaʹs 13 million inhabitants comes from the Umiray‐Angat‐
Ipo system of reservoirs, tunnels and aqueducts. Aside from the Metro Manila demands, the
transmission system also supplies San Jose del Monte water treatment plant and other private users,
including some illegal users.
Currently, the water transmission system fails to supply the 46m3/s granted water allocation. Also, the
water transmission system needs improvement to supply future demands. MWSS and the two
concessionaires Manila Water Company Inc. (MWCI) and Maynilad Water Services Inc. (MWSI) have
prepared several demand scenarios for future water requirements in Metro Manila, which vary
between 35m3/s and over 80m3/s by 2035.
The Angat Water Supply Transmission Improvement Project seeks to improve the reliability and
security of the raw water transmission system through partial transmission system rehabilitation from
Ipo to La Mesa and the implementation of water safety, risk and asset management plans. As part of
the project, it is proposed to build a new tunnel to augment the water conveyance capacity provided by
the three existing tunnels. Once completed, it is possible to drain and inspect each of the tunnels and
assess the need for further works.
The proposed scheme comprises a new tunnel, alongside the three existing tunnels, to convey water
from Ipo reservoir to MWSS Bigte portal in Bulacan Province (Luzon Island), about 35km northeast of
Manila. The proposed tunnel is about 6.5km in length and 4m in diameter and lying adjacent to the
existing Tunnel 1.
The project is classified as Category B based on ADB’s environmental safeguard policies, indicating
there are some potential adverse environmental impacts, but not sufficient for a full environmental
impact assessment (EIA).
The study area comprises the full length of the new tunnel alignment, including the inlet and outlet
works, the Contractor’s work sites, and the temporary spoil disposal areas. The initial environmental
examination (IEE) commenced with the completion of ADB‘s Rapid Environmental Assessment (REA)
form, which was used to identify potential impacts. The baseline in the study area was characterized
by collecting secondary data and commissioning new surveys, consisting of surface water quality,
ambient air quality, ambient noise, terrestrial vegetation and wildlife, and aquatic ecology, in the study
area. GIS maps were prepared based on the survey results and available maps such as topographic and
hazard maps to characterize the study area. Environmental quality data was compared with the
Philippine environmental quality standards, and when these were not readily available locally,
compared with international criteria.
The Interaction Matrix (Leopold Matrix) was used to identify the potential adverse environmental
impacts along each tunnel alignment segment during the construction and operation phases.
Public consultation meetings were held within the communities of Brgys. Bigte and San Mateo.
Separate consultation, focused group discussions (FGDs) and interviews were held with the Dumagats,
an ethnic minority group, in Ipo dam site at Brgy. San Mateo.
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Project Description
Angat river water is transmitted from an upstream location of Ipo dam to Bigte through the three
existing tunnels. From Bigte, water is conveyed along six aqueducts (pipelines), with Aqueducts 1 and
2 carrying water to La Mesa reservoir and the remaining four aqueducts carrying water to La Mesa
water treatment plant. Existing infrastructure needs to be rehabilitated and expanded. The construction
of Tunnel 4 will augment the water supply to Aqueducts 5 and 6 to meet their full capacities. It will
then be possible to close and fully inspect the older Tunnels 1, 2, 3 and Aqueducts 1, 2, 3 and 4 to assess
their condition and determine the extent of the required rehabilitation.
The proposed location for Tunnel 4 is constrained by the following factors: (1) alignment of Tunnel 4
should be within the existing MWSS tunnel right of way (ROW); (2) optimum tunnel site would
minimize disruption to operations; (3) new tunnel intake should be in the same general area as the
existing intakes; and (4) intake needs to be located in an area where reservoir silting is at minimum.
With all these constraints, the most favorable location for the Tunnel 4 intake lies upstream of the
existing intakes and the proposed tunnel alignment lies close to Tunnel 1. No alternative was provided
given these constraints. An above‐ground conveyance system is not applicable due to the rugged
terrain of Brgy. San Mateo in the Municipality of Norzagaray, Province of Bulacan where intake and
majority of the tunnel alignment will be located.
The proposed Tunnel 4 will be 6.5km in length and 4m in clear internal diameter. The tunnel will be
located at about 100m to 150m below ground surface with maximum depth of 200m. The depth at the
inlet and outlet is about 10m and 8m, respectively.
According to the feasibility study, the tunnel will be excavated by drill and blast method with cast in
situ concrete lining formed in plain concrete and steel reinforced concrete linings.
The intake will be located between the new and old Ipo dams. The intake structure will comprise a
rectangular basin, with a trash rack to control debris entering the tunnel, and stoplogs for closure and
control of sluice gates to regulate the flow of water in the tunnel.
The outlet will be located at Brgy. Bigte and connected to a channel to convey water from the outlet to
Basin 3 at Bigte Portal. The outlet structure will comprise a rectangular basin with an observation deck
for maintenance and operation.
In cases of design deviation, such as shift of alignment resulting in tunnel being located outside the
MWSS ROW, changing inlet structure location and/or revising the method of construction, the MWSS
through its PMO should immediately: (1) seek the advice of EMB Central Office if such design
deviation warrants an ECC amendment; (2) inform ADB should EMB advise for ECC amendment; and
(2) seek ADBʹs clearance/concurrence for an IEE revision and/or EMP updating.
Environment Description
Physical Resources
Climate, Air Quality and Noise Level
Climate is tropical summer monsoon characterized by two pronounced seasons, a warm dry season
from November to April and a warm wet during the rest of the year. The mean annual rainfall is about
2,385mm, with the maximum falling between June and August. The mean monthly temperature ranges
between 26°C and 29°C. Climate change forecasts indicate increasing temperature and summer rainfall
over the next 50 years.
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Initial Environmental Examination – Output 2
No major air pollution source is found in the study area. The ambient air quality in the project area is
within DENR’s air quality standards. Ambient noise levels are within DENR’s limits, except for a
slight noise level exceedance observed in Bigte during night time, and this is generally typical among
rural areas.
Topography and Soil
Brgy. San Mateo, where most of the tunnel alignment will be located, is characterized by hilly to
mountainous terrain with an elevation between 85masl and 250masl. Within Brgy. Bigte, the terrain is a
combination of flat to gently sloping. Soils are of varying thickness and typical of the parent material.
An analysis of heavy metals in the rock samples from boreholes along the tunnel alignment indicates
that the heavy metal concentrations are below standard1 for habitat and agriculture so the spoil can be
reused.
Geology
The Ipo inlet area is underlain by the Bayabas Formation characterized by the massive agglomerate
and basalt, which is observed as hard when fresh. In situ weathering is slight to moderate with
residual soil approximated more than a meter deep, except when overlain by talus materials. The
tunnel will be in good ground rock mass rating more than 50%.
Tunnel 4 alignment from the inlet will pass through agglomerate and basalt and then go to equally
hard Alagao volcanics before proceeding to limestone toward tunnel outlet in Brgy. Bigte. Except for
localized faults and shears, the tunnel will be in good ground rock mass rating more than 60% and no
major problem is envisaged during the tunnelling. This is the fourth tunnel to be constructed along this
corridor.
Seismology
Very little seismic data are available in the project area. The West Valley Fault (WVF) trace has been
mapped fairly well. However, only general results such as earthquakes magnitude and peak ground
acceleration (PGA) are available. Data suggest that the WVF trace runs roughly parallel to an average
of 10km from the Angat Water Transmission Improvement System. It was estimated that the WVF can
generate a magnitude of 7.2 to 7.4 with a corresponding PGA of 0.67g. Additional study should be
performed to verify the current data.
Hydrology and Water Resources
Angat River is the main drainage system within the Angat watershed that is drained principally by the
Angat River and dammed twice. Angat dam generates hydroelectric power. Releases from Angat
reservoir, together with discharges from the river’s tributaries between Angat and Ipo dams,
contribute to the flow into Ipo reservoir.
Bigte River is the primary drainage system at the Bigte portal. The runoff of Bigte River contributes to
the flow into Sta. Maria River.
The surface water quality of Angat River from the downstream of Angat dam, Ipo dam site and Ipo
dam downstream is Class B freshwater. The sampling program during the rainy season recorded high
levels of turbidity, fecal and total coliforms at the Ipo dam site and Ipo dam downstream and elevated
levels of turbidity, color, fecal and total coliforms in the Bigte and Sta. Maria rivers.
1 Based on Thai Environmental Regulation. No standards established in the Philippines.
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Initial Environmental Examination – Output 2
The groundwater data in the project area was very limited. Data on groundwater levels were obtained
from 10 boreholes drilled in the area. The 2013 borehole report showed in Segment 1 that along the
tunnel alignment the water table lies at about 45m below ground (mbg). In Segment 4, the
groundwater was at about 50mbg, in Segment 6 at about 45mbg, and in Segment 7 from 20mbg to
30mbg. During construction, the expected groundwater flow into the tunnel could be relatively dry to
moderate inflow.
Results of the groundwater sampling and testing from community wells showed exceedances in
turbidity and color in Segments 5 and 6 and exceedances in fecal coliform in Segments 4 and 7.
Ecological Resources
Wildlife Ecology
Wildlife inventory for birds, mammals, amphibians and reptiles, and arthropods were compiled,
carrying out biodiversity assessment.
During the survey event, there were at least nine species found in the project area. Five species of birds
were present of which four were endemic to Luzon while two species were classified as threatened
species. The Luzon Tarictic and the Philippine Eagle Owl are classified as near‐threatened and
vulnerable. All of these avian species were recorded in Segment 1. Two mammals, the shrew rat
Chrotmys sp. was confined with Luzon; and the long‐tailed Macaque was heavily hunted either for food
or household pet and also listed in the Convention on International Trade on Endangered Species of
Wild Fauna and Flora (CITES).
Overall, Segment 1 has the highest biodiversity index compared to other project segments. The
biodiversity index, however, was still rated “moderate” at Segments 1 and 7 and “low” with the rest of
the project segments.
Protected Areas
The MWSS tunnel ROW near Ipo dam (Segment 1) lies within the indicative boundaries of the Angat
Watershed Forest Reserve, which is managed by NPC, and the Angat Watershed and Forest Range
(pilot) in the Ipo watershed, which is managed by MWSS. These watersheds are considered protected
areas under RA 7586 (NIPAS Act). Ipo dam and its related infrastructure are located at the boundaries
of these watersheds.
Terrestrial Ecology
The terrestrial habitats along the tunnel alignment comprise a combination of brushland and agro‐
ecosystem, dominated by common fruit trees interspersed with residential houses and other built‐up
areas. Segment 1vegetation by Ipo inlet works and proposed CWA location is co‐dominated by
bamboo known as buho alongside agricultural crops such as mango, coconut, banana and caimito and
other tree pioneers like binunga and alagasi. Few samples of the forest tree Pterocymbium tinctorium
were recorded. The vegetation biodiversity index is rated as low diversity.
The main habitat along Segments 2‐7 is an agroecosystem, with the vegetation dominated by
agricultural crops and in fallow and uncultivated areas by brush and weed species. The vegetation in
Bigte (Segment 7), where it is proposed to locate the Contractor’s work area, is dominated by mature
acacia (Samanea saman). The vegetation biodiversity index is rated as very low diversity in Segments 2
to 7.
The natural vegetation in the area is highly modified due to human intervention with many residential
houses and yards surrounded by domesticated plants such as mangoes, coconuts and other cash crops.
TA 8196-PHI: Angat Water Transmission Improvement Project
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Initial Environmental Examination – Output 2
One threatened species was recorded in Bigte area (Segment 7) known as narra (Pterocarpus indicus).
Three individuals were found.
Wildlife Ecology
Wildlife inventory for birds, mammals, amphibians and reptiles, arthropods were compiled, carrying
out biodiversity assessment.
During the survey, at least nine species were observed in the project area and regarded as noteworthy
as they were restricted to the Greater Luzon Biogeograhic Region. These were listed as globally
threatened by the International Union for Conservation of Nature (IUCN) or were heavily exploited for
food or taken as pets. Five of these noteworthy species were birds, four of which were endemic to
Luzon, namely: the Luzon Tarictic Penelopides manillae, scale‐feathered Malcoha Phaenicophaeus cumingi,
red‐crested Malcoha Phaenicophaeus supercillosus and the gray‐backed tailorbird Orthothomus derbianus.
The Luzon Tarictic and the Philippine eagle owl Bubo philippensis are classified as near‐threatened and
vulnerable. All of these bird species were recorded in Segment 1. Two mammals were noteworthy, the
shrew rat Chrotmys sp., which was confined to Luzon, and the long‐tailed Macaque Macaca fasciculari,
which was heavily hunted either for food or as pets and also listed in the CITES. The endemic frog
Platymantis mimulus was known only from a very few localities on Luzon Island and the monitor lizard
Varanus marmoratus was heavily hunted across its known distribution.
Overall, Segment 1 has the highest biodiversity index compared to other project segments. However,
the biodiversity index was still rated as moderate at Segments 1 and 7, and low along the rest of the
alignment.
River Ecology
Angat and Bigte rivers were identified as directly impacted bodies of water particularly in relation to
the Tunnel 4 construction. No insect larva was collected in the project area. The observed molluscs
during the survey were comparable to those found around the Philippines and two of the mollusc
species were collected by locals for food.
Angat river has higher biodiversity index than Bigte river. The dendograms of the aquatic species
showed that the Ipo reservoir and downstream of Angat river support similar assemblages of aquatic
species.
Exceedances in mercury levels were reported in fish species such as kanduli, biya, carpa and dalag
caught in the upstream of Angat river.
Social and Cultural Resources
According to the Comprehensive Land Use Plan (CLUP) of the Municipality of Norzagaray, the land
use in the project area is classified as a forest zone around Ipo dam and reservoir and forest buffer,
residential and agricultural zones along the rest of the tunnel alignment and other project components.
A housing subdivision was being developed at Segment 3 in Brgy. San Mateo, but the quality of
construction was poor and the defective housing units were already observed during the IEE study.
Indigenous peoples (IP) known as the Dumagats reside in the mountains of Norzagaray, particularly in
San Mateo and San Lorenzo. About 367 IPs live in San Mateo while 8 IPs live in Bigte.
Currently, Certificate of Ancestral Land Domain Title (CADT) application of the Dumagats of Brgy.
Kabayunan, Municipality of Dona Remedios Trinidad Bulacan, Brgys. San Lorenzo, San Mateo and
San Isidro, all in the municipality of Norzagaray, Bulacan is being processed by the National
Commission on Indigenous Peoples (NCIP) regional office. Social preparation activities were already
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Initial Environmental Examination – Output 2
undertaken as of November 2013 and delineation of the claimed ancestral domain is being prepared. A
total of 593 families are claiming Certificate of Ancestral Land Domain Title (CADT) ownership. About
209 families from Sitio Ipo, 13 families from Sitio Paco , 48 families from Sitio Anginan/Santol and 53
families from Sapang Munti, all from Brgy. San Mateo, Norzagaray, Bulacan are considered claimants
of CADT.
The main physical cultural resource (PCR) near the MWSS tunnel ROW is the Pinagrealan Cave, which
is known a historical landmark by the National Historical Commission of the Philippines. Application
for the cave as a protected area under National Integrated Protected Area System (NIPAS) is ongoing.
The Pinagrealan Cave is located near Bigte segment, about 450m away from the tunnel ROW. A local
cemetery about 300m is away from the tunnel ROW.
Environmental Management Plan
Forecasting Environmental Impacts and Mitigation Measures
Rapid environmental assessment (REA) was carried out using ADB REA form to identify potential
impacts. The Interaction Matrix (Leopold Matrix) was used to assess potential adverse environmental
impacts in every segment during construction and operation phase of the project.
Summary of Potential Impacts and Mitigation Measures
Preconstruction Phase
Project activity Potential environmental
impacts
Proposed mitigation measures Institutional responsibility
Completion of relevant project permits and clearances
Preparation of detailed design
Acceptability of project by the community, LGU and government agencies
Secure required permits/ clearances prior to Notice of Award to the D&B Contractor
Conduct of intensive social and environmental awareness program
Ensure an environmentally responsible procurement process by including an SPS-compliant EMP in the bidding document; EMP to be appended in the Agreement of the Contractor for basis in the preparation of C- EMP; C-EMP to be cleared/ approved by ADB prior to start of any activity
Incorporate various environmental design parameters in the detailed design as specified in the design and build bidding document
Conduct further studies such as geological and hydrogeological investigations to ensure that appropriate engineering measures are taken into account
MWSS
MWSS
MWSS
D&B Contractor
D&B Contractor
Construction Phase
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Initial Environmental Examination – Output 2
Project activity
Potential environmental
impacts
Proposed mitigation measures Institutional responsibility
Physical environment
Soil. Tunnel
drilling and blasting
Surface water resources.
Tunnel drilling and blasting and other related construction activities
Ground water. Tunnel drilling along the alignment
Air quality and noise.
Tunnel drilling and blasting
Soil erosion and landslide at the inlet and outlet sites
Mismanaged construction activities pose risk of severe erosion and/ or
landslide, particularly at the inlet and
outlet sites
Deterioration of surface water quality at Angat
river (in the
vicinity of Ipo
dam site) and
Bigte creek
Impact to groundwater resource
Deterioration of air quality and increase noise level at the project site and nearby community
Erosion control must be considered from the beginning of construction
Provide for adequate sanitation facilities and water supply at work sites and worker’s camp and enforcement of good sanitation practices by workers
Implement an eco-friendly solid and hazardous waste management
Proper storage of hazardous materials
Use cofferdams when constructing inlet and outlet structures
Prevent/ control siltation or sedimentation through proper storage of aggregates and spoils
Use efficient tunnelling technology that recycles tunnel drainage water to minimize extractor of surface water
Identify temporary stockpile of excavated soils in flat areas away from main surface drainage routes
Provide silt fences, silt traps and/or sandbags
Locate local emission sources away from sensitive receptors
Apply dust suppression techniques
Water exposed areas and stockpiles of aggregates and spoils at least twice daily or as necessary
Use of blast curtains/ nets
Require hauling trucks of aggregates, wastes and cement to have secure cover
Limit idling of equipment to five minutes
D&B Contractor
D&B Contractor
D&B Contractor
D&B Contractor
Biological environment
Tunnel construction
Clearing of vegetation and disturbance to habitat due to construction activities
Impact can be minimized by siting temporary
construction sites such as the construction camp and the temporary spoil disposal areas in
locations which are poorly vegetated, minimizing
the area to be cleared, and revegetating the sites on completion of construction
D&B Contractor
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Initial Environmental Examination – Output 2
Project activity
Health and safety
Potential environmental
impacts
Proposed mitigation measures Institutional responsibility
Forest at Ipo dam is contiguous with the Angat
watershed, which would provide a refuge for
displaced wildlife
Traffic.
Transport of spoil, heavy equipment to and from inlet/ outlet and temporary spoil disposal sites
Community health and safety. Tunnel
construction activities
Workers’
health and
Transportation network will be affected due to transport of heavy equipment and movement of haulage trucks to transport spoil form inlet and outlet to temporary disposal sites
Potential increase in road accidents and
incidents, especially along
Ipo road where
residential structures have encroached the ROW
Damage to roads
Potential risk to health and safety of the community
workers who
are directly and indirectly exposed to cross-cutting threats from impacts of air quality, increase in traffic, potential fire and explosion, communicable disease by other construction workers
Increased employment opportunity is very likely
Potential risk to health and safety of the
Prior coordination with the barangay and
municipality will be necessary for the formulation
of a traffic management and safety plan and clearing of encroaching structures. Contractor shall post traffic flagmen, equipped with two-way
radio at strategic points along the Ipo road.
Assistance from the Brgy. Tanod (community
police) may be requested
Health and safety plan should be in place and implemented.
Health and safety plan should be in place and implemented.
D&B Contractor
D&B Consultant
D&B Consultant
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Initial Environmental Examination – Output 2
Project activity
safety. Tunnel
construction activity especially drilling and blasting activities
Potential environmental
impacts
workers who are directly exposed to cross-cutting threats from impacts of air quality, increase in traffic, potential fire and explosion, communicable disease by other construction workers
Proposed mitigation measures Institutional responsibility
Waste disposal
An estimated 150,000m
3 of
excavated material is expected to be generated due to tunnelling works.
Excavated material is initially assessed to be a very good construction material. May be reused in the concreting of the tunnel lining, backfill of barangay
dirt roads in Brgys. San Mateo and Bigte.
D&B Consultant
Operation and Maintenance Phase
Project activity Potential environmental impacts
Proposed mitigation measures
Institutional responsibility
Conveyance of raw water to aqueducts
Maintenance activities of tunnel
Potential impact on the natural
water flow of Angat river as a
result of the conveyance of water to the aqueducts.
The transportation network will be affected due to the slight increase in the number of vehicles traveling to site Ipo dam site for the maintenance and operation.
Maintain the flow as required by AQ5 and 6
Road signs should be in
strategic location of Ipo road.
Maximum speed limit of 40kph should be implemented
Encroachment to ROW should not be allowed
MWSS, Concessionaires
MWSS, Concessionaires
Design and Location Considerations
Several scheme parameter constraints were considered for Tunnel 4. These include:
(a) Operation disruption of the existing transmission system during the tunnel construction to be
minimal.
(b) Tunnel 4 must be within the existing MWSS ROW.
(c) Tunnel 4 is not pass over or under the existing working tunnel as the risk of collapse and
disruption is unacceptable. This means Tunnel 4 is restricted to the corridor between Tunnel 1
and the southern boundary of the MWSS ROW.
(d) The scheme must convey 19m3/s (elevation of Ipo reservoir water level 100.3m; elevation of
TA 8196-PHI: Angat Water Transmission Improvement Project
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Initial Environmental Examination – Output 2
Basin 3 (AQ5 start) water level 95.5m; and hydraulic roughness of concrete to be taken as 4mm).
Tunnel 4 intake is recommended to be built between the old and new Ipo dams to reduce risk of silt
built‐up in front of the intake. Silt levels upstream of the old dam are at approximate elevation of 91m
and increasing by approximately 0.3m a year. In comparison, downstream levels of the old dam are
approximately 83m.
The outlet will be located at Bigte portal in Brgy. Bigte. A channel will be constructed to convey water
from the outlet to the Basin 3 at Bigte portal. The outlet structure includes observation deck for
maintenance and operation.
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a) ECC a) PhP 500,000.00 a) MWSS b) MOA between DENR RO 3, NPC and b) None b) MWSS
MWSS c) Part of construction c) D&B c) Permit to cut tree cost Contractor d) Permit to use explosives for construction d) Part of construction d) D&B
cost Contractor
Environmental Mitigation Plan
Pre-construction Phase
Potential
impact Possible approach/ Mitigating measures
Initial Environmental Examination – Output 2
Mitigation cost /
Enhancement Responsible Performance standard 1.1.3 Guarantee
Required permits/ clearances
Obtain the following prior to Notice of Award: Permits/clearances obtained prior to Notice of Award
Employer’s requirement document
Prepare relevant communities
Conduct intensive social and environmental awareness program at least one month prior to Notice of Award, covering: (i) communicable/ transmittable diseases that may be brought with the entry of workers; (ii) potential social conflicts between communities and workers; (iii) other health and safety hazards and impacts during construction and during maintenance and repair of completed works; and (iv) the grievance redress mechanism.
Included in OSP-AWTIP’s budget
OSP-AWTIP
Affected barangays
Ensure environmentally responsible procurement
Include an SPS-compliant EMP in the bidding documents.
Not applicable OSP-AWTIP SPS-compliant EMP included in the bidding documents
Append EMP to the Contract for basis in the preparation of the C-EMP
OSP-AWTIP EMP appended in the Contract
In Contract, require D&B Contractor to submit monthly and semi-annual environmental monitoring report
OSP-AWTIP Requirement stated in the Contract
Stipulate in the Contract the tie-up of progress payment and collection of performance bond with the performance in C-EMP implementation
OSP-AWTIP Stipulation in the Contract
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Initial Environmental Examination – Output 2
Potential
impact Possible approach/ Mitigating measures
Mitigation cost /
Enhancement Responsible Performance standard 1.1.3 Guarantee
Prepare C-EMP that addresses as minimum the requirements of the EMP. A final construction spoil management plan will be prepared by Contractor for endorsement / approval by both MWSS and ADB. The plan should be included in the C-EMP to be prepared by D&B Contractor.
D&B Contractor Presence of a C-EMP based on EMP
Evaluate the C-EMP quantitatively and qualitatively against the EMP
OSP-AWTIP Evaluation undertaken quantitatively and qualitatively
Clear the C-EMP before the start of any activity/work on site or establishment of any construction-related facility onsite by D&B Contractor
Endorsement/ approval of the final construction spoil management plan, which is part of C- EMP
ADB C-EMP cleared prior to
start of any mobilization activity on site by D&B Contractor
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Initial Environmental Examination – Output 2
EMP for Construction Phase
Potential impact Possible approach/ Mitigating measures Mitigation cost/
Enhancement
Responsible
Implement Monitor
Performance standard Guarantee
Physical (land) environment
Soil and erosion due to:
‐ soil disturbance ‐ vegetation
clearing
Location: Inlet structure and relevant work sites
Confine soil disturbance and/ or vegetation clearing to predefined and planned area that includes project footprint and needed easements
Stabilize exposed soils with temporary seeding, mulches, mats, and non-chemical- based soil binders
Protect slopes with any one or combination of bonded fiber matrices, erosion control blankets, silt fence, fiber rolls, and keeping stormwater off the slopes through diversion channels and/or berms
Revegetate disturbed soils/ slopes as soon as possible after completion of the construction works
Replace vegetation that died during the defects liability period
Part of project development cost
D&B Contractor
OSP- AWTIP
CEMP
At the active work sites
Provide temporary drainage with sedimentation tank or filters such as block and gravel, prior to discharge to water courses
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Initial Environmental Examination – Output 2
Potential impact Possible approach/ Mitigating measures Mitigation cost/
Enhancement
Responsible
Implement Monitor
Performance standard Guarantee
Impact on surface water quality due to/ from:
‐ Contaminants
from materials used and construction activities and processes
Siltation from soil erosion, spoil disposal area, drill and blasting, dewatering excavations, etc
At the active work sites
Mitigate contaminants
Provide adequate sanitation facilities and water supply at work sites and workers’ camp. Enforce observance of good sanitation practices by workers
Implement solid waste management that minimizes, re-uses, properly segregates and promptly and properly disposes of generated solid wastes
Implement hazardous waste management that minimizes, properly segregates and promptly and properly disposes of generated hazardous wastes
Store hazardous construction materials in appropriately contained and elevated area and at least100m away from surfacewater bodies
Immediately repair leaking (oil) equipment clearly off-site. No vehicle/ equipment maintenance, repair and refuelling to be allowed at the sites
Treat construction water before discharge. Install settling pond for water generated during tunnel boring. Allow water through grease trap or oil/collector and/or filters such as rock filled bags, block and gravel
Implement corrective action, when trigger thresholds of water quality are reached
During construction, the contractor shall take
corrective action to reduce concentration to below the standard
Part of project (construction) cost
D&B Contractor
OSP- AWTIP
Water column. Parameters to characterize the physico- chemical and biological status of the water column to include but not limited to: temperature, salinity, total suspended solids, turbidity, dissolved oxygen and bacteriological parameters.
Refer to DAO 34 and 35 for water quality standards
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Initial Environmental Examination – Output 2
Potential impact Possible approach/ Mitigating measures Mitigation cost/
Enhancement
Responsible
Implement Monitor
Performance standard Guarantee
Mitigate sedimentation
Build cofferdams when constructing inlet structure.
Extraction of water from the dam site (inlet) and creek (near the outlet) to be used as coolant during construction
Use any combination of perimeter controls at spoil disposal areas or stockpiles of aggregate materials, e.g. silt fences, sediment basins, sandbags, earth berm/ bund
Minimize/ control dewatering or extraction of tunnel water by storing and re-using pumped- out water from the tunnel
Use efficient tunnelling technology that recycles tunnel drainage water to minimize extraction of water
Part of project (construction) cost
D&B Contractor
OSP- AWTIP
If significant amount of water is to be used, a permit from the National Water Resources Board may be necessary
DAO 34 and 35 for water quality standards
Impact on groundwater
a) Deteriorating
water quality due to:
Silt/ sediments
Solid waste
Hazardous materials and waste
In all active work sites
Site temporary stockpile of excavated soils in flat areas, away from main surface drainage routes, limit to maximum of 2m high
Provide silt fences, silt traps, or sand bags, at stockpiles of aggregate materials
Dispose residual soil/spoil as soon as possible to the disposal areas or as free backfilling materials for LGU/barangay roads
Avoid stockpiling more aggregates than necessary
Part of project (construction) cost
D&B Contractor
OSP- AWTIP
DAO 1994- 26A for Philippine drinking water quality standards
a) Lowering of water level of wells in nearby communities due
Monitor for potential groundwater depletion in existing wells in the vicinity. Provide interim measures to avoid disrupting water supply to affected households. Investigate for proper
Part of project (construction) cost
D&B Contractor
OSP- AWTIP
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Parameter Averaging
Period Guide
µg/m3
SO2 24 hrs 20 NO2 1 year 40
1 hour
200 PM10 1 year 20
24 hrs
50 PM2.5 1 year 10
24 hrs
25
Initial Environmental Examination – Output 2
Potential impact Possible approach/ Mitigating measures Mitigation cost/
Enhancement
Responsible
Implement Monitor
Performance standard Guarantee
to tunnelling, pumping/extractin g of tunnel drainage water
corrective action
Air Quality and Noise
a) Deterioration of ambient air quality due to dust and gas emissions from:
Earthworks and other construction processes; tunnelling (drill and blast)
Stockpiling of aggregates and spoils, and conveyance of spoils to disposal areas
Increased transport activities in the construction areas and along Ipo Road
Burning of vegetation and wastes
Operation of mechanical equipment
At the project area, locate emission sources away from sensitive receptors, e.g. concrete batching and rock crushing plants at least 500m upwind of sensitive receptors.
In active work sites
Use of blast curtains / nets to capture dust from blasting
Apply dust suppression techniques, e.g. watering with bowsers, sheeting particularly at Bigte area
Water dry unpaved/exposed surfaces, stockpiles of sand and excavated materials, at least twice daily, or as necessary
Protect aggregate stockpiles with sheeting to restrict the movement of dust
Use of blast curtains / nets to capture dust from blasting
Require trucks, particularly those hauling aggregates, to have secure covers
Limit engine idling to five minutes
Prohibit open burning of vegetation and other waste in the project area
Ipo road, main access road, other roads in the
Part of project (construction) cost
D&B Contractor
OSP- AWTIP
Maintain air quality within national air quality standards, or if these are not available, internationally accepted air quality standards, such as WHO Air Quality Guidelines Global Update, 2005
D&B Contractor
Scope of Work
D&B Contractor’s C-EMP
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Initial Environmental Examination – Output 2
Potential impact Possible approach/ Mitigating measures Mitigation cost/
Enhancement
Responsible
Implement Monitor
Performance standard Guarantee
Project area
Limit speed of all construction vehicles to max of 40kph on the access road and max 30kph onsite
Ipo road, main access road, other roads in the Project area
Llimit speed of all construction vehicles to max of 40kph in the access road to, and max 30kph onsite
Noise and vibration in the project area from drill and blast activities, vehicle and equipment operations
Use only equipment that emit least noise and vibration and are well maintained
Use facility layout to minimize noise propagation e.g. using topography / existing buildings as barriers, where possible locate noisy activities away from local communities
Part of project (construction) cost
D&B Contractor
OSP-
AWTIP Adopt national standards for construction sites and residential areas if available. Alternatively use internationally accepted standards such as WHO.
D&B Contractor Scope of Work
D&B Contractor’s C-EMP
Control noise at source, e.g. low noise plant, muffling, acoustic screening, switch off campaigns
Restrict use of noisy and highly vibrating equipment from 8 a.m. to 5 p.m. Necessary overtime work should: (a) not go beyond 9:00 p.m.; (b) observe regulated noise and vibration levels; (c) not use noisy and highly vibrating equipment; and (d) should be coordinated with the barangay and affected households
Manage the ins and outs of hauling trucks. Spread out the schedule of material, waste and spoil transport in the day (off-peak hours)
Enforce the rule of no blowing of horns
Strictly enforce upon workers the compliance with wearing of ear mufflers, especially those
Reference /Jurisdiction
Ambient Standard
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Initial Environmental Examination – Output 2
Potential impact Possible approach/ Mitigating measures Mitigation cost/
Enhancement
Responsible
Implement Monitor
Performance standard Guarantee
who are operating equipment Guidelines for
Community Noise, WHO, 1999 International
Receptor: residential; institutional; educational
Daytime (07:00-22:00): 55dBA
Nighttime (22:00-07:00): 45dBA
Receptor: industrial; commercial
70dBA throughout the day
Biological environment
Loss of vegetation due to:
Vegetation clearing and potential trampling of trucks/ equipment beyond project footprints
Institute measures to avoid impacting on habitats and wildlife, such as:
minimize vegetation clearance at Bigte and especially at the intake;
fence off vegetation to be retained;
provide environmental training for workforce; and
enforce site rules and sanctions to discourage workforce from hunting, fishing and poaching.
Confine all construction activities to previously disturbed areas, to the extent practicable, e.g. workers’ quarters/camps
Use existing roads for project activities. Minimize new road construction
Part of project (construction) cost
D&B Contractor
OSP- AWTIP
Minimal number of trees applied for tree cutting permit from DENR.
Tree cutting permit
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Socio-economic
Traffic due to: Institute prior coordination with the barangay Part of project D&B Zero accident and related D&B Contractor Inadequate and municipality for the formulation of a traffic (construction) cost Contractor incidents Scope of Work
Initial Environmental Examination – Output 2
Potential impact Possible approach/ Mitigating measures Mitigation cost/
Enhancement
Responsible
Implement Monitor
Performance standard Guarantee
To avoid unnecessary clearing, mark/delineate areas to be cleared of vegetation, e.g. by fencing
Rehabilitate cleared areas to their pre-project conditions, unless otherwise agreed with the landowner
Re-vegetate construction sites using local, indigenous species
Re-vegetate watershed target sites especially in areas identified by the Watershed Management Plan
Limit any collection of wood for charcoal to exotic, e.g. non-native species
Disturbance to wildlife due to construction noise, vibration, dust, lighting, presence/ movement of people, etc. flying debris from blasting
Implement measures to mitigate noise, vibration and dust
Strategically place nets at the tunnel portals to prevent flying debris
Water to minimize dust accumulation and spreading
Part of project (construction) cost
D&B Contractor
PMO Record number of poaching and illegal trading of wildlife by workers
N/A
capacity of Ipo Road (access road)
Expected volume of truck movement
management and safety plan and clearing of structures encroaching into access road ROW
Prior to construction, clear easement of encroaching structures, most of them being temporary
Strategically post billboards informing the public about the expected increase in volume
D&B Contractor’s C-EMP
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Initial Environmental Examination – Output 2
Potential impact Possible approach/ Mitigating measures Mitigation cost/
Enhancement
Responsible
Implement Monitor
Performance standard Guarantee
of traffic in the influence area due to project implementation. Post at least two weeks prior to mobilization
Coordinate with the barangay for assistance in traffic management
Strategically post traffic flagmen along Ipo road, equipped with two-way radio
Post sufficiently legible (reflectorized) traffic safety notice and signage at strategic locations along the entire stretch of the access road
Limit speed to 40kph along Ipo road, and 30kph at construction sites and unpaved haulage roads
Potential damage of existing roads used as access roads due to movement of heavy equipment and vehicles
Coordinate with DPWH regarding the use of Ipo road
Restore access roads within the MWSS compound to the preconstruction condition or better
Part of project (construction) cost
D&B Contractor
D&B Contractor Scope of Work
D&B Contractor’s CEMP
Restricted access to the existing fish landing sites in Sitio Consultant (identified area as the Contractor’s Work Area) and boat landing at Sitio Ipo
Inform affected communities living in Ipo watershed on the impact of construction works on transportation and consult them for the best alternative route. Have alternative route and fish and boat landing sites ready for use prior to commencement of construction activities
Part of project (construction) cost
D&B Contractor
D&B Contractor Scope of Work
D&B Contractor’s CEMP
Community health and safety hazards
Inform local residents of the timing of blasting and prohibit entry of local residents into the construction area
Secure project area, including associated facilities particularly the storage for explosives, from unauthorized entry
Part of project (construction) cost
D&B Contractor
D&B Contractor Scope of Work
D&B Contractor’s CEMP
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Initial Environmental Examination – Output 2
Potential impact Possible approach/ Mitigating measures Mitigation cost/
Enhancement
Responsible
Implement Monitor
Performance standard Guarantee
Implement measures to mitigate impacts on air and water quality, noise, and traffic
Workers’ health and safety hazard
Mitigating impacts from blasting:
Include H&S protocols in the C-EMP on the safe procedures in the storage, handling and use of explosives during construction
Control the blasting by using small charges
Evacuation procedures in tunnel prior to setting charges
Set up a sufficiently equipped emergency first- response and health care team, linked to an ultimate response team
Provide safe housing with adequate basic services
Enforce use of protective wears when at work
Conduct premobilization orientation workshop on health and safety and emergency response and evacuation procedures
Handling and storage of explosives
Magazine storage should be far from residential areas, roads, transmission lines, dams and their appurtenant works
Site should be well-drained and sloping, accessible by road at least 100m from overhead power transmission lines
Detonators should not be stored together with explosives
Maintenance should follow the prescribed instructions for the explosives
Inside of all magazines should be kept thoroughly clean
Cigarettes and matches should not be taken into explosives should be used
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Initial Environmental Examination – Output 2
Potential impact Possible approach/ Mitigating measures Mitigation cost/
Enhancement
Responsible
Implement Monitor
Performance standard Guarantee
according to date of manufactured magazines. Its keeper should ensure this
Explosive boxes should be of wood or soft non-ferrous metal, e.g. brass and copper.
Magazine should be securely locked, when not attended
Detailed records of outgoing and incoming stocks should be kept
Magazines should be kept free from bushes and vegetation
Empty boxes, loose packing material or cotton waste should not be kept on the magazine premises
Do not open magazines during or in the approach of a thunderstorm. No person should remain in the vicinity of the magazine during such storm
Spoil generation and spoil disposal. Estimated 150,000m
3 is
expected to be generated due to tunnelling works, which is about
190,000m3
loose volume.
Prepare and implement a plan for the preparation of the spoil disposal areas
Minimize the volume of spoil to be disposed of by re-use in backfilling of roads, and offering as free filling materials to government projects needing backfill materials
Disposal area must be confined to solid ground of low ecological and agricultural value
Disposal area must not occupy drainage lines and streams, and create an obstacle to streams or induced flooding
Spoil heaps must be designed and shaped with stable side slopes and suitable drainage
Spoil heaps must be compacted during the earthworks
Part of project development cost
MWSS
DED Consultants
D&B Contractor
Detailed Engineering Design (DED) Scope of Work
Detailed Engineering and Design Plans
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Initial Environmental Examination – Output 2
Potential impact Possible approach/ Mitigating measures Mitigation cost/
Enhancement
Responsible
Implement Monitor
Performance standard Guarantee
When completed, the spoil heaps must be covered with the original top soil from the site and re-vegetated
Solid waste Implement an eco-friendly solid waste management at work sites and workers’ camp/s,
Part of project (construction) cost
MWSS
D&B
D&B Contractor Scope of Work
which minimize, re-use, segregate and promptly dispose generated solid waste contractor D&B Contractor’s
C-EMP
Hazardous waste Locate stationary ground storage for hazardous waste at least 100m away from water bodies, raised to min 1ft above high flood level. Or use mobile storage but should not be parked near water bodies
Part of project (construction) cost
D&B contractor
Construction D&B Contractor Scope of Work D&B Contractor’s C-EMP
Secure storage areas appropriately. Storage facilities must contain spillage
Dispose of waste promptly and appropriately
The Contractor shall be required to implement an appropriate hazardous waste management program
Storage of oil and grease used for the maintenance and operation of heavy equipment shall be properly built and maintained to include bunded storage for the capacity of the containers plus 10%, and oil traps on drainage outfalls
Public safety as related to future development and activities along the ROW
MWSS must secure the ROW. Existing above ground infrastructure along ROW should be limited. The public must not be allowed to encroach onto the ROW by constructing any buildings or farming the land
MWSS
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EMP during operation
Initial Environmental Examination – Output 2
Potential Impact
Public safety as related to future development and activities along the ROW
Changes in hydrology along Angat river during dry season
Possible approach/ Mitigating Measures
MWSS must secure the ROW. Existing above ground infrastructure along ROW should be limited. The public must not be allowed to encroach onto the ROW by constructing any buildings or farming the land.
During the operation phase, flows shall be monitored downstream of Ipo dam.
As practice in the Philippines, Ipo dam should maintain 10% riparian flow downstream. This flow aims to allow migration of fish species and maintain natural characteristics of the river downstream of the dam.
Cost of Mitigation/ enhancement
Part of project maintenance cost
Responsible
MWSS
CPF (represented by 2 water concessionaires -
MWCI and MWSI)
Performance Standard Guarantee
Concession agreement
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Initial Environmental Examination – Output 2
Institutional Requirements
The project implementation will require a Project Management Unit (PMU). For this project, it is called
Office of Special Project for AWTIP. An Environmental Officer within the OSP‐AWTIP should oversee
the implementation of the Environmental Management Plan, including the mitigation measures and
environmental monitoring program identified in the EMP and the compliance of the Contractor with
its C‐EMP.
Institution Prior to construction During construction During operation
MWSS Set up the OSP-AWTIP Decide on Decide on environmental Engage an Environmental Officer for the environmental management matters requiring OSP-AWTIP management senior management Organize the Multipartite Monitoring
Team (MMT)
Sign MOA with DENR and NPC on Angat Watershed and Forest Range Protected
matters requiring senior management intervention/ action/ resolution
intervention/ action/ resolution
Area Ensure an environmentally responsible procurement of a D&B Contractor Ensure an environmentally responsible maintenance policy OSP-AWTIP Update IEE and EMP, as necessary. Conduct inspections Conduct inspections and spot
Coordinate with D&B Contractor to and spot checks to checks to monitor the ensure the incorporation of updated monitor the Performance of the Operator in findings and mitigation performance of the implementing the EMP Measure design and bidding documents
Ensure EMP is part of the bidding documents, EMP clauses are incorporated in bidding documents, contracts
Ensure DENR’s approval of EIS is granted prior to Notice of Award of D&B Contract
Review D&B Contractor’s EMP (C-EMP) against EMP
D&B Contractor in implementing the C- EMP/EMP
Review Monthly and semi-annual EMRs of D&B Contractor.
Prepare the Project’s Semi-Annual EMRs for submission to ADB
Review Monthly and Annual EMRs of Operator
Prepare the Project’s Annual EMR for submission to the ADB, until loan closure or as agreed
Conduct IEC, together with the Social Safeguard Officer in the OSP-AWTIP, for social preparation Ensure D&B Contractor has obtained permits for tree-cutting and use of explosive for construction not later than three days after receipt of Notice of Award
Environment Provide technical assistance and Provide technical Specialist guidance to OSP-AWTIP in the: advice/assistance
- Update of IEE and EMP, as necessary e.g, preparation of - Review of bidding documents* Semi-annual EMR for - Incorporation of environmental criteria ADB, review of and weights in the evaluation of bids* results of - Review of environmental aspects of bid environmental effects documents* monitoring - Review of C-EMP against the SPS- compliant EMP ADB Review and clear updated IEE/EMP, if Review Semi-annual Review Annual EMR
applicable EMR.
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Design and Build (D&B)
Incorporate mitigation measures in design and bidding documents
Incorporate EMP as part of bidding
Implement mitigation measures and conduct internal EMP
Contractor documents, EMP clauses in bidding implementation documents, contracts monitoring
Prepare a Contractor’s EMP that Conduct addresses as minimum the requirements environmental quality of the EMP monitoring as Obtain Tree-Cutting Permit and Permit to
Use
Explosives for Construction not later than 3 after receipt of Notice of Award
prescribed in SPS- compliant EMP. (If an independent Licensed Laboratory will not be engaged)
Prepare Monthly and Semi-annual EMRs Operators Ensure an environmentally responsible Perform maintenance (MWSI and maintenance policy in congruence to works in accordance MWCI) MWSS maintenance policy with the maintenance
policy.
DENR Review and approve Project EIS Review MMT reports.
MMT Conduct environmental monitoring in compliance With DAO 03-30 Municipality Facilitate social preparation Participate in the and Barangay Participate in the MMT activities monitoring of the
performance of D&B Contractor in EMP implementation Facilitate (and participate in) public consultation/s and information
disclosure
Review EMRs Assist in ensuring the observance of the GRM
Initial Environmental Examination – Output 2
Institution Prior to construction During construction During operation
Implement mitigation measures and conduct internal EMP
implementation monitoring
Prepare Monthly and Annual
EMRs
Participate in the monitoring of the performance of Operator in EMP implementation
Facilitate (and participate in) public consultation/s and information disclosure Review EMRs
Assist in ensuring the observance of the GRM
Environmental Monitoring Plan
Two types of monitoring are required: environmental and compliance. Environmental monitoring
evaluates the residual impacts2 of construction and operation activities in the environment and as
necessary modifies the mitigation measures to ensure its effectiveness. Compliance monitoring ensures
that all parties comply with the environmental requirements as set under Philippine legislation and
policies, and the requirements described in this IEE and Contractor’s CEMP.
The hierarchy of compliance monitoring includes monitoring activities conducted by the Contractor,
CPF internal monitoring and MWSS, MMT external monitoring, DENR, ADB and an independent
monitoring team.
2 Residual impacts are impacts that cannot be mitigated
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Initial Environmental Examination – Output 2
The proposed Environmental Monitoring Plan covers water quality, air quality, noise, and vegetation
clearance. It also includes key parameters, sampling methodology and testing. The monitoring plan is
focused on the construction period as no significant impact was identified during the operation phase.
The Environmental Monitoring Plan will be updated as needed.
Public Consultation and Disclosure
Public consultations were held within the communities of Brgys. San Mateo and Bigte. A separate
consultation meeting was held with the Dumagats of Ipo watershed discussing issues such as:
(a) Lack of domestic water supply in Brgys. Bigte and San Mateo. There is a separate program to
address provision of water supply in the area and currently with an understudy within MWSS.
(b) Identification of APs, especially the residents along MWSS ROW. Issues regarding the
demolition of properties (with land titles and illegal resettlers) along MWSS ROW were laid
out.
(c) Impacts on road safety due to traffic congestion, transportation of spoil from the construction
site to temporary spoil disposal. Road identification is likely to be affected, especially during
construction phase.
(d) Employment opportunities for the local population (Brgys. Bigte and San Mateo).
(e) Spoil generation and management. Residents requested use of the spoil for their personal use,
e.g. backfill materials in their house plots. Spoil can also be used as community road backfill,
especially in dirty roads.
(f) Commencement of the project construction.
(g) The barangays (communities) are keen to have another consultation / discussion on the proper
project implementation prior to project construction.
(h) Determination of alternative routes and fish landing at Sitio Ipo.
Survey results and studies conducted in relation to the construction of Tunnel 4 were discussed within
the communities of Dumagats in Brgys. San Mateo and Bigte.
Findings
Large volume of excavated materials will be generated in the tunnel construction. The spoil is a very
good construction material that can be used in the tunnel construction. The spoil may also be used as
backfill materials in about 14km barangay roads of Brgys. Bigte and San Mateo. The rock material can
be used by cement companies with ready mix products if rock material qualifies to the needed
materials. Temporary spoil disposal areas are identified near the location of the structures.
The construction work area (CWA‐Ipo) of about 1ha area called “Consultant” in Ipo dam site entails
vegetation clearing prior to construction. This would sacrifice some 67 trees/ha in the area, although
most are low diameter and non‐timber, non‐commercial species. The same is true for Bigte tunnel
outlet construction site where there will also be clearing and where some mature rain trees will be
affected. This impact is localized and can be mitigated by replacing the species that will be cut with the
same species and plant the same in the open portions of the property. Also, a planned clearing of
vegetation and keeping the vegetation clearing to a minimum will need to be done.
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Initial Environmental Examination – Output 2
Temporary disturbance to wildlife will be experienced during the construction phase. The contiguous
Angat watershed will serve as the wildlife refuge while construction is ongoing. The initial survey
conducted during the wet season shall establish wildlife population data and used as a baseline for the
subsequent monitoring of populations, especially in the construction and adjacent areas of Isla Puting
Bato in Angat watershed area.
Traffic congestion is expected along Ipo road once construction phase commences. Although the
impact is temporary, mitigating measures should be strictly implemented to avoid any case of road
accidents. Traffic management at Ipo road is poor with no road signs in strategic road sections, speed
limit and encroachment of some houses in the road ROW.
There are two river systems draining a seemingly separate watershed area that are the immediate
project impact areas. The tunnel inlet construction will impact the Angat river system and the tunnel
outlet construction will impact the Bigte‐Sta. Maria river system. It would be desirable to look at the
dry season of the macro‐benthic communities in various sites.
High coliform content of the water in Ipo dam/Angat river waters and the Bigte‐Sta. Maria channel
may be due to human and animal (domesticated) waste being thrown to the river waters. Immediate
contact with these waters may lead to medical/sanitary problems within the area. Turbidity and
siltation of these water systems are prevalent, especially during wet season.
The presence of mercury in the fish samples may also produce health hazards to the local population
who eat locally caught fishes. The tunnel ROW traverses the AFP housing in Segment 3. Defective
housing units are observed in the AFP housing project in Brgy. San Mateo. This observation is made
prior to tunnel construction. Such defects are not valid to be associated to the ground vibrations due to
the tunnel construction.
Conclusions and Recommendations
The Project will improve and expand the raw water transmission system, increasing the reliability and
security of raw water transmission and ensuring sustainable water supply services to Metro Manila.
The IEE concludes that most of the environmental impacts associated with the Tunnel 4 are expected to
arise during construction. Potential impacts will be localized and site‐specific. Most of the identified
impacts are low and temporary and if assessed adversely, it can be mitigated to an acceptable level
without difficulty through standard site, engineering and construction practices. No significant adverse
impacts have been identified during operation phase.
The few impacts of high magnitude (without mitigation) during construction will not be distinct.
Tunnel 4 will be the fourth tunnel to be constructed in the MWSS ROW. These impacts will not be
sufficient to threaten the surrounding resources. During operation, low to moderate impacts will come
from maintenance and repair.
Wildlife and river ecology surveys were done during the wet season. There is a need to assess the
same parameters during the dry season, which is considered the base‐flow period to provide a more
robust baseline data. The EMP should be updated where necessary.
More detailed infrastructure survey should be carried out and existing conditions of the infrastructure
should be noted. At the preliminary stage of the Tunnel 4 project, it was observed that there were
poorly constructed housing units of the AFP subdivision. Such defects occurred prior to the tunnel
construction and cannot be associated as impact of the activity.
During the detailed design phase, further consultation is required to address the concerns raised
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Initial Environmental Examination – Output 2
during previous consultations to ensure that all public concerns are updated and publicly
acknowledged and incorporated into detailed design and updated EMP.
During the detailed design, environmental due diligence should be conducted on the key associated
facilities, namely: Ipo dam, Basin 3 and Aqueduct 5.
The EMP presented should be updated during the detail design phase to:
a) Update the legislation and administrative arrangements,
b) Incorporate the results of further terrestrial and aquatic surveys, and land use surveys,
c) Update the impacts and mitigation presented herein,
d) Expand upon the mitigation and monitoring plans, and
e) Develop capacity building needs.
In the event of design deviation, such as shift of alignment resulting in tunnel being located outside the
MWSS ROW, change in inlet structure location and/or change in the method of construction, the MWSS
through its PMO should immediately: (1) seek the advice of EMB Central Office if such design
deviation warrants an ECC amendment; and (2) inform ADB should EMB advise for ECC amendment
and finally, (2) seek ADBʹs clearance/concurrence for an IEE revision and/or EMP updating.
The successful Contractor shall be required to prepare and implement a C‐EMP based on SPS
compliant EMP. The following specific sub‐management plans should form part of the C‐EMP: chance
finds recovery and removal; and include with the excavation subplan placement of temporary berms
and plastic sheeting between excavations and adjacent land, surface waters, and property to prevent
erosion, sedimentation, or contamination from excavation work, noise control plan, dust control plan;
and workers and staff health and safety plan.
Based on the above conclusions and recommendations, no further detailed EIA needs to be undertaken
to comply with the SPS of the ADB. Under GOP policy, an EIS is required. The EIS will be based on
this IEE.
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Initial Environmental Examination – Output 2
1 Introduction
This report presents the findings of the Initial Environmental Examination (IEE) of the Angat Water
Transmission Improvement Project (the proposed project) to improve reliability of water supply to
Metro Manila. The project is located in Bulacan Province (Luzon Island), about 35km northeast of
Manila (Figure 1). Metropolitan Waterworks and Sewerage System (MWSS), the project proponent, is
seeking a loan from the Asian Development Bank (ADB). This IEE has been prepared to comply with
ADB environmental safeguard requirements.
Figure 1: Project Location
Angat Dam
Ipo Dam
MWSS Bigte Portal
1.2 IEE Report
This IEE study report is Output 2 of our PPTA. It covers the details of the initial environmental
assessment of the new Tunnel 4 from Ipo to Bigte in Norzagaray, Bulacan and associated intake and
outlet works, identified in the feasibility study report (also a deliverable under Output 2). The
proposed tunnel construction is considered a priority scheme for the transmission system based on the
assessment report (Output 1). Once constructed, it will facilitate the subsequent rehabilitation of the
whole transmission system identified in the assessment report.
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Initial Environmental Examination – Output 2
1.2 IEE Approach and Methodology
1.2.1 IEE Scope
The IEE is focused on identifying environmental issues in the study area, potential environmental
impacts and risks associated with the construction and operation of the proposed project, facilitating
mitigation measures, and setting out an outline of the environmental management plan (EMP) to
minimize adverse environmental impacts.
The IEE study includes an environmental assessment of the tunnel alignment and related project
components such as the Contractor’s work areas and spoil disposal areas, most of which are within the
MWSS infrastructure compound.
The study was carried out following the ADB SPS 2009 and in reference to the national policy and
regulatory framework discussed in Section 2.
1.2.2 Rapid Environmental Appraisal and Categorization
ADB‘s Rapid Environmental Assessment (REA) form was used initially to identify potential impacts as
presented in Appendix 1.
The project has been classified as Category B based on the type of environmental assessment required
following ADB safeguard policies, indicating that there are potentially some adverse environmental
impacts, but not sufficient to warrant a full environmental impact assessment (EIA).
1.2.3 Identification of Study Area
The optimum location of the tunnel alignment from the inlet through the entire alignment to the outlet
has been selected to mitigate the potential impacts of tunnel construction and operation works on air,
water, flora and fauna, and within the communities.
The study area extends along the full length of the new tunnel alignment, including the project related
sites for the construction on the inlet and outlet works, and the temporary spoil disposal sites.
The tunnel alignment was subdivided into 1km lengths resulting in seven segments for the entire
project. The characteristics of the study area and the potential for environmental and social impacts
were then assessed in each segment.
Segments 1 and 7 at either end of the project include inlet and outlet works, tunnel portal, Contractor’s
work areas, and temporary spoil disposal sites. Most of the construction‐related impacts are associated
with these segments. Segments 2 to 6 lie along the alignment of the tunnel, where there would be
limited effects from tunnelling.
1.2.4 Baseline Data Collection
Environmental surveys for surface water quality, ambient air quality, noise, terrestrial vegetation and
wildlife, and aquatic ecology, were undertaken in the study area. Where appropriate, the
environmental quality data were compared with the Philippine environmental quality standards, and
where national standards were not available, with international criteria. Detailed terrestrial vegetation
and fauna surveys were undertaken in Segments 1 and 7, with less detailed surveys along Segments 2
to 6. The data are presented in Chapter 3 on the baseline together with secondary data gathered from
various government agencies and other related literature. A GIS mapping exercise was undertaken
with the various inputs from surveys and existing maps such as topographic maps and hazard maps to
characterize the project site.
Figure 2: Segments of Tunnel 4 Project Component
TA 8196-PHI: Angat Water Transmission Improvement Project
Initial Environmental Examination – Output 2
Inlet Structure
6
7
Segment 1
Segment 3
Segment 2
Outlet
Structure
Segment 5
Segment 4
Segment 6
Segment 7
3
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Initial Environmental Examination – Output 2
1.2.5 Impact Assessment and Mitigation
The Interaction Matrix (Leopold Matrix) was used to identify the potential adverse environmental
impacts along each segment of the tunnel alignment during the construction and operation. These
impacts were described qualitatively and proposals for appropriate mitigation put forward.
1.2.6 Environmental Management Plan
An outline Environmental Management Plan (EMP) was developed to summarize the proposed
requirements for mitigation measures, monitoring plan, and the institutional arrangements required to
implement the EMP. During detailed design, the EMP should be developed further, as more
information becomes available about the design and proposed construction methods.
1.2.7 Public Consultation
Public consultation meetings were held with the communities in Brgys. Bigte and San Mateo. Separate
consultation, focus group discussions (FGDs) and interviews were held with the Dumagats, an ethnic
minority group, in Ipo dam site in Brgy. San Mateo.
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Initial Environmental Examination – Output 2
2 Policy, Legal and Administrative Framework
2.1 National Policy and Regulatory Framework
The following laws/policies cover the framework for environmental assessment in the Philippines:
a) The 1987 Philippine Constitution, Section 16, Article II and Section 15, sets the basic framework
for the country’s Policy on Environment, stating: “The State shall protect and advance the right
of the people to a balanced and healthful ecology in accord with the rhythm and harmony of
nature. The State is mandated to protect and promote the people’s right to health.”
b) Presidential Decrees (PD) 1586, 1978 established the Philippine EIS system, an assessment
process through which all projects categorized as environmentally critical or situated within
environmentally critical areas are required to undertake.
c) Presidential Decree 1151, 1979 represents the Philippine Environmental Policy, requiring all
proponents of projects that significantly affect the quality of the environment to prepare a
detail statement on: (i) environmental impacts of the proposed project; (ii) any unavoidable
adverse environmental effect of the project when implemented; (iii) alternative to the proposed
action; (iv) determination that the short‐term uses of the resources of the environment are
consistent with the maintenance and enhancement of the long‐term productivity of the same;
and (v) finding to be made that such use and commitment are warranted, in case a proposed
project will involve the use of non‐renewable resources.
d) Proclamation 2146, 1981 declared certain types of project and areas as environmentally critical
and within the scope of the EIS System. Proclamation No. 803, 1996 added one type of project
as environmentally critical.
e) DENR Administrative Order 30 in 2003 (DAO 03‐30) sets out the Implementing Rules and
Regulations of the Philippine EIS System.
f) Revised Procedural Manual for DAO 03‐30, 2008 prescribes the procedures for the processing
of applications for Environmental Compliance Certificates (ECCs) and Certificates of Non‐
Coverage (CNCs).
g) DENR Memorandum Circular No. 2007‐08, 2007 segregates the practice of requiring permits,
clearances, licenses, endorsements, resolutions and other government approvals under the
jurisdictions other National Government Agencies (NGAs) and Local Government Units
(LGUs) so as not to pre‐empt the EIA evaluation process. As such, the EIA findings and
recommendations are transmitted through the ECC for consideration by the NGAs and LGUs
in the processing or prior to the issuance of their respective permits/clearances. It stipulates
that the issuance of ECC or CNC for a project does not exempt the proponent from securing
other government permits and clearances as required by other laws.
Other legal environmental issuances most relevant to the Project are presented in Table 1. These
issuances regulate activities within the protected areas and their buffer zones and will be supported
under the Project.
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Initial Environmental Examination – Output 2
Table 1: Other Relevant Laws, Regulations and Guidelines
Law / Regulation / Guideline Year Relevant provisions Remarks
Protected area management
Republic Act No. 7586
The National Integrated Protected Areas System (NIPAS) Act
1992 Proposals for activities that are outside the scope of the management plan for protected areas (PAs) shall be subject to an EIA before they are adopted, and the results thereof shall be taken into consideration in the decision- making process. An EEC is required prior to the actual implementation of such activities. When allowed to undertake activities, the proponent shall plan and institute measures to minimize any adverse effects and take preventive and remedial action when appropriate.
Although the Project is within a PA classified as initial component, the NIPAS may not be applicable because the Ipo watershed does not have an organized Protected Area Management Board (PAMB) for the watershed PA.
The MWSS ROW is included in the management plan of the Angat Watershed Reserve and Forest Range (Pilot), a protected area. Nevertheless, the Project will secure an ECC in compliance to the Philippine EIS System.
DENR Administrative Order No. 17
Rules and Regulations Governing Special Uses within Protected Areas
2007 A Special Use Agreement in the Protected Areas (SAPA) may be issued within PAs except in strict nature reserves and shall be confined only to the management zones of the PA appropriate for the purpose.
Issuance of SAPA is currently suspended. DENR Region 3 has advised that a Memorandum of Agreement (MOA) is applicable for the Project. An initial draft MOA between the National Power Corporation (NPC), MWSS and DENR has been drafted by DENR and the Consultant on 7 November 2013. Copy has been forwarded to MWSS for its review. It is aimed to secure this MOA promptly.
DENR Administrative Order No. 26
Revised Implementing Rules and Regulations of the NIPAS Act
2008 Prohibited acts within protected areas includes:
(1) destroying and disturbing plants or animals; (2) dumping of wastes; (3) destroying objects of natural beauty or of interest to cultural communities; (4) damaging roads and trails; (5) squatting or occupying any land within; (6) constructing structure without permit; (7) leaving the PA in unsanitary conditions with refuse, debris or depositions in water bodies; and (8) removing or destroying boundary marks or signs.
Project will be implemented within the MWSS ROW. Appropriate measures are recommended I the EMP to ensure such prohibited acts are prevented during construction and operation.
Technical Bulletin No. 2013-01:
List of Protected Areas Under NIPAS System
2013 Lists the Angat Watershed and Forest Range (Pilot) among the PAs under the NIPAS.
This has been considered in the feasibility study.
Tree-cutting
Executive Order No. 277, Amending Secion 68 of the PD No. 705 (Revised Forestry Code)
1987 Watershed reserves are included under forest lands in the Revised Forestry Code. Cutting of trees in forest lands without license is a criminal offense.
Tree-cutting permit is not necessary when cutting trees of common species.
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Initial Environmental Examination – Output 2
DENR Administrative Order No. 21
Revised Guidelines on the Issuance of Private Land Timber Permit/Special Private Land Timber Permit
2000 Tree-cutting permit is required for cutting premium hardwood. Same permit is not required for trees of common species.
Some trees need to be cleared to give way to the construction activities. Some of the affected trees at the outlet area would qualify for a permit. As such, a tree-cutting permit is necessary.
Executive Order (EO) 23 dated 1 Feb 2011
Moratorium on cutting of timber in natural and residual forests
2011 The DENR is prohibited from issuing tree-cutting permits in all natural and residual forests nationwide, except for clearing of ROW by DPWH, site preparation for tree plantations, silvicultural treatment and similar activities, provided that logs derived from the cutting permits shall be turned over to DENR for proper disposal.
Exemptions may be considered if project is a priority by Government of the Philippines (GOP).
Health and Safety
DOLE Department Order No. 13
Guidelines governing occupational safety and health in the construction industry
1998 Provisions on safety rules, including rules in working at hazardous workplace.
This is considered in the EMP.
DOLE: Occupational Safety and Health Standards (as amended, 1989
2013 May
Provision on duties of employers, workers and other persons, safety rules, including rules in working at hazardous workplace.
This is considered in the EMP.
IRR of RA 8294 dated 06 June 1997 Permit for the use of explosives. This is considered in the EMP.
Four environment‐related clearances/agreements/permits/licenses have emerged as requisite
documents to be secured prior to Project implementation, i.e., prior to the issuance of Notice of Award
or Notice to Proceed as shown in Figure 3. These are:
a) ECC, which will require the submission of an EIS that is prepared and submitted for approval
to the DENR Environmental Management Bureau (EMB) Central Office following the EIA
process described in Table 2. An ECC will be required prior to Notice of Award.
An ECC or proof of submission of the Project EIS to the EMB Central Office for processing is a
requisite document for ICC clearance/NEDA Board approval for the Project loan.
Proof of submission of EIS to the EMB Central Office for processing is a requisite document for
the application of a tree‐cutting permit.
b) MoA among MWSS, NPC, and DENR in place of SAPA as advised by DENR Regional Office 3
(Appendix 8). This will be required prior to the submission of the EIA to EMB Central Office
for processing.
A draft MoA prepared jointly by DENR and Consultant has been forwarded to the MWSS for
review on 7 November 2013 and consequently forwarded to NPC by MWSS. The MOA will be
attached as supporting document to the application of the tree‐cutting permit by MWSS.
c) Tree‐cutting permit, which will be secured from DENR RO3 by MWSS as the authorized land
user of MWSS ROW. This will be applied for only when the EIS has been submitted to the
EMB Central Office for processing; but should have been secured prior to Notice of Award.
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Initial Environmental Examination – Output 2
According to DAO 2000‐21, the following documents will be required: (i) letter application; (ii)
sketch map of area applied for; (iii) development plan, if application covers 10ha or larger with
at least 50% of the area covered with forest trees; (iv) endorsement from any of the following
LGU officials, namely: concerned Barangay Chairman, Municipal/City Mayor, or Provincial
Governor; and (v) inventory fee based on existing regulations. DENR RO3 advised that the
MOA among MWSS, NPC and DENR will be attached to the application as supporting
document.
In addition to the application requirements, a 100% timber inventory needs to be undertaken
by registered forester/s of Region 3 in accordance with the guidelines set in Section 6 of DAO
2000‐21.
A proof of submission of the Project EIS to the EMB Central Office for processing will be used
as basis for permit issuance.
d) License to use explosives in construction, which shall be secured from the Philippine National
Police (PNP) by the Contractor (Purchaser License) and his chief blaster (Foreman Blaster
License). This can only be applied for after Contractor has received the Notice of Award but
should have been secured prior to Notice to Proceed. Application shall be addressed to the
Chief, PNP through the Chief of the Fire and Explosives Division (FED). Processing period for
both licenses is 15 working days.
Any movement of explosives/explosive ingredients from the Port of Manila or from one province to
another or within the same province but from one license to another shall require prior approval of the
FED Chief. Approval should be secured only prior to commencement of blasting activities to minimize
storage of explosives onsite
Table 2: Document Requirements for Foreman Blaster and Purchaser Licenses
Documentary Requirements A B
1. Letter of Request addressed to Chief PNP through the Chief of FED √ √ 2. Accomplished PNP Form No. 6 (Application for License to Possess Explosives √ - 3. Certification from the Contractor/Sub-contractor (which is a FED explosives licensee) √ - 4. Certificate of being capable in handling explosives from mining engineer Iif applicant not a mining eng’r √ - 5. Contractor’s/Sub-contractor’s Purchaser License √ - 6. Biodata √ √ 7. Drug test √ - 8. Local clearances (court, police, mayor, NBI) √ √ 9. Recent ID photo of licensee (2x2) √ - 10. Endorsement from Bureau of Mines, if employed in a mining firm) √ - 11. Authenticated registration with SEC &/or DTI for single proprietor and a copy of Articles of Incorporation
and its By-Laws or copy of Articles of Partnership or Articles of Cooperation with Cooperative Dev’t. Authority, as applicable. - √
12. Certificate of Registration of business (if single proprietorship) & Certificate of Mun. Treasurer stating capital investment in the business - √
13. Inspection Report/Security or Survey signed by the FED Inspector - √ 14. Pictures, details and location of the existing magazine (warehouse) - √ 15. Copy of endorsement letter from concerned agencies (DENR-Mines and Geosciences Bureau, Dept. of - √
Energy, Phil. Coast Guard, Pesticide Authority DPWH) A Foreman Blaster License (for chief blaster) B Purchaser License (for Contractor)
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Initial Environmental Examination – Output 2
The key environmental quality standards applied in this IEE include: (i) National Ambient Air Quality
Criteria for Pollutants, 1998; (ii) Noise Control Regulations, 1980; and (iii) Water Quality Standards
(DAO 35, 1990). International standards referred to include the WHO Air Quality Guidelines, Global
Update 2005; WHO Guideline for Community Noise, 1999; WB Pollution Prevention and Abatement
Handbook, 1998; IFC Environmental, Health and Safety (EHS) Guidelines; and Assessing Vibration:
Technical Guide, 2006 in the absence of a national vibration guideline.
The Philippines became part of the following three international environmental agreements most
relevant to the Project: (i) UNESCO World Heritage Convention in 1985, committing to ensure the
protection and conservation of the cultural and natural heritage situated on territory of, and primarily
belonging to, the State; and (ii) Convention of Biodiversity in 1993, committing to require
environmental assessment of projects that are likely to have significant adverse effects on biological
diversity with a view of avoiding or minimizing such effects; and (iii) Convention on Wetlands of
International Importance especially as Waterfowl Habitat (Ramsar Convention), in 1994, committing to
conserve and wisely use wetlands (i.e., maintaining ecological character) as a contribution toward
achieving sustainable development locally and worldwide.
The list of specific clearances / permits and timeline relevant to the project is presented in Figure 3.
Figure 3: Timeline for Securing Required Clearance / Agreement / Permit / License
2.2 Administrative Framework
DENR is the primary government agency responsible for the conservation and protection of the
environment, including natural resources in reservations and watershed areas. It is also mandated to
enforce the implementation of the EIS System. Pursuant to PD 1586, the EIS System covers projects
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Initial Environmental Examination – Output 2
that have been declared as environmentally critical projects (ECPs) and projects situated in
environmentally critical areas (ECAs), presumed to have significant impacts on the quality of the
environment. The law provides the non‐covered projects, which may be required environmental
safeguards if deemed necessary by DENR. New projects will require EIS, Programmatic EIS, Initial
Environmental Examination (IEE) Report, IEE Checklist or Project Description Report. The proposed
Angat Water Transmission Improvement Project will require an EIS, as indicated by DENR.
The country’s environmental impact assessment (EIA) process involves the following stages: (i) project
screening; (ii) EIA study scoping; (iii) conduct of the EIA study and preparation of the EIA report for
the application for an environmental compliance certificate (ECC) or certificate of non‐coverage (CNC);
(iv) review and evaluation of the EIA Report; (v) decision‐making; and (vi) environmental impact
monitoring, validation and evaluation/audit. The process, applicable to the Project, is summarized
below:
Table 3: The Philippines’ Environmental Impact Assessment Process
Steps in the Process Responsible Entity
Screening
Self-screening by referring to Annex 2.1a of the Revised Procedural Manual for DAO 2003-30 MWSS
Screening validation using the same Annex DENR CO
Scoping
Conduct of Information, Education and Communication (IEC) of LGUs within which the Project will be implemented
Request for scoping Submit 5 sets of Pro-forma Project Description Scoping with supporting documents: Map and description of preliminary impact areas Stakeholder ID form Summary of IEC documentation Filled-out scoping portion of the appropriate EIA Scoping/Procedural Screening Checklist (SPSC).
Review Team formation, scheduling of three-level scoping activity (within 5 working days from receipt of letter-request for scoping)
Conduct 3-level scoping activity to be done one-time on site or in the region of project location. 1st level, Project Briefing Meeting with Review Team 2nd level, Public Scoping with Community
3rd level, Technical Scoping with Review Team
MWSS
MWSS
EMB CO
MWSS-driven
Final approval of scoping checklist EMB CO
EIA Study and Report Preparation MWSS
EIA Report Review and Evaluation
Submit 1 copy of EIA Report Filled-out Procedural Screening portion of the SPSC
MWSS
Validates procedural screening by the proponent – within 3 days from receipt of EIA Report EMB CO
Payment of filing fee/set up Review Fund MWSS
Submission of Procedurally-accepted Application Documents (for EIS, 7 hard copies and 1 CD/e-copy)
MWSS
Review and Evaluation of EIA Report (estimated workdays, 120 days) EMB CO
Decision Making DENR
Monitoring, Validation and Evaluation/Audit MWSS-driven
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Initial Environmental Examination – Output 2
3 Project Description
3.1 Project Rationale
3.1.1 Water Demand Supply
The bulk of the water supply for Metro Manilaʹs 13 million inhabitants comes from the Umiray‐Angat‐
Ipo system of reservoirs, tunnels and aqueducts. The main feature of the existing system is the
regulation of Angat river, along Angat and Ipo dams, having two reservoirs in the river. Three tunnels
are located close to each other, conveying water from the Angat river upstream of Ipo dam through the
hilly terrains that supply six aqueducts. These in turn convey water to La Mesa reservoir and La Mesa
water treatment plant.
In addition to supplying water to Metro Manila, the transmission system supplies 0.5m3/s to San Jose
del Monte water treatment plant and other private users. A large number of illegal users take up an
estimated 0.1 m3/s. Moreover, the Bulacan Bulk Water Supply Project currently understudy within
MWSS is likely to require up to 5.5 m3/s from a take‐off on the aqueducts at Pleasant Hills, about
10.2km south of Bigte portal.
The MWSS and the two concessionaires – Manila Water Company Inc (MWCI) and Maynilad Water
Services Inc (MWSI) – have looked at the future water demands for Metro Manila. Several demand
scenarios have been identified (Figure 4). By 2035, forecast demand varies between 35m3/s and over
80m3/s.
Figure 4: Manila Water Demand with and without 15% Buffer
At present, there is a granted water allocation of 46m3/s from Angat reservoir but the water flow
available to MWSS is often below the water allocation. Existing water resources would provide up to
51.7m3/s, given the flow of 46 m3/s from Angat is secure and the relevant treatment plant and
distribution infrastructure are constructed.
Table 4: Water Available to MWSS from Angat Reservoir
Probability Flow to MWSS is
below - m³/s
Flow to MWSS is above - m³/s
Granted water right - m³/s
10% 27.5 48.6 46
20% 32.3 45.8 46
50% 39.2 39.2 46
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Initial Environmental Examination – Output 2
To improve the reliability and security of the raw water transmission system, partial rehabilitation of
the transmission system from Ipo to La Mesa and the implementation of water safety, risk and asset
management plans is proposed through the Angat Water Supply Transmission Improvement Project.
3.1.2 Existing Transmission System
Needs and Rehabilitation
Water from the Angat river is
transmitted from a location upstream
of Ipo dam to Bigte through the three
existing tunnels. From Bigte, water is
conveyed along six aqueducts
(pipelines), with Aqueducts 1 and 2
carrying water to La Mesa reservoir
and the remaining four aqueducts
carrying water to La Mesa water
treatment plant. A schematic outline of
the system is shown in Figure 5.
Based on the condition assessment, the
main pipelines appear in reasonable
condition, although the older
Aqueducts 1 and 2, 3 and 4 show
leakage totalling nearly 10%. This level
of leakage will become unacceptable as
demand increases, given that water
availability is limited. Rehabilitation is
likely to involve local repair and/or
replacement of longer lengths of pipe.
The tunnels continue to convey
significant volumes of raw water,
which indicate that they are intact with
no major collapse. To check the actual
conditions and extent of remediation
needed by existing tunnels, internal
access is required. A completed Tunnel
4 internal access will be possible
without disrupting water supply to
Figure 5: Ipo-La Mesa Transmission System Schematic
Metro Manila and other areas served by the system.
Based on a hydraulic assessment, there is no flexibility in the system to allow closure of a conveyance
for maintenance and rehabilitation: (i) the capacity of the existing tunnels is below the anticipated
maximum flow of 48m3/s and needs to increase in the next few years to meet future demands; and (ii)
only one of Aqueducts 5 and 6 can be supplied to its full capacity by Tunnel 3, reducing the effective
capacity to 42m3/sec. Hence, hydraulically, the first requirement is to construct a new Tunnel 4 to: (i)
augment supply to Aqueducts 5 and 6 to their full capacities and allow closure of existing tunnels and
the remaining four aqueducts for inspection, maintenance and rehabilitation.
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Initial Environmental Examination – Output 2
3.2 Proposed Scheme
The proposed scheme will involve the construction of a fourth tunnel (Tunnel 4) and associated
structures, namely: (1) intake structure; (2) outlet structure, and (3) channel connecting Tunnel 4 outlet
portal to existing Basin 3 and Aqueduct 5.
For ease of social and environmental due diligence, the tunnel alignment was divided into 1km
lengths, resulting in seven segments (see Figure 2):
Segment 1 (Ipo dam site) includes <1km length of the tunnel and the intake structure and traverses
through a forest zone and partly in a built‐up zone of the Ipo watershed controlled zone. Segment 1
also includes Contractors’ work area (CWA) and temporary spoil disposal sites which are considered
construction support facilities.
Segments 2 to 6 include mainly the tunnel at 1km length each. Segment 2 (San Mateo Rolling Terrain)
is found within the indicative boundary of the Angat Watershed Forest Reserve, traversing through
residential zone, forest zone and forest buffer area. Segment 3 (AFP Housing) is outside the forest
buffer area and is not part of the protected area. Segment 4 (Grassland) traverses a forest buffer area
and residential buffer zone. Segments 5 (Road ROW) and 6 (Grassland) traverse residential and
agricultural zones outside the protected area.
Segment 7 (Brgy. Bigte) includes the remaining <1km length of the tunnel, outlet structure and channel
to Basin 3 and Aqueduct 5. It traverses through residential, agricultural and quarry zones. Segment 7
also includes CWA and two temporary spoil disposal sites which are considered construction support
facilities.
3.2.1 Tunnel
The proposed Tunnel 4 will be 6.5km long and 4m in diameter (finished internal diameter), lying
within the MWSS ROW and adjacent to Tunnel 1, and running from Ipo reservoir to Bigte. Much of the
tunnel will be located at depths from 100m to 150m below the ground surface, with a maximum depth
of approximately 200m. The tunnel will have a permanent in situ cast concrete lining with steel
reinforcement to ensure structural integrity and raw water flows over the long term.
Significant consideration has been given to the siting of the new tunnel and portal. The existing MWSS
right‐of‐way (ROW) is on average 60m wide and centered on Tunnel 1. MWSS requires that the new
tunnel be within this ROW. The optimum tunnel site would also minimize disruption to existing
operations. Notwithstanding the above, the new tunnel intake should be located in the same general
area as the existing intakes. Taking all the constraints into account, the most favorable location for
Tunnel 4 intake lies upstream of the existing intakes and in an area where reservoir silting is minimal
(see Figure 6).
3.2.2 Intake Structure
The intake structure provides a conduit between the reservoir and the tunnel inlet portal located
between the new and old Ipo dams. Such structure comprises a rectangular box with nominal
dimensions of 10m wide and 18m long. A transition structure, approximately 10m long and 4m wide,
allows for transition from the rectangular section to the circular profile at the tunnel. The intake
structure invert is set at a relative elevation of 95.7m, nearly 5m below the normal reservoir operating
level. The top deck is set at relative elevation of 103.5m. The intake structure includes a trash rack to
control debris entering the tunnel, stoplogs for closure, and control or sluice gates to regulate the flow
to the tunnel. The inlet works will be located at depths of approximately 10m.
TA 8196-PHI: Angat Water Transmission Improvement Project
Initial Environmental Examination – Output 2
Figure 6: Inlet Structure including Coffer Dam
New Ipo Dam
Old Ipo Dam
Tunnel 3
Inlet
Tunnel 2
Tunnel 1
Tunnel 4
14
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Initial Environmental Examination – Output 2
3.2.3 Outlet Structure
The outlet structure is located at the Bigte end of Tunnel 4 and provides a transition between the tunnel
cross‐section and the channel that carries water to Basin 3 (see Figure 7). The outlet structure comprises
an uncovered rectangular basin 4m wide and 7m long, with an outlet invert elevation at about 92.3m.
There is also an observation deck for maintenance and operation. The outlet works will be located at
depths of approximately 8m.
3.2.4 Channel
The channel connects (or carries water from) Tunnel 4 outlet portal to the existing Basin 3 and
Aqueduct 5. Its alignment will generally follow the contour of the hill behind the existing Bigte basins.
It is rectangular in section of 4m wide and 45m deep.
3.2.5 Construction Support Facilities
Construction support facilities include CWAs and temporary spoil disposal area at the inlet and outlet.
a) CWA
CWA is a piece of land that is not contiguous to the project footprint but is necessary to securely site the
workers’ camp, project office, emergency first‐response station, construction materials storage,
explosive storage, equipment parking, and some necessary pre‐fabrication and maintenance works.
The workers’ camp will include adequate housing for construction workers and basic services and
facilities to meet personal and domestic needs for safe water, sanitation/sewage disposal, garbage
disposal, natural and artificial lighting, cooking, food storage and laundry. Outside the workers’ camp,
sanitation facilities, water supply systems, lighting and internal accesses will be provided for the other
activities and works. The explosive storage area should be located and constructed in accordance with
Rule 19 of the IRR of RA 82943.
Preliminary CWA sites have been identified as follows:
• In Segment 1, one CWA site near the intake structure (see Figure 22). Access to the CWA will
be on the landside through an existing narrow dirt road and on the waterside by utilizing a barge. The
existing dirt road will be widened under the project to facilitate mobility of workers and materials
during construction.
• In Segment 7, two CWA sites near the outlet structure (see Figure 23). Access will be through
an existing concrete road.
b) Temporary Spoil Disposal Sites
Temporary spoil disposal area is a staging area for debris, spoils and residual soils from construction
works. In Segment 1, the site that was used as temporary disposal area during the construction of the
New Ipo dam and Tunnel 3 will be used in the project as the temporary spoil disposal area near the
intake structure works. It is currently an open area dominated by grasses. Two temporary spoil
3 Rules and regulations governing the administration and enforcement of the PD 1866 dated 29 June 1983 as amended by RA 8294, dated 06 June 1997 entitled “Codifying the laws on illegal/unlawful possession, manufacture, dealing in,
acquisition or disposition of firearms, ammunition or explosives/explosive ingredients or instruments used in the manufacture of firearms, ammunition or explosives, and imposing stiffer penalties for certain violations thereof and for
relevant purposes.
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Initial Environmental Examination – Output 2
disposal areas, both with open‐type vegetation, have been identified near the outlet structure in
Segment 7 (see Figures 22 and 23).
Figure 7: Outlet Structure and Temporary Spoil Disposal Area
Tunnel 3
Basin 3
Tunnel 2
Proposed Open
Channel
Tunnel 1
Tunnel 4
Outlet
3.2.6 Construction Program and Methods
Indicative design and construction period of the proposed Tunnel 4 is about 52‐months, including 3.5
years for tunnel construction, plus a 12‐month defects notification period.
According to the feasibility study, the preferred method for tunnel construction is drill and blast two
pass with cast in‐situ concrete lining. The construction sequence for the undrained tunnel is
summarized as follows:
a) Probing ahead will be undertaken from the tunnel face. The purpose of the probing is to
investigate the ground conditions ahead of the tunnel face, as the majority of fault zone and
portal tunnel sections will be excavated in low quality ground.
b) Grouting of the ground in advance of excavation can be undertaken at the portal end to
improve the ground conditions and control groundwater inflow.
c) Full face excavation of the tunnel heading will be undertaken using drill and blast (or
mechanical depending on the Contractor’s preference) methods. The length of each advance
will vary in response to the actual ground conditions. Excavation profile will be carefully
controlled to minimize over breaking and damage to the surrounding rock mass.
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Initial Environmental Examination – Output 2
d) Rock support will generally consist of steel sets and sprayed concrete in the poor ground
conditions, with combinations of temporary rock bolts and steel fiber reinforced sprayed
concrete if ground conditions are suitable.
e) Reinforced concrete invert is placed first. The edges of the invert arch pour will form the
footing for the tunnel arch formwork.
f) Concrete arch lining can be cast in situ from 10m to 12m long sections. Consideration of the
effects of the tight radius bend at the Ipo end of the works will be needed, and the use of a
shorter shutter length may be required.
g) Contact grouting will be carried out at the completion of concrete lining to fill any remaining
void in the tunnel crown so that the concrete lining is in intimate contact with the rock
around the tunnel.
h) Contact grouting is carried out at low pressure between the excavated surface and the
extrados of the concrete lining.
3.2.7 Alternatives Considered
No alternative was considered given the constraints on project siting. Above ground conveyance
system is not applicable due to the rugged terrain of San Mateo. The proposed tunnel lies within the
existing MSWW ROW.
3.2.8 Associated Facilities
According to Paragraph 6, Appendix 1 of the SPS 2009, impacts and risks will be analyzed in the
context of project’s area of influence. This area of influence encompasses, among others, associated
facilities that are not funded as part of the project and whose viability and existence depend exclusively
on the project and whose goods or services are essential for the successful operation of the project.
The PPTA Team’s assessment of the identified associated facility is presented in Table 5. The associated
facilities are not funded as part of the project. The viability and existence of such facilities are not
dependent exclusively on the project. The facilities, despite their age, particularly for Ipo dam and
Basin 3, were assessed to be in good/reasonable condition to provide services essential to the successful
operation of Tunnel 4. Further due diligence is not necessary.
Table 5: Associated Facilities of Tunnel 4
Identified Is it funded as Are its viability Are its services PPTA’s assessment of the associated part of the and existence essential for identified associated facility facility project? depending the successful exclusivity on operation of the the Project? Project? Dam No No Yes Commissioned in 1984, this gravity dam is some 30 years of age. It is not
programmed for any rehabilitation; hence it is assumed to be in reasonable condition.
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Initial Environmental Examination – Output 2
Identified associated facility
Is it funded as part of the project?
Are its viability and existence depending exclusivity on the Project?
Are its services essential for the successful operation of the Project?
PPTA’s assessment of the identified associated facility
Basin 3 No No Yes Basin 3 is more than 20 years. Based on the facilities inventory and
assessment conducted by the PPTA Team using available drawings, site visits, the CPF asset register, limited repair and maintenance information, discussion with operators and other parties, and assessment of losses, the main basins at Bigte, which includes Basin 3, are in reasonable condition.
Aqueduct 5 No No Yes Aqueduct 5, of size 3.6m x 16 km, has a capacity of 1,640mld and has been
rehabilitated under Phase 2 of the Angat Water Utilization and Aqueduct Improvement Project (between 2010 and 2013). According to the hydraulic assessment by the PPTA Team, Aqueduct 5 is not showing signs of leak and can be supplied to its full capacity. The assessment of structural resilience of aqueducts indicates that there are no major issues which need to be urgently addressed. The main concern is damage that will occur at hard/stiff points along the pipeline. It is considered that this risk is best dealt with post- earthquake repair, rather than installation of flexible joints.
Ipo Road No No Yes The Ipo road is a two-lane concrete road from Bigte to Ipo dam Compound. It has
sections that are winding; hence additional road signs along the road are needed as precautionary and safety measures. From site visit, the road is in good condition.
3.3 Contracting Method
The contracting method is design‐and‐build (D&B) for the construction of Tunnel 4 (Ipo to Bigte). The
bid document explicitly states that the Tunnel 4 should be parallel to the existing three tunnels, from
Ipo to Bigte, where it shall be connected to Aqueduct 5.
Scope of work of the D&B Contractor includes:
1. Complete design, construction, installation and commissioning in accordance with the Contract
requirements of:
a. New Tunnel 4 intake structure at Ipo reservoir;
b. New Tunnel 4 connecting Ipo reservoir to a new transition basin at Bigte;
c. New transition basin at Bigte;
d. New conveyance connecting the new transition basin at Bigte to the existing transition
Basin 3 at Bigte;
e. Necessary modifications to the existing transition Basin 3 at Bigte to enable the unimpeded
flow of not less than 19m³/s of water from the Ipo dam to the existing Aqueduct, which
conveys water from Bigte to the portals at the La Mesa reservoir in Novaliches.
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Initial Environmental Examination – Output 2
2. Complete design and construction of site ancillaries including, but not limited to:
a. Permanent access to the new Tunnel 4 intake structure at Ipo reservoir.
b. Provision of temporary accommodation and equipment for Employer/Engineer
c. All temporary works necessary for the construction of Tunnel 4
3. Disposal of spoils resulting from excavation works
4. Preparation and submission of as‐built drawings, O&M manuals, list of any spare parts which may
be required for operation of equipment supplied by the Contractor.
5. Training of Employer’s personnel in operation of the works.
6. Commissioning and performance testing of the completed works
The proposed tunnel construction method in the feasibility study is drill and blast. The bid document
has not set restrictions on tunnel construction methodology. Instead, scheme design criteria are
specified to guide D&B contractor on the appropriate tunnel construction methodology. The scheme
design criteria include:
1. Design life of the tunnel shall be 100 years.
2. Design life of Ipo intake structure, Bigte outlet structure, and connecting channels shall be 75 years.
3. Elevation of Ipo reservoir hydraulic design water level shall be taken as 100.3m above MWSS data.
4. Normal operating level of Ipo reservoir shall be assumed to vary between 100m and 101m above
MWSS data.
5. Elevation of Basin 3 (Aqueduct 5 start) hydraulic design water level 95.5m above MWSS datum.
6. Finished hydraulic radius of both the completed tunnel and the connecting channel shall be
sufficient to ensure a minimum flow of 19m³/s to the start of Aqueduct 5 at Basin 3.
a. The Contractor shall confirm the basis upon which this minimum flow is to be achieved
over the design life of the works, and in particular, upon the assumed absolute roughness
values or friction coefficients adopted for both “as constructed” and “ultimate” condition
of the surfaces in contact with the fluid.
b. The Contractor shall provide justification for the selected values of the roughness values or
friction coefficients so selected.
7. Sluice gates shall be used at the Ipo intake structure to regulate flow through Tunnel 4
a. Stop‐logs shall be provided both upstream and downstream of each sluice gate so that
they can be taken out of service individually for inspection or repair.
8. Suitable barriers and/or screens shall be provided at the intake works to prevent large suspended
and floating debris from entering the tunnel.
9. The new intake must be located to the downstream side (western side) of the old, flooded, Ipo dam
to minimize the possibility of abstracting sediment.
10. Tunnel 4 must be located within the MWSS ROW. It should be noted that the alignment of both
existing Tunnels 2 and 3 lies outside MWSS’ current ROW, and that a small section of the existing
Tunnel 1 alignment also lies outside MWSS’ current ROW.
11. Tunnel 4 shall not pass over or under the existing working tunnels as the risk of collapse and
subsequent disruption to supply is unacceptable. Criteria 10 and 11 suggest that the alignment of
Tunnel 4 is restricted to the corridor between existing Tunnel 1 and the southern boundary of
MWSS ROW.
Also, the D&B Contractor is required to draft Design Quality Plan (DQP). The DQP shall define the
D&B Contractor’s structure, policies, procedures and Quality Management Plan (QMP) documents for
the quality control of design activities for the design and construction of the tunnel.
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Initial Environmental Examination – Output 2
The DQP shall include, among others:
a. Procedures and event triggers for creating corrective action teams;
b. Procedures for control of design changes during both design and construction phases; and
c. Process to verify the accuracy and completeness of as‐built drawings, specifications, and other
construction documentation to foster the future ability of the Employer to locate utilities, make
minor modifications, and enhance or alter the final constructed works.
In addition, it is explicitly stated in the bid document that no changes or corrections other than the
changes and corrections noted by the Engineer shall be made to any Contractor’s documents which
have been reviewed as “proceed” except by re‐submittal with revisions appropriately noted. The
submission shall be accompanied by justification for the changes and corrections, including necessary
design calculations.
In the event of design deviation, such as shift of alignment resulting in tunnel being located outside the
MWSS ROW, change in inlet structure location and/or change in the method of construction, the MWSS
through its PMO should immediately: (i) seek the advice of EMB Central Office if such design
deviation warrants an ECC amendment; and (ii) inform ADB should EMB advise for ECC amendment
and finally, (iii) seek ADBʹs clearance/concurrence for an IEE revision and/or EMP updating.
TA 8196-PHI: Angat Water Transmission Improvement Project
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DJF MAM JJA SON DJF MAM JJA SON DJF MAM JJA SON
Initial Environmental Examination – Output 2
4 Environment Description
4.1 Climate
The project area climate falls under Type I climate of the modified coronas classification characterized
as having two pronounced seasons, dry from November to April and wet during the rest of the year.
Typhoons have a greatly affected the climate and weather conditions in the area. An annual average of
nine typhoons (1948‐2004) made landfall or crossed the country, the majority of which hit Luzon Island
where the project is located.
Climate trends were analyzed by DOST PAGASA using available observed data from 1951 to 2009 with
the average for 1971 as the reference value. Table 6a summarizes seasonal temperature and rainfall for
the recent baseline (1971 to 2000) with future projections for Bulacan Province to 2065. At present, the
temperature is equitable all‐year round, with slightly higher temperatures in the dry season from
March to May and prior to the main summer rains. The mean annual rainfall is about 2,385mm, with
the maximum rainfall falling from June to August and least amount of rain observed from December to
May. Future trends indicate an increase in mean monthly temperature of about 2°C by 2065, and an
increase in annual rainfall to about 2,470mm with a seasonal shift to a more peaked rainfall distribution
in the three summer months from June to August.
Table 6: Projected Temperature and Rainfall Change in Bulacan Province
a. Seasonal increase in temperature and rainfall
Observed baseline
Change in 2020
Change in 2050
1971-2000 2006-2035 2036-2065
Seasonal increase in temperature
Seasonal rainfall
25.60 27.90 27.10 26.70 26.50 29.00 28.00 27.70 27.50 30.00 28.80 28.60
change 212.40 288.90 1041.40 842.10 221.32 288.24 1042.73 841.86 184.36 183.74 1287.17 814.31
b. Frequency on Extreme Events
Provinces Stations No of Days w/ Tmax > 35°C No. of dry days No. of days with rainfall >200mm
OBS (1971-
2020 2050 OBS (1971-
2020 2050 OBS 2020 (1971-
2050
2000) 2000) 2000) Frequency of extreme
Manila Science garden
1095 1984 3126 7476 6302 6220 9 13 17
event Source: Climate Change in the Philippines, February 2011, DOST-PAGASA
The study by DOST‐PAGASA (Table 6b) predicted that the number of days with a maximum
temperature greater than 35°C would almost double in the period 2006‐2035 and triple in the period
2036‐2065, compared with the baseline (1971‐2000). The study also predicted that the number of dry
TA 8196-PHI: Angat Water Transmission Improvement Project
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Initial Environmental Examination – Output 2
days would decrease over the coming 50 years compared with the baseline with 7,476 days, falling to
6,302 between 2006 and 2035, and decreasing to 6,220 dry days in the period 2036‐2065. There is also
forecast to be a slight increase in the number of days with rainfall greater than 200mm from nine days
for the baseline, to 13 days in 2006‐2035, and 17 days in 2036‐2065.
4.2 Air Quality and Noise Level
Air quality and ambient noise levels in the study area were monitored from 30 July to 2 August 2013.
Details of the methodology are presented in Appendix 2.
There are no major sources of air pollution in the study area, which is largely given over to rural land
uses. The ambient air quality sampled at Ipo dam site, San Mateo Barangay Hall and Bigte portal are
within the DENR ambient air quality standards. The results are presented in Table 7.
PM10
TA 8196-PHI: Angat Water Transmission Improvement Project
Initial Environmental Examination – Output 2
Table 7: Ambient Air Quality Results
AT4- A1
AT4- A2
AT4 A3
Parameter Sampling method Test method DENR
standards
TSP
Filtration method by high
Reporting limits
Units Near MWSS
Bigte property
(30-31 July 2013)
San Mateo Barangay Hall
(31 July- 1 Aug 2013)
Ipo dam site (1-2 Aug
2013)
volume sampler flame AAS 230 0.1 µg/Ncm 119.87 33.9 35.4
SO2 Absorption in liquids for
gaseous pollutants - Kimoto Brand (sampler)
flame AAS 180 0.4 µg/Ncm 15.26 15.26 13.9
NO2 Absorption in liquids for
gaseous pollutants - Kimoto Brand (sampler)
flame AAS 150 0.4 µg/Ncm 3.57 3.42 6.56
Filtration method by high
volume sampler flame AAS 150 20 µg/Ncm 71.09 30 33.19
Pb Filtration method by high
volume sampler flame AAS N/A 0.8 µg/Ncm ND ND ND
CO Direct read out analyzer flame AAS N/A 0.4 µg/Ncm 3.16 1.83 ND
23
24
Initial Environmental Examination – Output 2
Main sources of noise in the study area arise from people going about their daily work, traffic near
roads, and wind. Noise level at the project site was measured using a digital sound level meter
(precision type). Noise levels in Brgy. San Mateo and the Ipo dam site are all within the DENR limits
and are typical of day‐time noise levels in rural areas. There is a slight noise level exceedance observed
in Bigte during the nighttime (1900‐2100). Results are presented in Tables 8 to 10.
Table 8: Noise Level Monitoring Results at MWSS Property Brgy. Bigte
Sampling time / Date Average dB (A) DENR standard maximum
allowable noise level
Remarks
1057-1257 / 30 July 2013 61.6 70 Passed
1257-1257 / 30 July 2013 61.1 70 Passed
1457-1657 / 30 July 2013 59.5 65 Passed
1657-1857 / 30 July 2013 55.3 65 Passed
1857-2057 / 30 July 2013 66.5 60 Exceeded
2057-2257 / 30 July 2013 52.5 60 Passed
2257- 0057 / 30-31 July 2013 52.3 60 Passed
0057-0257 / 31 July 2013 43.6 60 Passed
0257-0457 / 31 July 2013 42.5 65 Passed
0457-0657 / 31 July 2013 64.0 65 Passed
0657-0857 / 31 July 2013 62.6 70 Passed
0857-1057 / 31 July 2013 68.2 70 Passed
Table 9: Noise Level Monitoring Results at Brgy. Hall San Mateo
Sampling Time / Date Average dB (A)
DENR Standard maximum allowable
noise level
Remarks
1250-1450 / 31 July 2013 66.8 70 Passed
1450-1650 / 31 July 2013 60.9 70 Passed
1650-1850 / 31 July 2013 64.2 65 Passed
1850-2050 / 31 July 2013 59.4 65 Passed
2050-2250 / 31 July 2013 61.4 60 Passed
2250-0050 / 31 July-1 Aug 2013 54.2 60 Passed
0050-0250 / 1 Aug 2013 47.5 60 Passed
0250-0450 / 1 Aug 2013 43.9 60 Passed
0450-0650 / 1 Aug 2013 51.6 65 Passed
0650-085 / 1 Aug 2013 64.0 65 Passed
0850-1050 / 1 Aug 2013 63.6 70 Passed
1050-1250 / 1 Aug 2013 62.2 70 Passed
25
Initial Environmental Examination – Output 2
Table 10: Noise Level Monitoring Results at Ipo Dam Site
Sampling time / Date Average dB (A)
DENR standard maximum
allowable noise level
Remarks
1345-1545 / 1 Aug 2013 52.9 70 Passed
1545-1745 / 1 Aug 2013 54.1 70 Passed
1745 -1945 / 1 Aug 2013 54.1 65 Passed
1945-2145 / 1 Aug 2013 51.4 65 Passed
2145-2345 / 1 Aug 2013 51.5 60 Passed
2345-0145 / 1-2 Aug 2013 51.0 60 Passed
0145-0345 / 2 Aug 2013 50.7 60 Passed
0345-0545 / 2 Aug 2013 51.5 60 Passed
0545-0745 / 2 Aug 2013 56.9 65 Passed
0745-0945 / 2 Aug 2013 54.2 65 Passed
0945-1145 / 2 Aug 2013 53.2 70 Passed
1145-1345 / 2 Aug 2013 51.5 70 Passed
4.3 Topography and Soils
Brgy. San Mateo of the Municipality of Norzagaray, where the greater part of the alignment is located,
is characterized by hilly to mountainous terrain whose elevation varies from 85masl to 250masl. Brgy.
Bigte is characterized by a combination of flat to gently sloping areas and hilly lands with highest
elevation of about 95masl.
The projected tunnel depth in Brgy. San Mateo is about 200m to 600m below ground (mbg) while in
Bigte, the tunnel is at 50mbg (see Figure 8).
Borehole samples were tested for heavy metals to determine if the excavated material which will be
disposed in temporary spoil disposal sites may be above sediment quality standard. Adopted criteria
used are based on the Thai Environmental Regulation for Habitat and Agriculture as there is no
standard established in the Philippines. The results show the rock samples are within standards for
heavy metals in soil (see Table 11).
TA 8196-PHI: Angat Water Transmission Improvement Project
Initial Environmental Examination – Output 2
Figure 8: Projected Tunnel Geology and Ground Elevation
26
TA 8196-PHI: Angat Water Transmission Improvement Project
Initial Environmental Examination – Output 2
Table 11: Borehole Sediment Quality
Sample code Unit Adopted criteria7 BH 3 BH4 BH5
Sampling date 20 July 2013 20 July 2013 20 July 2013
Depth (m) 15.5-17 31-32.5 27.5-29
Segment location Segment 1 Segment 4 Segment 7
Cadmium mg/kg 37 ND ND 0.3
Chromium mg/kg 300 5.7 9.7 11
Copper mg/kg 1,560 196 106
Iron mg/kg 84,400 30,900 2,140
Lead mg/kg 400 12 19 10
Manganese mg/kg 1800 371 576 48
Nickel mg/kg 1600 9 15 12
Zinc mg/kg 63 63 8.5
4.4 Geology
4.4.1 IPO Dam
The dam site is underlain by the eocene‐oligocene Bayabas Formation, an extensive bedded sequence
of highly indurated sandstone, shale, chert and pyroclastics mainly agglomerate and welded tuff, and
volcanic flows predominantly amygdaloidal basalt with associated minor andesite pillows sometimes
framed by chert materials. Surface geology comprises agglomerates and basalts which are hard
enough to form abutments for a concrete gravity dam though may require some grouting.
4.4.2 IPO Inlet
The area around the Ipo inlet is underlain by the Bayabas Formation or specifically by the massive
agglomerate and basalt which was observed to be hard to very hard when fresh. In situ weathering is
slight to moderate with residual soil approximated to be no more than a meter deep, except when
overlain by talus materials. Various fracture orientations with utmost two joint sets plus random could
be present. Except for localized faults/shears, the tunnel will be in good ground with rock mass rating
more than 50%.
4.4.3 Proposed Tunnel 4 Alignment
Tunnel 4 alignment passes through the Buenacop limestone upper member of the Madlum Formation,
hence traverses for the most stretch of the tunnel in the middle part of same formation labeled as
Alagao volcanics before going into the equally hard Bayabas Formation composed of agglomerate and
basalts.
The area is underlain by the Bayabas Formation or specifically by the massive agglomerate and basalt
7 Thai Environmental Regulation for habitat and agriculture
27
TA 8196-PHI: Angat Water Transmission Improvement Project
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Initial Environmental Examination – Output 2
which was observed to be hard to very hard when fresh. Joint set spacings could be from 1m to 2m. In
situ weathering is slight to moderate with residual soil approximated to be no more than a meter deep,
except when overlain by talus materials. Various fracture orientations with utmost two joint sets plus
random could be present.
Except for localized faults/shears, the tunnel will be in good ground with rock mass rating more than
60%. Estimated rock quality categorized into good, moderate and bad rock could be 50%, 25% and
25%, respectively. No major problems are envisaged during tunnelling, this being the fourth tunnel to
be constructed along this corridor. Expected groundwater flow can be relatively dry to moderate
inflow.
Figure 9: Geology in the Study Area
4.4.4 Tunnel 4 Outlet at Bigte
The tunnel outlet at Bigte will be hard and massive limestone with fracture spacings more than 2m.
Rock mass rating8 will be more than 60%, which means the rock material is a very good quality rock.
4.4.5 Bigte Interconnecting Basins
Like Tunnel 4 outlet, the lithology is limestone with minimal soil cover of no more than 2m. The soil
profile is characterized by gravelly/bouldery silt with some clay and sand transported soil if not
moderately weathered limestone. Groundwater levels are quite deep of more than 5m.
4.5 Seismology
Very little seismic data are available for the project area. The West Valley Fault (WVF) trace has been
8 The rock mass rating (RMR) system is based on the following parameters: (a) uniaxial compreseeive strength of
rock material; (2) rock quality designation; (3) conditions of discontinuities; (5) groundwater conditions; and (6)
orientation of discontinuities
TA 8196-PHI: Angat Water Transmission Improvement Project
29
Initial Environmental Examination – Output 2
mapped fairly well and one study has been undertaken to establish seismic design parameters for the
La Mesa dam, intake structures and spillway. However, only general results such as earthquake
magnitude and peak ground acceleration (PGA) are available. In addition, available data suggest that
the WVF trace runs roughly parallel to an average of 10km from the Angat Water Transmission
Improvement System. It has been estimated that the WVF can generate a magnitude 7.2 to 7.4 event
with a corresponding peak ground acceleration of approximately 0.67g.
4.5.1 Hydrology and Surface Water
Resources
Figure 10: Surface Water Quality and River Ecology Sampling Stations at Ipo Watershed
The project is located in the Angat Watershed
shown in the project location map (Figure 10).
The extensive area of the watershed results in a
large volume run‐off that is temporarily
retained upstream of Angat dam although there
are times when the water level rises to critical
levels necessitating the release of extra run‐off
into the Angat river system. Releases from
Angat dam, together with inflows from several
small tributaries, flow into Ipo reservoir.
The low‐lying embankment west of Brgy.
Poblacion of Municipality of Norzagaray within
the vicinity of Matictic Bridge is usually submerged under water if Angat dam releases water. During
high volume rainfall, the areas on the western side of the river further downstream are also submerged
from the run‐off drained by Bayabas river that feeds into Angat river. These two areas are expected to
be regularly inundated, and increasingly so in the future with the more intense rainfall events due to
climate change. The rolling topography of the rest of the municipality with pockets of flat lands
contributes to the concentration of extensive and regular flooding in these two areas.
4.5.2 Surface Water Quality of the Angat Upper Reach
The Angat Upper Reach between Angat
dam and Ipo dam is classified as Class
B fresh surface water9. This means that
the river water quality is suitable for
primary contact recreation such as
bathing, swimming, and skin diving,
particularly those designated for
tourism purposes.
Water quality sampling and rapid site
assessment were undertaken on 22 May
2013. Water samples were collected by
grab sampling technique from eight
sampling points from 5km upstream of
Ipo dam to 0.8km downstream. A suit
Figure 11: Average Turbidity Level at Ipo Dam
of samples was collected from Angat river in the Municipality of Angat. The sampling points are
9 Based on DENR Administrative Order 90‐34. Freshwater Classification
TA 8196-PHI: Angat Water Transmission Improvement Project
30
IPO IPO IPO IPO4 IPO3 IPO2 IPO1 US1 DS1 DS2
par ameter
135.15 135.65 156 138.4 150.6 149.9 151.7 151.5 220.30
5 DA O 90-34 1.91 2.325 113.6 15.4 20.4 44.05 5.135 6.405 63.70
500 DA O 90-34 85.72 85.005 97.08 86.6 94.15 93.305 5.135 94.71 174.80
DAO90-34
stabilizing
ORP (mV)
Initial Environmental Examination – Output 2
shown in Table 12.
The in situ and laboratory results confirmed that the water quality is within the Class B standards for
fresh surface water (see Table 13 for the full surface water quality results). Elevated fecal and total
coliform are reported at the Ipo dam site and downstream of Ipo dam. These elevated measures can be
attributed to settlements found near the dam site and downstream which is due to poor sanitation
practices of the community.
Based on a one‐year turbidity measurement made by CPF, it can be observed that the turbidity levels
are high during the wet season (see Figure 11).
Table 12: Surface Water Quality in Angat River (Upstream and Downstream of Ipo Dam)
Parameter, mg/L (unless stated)
Sampling date/
Adopted
Criteria Reference
IPO US2
22 May 22 May
22 May
22 May
22 May
22 May
22 May
22 May
Angat River Downstream (Municipality of Angat)
25 Aug 2013/
time
Physical Characteristics
2013/ 14:48
2013/ 15:07
2013/ 15:24
2013/ 15:34
2013/ 15:47
2013/ 15:57
2013/ 16:46
2013/ 16:30
15:35
Temp (°C) Stabilizing parameter
27.55 28.75 31.8 28.3 31.3 30.95 31.3 31.3 25.80
Salinity (%)
Parameter not included in
8.65 8.68 9.98 8.86 9.64 9.59 9.71 9.70 14.10
Electric Cond. (mS/cm)
Turbidity (NTU)
TDS
Inorganic and Non-metallic Constituents
pH 6.5 - 8.5 DAO 90-34 7.83 7.835 8.03 7.81 8.115 7.86 8.315 8.53 7.60
stabilizing
parameter 216.5 235.5 254 241 234.5 229.5 212 190.5 211.00
Organic and Biological Constituents
Fecal Coliform (MPN/100mL)
200 DAO 90-34 27 70 350 110 350 170 130 350 3,500
Total Coliform (MPN/100mL)
1000 DAO 90-34 540 350 3,500 16,000 3,500 3,500 1,600 9,200 5,400
Heavy Metals
Antimony (Sb) 0.005 DAO 90 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001
Arsenic (As) 0.01 DAO 90 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Cadmium (Cd) 0.003 DAO 90 <0.006 <0.006 <0.006 <0.006 <0.006 <0.006 <0.006 <0.006 <0.006
Copper (Cu) 1 DAO 90 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02
TA 8196-PHI: Angat Water Transmission Improvement Project
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Temp (°C) 26.85 27.00 27.30
Salinity (%) 27.69 14.06 15.74
TSS 86 10.00 657.00
Electric Cond. (mS/cm) 432.7 219.70 246.00
Turbidity (NTU) 5 62.00 12.60 51.40
Colour (Apparent, PCU) 5 100 20.00 500.00
TDS 500 285.95 141.10 158.00
Inorganic and Nonmetallic Constituents
pH 6.5 - 8.5 7.65 8.33 8.20
ORP (mV) 201 211.00 187.00
Nitrogen (as NO₃¯) Nr 0.4 0.2 0.1
Phosphorus (as PO₄³¯)
Organic and Biological Constituents
0.2 0.2 0.08 0.7
Dissolved Oxygen 5 13.40 22.5 not measured
BOD5 5 3 2 14
COD 9.9 9.8 49
Initial Environmental Examination – Output 2
Lead (Pb) 0.01 DAO 90 <0.04 <0.04 <0.04 <0.04 <0.04 <0.04 <0.04 <0.04 <0.04
Mercury (Hg) 0.001 DAO 90-34 <0.000
1
<0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001
Nickel (Ni) 0.075 WHO <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Vanadium (V) 0.075 WHO <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0
Zinc (Zn) 5 DAO 90-34 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02
Bromide 4.1 2 2.6 1.6 2.5 6.7 2.5 1.6 not measured
4.5.3 Surface Water Quality at Bigte
Surface water samples were collected from Bigte Creek during rainy season (August 2013, see Figure
12). Samples were collected employing grab sampling technique from Bigte River, the creek near the
MWSS property, and Sta. Maria River. Based on Class B surface water criteria, elevated measures were
reported for turbidity, color, and total coliforms at all sites. Phosphorus and BOD are seen to have
slightly elevated measures in Sta. Maria River.
Table 13: Surface Water Quality in Bigte River and Sta. Maria River
Parameter, mg/L
(Unless Stated)
Adopted Criteria
SW2 SW03 SW Sta. Maria
Description
(Class B, DAO 90-34)
Bigte river, sampling site is near the bridge
At Bigte, with the Salonga Property
Sta. Maria River
Physical Characteristics
Water use
laundry, swimming, domestic
laundry, swimming, domestic
TA 8196-PHI: Angat Water Transmission Improvement Project
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Initial Environmental Examination – Output 2
Parameter, mg/L
(Unless Stated)
Adopted Criteria
SW2 SW03 SW Sta. Maria
Description
(Class B, DAO 90-34)
Bigte river, sampling site is near the bridge
At Bigte, with the Salonga Property
Sta. Maria River
Faecal Coliform (MPN/100mL) 200 24,000 9,200 920,000
Total Coliform (MPN/100mL) 1000 240,000 92,000 920,000
Oil and Grease 1 0.3 0.3 <0.3
Heavy Metals
Antimony (Sb) 0.005 <0.001 <0.001 <0.001
Arsenic (As) 0.01 <0.01 <0.01 <0.01
Cadmium (Cd) 0.003 <0.006 <0.006 <0.006
Chromium (hexavalent, Cr(VI)) 0.03 <0.003 <0.003 <0.003
Copper (Cu) 1 <0.02 <0.02 <0.02
Lead (Pb) 0.01 <0.04 <0.04 <0.04
Manganese (Mn) 0.5 0.07 0.07 0.4
Mercury (Hg) 0.001 <0.0001 <0.0001 <0.0001
Nickel (Ni) 0.075 <0.01 <0.01 <0.01
Vanadium (V) 0.075 <1.0 <1.0 <1.0
Zinc (Zn) 5 <0.02 <0.02 0.1
TA 8196-PHI: Angat Water Transmission Improvement Project
Initial Environmental Examination – Output 2
Figure 12: Surface Water and Groundwater Sampling Stations along Tunnel Segments
33
TA 8196-PHI: Angat Water Transmission Improvement Project
34
Initial Environmental Examination – Output 2
4.5.4 Groundwater
Based on the Groundwater Availability Map of the Philippines10, the project area is underlain by
impermeable rocks with limited potential for groundwater resource. The geology varies from rocks
without any known significant groundwater obtained through drilled wells to rock with limited
potential to moderate permeability. Shallow water yields of less than 0.01L/s to 0.03L/s. Groundwater
quality is soft to moderately hard.
The information on groundwater use in the project area is very limited. Communities are getting their
drinking water supply from the local water district (LWUA, Local Water Utilities Administration) and
distributed by water trucks or shallow wells.
Groundwater wells registered at the National Water Resources Board (NWRB) include two Norzagaray
water district wells in Brgys. Partida and Matictic in the Municipality of Norzagaray, Province of
Bulacan with 31.95m and 8.11m pumping water level, respectively.
Data on groundwater levels were also obtained from 10 boreholes drilled within the project area (Table
14). The 2013 borehole report shows that the water table is found in Segment 4 at about 4.5mbg;
Segment 6 at about 15.5mbg and Segment 7 at 9.5mbg.
Table 14: 2013 Borehole and Water Table
Borehole
no. Location
BH-1
River hole. Bedrock not reached
Elevation (masl)
Depth as drilled meters
Depth to water
table Remarks
River hole; no
(Segment 1) 82.469 16 -
measurement of water
River hole; no
BH-1A River hole. Be (Segment 1)
drock reached 25.5 - measurement of water
BH-2 Intake Area (T (Segment 1)
unnel) 98.969 Not drilled Not drilled -
BH-3 Tunnel (Segm ent 1) 142.015 25 15.10 -
BH-4 Tunnel (Segm ent 4) 248.156 45 4.5 -
BH-4A Tunnel (Segm ent 6) 40 15.5 -
BH-5 Upstream, Tunnel Outlet Portal (Segment 7)
122.746 30 - Hole dry
BH-6 Tunnel Outlet 7)
Portal (Segment 97.189
20 8.45 -
BH-7 Connecting Channel (Segment 7)
96.139
16.5
-
Hole dry
BH-8 Connecting Channel (Segment 7)
97.849
12
9.5
10 Groundwater Availability Map of the Philippines Plate XVI. Ministry of Bureau of Mines and Geosciences
TA 8196-PHI: Angat Water Transmission Improvement Project
35
6.5 - 8.5 6.64 7.55 6.69 6.78 6.91 7.20
232.00 212 152 195.00 190.00 214.00
2.9 0.1 <0.006 17 16 2.8
0.06 <0.006 <0.006 0.1 0.1 0.1
oxygen 4.60 8.1 5.4 5.40 5.80 16.
BOD5 <1 1 1 1 <1 <1 COD 4.9 4.9 4.9 4.9 4.9 4.9
Initial Environmental Examination – Output 2
Groundwater samples from community wells used for drinking water supply were collected, tested
and compared to the Philippine Standards for Drinking Water (DAO 1994‐26‐A). Results showed
exceedances in turbidity and color in wells found in Segments 5 and 6, and exceedances in fecal
coliform are reported in Segments 4 and 7 (see Table 15).
Table 15: Groundwater Quality along the Tunnel Segments
Parameter, mg/L (unless stated)
Project
Adopted criteria (DOH DAO 2007- 0012)
GW 1 GW 2 GW 3 GW 3A GW 4 GW 5
segment location
Segment 2
Segment 4
Segment 5
Segment 6
Segment 7
Segment 7
Description The square Locally The water is Communal Near Bigte. Communal well is made of concrete.
known as the from a 'Naget', deep shallow
well. Walls are made of
Owned by Norma Palad
well at Bigte area
Located at the community near the gate of MWSS
well which distributes water supply using water trucks to houses
concrete well and is pumped out using a manual corroded hand pump
hollow blocks
Water use Domestic, Domestic, Domestic Domestic Domestic, Domestic drinking water drinking water during summer
drinking water
Physical characteristics
Temp (°C) 26.20 26.6 25.6 25.80 27.50 26.10
Salinity (%) 19.3280 36.6720 18.0512 18.7648 34.7328 41.4208
TSS 4 4 8 <2.5 <2.5 8.00 Electric Cond. (mS/cm) 302.00 573 282.05 293.20 542.70 647.20 Turbidity
(NTU) 5 2.27 0.46 7.11 7.19 0.65 1.63
Color (apparent, 10 PCU)
<3 <3 8 8 <3 5
TDS 500 197.40 382.5 181.8 189.90 360.60 435.30
Inorganic and nonmetallic constituents
pH
ORP (mV)
Nitrogen (as
NO₃¯)
Phosphorus
(as PO₄³¯)
Organic and biological constituents
Dissolved 20
TA 8196-PHI: Angat Water Transmission Improvement Project
36
<1.1 >23
<0.3
>23
0.3
>23
0.3
>23
0.3
>23
<0.3
>23
0.3
0.02
<0.001
<0.001
<0.001
<0.001
<0.001
<0.001
0.05 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 0.003 <0.003 <0.003 <0.003 <0.003 <0.003 <0.003
0.05* <0.003 <0.003 <0.003 <0.003 <0.003 <0.003
<0.02 <0.02 <0.02 <0.02 <0.02 <0.02
0.01 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001
0.4 <0.02 <0.02 0.38 0.38 0.38 0.38
0.001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 0.02 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
<1.0 <1.0 <1.0 <1.0 <1.0 <1.0
5.0 <0.02 <0.02 <0.02 <0.02 <0.02 <0.02
Initial Environmental Examination – Output 2
Parameter, mg/L (unless stated)
Adopted criteria (DOH DAO 2007- 0012)
GW 1 GW 2 GW 3 GW 3A GW 4 GW 5
Project segment location Fecal coliform
Segment 2
Segment 4
Segment 5
Segment 6
Segment 7
Segment 7
(MPN/100mL) <1.1 >23 1.1 >23 >23 16 >23
Total coliform (MPN/100mL)
Oil and grease
Heavy metals
Antimony (Sb)
Arsenic (As)
Cadmium (Cd)
Chromium (hexavalent, Cr(VI))
Copper (Cu)
Lead (Pb)
Manganese
(Mn)
Mercury (Hg)
Nickel (Ni)
Vanadium (V)
Zinc (Zn)
*Chromium (total) maximum value. No value on hexavalent chromium
4.6 Ecological Resources
Flora and fauna surveys, including river ecology survey, have been carried out to characterize the
project location in terms of ecological resources for each of the segments discussed in Section 1 of this
report. Segments 1‐7 are initially delineated as the direct impact areas. Considerable survey effort was
done in Segment 1 at Ipo dam site and Segment 7 at Bigte where the intake and outlet structures will be
constructed; and temporary site for CWA and temporary spoil disposal site.
4.6.1 Protected Areas
The MWSS tunnel ROW at the Ipo dam segment lies within the indicative boundaries11 of the Angat
Watershed Forest Reserve and the Angat Watershed and Forest Range (Pilot) in the Ipo watershed. The
Angat Watershed Forest Reserve, which covers about 55,707ha, is managed by National Power
Corporation12 while the Angat Watershed and Forest Range and the Ipo watershed are managed by
MWSS13. The Angat Watershed Forest Reserve and the Angat Watershed and Forest Range are
11 The boundaries of the watersheds are in the process of validation according to DENR‐Protected Areas and Wildlife
Bureau
12 The Angat Watershed Forest Reserve was proclaimed a watershed forest under Proclamation 71 dated 27 March
2010.
13 The Angat Watershed and Forest Range (Pilot) was proclaimed a watershed forest reserve under Proclamation
TA 8196-PHI: Angat Water Transmission Improvement Project
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Initial Environmental Examination – Output 2
considered protected areas under Republic Act (RA) 7586, which is the National Integrated Protected
Area System (NIPAS) Act14.
4.6.2 Terrestrial Ecology
4.6.2.1 Vegetation Survey
A vegetation survey was undertaken in the study area using the quadrat method of sampling to
characterize the vegetation cover in the project site. The vegetation survey details are presented in
Appendix 3. Vegetation inventory and biodiversity assessment was done. Quantitative structure
analysis was performed to determine the density of the individuals, basal area, and occurrence
frequency and importance value of each species in the community. Further computations were also
undertaken to determine the diversity of the community using species richness (SR), Shannon‐Wiener
diversity index (H’) and evenness index (J) as discussed in Kent and Coker (1992).
4.6.2.2 General Vegetation Description
Habitats in Segments 1 to 7 are a combination of brushland and agro‐ecosystems, dominated by
common fruit trees such as mango, santol, caimito and banana, interspersed by residential houses and
other built‐up areas such as community infrastructure sites. A complete record of flora inventory is
presented in Appendix 2. Segment 1, where the intake structure and temporary CWA will be located,
is within the boundaries of the Angat Watershed and Forest Reserve, which is a protected area and the
site where inlet structure will be located. Hence, a more detailed survey was carried out.
In Segment 1, a total of 75 species were recorded, of which 38 were classified as trees, 16 shrub
species, 20 herbaceous species and 1 bamboo species as shown in Appendix 2. From the total, 18 are
agricultural crops and the rest are brushland species with two to three species forest/timber species. Of
the tree species, 12 are agricultural crops and the rest of the trees are pioneer species common in
brushland and other secondary vegetation.
The vegetation in Segment 1 is co‐dominated by bamboo known as buho alongside with agricultural
crops like mango, coconut, banana and caimito and some other tree pioneers associated with secondary
vegetation such as binunga and alagasi. Some forest trees like Taluto (Pterocymbium tinctorium), a
medium diameter tree, were also recorded but only a few were found.
In Segments 2 to 7, a total of 69 species were recorded, of which 44 were classified as trees, four shrub
species, 18 herbaceous species and three bamboo species. From the total, 20 species were either
agricultural crops (17 species) or tree plantation crop (three species).
As the area is an agro‐ecosystem type, the vegetation is expectedly dominated by agricultural crops
like mango, coconut, banana and caimito. The areas under fallow and currently non‐cultivated areas
are dominated by brush and weed species such as alim, binunga, hagonoy and dita, among others.
391 dated 30 April 1968. It covers about 6,600 ha.
14 Protected Areas and Wildlife Bureau, Technical Bulletin No2013‐01 dated January 10,2013
TA 8196-PHI: Angat Water Transmission Improvement Project
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Initial Environmental Examination – Output 2
4.6.2.3 Quantitative Structure: DBH, Basal Area, Density and Importance Value
The Bigte area and Ipo dam site, where most of the construction activity would be located (including
the construction camps, tunnel portals, and spoil disposal areas), are vegetated with large trees.
Elsewhere the vegetation is characterized by open, cultivated or brushland habitats.
The highest recorded diameter at breast height (DBH) at Ipo dam site is 85cm while the lowest is 5cm.
A tree locally called kupang (Parkia roxburghii) of family Fabaceae (narra family) has the highest
diameter. Among the tree species with the lowest diameter is niog‐niogan (Ficus pseudopalma) of family
Fabaceae (Fig family), which is common in secondary semi‐open vegetation. Most trees at the Ipo dam
site have a DBH of at least 15cm with some of them reaching above 40cm DBH.
Basal area is the area of land covered by the trunk of individual trees. It is computed from the values of
DBH and summed per species. Density is the number of individuals in a defined area. It is also an
objective measure of abundance. The total basal area of trees in Segment 1 is low at 11.25sqm per
hectare of land. The density of trees (5cm and up in DBH) in Segment 1 is low at 305 individuals per
hectare, on average.
The Segment 1 vegetation is dominated by local bamboo species called buho, along with other
agricultural crops such as coconut and mango, and open‐loving species like kupang, dita and tibig.
Among other species recorded in the section, buho, a local bamboo species, registered the highest
importance value of 38.5% with density of 33.3 clumps per hectare (with around 30 to 50 culms per
clump), basal area of 2.32m2/ha and appeared in six of the 12 plots. Among the trees with the lowest
importance value (IV) are pioneer species Bridelia and Mallotus, each registered with only 1.9 IV due
to their lowest density, basal area and frequency of occurrence.
In the proposed Contractor’s work are in Bigte, the trees are dominated by mature individuals of rain
tree (Samanea saman), locally known as akasya, an introduced/exotic species. Also, in Bigte Contractor’s
work area there are some 67 trees/ha. The DBH of trees ranges from 5cm to 84cm with an average of
38cm. Majority trees in the area are mature with 61% of them having a DBH of above 20cm. The basal
area of standing trees is 11.19m2/ha.
Figure 13: Raintree and Mahogany-Dominated Vegetation in Bigte Proposed as Contractor’s Work Area
At the Bigte tunnel outlet, the average DBH of trees is a high of 28.2cm due to large raintree (akasya)
and balete individuals. The DBH ranges from 8cm to above 60cm. The nine individuals of raintree in
the area have DBH range from 55cm to 82cm. The basal area of trees in the site is 14.4m2/ha with a
density of 115 trees/ha. The tree is dominated by raintree (akasya) as shown.
TA 8196-PHI: Angat Water Transmission Improvement Project
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Initial Environmental Examination – Output 2
Figure 14: Tree-Dominated Vegetation (Raintree and Balete) in Bigte Tunnel Outlet
Along the tunnel alignment (Segments 2 to 7), the main habitat is an agro‐ecosystem and open area
interspersed with residential houses. Fruit trees such as mango, coconut, banana, santol and caimito
dominate. Other trees include some pioneer trees in the open and areas under fallow such as ipil‐ipil,
alim, aratiles and binunga. The DBH of trees is at most 25cm. The density of trees, albeit mostly are
fruit trees, is estimated to be 30 to 50 trees/ha only.
Figure 15: Brushland Vegetation in Segment 2
Figure 16: Residential Subdivision and Cultivated Area cum Brushland in Segment 3
TA 8196-PHI: Angat Water Transmission Improvement Project
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Initial Environmental Examination – Output 2
Figure 17: Brushland Vegetation in Segment 7 above the Tunnel Outlet in Bigte
The proposed spoil disposal area in Segment 1 is open and dominated by grasses such as cogon,
carabao grass and aguingay and bounded by few pioneer trees such as ipil‐ipil, hawili and binunga
which are at most 12cm in DBH. The trees are estimated as only 15‐20 trees/ha.
Figure 18: Open-type Vegetation in Bigte Proposed for Disposal Area
4.6.2.4 Biodiversity Indexes: Richness, Shannon Index and Evenness Index
Table 16 presents the biodiversity index in the different segments of the study site.
Table 16: Different Segments of the Study Site
TA 8196-PHI: Angat Water Transmission Improvement Project
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Initial Environmental Examination – Output 2
Segment Species richness Shannon diversity
iIndex
Evenness index
Ipo Dam Disposal Area (Segment 1) 17 2.432 0.86
Segment 2 14 2.1 0.83
Segment 3 17 2.28 0.57
Segment 4 26 2.7 0.83
Segment 5 19 2.46 0.84
Segment 6 14 1.98 0.75
Segment 7.Bigte Tunnel Outlet 22 2.6 0.83
Segment 7. Bigte Workers Area 22 2.079 0.67
Segment 7. Bigte Disposal Area 14 1.038 0.39
Mean 18.33 2.185 0.73
The mean Species Richness is 19 while the mean Diversity Index is 2.185 which is low as expected
based on Modified Fernando’s Biodiversity Scale. Some plants recorded are exotic and domesticated
either as agricultural crops or plantation tree species and their associated weeds with low diameter
pioneer trees.
4.6.2.5 Observation on Phenological Stages
Coconuts and santol trees are fruiting alongside with coconuts during the survey time. Local clumps
of bamboo buho in the area are continuously reproducing through the production of shoots.
4.6.2.6 Observed Disturbances
The natural vegetation in the area is highly modified due to human intervention, with many residential
houses and yards with their domesticated plants such as mango, coconut and banana fruit trees and
other cash crops.
4.6.2.7 Threatened Species
One threatened species was recorded such as narra (Pterocarpus indicus) classified as vulnerable by the
IUCN. Three individuals with diameters of 80cm, 221cm and 248cm were found in the MWSS Bigte
Portal.
4.6.3 Wildlife
4.6.3.1 Sampling Sites and Methodology
Wildlife surveys were undertaken for birds, herptofauna, small rodents, bats and arthropods.
Five sampling sites were selected. The first three sampling sites were situated within the vicinity of Ipo
dam, namely: (1) the Contractorʹs Working Area ( the “Consultant”) for the inlet works, (2) the Spoil
Disposal Area (known as Miranda), and (3) Isla Puting Bato. A fourth sampling site was located in the
vicinity of Segments 5 and 6 along the tunnel alignment, and the fifth site is located by the tunnel outlet
at Brgy. Bigte.
In each of the sampling sites, bird census was carried out at predetermined sampling intervals (0600h‐
0900h and 1500h‐1730h) by walking along the 1km to 1.2 km transect lines on established trails. All
bird species seen or heard were noted using the following information: species name, number of
individuals, habitat and elevation, if seen singly or in a group, feeding singly, as a group or in mixed
flocks.
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No standardized method was employed in the survey of herpetofauna. Instead, a wide array of
possible microhabitats (sensu Alcala and Brown, 1998) for frogs and reptiles were examined intensively
for the duration of the fieldwork. Sampling periods were usually conducted in the afternoon and the
rest of the evening, although sampling in the morning was occasionally done after servicing the nets
and traps.
Cage traps were used to capture rodents and shrews. For the ground surface trapping, the traps were
placed in various suitable locations (i.e. under root tangles, in front of burrow entrances, along
runways, and on top of fallen logs). Traps were baited with either live earthworms or fried coconut
coated with peanut butter. All traplines were maintained for three nights. Mistnets were used for
capturing bats and were set on ridgetops, across trails and streams, and at edges of clearing adjacent to
forest.
Wildlife inventory was complied and biodiversity assessment was carried out for birds, amphibians
and reptiles, and mammals. The detail of methodology and wildlife biodiversity assessment is
presented in Appendix 5.
4.6.3.2 Birds
A total of 470 individuals representing 60 species of birds were recorded during transects across the
five sampling sites. At least 33 species are non‐endemic resident breeders, whereas 21 species are
endemic to the Philippines. Also, at least four species are considered as restricted to Luzon Island,
namely: the Luzon Tarictic (Penelopides manillae), scale‐feathered Malcoha (Phaenicophaeus cumingi), red‐
crested Malcoha (Phaenicophaeus supercillosus), and the gray‐backed tailorbird (Orthothomus derbianus).
Most endemic species recorded are strongly associated (with highest abundance) with forest habitats,
especially at Segment 1 (CWA, Site 1), Isla Puting Bato where vegetation is dominated by early to
mature second‐growth forest; these sites have 13 and 12 endemic species, respectively. The proposed
spoil disposal area (Site 2) and Isla Puting Bato (Site 3) have isolated aggregates of early second growth
forest (mostly dominated by pioneer plant species) and expectedly would harbor a substantial number
of endemics as well (nine and seven species, respectively). Segments 5‐6 (Site 4) has only two species of
endemics and the rest of its avian diversity are strongly associated with open habitats.
A total of six species recorded are winter migrants which include the Japanese sparrowhawk (Accipiter
gularis), little heron (Butorides striatus), an unidentified plover (Charadrius sp.), grey‐tailed tattler
(Heteroscelus brevipes), common kingfisher (Alcedo athis), and the brown shrike (Lanius cristatus).
September is usually the onset winter migration for these birds, although there are some species that
are known to come early by July. It is expected that the number of winter migrants will increase with
the coming months (especially in November).
Across the five sites, the Contractorʹs work area at Segment 1 has the highest number of avian species
with 31 recorded species. It also has the highest number of endemics (13) and has all the Luzon
endemic birds. Site 3 has 23 species and an equally high number of endemics (12), and two of the
Luzon endemics. Both sites have predominantly forested habitats. The proposed spoil disposal area
has higher species richness than Site 3 with 26 species but has a lower proportion of endemics, and a
majority of the bird assemblage is associated with open habitats. MWSS Bigte Portal (Site 5) has
relatively low species richness although the presence of seven endemic species is attributed to the
presence of early secondary growth forest within its vicinity. Site 4 has the lowest species richness with
11 species and only two endemics; almost all species are associated with open habitats as clearly
evident in its landscape.
Average diversity index of birds for the five sites is at 2.51. Such modest index is fuelled mostly by the
high indices from CWA at Ipo dam site (Segment 1); Isla Puting Bato and spoil disposal area at Ipo dam
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site, which generally have the similar values (2.82 to 2.91). These sites have the highest diversity index
values, indicative of the high number of species that are concentrated in the vicinity of Ipo dam. As
expected, Segment 5‐6 and MWSS Bigte Portal have the lowest indices, owing mostly to relatively low
species diversity, especially at Segments 5 to 6.
Evenness and dominance index values show a different trend across the five sites. Isla Puting Bato and
Segment 5‐6 sites have highest evenness and lowest dominance indices (Site 3‐0.87 and 0.079; Site 4‐
0.93 and 0.068), which indicate that these sites have a relatively equally distributed abundances among
the species recorded and that numerical dominance is not confined to two or three species. Despite the
high diversity index for Ipo CWA, dominance is relatively high attributed to the numerical dominance
of only one species, the Philippine Bulbul (Hypsipetes philippinus) with 28 individuals. Segments 5‐6 and
MWSS Bigte Portal sites are among the highest in terms of Dominance Index and this is reflective of the
unequal distribution of species abundance.
4.6.3.3 Mammals
From mist‐netting, trapping, ocular evidences, and interviews with local guides, a total of 12 species of
mammals were recorded in all five sampling sites (see Appendix 5). This total comprised of four
species of bats, four species of rodents, one macaque, and one civet. Two mammals species are
considered as endemics, the Musky fruit bat (Ptenochirus jagori), and an unidentified shrew rat of the
genus Chrotomys (captured by hand at Ipo CWA). Five species are considered as residents, including
the three species of bats (Cynopterus, Rousettus, and Tylonycteris), and the macaque Macaca fascicularis
(known to occur at Ipo CWA, Isla Puting Bato and MWSS Bigte Portal), and the Palm Civet
(Paradoxurus hermaphroditus) whose presence was based on fecal matter seen at Sites 1 and 5. The three
invasive pest species recorded were all rodents, and are known to inflict damage to crops, reside in
houses and adjacent vegetation, and carry infectious diseases such as Leptospirosis. Virtually all of
these invasive, pest rodents occur at all the five sampling sites.
Trapping effort of 105 trap‐nights resulted in captures of 11 rodents representing three species; all are
invasive pests. At Ipo dam sites (Sites 1‐3), trapping success were at 10% (Ipo CWA), 20% (Ipo Disposal
Area) and 13% (Site 3). The low capture rates are attributed to the heavy rains during nighttime which
rendered the traps less effective. A total of 16 individuals of bats representing four species were
captured in mist nets. Netting success ranged from 0.72 bat per net‐night (Ipo spoil disposal area) to 1
bat per net‐night, which indicates low capture rates and attributable to nighttime rains.
4.6.3.4 Amphibians and Reptiles
A total of five species of amphibians and seven species of reptiles were recorded within the four
sampling sites. No survey was done along Segments 5 to 6 as effort was concentrated on bird survey.
The lone endemic frog, Platymantis minulus, is a Luzon endemic and usually restricted to forest
habitats; this species was recorded only at Ipo CWA. Two resident frog species, Fejervarya cancrivora
and Polypedates leucomystax, are common inhabitants of open areas and early secondary growth forest.
Two invasive species, Rhinella marina and Kaloula pulchra, are strongly associated with human
habitation and open areas. These two invasive species were present in Sites 1 and 5; it is highly likely
that they are also present in other sites.
The seven species of reptiles are comprised of five residents, and two endemic species. The two
endemics, the agamid Draco spilopterus and the monitor lizard Varanus marmoratus were recorded in
forested habitats, at CWA at Ipo Dam site (Segment 1) and Isla Puting Bato, respectively. All five
resident reptiles are strongly associated with residential, agricultural areas, and occasionally on scrub‐
type vegetation.
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4.6.3.5 Arthropods
Above‐ground sweeping and soil‐litter sampling of arthropods within the project site resulted in a total
of 642 individual arthropods representing 14 orders and 69 families recorded (Appendix 5.8). The most
represented order (in terms of number of member families) were Coleoptera (beetles) and Diptera (flies)
with 15 families each, Lepidoptera (butterflies and moths) and Orthoptera (grasshoppers) with six
families, and Hymenoptera (ants, bees, and wasps) with five families. Much of the total abundance was
attributed to only three orders, which accounted for more than 70% of the total number of recorded
individuals. These were Hymenoptera with 218 individuals, Diptera with 180 individuals, and
Lepidoptera with 73 individuals. Among the most dominant families were Formicidae (ants ‐ O.
Hymenoptera) with 211 individuals, Psychodidae (moth flies ‐ O. Diptera) with 72 individuals, Sciaridae
(fungus gnats ‐ O. Diptera) with 69 individuals, and Nymphalidae (butterflies ‐ O. Lepidoptera) with 35
individuals.
Among sampling sites, the Contractorʹs area had the most number of arthropod orders and families
recorded with 12 and 45, respectively. A total of 198 individuals were captured, of which almost 50%
were psychodid flies and ants. Coleopterans and dipterans were most represented with 12 and 10
families, respectively.
Segment 5 to 6 had 36 families and nine orders, and had the highest number of individuals captured
with 339. Much of the total abundance for this site is dominated by Formicid ants (53%) and fungus
gnats (17%). Hemipterans (hoppers and bugs) were highly represented at this site with nine families.
At least 29 families representing 10 orders were recorded at Brgy. Bigte; nympahlid butterflies were
most numerous at this site with 14 individuals captured. Most represented orders within the site had
relatively even number of families: Orthoptera and Hemiptera with six, Lepidoptera with five, and
Diptera with four families.
Most of the sampling effort was concentrated at the cited sites; sampling at the disposal area and Isla
putting Bato were incidental in nature (i.e. during conduct of bird transects) so that diversity and
abundance numbers at these areas were comparatively sparse.
Above-ground Arthropods
Sampling at above‐ground stratum resulted to a tally of 13 orders, 61 families and 515 individuals
(Appendix 5.8); roughly 80% of all arthropods were recorded in this stratum. Dipterans had the most
number of families represented with 15, whereas coleopterans and hemipterans accounted for 10
families apiece. A substantial proportion of individuals (70%) were hymnenopterans (195), dipterans
(95), and lepidopterans (73). Highly represented orders such as coleoopterans and hemipterans
accounted for only 11% of total number arthropod individuals captured. Computed overall diversity
index (in terms of number of families and their respective abundance) was more or less modest with
2.75 (a value of 3 or higher denotes a high index and thus more diverse). The sampling site within the
Contractorʹs area had the highest diversity index with 3.22, and followed by Brgy. Bigte with 2.98.
Segments 5 to 6 had a low index (1.92), despite having the highest number of families and abundance.
This can be attributed to numerical dominance of only a few families, of which Sciaridae and Formicidae
accounted for more than 70% of the total abundance for the sampling site.
Soil-litter Arthropods
Arthropod diversity was much depressed in the soil‐litter strata (Appendix 5.8). At least half of the
arthropod order, and more than two‐thirds of the families were not recorded. Total abundance and
diversity index were also considerably lower. On the other hand, soil‐litter strata harbor a distinct
arthropod assemblage, of which almost half of the families are exclusive dwellers. These include:
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Anthicidae, Bruchidae, Carabidae, Dermestidae, and Erotylidae‐ all coleopterans, and the psocopterans
(barklice) Lepidosocisdae, Pachytrochidae, and Stenopcidae.
4.6.3.6 Species of Conservation Significance
At least nine species present in the project area were chosen as noteworthy based on several
characteristics: (1) restricted to Greater Luzon Biogeographic Region, (2) listed as globally threatened
by IUCN, and (3) heavily exploited for food or taken as household pets. Five species of birds are
noteworthy of which four are endemic to Luzon (already mentioned) whereas two species are
classified as threatened species. The Luzon Tarictic and the Philippine Eagle Owl (Bubo philippensis) are
classified as near‐threatened and vulnerable, respectively. All of these noteworthy avian species were
recorded at Ipo CWA and Isla Puting Bato.
Two species of mammals, the shrew rat Chrotomys sp. and the long‐tailed Macaque (Macaca fascicularis)
deserve special mention as the former is probably confined within Luzon (as most of its congeners are),
and that the latter is heavily hunted either as food or as pets. The long‐tailed Macaque is also listed in
the CITES.
Platymantis mimulus is known only from a very few localities on Luzon Island. It is a poorly known
species, with information on ecology, reproduction, and population severely lacking. The monitor
lizard Varanus marmoratus is heavily hunted across its known distribution.
4.6.4 Freshwater Ecology
4.6.4.1 Sampling Sites and Methodology
Sampling sites of the aquatic ecology cover two general areas that are perceived to be the ‘impact’ areas
of the proposed project: (a) within the vicinity of Ipo dam where the intake channel would be located
and (b) within the vicinity of Bigte river where the exit tunnel construction would be located. In each of
these sites a 50m stream length was designated as the sampling area. These sampling sites are
presented in Table 17.
An initial sampling activity was done in the first and third week of August 2013. It should be noted
that the sampling regimes were conducted during the “rainy” season of the year, with typhoon
“Maring” occurring in between the two sampling periods, bringing heavy rains even up to the second
sampling period.
Table 17: River Ecology Sampling Stations
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Sampling sites Date / Time General Remarks
Site 1. Ipo Dam upstream (IPO4 in map)
8/23/2013;
1050h
Sampling after storm Maring; cloudy; with few hours of sunlight in the morning but with light to heavy rains in the late afternoon and evening.
Sampling about 100m from the Angat spillway; depth about 3m; molluscan fauna are lesser in number; stone and rocks with few insects; 50m downstream with stony muddy substrate; reported by fishermen - tilapia, carp, kanduli, biya, halfbeaks, gourami.
Site 2. Ipo Dam midstream (IPO2 in map)
8/23/2013;
1220h
Banks with generally good vegetation cover but with one area observed to be recently eroded; with human habitation in relatively flat areas.
Site 3. Ipo Dam Infrastructure site (IPO1 in map)
8/23/2013;
1350h
Banks with infrastructure generally with good vegetation cover; proposed tunnel inlet site.
Site 4. Ipo Dam below dam (IPO DS1 in map)
8/23/2013;
1520h
Substratum stony-rocky with boulders; water murky; with about 50m.
Site 5. Bigte River tributary (SW Bigte 1 in map)
8/23/2013;
0850h
Small stream in the old seedling site of MWSS; stream joins Bigte River about 15m downstream; gravel-sand-mud substrate; proposed tunnel outlet site.
Site 6. Sta. Maria River
8/23/2013;
1130h
Santa Maria River underneath bridge in San Jose del Monte in Bulacan; Bigte River is a tributary of this channel.
Site 7. Angat River in the Municipality of Angat
8/23/2013;
1530h
Main channel of Angat River in Angat town.
The riparian, channel and environmental (RCE) inventory has been developed to assess the physical
and biological condition of small streams in the lowland and agricultural landscape. It consists of 14
characteristics which define the structure of the riparian zone, stream channel morphology, and the
biological condition in both habitats. The scoreboard is presented in Appendix 4 for the conditions in
the site up to 50m upstream and downstream of the recorder. The RCE was developed for flowing‐
water streams.
Zooplankton and phytoplankton samples were collected from the water column using plankton net of
60μm mesh size. Approximately 50L water was collected, mostly from slow‐moving sections of the
stream. Samples were immediately placed in plastic leak‐proof bottles, and preserved in 70% ethyl
alcohol.
Plankton identification and counts were determined in the laboratory. Each water sample was tapped
with additional water to make 10ml. From this 10ml sample, a 1ml sub‐sample was taken after
thorough mixing for plankton identification and counts.
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Where the substratum was composed of stones, attached algae were scraped off using a plastic brush
with very pliable bristles, from a 10m riverbank transect for an approximate total of 1m2 of surface area
of stones and other suitable substrates (leaf litter, wood, etc). In sandy or muddy substrates,
approximately 1m2 (cumulative) of substrate (taken 1‐inch deep) was passed through a 1mm sieve.
Insects are also often used as biological indicators of disturbance. Thus, the presence of disturbance‐
sensitive organisms like plecopterans, ephemeropterans, trichopterans, riffle beetles, blackfly and
cranefly larvae, may be indicators of relatively good water quality.
A locally made electro‐fishing gear was used in the study. In each site, an approximately 30m length of
the stream was subjected to electro‐fishing in wadable sections of the river. Fish samples were
immediately preliminarily sorted, identified, and preserved in ice.
The prevailing stormy weather condition at the times of sampling most probably hindered the
collection effort for fish samples for eco‐toxicological analysis. Thus, only five species were used for the
analysis. These are Arius dispar (kanduli), Glossogobius giuris (biya), Channa striata (dalag), Oreochromis
niloticus (tilapia), and Labeo rohita (karpa). These species are edible and reported to be common in Ipo
dam.
4.6.4.2 Riparian Channel Evaluation (RCE)
The RCE scores at the Ipo river sites and the Channel at Bigte are presented in Appendix 4.2. Since no
existing RCE can be used for comparison, the data provide a baseline against which the effect of new
development activities can be assessed.
The use of the RCE in the Philippines is not yet extensively used and well studied. Even the ratinale of
the scoreboard has not yet been evaluated within our own country setting. It is included in the IEE not
so much as a definitive test of “quality” but more for the search of “quality standards” and monitoring
changes within a stream for long periods of time.
4.6.4.3 Freshwater Biota - Plankton
The plankton catch in all the sites is almost nil. Only a few nauplius larvae were collected from the
midstream portion of the Ipo dam lake. It is possible that the intense precipitation has diluted much the
plankton density in the sampling sites.
4.6.4.4 Freshwater Biota - Macro-benthos
Insects
No insect larva was collected in the suitable environments. Macrobenthic insects usually prefer a hard
substratum. The conditions in the dam sites do not generally satisfy this requirement. With the large
quantity and the turbidity of water, this becomes a stressful environment for aquatic macro‐benthic
insects. In the river sites, the increase flow and volume of water can easily displace these organisms
from their habitat.
Molluscs
Collected molluscs are typical and comparable to those found all over the Philippines. Of the
molluscan species collected, Brotia asperata and Corbicula manilensis are also collected for table
consumption by the locals.
Table 18: Mollusc Diversity Index
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Sites Index Evenness Richness
Site 1-3 Angat river 1.673 0.934 6
Site 4 downstream of Ipo dam 1.026 0.637 5
Site 5 Bigte river 0.687 0.625 3
The lake waters present the most favorable environment for the molluscs, among the three sites
compared. The neritid Clithon corona is characteristic of relatively clean river waters, and they are
abundant in Site 4. In the river environment of Site 5, this species was not present in the collection site
sampled. This species may be a good indicator of relative disturbance for assessing the project impact.
A cluster dendrogram for molluscan similarity of the sites (UPGMA clustering; Jaccard’s similarity
index) was presented below. Jaccard’s similarity index takes into consideration only the presence or
absence of the species. This indicates that mollusc population at Ipo reservoir is the same with the
mollusc population downstream of the Ipo dam.
Figure 19: Angat River Mollusc Dendogram
Macro-crustaceans
The shrimp and crab fauna are still relatively species poor with only four genera present,
Macrobrachium, Atyopsis, Caridina, and Varuna. Almost all taxa were present in the sites where fish
sampling was also done. The catch is small, just about 100g.
4.6.4.5 Freshwater Biota - Fish Fauna
Fourteen species of fishes were collected from the sites. More species were collected in the lake waters,
with the predominance of tilapia and ayungin in the catch. Because of the unfavourable weather
conditions, a less than systematic sampling could only be done.
Table 17 shows the fish diversity index of the three sites above.
Table 19: Fish Diversity Index
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Sample Index Evenness Richness
Sites 1-3 Angat river 2.104 0.878 11
Site 4 Ipo dam downstream 2.101 0.819 13
Site 5 Bigte river 2.062 0.895 10
The lake water (Sites 1‐3) has the highest diversity index although only 11 species were collected. Site 4
was second, but was richer in two more species. The lowest species richness was found at Bigte with 10
species, but the differences are small. Cluster analysis was done to assess site similarity and the result
was given in the dendrogram in Figure 20 below.
Figure 20: Angat River Fish Dendogram
The Ipo lake area and the portion of Angat river below the dam structure are about 70% similar in the
presence or absence of a specific fish species.
4.6.4.6 Ecotoxicological Studies
Fish samples were sent to laboratory for heavy metal testing. Only the flesh of the fish was tested for
arsenic, cadmium, chromium, lead, mercury and selenium. Results show that only mercury was above
the acceptable limit in most of the fish samples (except for tilapia from Angat river upper reach).
Table 20: Heavy Metals in Fish
Sample code AT4-F1 AT4-F2 AT4-F3 AT4-F4 AT5-F5 fish species (Common Test Reporting
name) method limits Unit
Kanduli Biya Tilapia Carpa Dalag
Sampling site
Angat upstream
Angat upstream
Angat upstream
Angat upstream
Bigte
Arsenic Gaseous
hydride AAS 0.01
mg/kg
ND
ND
ND
ND
ND
Cadmium Flame AAS 0.02 mg/kg ND ND ND ND ND
Chromium Flame AAS 0.05 mg/kg ND ND ND ND ND
Lead Flame AAS 0.1 mg/kg ND ND ND ND ND
Mercury Manual cold vapor ASS
0.005 mg/kg 0.2 0.06 ND 0.2 0.2
Selenium Gaseous
0.005 mg/kg ND ND ND ND ND hydride AAS
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4.6.5 Summary Description of the Project Segments
Table 21 has the description of the environment in every segment from Ipo dam site to MWW Bigte
portal.
Segment 1 (Ipo dam site) is a forest zone. It is also in a build up zone of the Ipo watershed controlled
zone. It is a part of a protected area, the Angat Watershed Forest Reserve (55,000ha managed by NPC),
Angat Watershed and Forest Range (Pilot)/Ipo Watershed managed by DENR and MWSS. There are no
physical cultural resources found in this segment. About 49 structures were found at 60m ROW. The
depth of the tunnel is about 100m to 200m in the basalt rock formation at this segment. The segment is
covered with tree‐dominated vegetation, mostly domestic trees but has low diversity. No endemic
vegetation species was found. There is a moderate diversity in wildlife. Groundwater quality must be
within DENR standards. Results in surface water have shown that coliform counts were reported at the
confluence of Sapang Munti and Ipo and downstream of the dam past the community site. The air
quality should also be within DENR standards.
The CWA for the construction of the inlet structure will be located at Segment 1 which is about 1ha.
The CWA includes material storage, workers’ cam. An existing dirt road down the hill and finally to
the intake structure site can be used during the construction phase.
Figure 21: Project Segments
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Figure 22: Location of the Inlet and Associated Works
TEMPORARY SPOIL DISPOSAL AREA
CONTRACTOR’S WORKERS’ AREA
Segment 2 (San Mateo Rolling Terrain) is located in a residential zone, forest zone and forest buffer
zone. It is found within the indicative boundary of Angat Watershed Forest Reserve. A total of 18
infrastructure were found within the 60m ROW. The tunnel will traverse basalt and sediment rock
formation at about 125mbg to 200mbg. Segment 2 vegetation was dominated by brushland. No
endemic vegetation species was found. This segment has low to very low vegetation diversity and low
wildlife diversity. No endemic wildlife species was found. The groundwater and surface water qualities
must be within the DENR standards and air quality.
Segment 3 (AFP housing) is located in a forest buffer zone. It was not a part of protected area and no
physical cultural resources were found on this segment. A total of 201 infrastructure, mostly housing
units of the AFP subdivision, were identified within the 60m ROW. The tunnel traverses sediment and
volcanic rock formation at about 100mbg to 125 mbg. This segment is covered by residential,
subdivisions, cultivated area and brushland. It has low to very low vegetation diversity and low
wildlife diversity. No endemic wildlife species were found. Groundwater and surface water qualities
must be within the DENR standards and air quality.
Segment 4 (Grassland) is located in a forest and residential buffer zones. The barangay cemetery is
located 300m away from the tunnel ROW. A total of eight infrastructure were found within the 60m
ROW. The tunnel traverses Alagao volcanic rock formation at a depth of about 100m to 125 m. The
vegetation in this segment comprises of grassland and brushland. This segment has low to very low
vegetation diversity and low wildlife diversity. No endemic wildlife species was found. Groundwater
and surface water qualities must be within DENR standards and air quality.
Segment 5 (Road ROW) is located in residential and agricultural zones. It is not a part of a protected
area. No physical cultural resources were found near this segment. A total of 13 infrastructure were
found within the 60m ROW. The tunnel depth is about 100m to 125m and traverses Alagao volcanic
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rock formation. Segment 5 vegetation comprises of grassland and brushland. This segment has low to
very low vegetation diversity and low wildlife diversity. Groundwater and surface water qualities must
be within DENR standards and air quality.
Segment 6 (Grassland) is located in a residential and agricultural zones. It is not a part of a protected
area. No physical cultural resources identified near this segment. A total of 12 infrastructure are within
the 60m ROW. The tunnel depth is about 50m to 100 m and traverses Alagao volcanic rock formation.
This segment is dominated with grassland and brushland. This segment has low to very low vegetation
diversity and low wildlife diversity. No endemic wildlife species were found. Groundwater and surface
water qualities must be within DENR standards. The elevated noise level is observed at 19:00 to 21:01.
Segment 7 (Brgy. Bigte) is located in residential, agricultural zone and quarry zone. Pinagrealan Cave is
about 450m away from tunnel ROW. It is considered tourist attraction and historical landmark in
Norzagaray. There are about 23 infrastructure found within the 60m ROW. The tunnel depth is about
20mbg to 50 mbg and traverses volcanic and limestone rock formation. This is the outlet location and
the area is dominated by rain tree and mahogany while the proposed disposal area is dominated by
open‐type vegetation. This segment has low to very low vegetation diversity. Endemic species found is
narra (Pterocarpus indicus). There is moderate wildlife diversity in this segment. Groundwater quality
must be within DENR standards, while results in surface water have shown a high coliform measure.
Elevated noise level is observed at nighttime between 19:00 to 21:00.
Figure 23: Location of the Outlet Structure
TEMPORARY SPOIL DISPOSAL AREA
CONTRACTORS’ WORK AREA
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Table 21: Summary Description of Tunnel Segments
Segment
description 1
2
Ipo dam site San Mateo rolling
terrain
3
AFP housing
4
Grassland
5
Road ROW
6
Grassland
7
Bigte
Land use based on Forest zone; built Residential zone, Forest buffer zone Forest buffer zone. Residential zone, Residential zone, Residential zone, CLUP up zone of the IPO forest zone, forest Residential zone agricultural zone agricultural zone agricultural zone,
watershed buffer zone quarry controlled zone
Protected area Angat Watershed Indicative None None None None None Forest Reserve boundary of Angat (55,500ha Watershed Forest managed by NPC), Reserve Angat Watershed and Forest Range (Pilot)/ Ipo
Watershed
managed by DENR and MWSS
Physical cultural None None None ROW is 300m None None 450m away from resources away from Pinagrealan Cave
cemetery Infrastructure (60m 49 18 201 8 13 12 23 ROW) Tunnel depth (mbg) 100-200 125-200 100-125 100-125 100-125 50-100 20-50
Rock formation at ROW Basalt 25%basalt; 75% 70% sediment; Alagao volcanics Alagao volcanics Alagao volcanics 20% volcanics; sediments 30% volcanic 80% limestone
Vegetation cover Tree-dominated Brushland Residential Grassland and Grassland and Grassland and Rain tree and vegetation mostly vegetation subdivision, brushland brushland brushland mahogany - domesticated trees cultivated area and vegetation vegetation vegetation dominated brushland vegetation in Bigte; Open type vegetation in the proposed disposal area
Vegetation diversity Low diversity Low to very low Low to very low Low to very low Low to very low Low to very low Low to very low diversity diversity diversity diversity diversity diversity
Endemic vegetation None None Narra (Pterocarpus species indicus)
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Initial Environmental Examination – Output 2
Segment description
1 2
Ipo dam site San Mateo rolling
terrain
3
AFP housing
4
Grassland
5
Road ROW
6
Grassland
7
Bigte
Wildlife diversity Moderate diversity Low diversity Low diversity Low diversity Low diversity Low diversity Moderate diversity
Endemic wildlife species Macropygia tenuirostris (Brown cuckoo dove), Phapitreron leucotis (White- eared brown dove), Bolbopsittacus
lunulatus (Guiabero), Phaenicophaeus cumingi (Scale- feathered malkoha), Phaenicophaeus superciliosus (Red- crested malkoha), Collocalia
troglodytes (Pygmy Swiftlet), Penelopides manillae (Tarictic hornbill),Dendrocop os maculatus (Philippine Woodpecker), Hypsipetes philippinus (Philippine bulbul),
Dicrurus balicassius (Balicassiao), Copsychus luzoniensis (White- browed shama), Orthotomus derbianus (Grey- backed tailorbird), Phylloscopus
cebuensis (Lemon- throated leaf- warbler), Sarcops calvus (Coleto),
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Initial Environmental Examination – Output 2
Segment description
1 2
Ipo dam site San Mateo rolling
3
AFP housing
4
Grassland
5
Road ROW
6
Grassland
7
Bigte terrain
Dicaeum australe (Red-keeled Flowerpecker)
Water quality Groundwater Within DENR Within DENR Within DENR Fecal coliform Within DENR Within DENR Within DENR
standards standards standards reported standards standards standards Surface water Coliform counts Within DENR Within DENR Within DENR Within DENR Within DENR High coliform
reported at the standards standards standards standards standards measure reported confluence of Sapang Munti and Ipo; and downstream of the
dam past the
community site Air quality Within DENR Within DENR Within DENR Within DENR Within DENR Elevated noise Elevated noise
standards standards standards standards standards level observed at level observed at 19:00 - 21:01 19:00 - 21:00
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Initial Environmental Examination – Output 2
4.7 Economic Development
4.7.1 Land Use
The Ipo dam area (Segment 1) is within the watershed area and considered a protected area. This zone
is classified as forest zone based on the CLUP of the Municipality of Norzagaray. Segment 1 area is
within the built up zone of the Ipo watershed controlled zone. The rest of the segments of the tunnel
alignment and project components are within forest buffer, residential and agricultural zones.
4.7.2 Infrastructure Facilities
The infrastructure facilities at Brgys. Bigte and San Mateo include the MWSS tunnel 1, 2 and 3, Ipo
dam and related infrastructure. The Ipo road, which links the MWSS Bigte portal and Ipo dam site, is a
national road maintained by DPWH.
The AFP housing subdivision is being
developed in Segment 3 (near San Mateo
Barangay Hall). An area of the
subdivision traverses the MWSS tunnel
ROW. Defects in the housing units were
already observed during the ocular
survey of the tunnel ROW and prior to
any construction activities of Tunnel 4.
4.7.3 Transportation
Figure 24: Defective Housing Unit of AFP Subdivision in Segment 3
The means of transport at Bigte and San
Mateo are jeepney and tricycle travelling
along Ipo road. Some barangay roads are
paved especially the ones connecting to the national road. There are about 7km barangay dirt roads of
San Mateo and Brgy. Bigte. These roads are muddy and often not passable by vehicle during wet
season. Private vehicles of communities and transport services of the MWSS, CPF (transport service of
MWSI and MWCI) are the common Ipo road users.
4.7.4 Power Sources and Transmission
Communities in the watershed have very limited or no power sources. Some communities rely on the
solar power units installed in the communities. Most of these, however, are no longer operational. The
Bulacan Bulk Water Project is currently being planned by the MWSS and Manila Water to supply the
needs of the municipalities of the Province of Bulacan.
4.7.5 Agricultural Development, Mineral Development, and Tourism Facilities
Segments 2 to 6 are mostly rain‐fed agricultural land. Quarry for limestone and Pinagrealan Cave is
located at Segment 7. The quarry area is the site where Spar Corporation and La Farge Cement
Company are operating. The Pinagrealan Cave, about 450m away from the Tunnel 4, is considered a
tourist attraction in Norzagaray.
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4.8 Social and Cultural Resources
4.8.1 Population and Communities
The Municipality of Norzagaray, where the water transmission line (Tunnel 4) will be constructed, is in
the southeast of Bulacan bordering the Municipality of Montalban, Rizal Province. It is bound on the
north by the Municipality of Doña Remedios Trinidad, by the Municipalities of Angat and Sta. Maria in
the west and by the City of San Jose del Monte in the southwest. It is part of the third congressional
District of Bulacan together with Angat, San Rafael, San Ildefonso and San Miguel, all on the eastern
side of Bulacan.
More than one‐third of the municipality‘s land area is within Angat watershed that was delineated
through Proclamation 71 dated 10 March 1927 covering a total area of some 62,310ha of the Sierra
Madre Mountain Range in the Province of Bulacan and Nueva Ecija. The Angat and Ipo dams are
located in the watershed boundary. The dams are notable for being a major water and power supply for
Metro Manila.
Ipo dam is located downstream of the Angat Multi‐purpose Dam below the confluence with the Ipo
river. Proclamation No.391 (April 30 1968) transferred the administration and management of the Ipo
dam watershed from NPC to MWSS and DENR. The management includes the regulation of
occupancy and use of the watershed forest reserve, cutting, collection, and removal of timber and other
forest products within the watershed in accordance with forest laws and regulation.
Norzagaray belongs to the third district of Bulacan and is classified as 1st class municipality.15 It has a
total land area of about 288.52km² (Table 22).
Table 22: Municipal Profile of Norzagaray, Bulacan
Founded 1857
Total of barangays 13
Total area 288.52km²
Population 2010 103,095
Density 360 km²
District 3rd
District
Income class 1st Class
Regional classification Region 3
At present, Norzagaray is divided into 13 barangays with an estimated total land area of some
30,819ha, excluding some 1,607ha contested with Doña Remedios Trinidad and San Jose del Monte.
Brgy. San Mateo is the second largest in terms of land area representing 24.13% while Bigte is the 9th
largest representing 1.89% of the total municipal land area.
15 Municipalities in the Philippines are divided into income classes according to average annual income during the
previous four calendar years. First class municipality has an average annual income of 55M Php or more.
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Year Population
1995 51,015 2000 76,978 2007 105,470 2010 103,095
Initial Environmental Examination – Output 2
Table 23: Population/Growth Rate of Norzagaray, Bulacan
±% p.a
- 8.58 4.60 -0.76
Between 1995 and 2007, the municipal population was more than double. This was the result of the
relocation programs of the national government, the populations of Brgys. Tigbe and Bitungol
increased rapidly between 1995 and2000 primarily due to migration toward the resettlement sites of
North Village Housing (NVH) and Friendship Village Resources (FVR). On average, 2,226 persons
annually relocated into Norzagaray between 2000 and 2007. This caused undue burden for the local
government unit (LGU) to provide for the increase demand for social services and facilities.
Norzagaray is a net in‐migration area from 2000 to 2007 (NCSO/Municipal Civil Registrar Office). In
2010, however, population slightly decreased due to out‐migration.
Indigenous peoples (IP), known as Dumagats, reside in the mountains of Norzagaray, particularly in
San Mateo and San Lorenzo. About 367 IPs live in San Mateo while 8 IPs live in Bigte.
Currently, CADT application of the Dumagats of Brgy. Kabayunan, Municipality of Dona Remedios
Trinidad Bulacan, Brgys. San Lorenzo, San Mateo and San Isidro, all in the municipality of Norzagaray
Bulacan is being processed by the NCIP regional office. Social preparation activities were already
undertaken as of November 2013 and delineation of the claimed ancestral domain is being prepared. A
total of 593 families are claiming CADT ownership. About 209 families from Sitio Ipo, 13 families from
Sitio Paco , 48 families from Sitio Anginan/Santol and 53 families from Sapang Munti, all from Brgy.
San Mateo, Norzagaray Bulacan are included as CADT claimants.
The Karahume Ancestral Domain Sustainable Development and Protection Plan (ADSDPP) was
completed in December 2008 and endorsed by the Sangguniang Bayan of Norzagaray on 20 July 2009.
The ADSDPP of Karahume envisions, “to have a peaceful, progressive, environment friendly and self‐
sustaining Dumagat community wherein human rights is respected by the state and the rights for
better education, good health, better livelihood programs is guaranteed by government.”
The ADSDPP implementation, covering about 1,145ha targeted as mix land use, faces crucial
challenges due to multiplicity of land tenure instruments over portions of the CADT, of which portions
of the CADT fall within the proclaimed forest reserves of the MWSS and NPC (Presidential
Proclamation Nos. 391 and 599 and a CBFM issued by DENR). The mixed land use includes (i)
agricultural (351ha), (ii) cemetery (2ha), (iii) communal forest (303ha), (iv) eco‐tourism (7ha), (v)
pasture land (59ha), (vi) reforestation (782ha), (vii) residential (81ha), and (viii) sanctuary (232ha). The
other issues include the intrusion of the non‐IPs upland farmers and trading of land rights over
portions of CADT.
At present, in addition to the Karahume CADT, the Dumagats have applied CADT for the entire Angat
Watershed and Forest Reserve, including the portion of the project site – Segment 1.
There are significant number of laborers and unskilled workers among the employed persons,
followed by trade and related workers, plant and machine operators and assemblers, farmers, forestry
workers and fishermen. With the increase of the construction activities in the area due to Tunnel 4
construction, including the increased requirement of the cement factories and their respective quarry
sites, the inadequacy of livelihood and employment opportunities were given a boost and this included
the resettled families in the area. Skills training, capability building and financial assistance were
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Initial Environmental Examination – Output 2
provided to the new settlers and several women were trained in rag‐making which grew into a
livelihood opportunity for the residents.
Norzagaray, being a first class municipality, generates more than half of its revenue from local
business locators, quarrying and cement manufacturing, including hydropower plant and other
industries. Less than 40% come from Internal Revenue Allotment (IRA) from the national government.
4.8.2 Health Facilities
Primary health services are provided to Norzagaray residents through a network of a municipal
hospital and two rural health units. This is complemented by six privately operated health facilities.
The Norzagaray Municipal Hospital is located in Brgy. Poblacion and is being operated by the
municipal government and also caters for the primary health care needs of neighboring municipalities.
In terms of water access, only 66.45% have access to safe water in Bigte and 28.45 % in San Mateo. The
Bulacan Bulk Water project is currently being planned by the MWSS and Manila Water to supply the
needs of the municipalities of the Province of Bulacan.
Table 24: Percent Households by Type of Water Facility Used (San Mateo)
Water facility type
Household (%)
Community Water System (WS) owned 35.55 Community WS shared 19.59
Deep well owned 3.56 Deep well Shared 16.11
Dug/Shallow well owned 1.08
Dug/Shallow well shared 4.11
River, stream, lake, spring bodies of water 10.24
Bottled water 6.3
Others 1.50
Total 100.00 Source: CBMS 2006 results
4.8.3 Education Facilities
The municipality provides the basic primary high school and a municipal college for its constituents.
Pre‐school and day‐care and kindergarten are operated in each barangay of the municipality.
4.8.4 Socio‐economic Conditions
The local economy is dominated by the service sector, followed by industry, and then the agriculture,
fishery and forestry sector. Table 25 shows the distribution of employment by sector.
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2.47 322 9.27
5.25 853 4.6
Bulacan Norzagaray
Municipality (%) Prov Sector (%)
12.40 12.43 3.27
27.26 29.21 3.50
60.34 58.36 3.16 100.00 100.00 3.27
Initial Environmental Examination – Output 2
Sector
Table 25: Sectoral Distribution of Employment CY 2000, Bulacan and Norzagaray
Agricultural, Fishery, and Forestry
Industry
Services
Total
Source: CLUP Norzagaray/National Statistics Office (NSO)
The contribution of the mining sub‐sector in the industry is significant and slightly higher in
Norzagaray than the province. However, it may be seen that the total employment share of Norzagaray
is a mere 3.27% of the province. The high location quotient is due to the accessibility of the quarry areas
and establishments of the three large cement manufacturing plants (Republic cement, Holcim and La
Farge) contribute to this comparative advantage. In addition, it has also exhibited and continues to
exhibit an advantage compared to the other municipalities of Bulacan in electricity, gas and water,
construction and wholesale and retail trade. This is due to the continuing operation of NPC’s Angat
Dam Hydro Electric Power Plant, the Trans Asia Power Generation Corporation and the MWSS Ipo
Dam.
Data from the Municipal Agricultural Office show that as of December 2007, the municipality has an
estimated 9,250ha of agricultural lands but more than half of the of this is not used for crop production
and remains covered with grass. Of the municipality’s agricultural lands, only around 44% are used for
production activities. Almost a third (3,278ha) is used for crop production while some 780ha are used
for livestock and fishery production. Rice, mango, banana, and root crops are the mostly extensively
grown crops. But only 14% of the rice lands are irrigated. In some areas, rice lands have remained
untilled or abandoned as prospective expansion areas of the existing quarry operations.
Table 26: Extent and Average Yields of Agriculture Land Use: Norzagaray
Crops/Livestock Area (Has) (%) No. of Farmers Ave. yield /
mt / ha / year
Crops 3,287.43 35.51 4,379
Rice
‐ Rainfed 1,152 12.44 1,o56 4.17
‐ Irrigated 162 1.75 268 3.77
Mango 665.71 7.19 885 5.37 429.82 4.64 575 4.19
Banana
Coconut 142.04 1.53 630 11.34
Coffee 21.15 0.23 55 0.16
Root Crops 228.71
Other crops 486
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780.52 8.43 2,900
20.9 0.23 602
303.1 3.27 1,366
0.87 0.01 605
4.37 0.05 167
450.92 4.87 160
Initial Environmental Examination – Output 2
Crops/Livestock Area (Has) (%) No. of Farmers Ave. yield /
mt / ha / year
Livestock
Swine
Large Cattle
Native Chicken
Broiler
Fishery
Grassland 5,190.05 56.06 0
Total 9,258.00 100 7,279
Source: CLUP Norzagaray/ 2007 Municipal Agricultural Profile
7.05
7.05
4.32
4.32
0.59
In addition to cement production, Norzagaray hosts companies that manufacture feeds (Subjin),
roofing materials (Vasquez), agrochemicals (Oria), fireworks (Nomilyn and DSP), and corrugated
carton (Jennson), among others.
4.8.5 Physical Cultural Resources
The only physical cultural resource16 (PCR) near the MWSS tunnel ROW is Pinagrealan Cave. The
Pinagrealan Cave near the Bigte segment and is about 450m away from the tunnel ROW. It is a
declared historical landmark by the National Historical Commission of the Philippines. The local
government of Norzagaray also recognizes its historical and tourism importance17. The application of
the cave as protected area under NIPAS is ongoing.
16 Physical and cultural resources are defined as movable or immovable objects, sites, structures, groups of structures, and natural features and landscapes that have archaeological, paleontological, historical, architectural, religious, aesthetic or other cultural significance. PCRs are important as sources of valuable scientific and historical information, as assets for economic and social development and as integral parts of a people’s cultural identity and practices.
17 This was included in Norzagaray CLUP 2011‐2020
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5 Anticipated Environmental Impacts and Mitigation Measures
5.1 Approach
ADB’s Rapid Environmental Assessment Checklist for urban and water infrastructure projects was
used to identify potential impacts of the project (Appendix 1). An Interaction Matrix (Leopold Matrix)
was then developed to identify the types and locations of potential impacts during the construction
and operation phases (Tables 25 and 26). Following identification of the main impacts, an outline
environmental management plan was prepared to set out the proposed mitigation and implementation
issues (Tables 27 to 29).
For this project, most of the adverse environmental impacts are associated with the tunnel construction
and associated spoil disposal. Areas most likely to be affected by construction activities are the sites of
the tunnel inlet/outlet works, the temporary and final spoil disposal areas, the construction
compounds, and haulage routes to and from site.
During operations, the main impact of the scheme would be a year‐round reduction of water in the
Angat river (Table 26).
5. 2 Issues and Concerns Relative to Siting, Planning and Design
Screening using the REA checklist has revealed the following siting concerns for consideration in
planning and design of the Project, including the method/s of construction.
a) Although urban development within the MWSS ROW is not significant, the following, found
within it and in close proximity, need to be considered as they will be exposed to potential
impacts from the Project, mainly during construction and to a lesser extent during
maintenance/repair works: (1) few people residing, their structural assets, their source of water
(groundwater), and economic activities; (2) existing relevant community and protected area
roads; and (3) components of the existing raw water transmission system, i.e. tunnels,
aqueducts, inlets, outlets and their appurtenances.
b) The project area is within the Angat Watershed and Forest Range, a protected area, and its
buffer zone. The inlet structure is at the indicative boundary of the protected area; and tunnel
Segments 1 and 2 traverse the buffer zone. MWSS ROW is included in the management plan for
the protected area and its buffer zone.
c) Angat river and Bigte creek will be subject to potential water quality impacts during
construction.
d) Existing Ipo road is about 5m wide and winding. Some household structures have encroached
into the road ROWs.
e) Situated in a tectonically active region, the Project area is subject to earthquake events. Project
area is also subject to flooding and landslides.
Additionally, planning and design must adequately address environmental parameters and concerns
regarding:
a) Climate change‐induced wind and floods and precipitation that would lead to unanticipated
necessary flow release of dam/s;
b) Seismicity and the applicable maximum design earthquake;
c) Other physical hazards that may be induced by tunnel construction, e.g. ground
collapse/landslides/subsidence
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d) Vulnerability of groundwater tables with tunnelling, e.g. potential impact on quality and/or
their flow
e) Spoil to be generated during construction
f) Impacts of the proposed spoil disposal area near Angat river
g) Safe storage of explosives for blasting;
h) Provision of interim fish landing to temporarily replace the existing fish landing that will be
have to be closed during construction of the intake structure
i) Potential social issues and concerns and stakeholders ’opinions on the Project, including the
Dumagat group of indigenous people living within the Ipo watershed area.
In preparing feasibility study and conducting social due diligence and this IEE, the following
mitigation measures have been undertaken to minimize the project’s environmental and socio‐
economic impacts:
a) In the conduct of social due diligence, activities to assess the Project’s potential impacts on
people, structures, land/assets and tree crops were conducted and included in the FS report.
The activities revealed no involuntary resettlement will take place.
To address concerns regarding indigenous people, adequate consultation and assessment were
carried out (see Appendix 7) and included in the FS report. During the consultation, the IPs
were informed of the current environmental and social status of the area, activities for the
tunnel construction and potential Contractor’s work area. The activities revealed no
resettlement or permanent displacement of IP will be involved. At the time of preparation of
this IEE, the CADT is in the process of application by Dumagats. The area of the ancestral
domain being applied for covers majority of the Angat Forest Reserve, which includes the
Contractor’s Work Area.
b) In the conduct of IEE, protected area relevant concerns were addressed through: (1)
consultations with DENR’s PAWB and Regional Office, the watershed management
Consultants of MWSS, the Dumagats residing within the Ipo watershed; (2) review of policies
and regulations governing and/or relevant to protected areas, watershed management plans; (3)
conduct of detailed surveys of terrestrial vegetation, wildlife and freshwater ecology; and (4)
assessment of the project’s impacts and risks on biodiversity and natural resources in
accordance with SPS 2009.
PAWB Technical Bulletin 2013‐01 indicates that the Angat Watershed is not designated
as critical habitat. With the issuance of SAPA currently suspended and the absence of
an established PAMB (a pre‐requisite for a SAPA) for the Angat Watershed and Forest
Reserve, the DENR RO 3 has advised that the applicable instrument for the Project is an
MOA among DENR, NPC and MWSS. DENR is yet to provide a letter to MWSS to
formally document such advice (see Appendix 8). Advance copy of the letter from
DENR ‐ unsigned). The draft MOA drawn together by DENR RO 3 and Consultant has
been forwarded to the MWSS for review.
Results of the detailed surveys of terrestrial vegetation and wildlife; and freshwater
ecology revealed that biodiversity at the project areas is low to very low.
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Initial Environmental Examination – Output 2
Existence of physical cultural resources was investigated. The Pinagrealan Cave, a
declared national historical landmark, is about 450m away from the Bigte outlet. A
barangay cemetery is about 400m from the MWSS RoW. Both will not be affected by
the Project.
Environmental concerns of stakeholders were solicited and obtained through
consultation meeting and focus group discussion (refer Appendix 7).
Although the project is partially within protected area, there is no natural habitat and
critical habitat that will be affected. The project is within an area of modified habitat
and partially within the legally protected area (see Section 5.2.1 and Appendix 1.2).
c) MWSS requires Tunnel 4 should be constructed within the existing tunnel ROW. In preliminary
engineering design, the following were considered/ incorporated:
Provision of sluice gate and stop logs at the intake structure to control the water flow to
the tunnel during extreme precipitation events.
Potential hazards caused by the nature of geology, soils and topography conditions in
the Project area such as :
‐ building intake structure on fill with a cofferdam and in situ weathered basalt,
considering the poor rock quality at the inlet;
‐ locating intake structure between the new and old Ipo to avoid siltation;
‐ strengthening cut slopes with steel fiber, reinforced shotcrete and rock bolt;
‐ installing temporary rock support during drill and blast; and
‐ applying baseline value used for assessing earthquakes/ seismic loads in the tunnel
design.
An estimated 150,000m3 of compacted spoils (equivalent of 190,000m3 loose volume)
will be generated during construction. About 11,000m3 can be reused and utilized for
tunnel construction. Brgys. San Mateo and Bigte are in need of rock material to be used
a backfill to 14km barangay roads and this will require about 49,000 m3 of rock
materials. An estimate from 90 m3 to 130m3 of residual spoil needs to be managed by
the Contractor for final disposal. Temporary disposal sites were identified during the
preliminary engineering design. Temporary sites were near the location of the inlet and
outlet structures.
Potential impacts, issues and concerns that could arise during construction and operation can be
avoided or, at least, mitigated with the:
a) Incorporation/consideration during detailed design of the environmental design parameters
used at preliminary design, as appropriate, and the following:
wind and floods during extreme wet weather events;
maximum design earthquake;
existing conditions of community and protected area roads that will be used by heavy
construction vehicles to access the Project area;
relevant feedback/suggestions obtained during stakeholder consultations;
measures to mitigate the temporary impacts on users of the fish landing that will be
closed during construction of the inlet structure;
safe storage for the explosives; and
ensured safety of the workers with the proposed method of construction.
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b) Conduct of the following during detailed design:
more detailed geological and geotechnical mapping to ensure appropriate engineering
measures are designed to mitigate slope failure; and
hydrogeological investigation to design measures to mitigate impacts on groundwater‐
dependent households.
review available seismic information and determine whether D&B Contractor could
meet the project performance expectations using available data. If not, then the D&B
Contractor needs to determine what additional data they need and plan the
exploratory/ fieldwork accordingly. The exploratory work such as gathering additional
data could be done while design is going on. Conservative assumptions shall be
applied in the design and the field work would be used to confirm assumptions.
5.2.1 Assessment of Impacts on Biodiversity and Natural Resources
This sub‐section summarizes the results of the assessment of impacts on biodiversity and
natural resources. Appendix 1.2 details the context and findings/results of the assessment.
Modified Habitats
The natural habitats of all 7 segments have been altered. Based on anecdotal record, Segments
1‐3 used to be forested areas until 1970s. The recent vegetation survey results show that
Segment 1 is co‐dominated by bamboo with agricultural trees like mango, coconut, banana and
caimito and some other tree pioneers associated with secondary vegetation such as binunga
and alagasi. Segment 2‐7 is an agro‐ecosystem type of vegetation dominated by agricultural
crops; uncultivated areas are dominated by brush and weed species.
Opportunities for Project to enhance habitat during operation include:
Identifying area/s within the study area where new trees of the species that are endemic
in the watershed reserve may be planted to replace the trees needed to be cleared to
give way to construction activities. The objective is not just to reforest but to try to
patch up the habitat fragmentation of the watershed forest in some way. In this
identified area, implement the condition in the tree‐cutting permit regarding planting of
endemic tree species at the watershed area.
Fencing of the MWSS RoW with dense rows of trees to mark the boundary, as
appropriate. Fast growing trees such as madre de cacao or ipil ipil which will initially
serve as ROW marker and interspersed with endemic tree species.
Active participation of nearest communities to watershed reforestation program
Promotion of MWSS on watershed protection/ watershed management by continued
implementation of tree planting activities in the Ipo watershed area by groups of
individuals.
Measures to mitigate further conversion or degradation of the habitats include:
During operation
Fence in MWSS RoW with dense rows of trees to mark the boundary, as appropriate. It
may be reinforced with barbed wire fence with warning signage at strategic points of
the boundary to prohibit unauthorized entry and settlement.
Vigilant monitoring of, and prompt action on, illegal/unauthorized entries.
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Initial Environmental Examination – Output 2
Enjoin and collaborate with the nearest communities in the vigilant watch over the
RoW.
During construction and during operation (maintenance and repair)
Spoil disposal area, contractor’s work area, worker’s camp site should be in areas that
will no longer involve or will involve least land clearing.
Eco‐friendly solid and hazardous waste management.
Proper storage of explosives and other hazardous materials. Manage/limit the quantity
of explosives/hazardous materials stored on site to only what is needed in the short
term.
Manage soil erosion and sedimentation to protect the quality of Angat River.
No construction equipment/vehicle repair to be done in the Study area.
Use least noisy equipment and processes.
Natural Habitats
There is no natural habitat in the Project area.
Critical Habitats
PAWB Technical Bulletin 2013‐01 indicates that the Angat Watershed is not designated as
critical habitat.
Legally Protected Areas
Segment 1 is fully within, and Segment 2 is partly within the indicative boundary of, the
legally protected areas.
Provision and
requirement of the SPS
2009 on Legally Protected
Areas
Action to be carried out by the
Consultant Result to be included in the REA
Act in a manner
consistent with defined
protected area
management plans
The IPO Watershed Management
Plan has been reviewed by the
consultant.
According to the management
plan, the proposed project area is
classified as built up zone of the
controlled zone of the watershed.
Although the inlet of the tunnel is within
the indicative boundary of Angat
watershed, the project area has been
considered in the management plan of
the watershed. All project activities are
within existing ROW and will mostly be
underground. Nonetheless, appropriate
mitigating measures including
compensatory (or offset) measures have
been included in the EMP and C/EMP to
achieve no net loss of biodiversity.
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Consult protected area
sponsors and managers,
local communities, and
other key stakeholders on
the proposed project
Consultations were made with
the MWSS Watershed Unit,
DENR Protected Areas and
Wildlife Bureau and DENR
Region 3 Office.
Discussion with MWSS
Watershed Management Unit
included area of watershed
covered by the plan, programs to
promote and enhance the
conservation and protection of
the water and protected
watershed and its
implementation.
Enhancement measures (e.g. through the
watershed management program of
MWSS) have been and will continue to
be implemented.
5.3 Issues and Concerns Prior to Construction
Prior to construction, environmental issues/concerns include: (1) obtaining the required
permits/clearances, e.g. ECC, MOA in place of SAPA, permit to cut trees and permit to use explosives
for construction; (2) preparing relevant communities; and (3) ensuring an environmentally responsible
procurement.
The above concerns shall be addressed as follows:
a) Obtain the aforementioned required permits/clearances prior to Notice of Award.
b) Conduct intensive social and environmental awareness program at least one month prior to
Notice of Award, covering: (1) communicable/ transmittable diseases that may be brought with
the entry of workers; (2) potential social conflicts between communities and workers; (3) other
health and safety hazards and impacts during construction and during maintenance and repair
of completed works; and (4) the grievance redress mechanism.
c) Ensure an environmentally responsible procurement by such measures as, among others: (1)
including an SPS‐compliant EMP in the bidding documents; (2) EMP to be appended in the
Contract for basis in the preparation of Contractor’s EMP (C‐EMP); and (3) C‐EMP to be
cleared by ADB prior to start of any activity/work on site and/or establishment of any
construction‐related facilities on site.
5.4 Impacts during Construction
Potential impacts were mostly identified at Segments 1 and 7 where most of the construction activities
will take place.
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Table 27: Interaction Matrix during Construction Phase
Category Description 1 2 3 4 5 6 7 Ipo dam San Mateo AFP San Mateo Road ROW Grassland Bigte site rolling housing grassland terrain
A. Physical and chemical characteristics
Earth/Land Mineral resources
soils Low impact
landform
unique physical features
Water surface high impact low impact
quality high impact low impact
underground Low impact
temperature
recharge
Air quality moderate impact
noise moderate impact
moderate
impact
moderate impact
climate
temperature
Processes floods
stability (slides, slumps)
stress-strain (earthquake)
low impact
low impact
fire low impact
air movements
B. Biological conditions
Flora trees, grass moderate impact
microflora moderate impact
moderate
impact moderate impact
Endangered
species
endemic
species
crops
fauna birds
endangered
species endemic
species
low impact
low impact
low impact
low impact
insects low impact
bentthic organism
low impact
Biological Interactions
microfauna low impact
ecological
relationships, ecosystem based processes, food chains
C. Cultural factors
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Category Description 1 Ipo dam
site
Landuse wilderness
wetlands
forestry moderate impact
2 San Mateo
rolling terrain
3 AFP
housing
4 San Mateo grassland
5 Road ROW
6 Grassland
7 Bigte
peatlands
agricultural
residential
commercial
industry
Recreation hunting
fishing low impact
boating low impact
swimming low impact
camping and
hiking resorts
Aesthetics scenic views
and vistas open space
Cultural Status
parks and
reserves unique physical
features
rare and uniqe ecosystems historical or
archeological sites and objects
Cultural patterns (lifestyle)
health and safety
moderate impact
moderate impact
low impact
low impact
employment moderate impact
moderate impact
moderate impact
moderate impact
moderate impact
moderate impact
moderate impact
Manufacture d facilities and activities
population density transportation network (movement, access)
utility networks
high impact moderate
impact
moderate impact
moderate impact
moderate impact
moderate impact
moderate impact
waste disposal high impact high impact
structures
government
activities
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5.4.1 Soil Erosion and Landslide
The potential of soil and sediment eroding from the
area locally known as ‘Consultant’ and degrading
surface water quality of Angat river is very likely.
Erosion may cause significant loading of sediments
to Angat river, especially during wet season and
severe typhoon events. Erosion control must be
considered from the beginning of construction. The
main factors influencing erosion include the volume
and velocity of the runoff from rain events, the rate of
precipitation infiltration downward through the soil,
the amount of vegetative cover, slope length or the
distance from the point of origin of overland flow to
the point where deposition begins, and operational
erosion/ slide control structures.
Tunnel 4 inlet location
‘Consultant’
Mismanaged construction activities pose risk of severe erosion and/ or landslide particularly at the
inlet and outlet sites. With faulty drilling or blasting activities during tunnel construction, potential
rock fractures will be created and may render vulnerability to earthquakes.
5.4.2 Surface Water Resources
There are potentially high impacts on surface water quality at the Ipo dam site and Bigte creek due to
construction activities of the inlet and outlet of the tunnel.
Turbidity levels at Ipo dam site have been a concern in the past and still evident at the dam site,
especially during the wet season. The turbidity measure usually peaks during wet season. This is
mainly attributed to erosion due to degraded forests in the area, which has resulted in significant
siltation in both Angat and Ipo reservoirs.
There are no wetlands at the vicinity supported by the river system. The water quality of the raw
water conveyed to Tunnels 1 to 3 is potentially affected. However, mitigating measures shall be in place
to avoid disruption to operations of the existing transmission system (Tunnels 1to 3) during
construction.
Some measures to mitigate contamination of waters in Angat river, Ipo dam and Bigte creek include:
(1) provisions for adequate sanitation facilities and water supply at work sites and worker’s camp and
enforcement of good sanitation practices by workers; (2) implementing an eco‐friendly solid and
hazardous waste management; (3) proper storage of hazardous materials; (4) use of cofferdams when
constructing inlet and outlet structures; (5) preventing/controlling siltation or sedimentation through
proper storage of aggregates and spoils; and (6) using efficient tunnelling technology that recycles
tunnel drainage water to minimize extractor of surface water.
5.4.3 Groundwater Resources
There is a low impact on groundwater along the alignment of the tunnel from Ipo dam site to Bigte.
The data on the level of groundwater in the project area are very limited. From the BHs drilled, water
table near the inlet is at 4.5mbg to 15.5mbg while in the outlet structure it is at 8.45mbg.
To mitigate impact on groundwater resources, among others: (1) site temporary stockpile of excavated
soils in flat areas away from main surface drainage routes; (2) provide silt fences, silt traps and/or
sandbags.
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5.4.4 Air Quality and Noise Level
Air Quality
Tunnel construction will require transport of heavy equipment to the construction sites (at the inlet and
outlet) and hauling of excavated materials to the temporary spoil disposal area. Air quality will be
deteriorated due to frequent movement of vehicles at the construction site, transportation of spoil and
blasting activities. High noise level near construction sites will be observed by communities living near
the outlet and inlet sites.
Construction activities can lead to elevated concentrations of NO2, SOx, CO2, and dust in the
atmosphere. The main source of pollutants is from combustion of fuel in vehicles and plant.
Construction dust also arises from the tunnelling, earthworks, and transportation. Construction of the
tunnel will require the transport of heavy equipment to the construction sites (at the inlet and outlet
works) and haulage of excavated materials to the temporary spoil disposal area. It is likely that the
local air quality will deteriorate temporarily due to dust from tunnelling, frequent movement of
vehicles at the construction site, and the dumping and compaction of spoil as the disposal site.
Emissions from vehicles and plant are unlikely to result in exceedance of the air quality standards.
Construction dust is typically confined to within 100m to 200m of the construction site as the dust is
deposited close to the source. Whether construction dust causes a nuisance depends on various factors,
such as the construction activity, wind speed and direction, recent weather, and the existence of
sensitive receptors such as residential areas nearby.
The main receptors are likely to be construction workers and people living and working within 200m
of open air construction sites and haulage routes. There will be no impact on air quality along the
tunnel alignment, away from the tunnel portals.
Measures to mitigate dust include, but not limited to: (1) locating local emission sources away from
sensitive receptors; (2) applying dust suppression techniques; (3) watering exposed areas and
stockpiles of aggregates and spoils at least twice daily or as necessary; (4) use of blast curtains/nets; (5)
requiring hauling trucks of aggregates, wastes and cement to have secure cover; and (6) limiting idling
of equipment to 5 minutes.
Noise and Vibration
The main sources of noise during construction would be the works to build the in‐take and off‐take
structures, tunnelling works near the portal entrances, heavy goods vehicles required to move spoil
from the tunnel to the final disposal sites, movement of machinery to compact the spoil disposal sites,
and road haulage. Blasting for the tunnelling would have to be carefully controlled to reduce the noise
impact. As the tunnelling progresses, the propagation of noise levels will be attenuated by the
surrounding ground.
The main receptors likely to be affected by construction noise are the construction workers themselves,
people living and working within about 200m of the construction sites of the intake / outlet works, and
wildlife. People living and working along the alignment of the tunnel would not be affected by
construction noise, but may be affected by noise from haulage traffic along the roads.
The Contractor would be required to implement a Noise Control Plan to minimize noisy activities.
5.4.5 Flora and Fauna
There will be a direct impact on vegetation in the construction sites which will have to be cleared. The
impact can be minimized by siting temporary construction sites such as construction camp and
temporary spoil disposal areas in locations which are poorly vegetated, minimizing the area to be
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cleared, and re‐vegetating the sites on completion of construction.
Virtually all species of fauna are susceptible to disturbance due to construction, for example from
noise, vibration, poor air quality, lights, and the presence of people. Many mobile species may resort to
re‐locating away from the construction sites. The nine noteworthy species (by virtue of being a Luzon
endemic, globally threatened, or actively hunted) were recorded in Sites 1 and 3, where disturbance
would have the greatest adverse effect. However, the forest at Ipo dam is contiguous with the Angat
watershed, which would provide a refuge for displaced wildlife. The potential impact on wildlife is
expected to be minimal, given that construction works are highly localized and confined near existing
facilities. Measures to mitigate noise, vibration, dust and flying debris from blasting will mitigate
disturbance to wildlife.
5.4.6 Traffic
Ipo road is about 5m wide and serves two‐way traffic. Communities along Ipo road, especially those
situated toward the Ipo dam compound, have temporary structures encroached into the road ROW,
somehow constraining traffic flow. During construction, heavy construction trucks and equipment will
be using this road to access the Project area from Quirino Highway. Traffic congestion is expected
along Ipo road and at its junction with Quirino Highway. Delivery of goods, services and people will
experience longer travel time. Residents and road users in the vicinity will be exposed to road safety
hazards.
Prior coordination with the Barangay and Municipality will be necessary for the formulation of a traffic
management and safety plan and for the clearing of encroaching structures. Contractor shall post
traffic flagmen, equipped with two‐way radio, at strategic points along the Ipo Road. Assistance from
the barangay tanod (community police) may be requested.
During construction phase, it is anticipated that the transportation network will be affected due to the
increase in the number of heavy equipment and haulage trucks to transport the spoil from the inlet and
outlet works to the temporary / final disposal sites. A significant increase in heavy vehicles on the roads
can result in slower journey times, higher accident risks, dirt on the roads from the vehicles, and driver
stress.
5.4.7 Damage to Roads and Utilities
During construction phase, the road network leading to the Project area will have to endure the
volume of heavy trucks to and from the Project area. Roads not designed to withstand large volume of
heavy construction trucks will be vulnerable to damage. Illegal water hoses near Ipo compound, used
for raw water distribution, were observed embedded along the road expansion joints.
Prior coordination with DPWH on the use of Ipo road and restoring the access roads within the MWSS
compound to pre‐construction conditions are the proposed mitigation measures. To succeed the
consultation with the community, MWSS should discuss the issue on the raw water supply.
5.4.8 Restricted Access to Fish and Boat Landings
The fish landing in Sitio Consultant, identified as CWA, and the boat landing at Sitio Ipo will be
temporarily closed during construction; thus disrupting the transport and economic activities of local
folks. Communities living in the Ipo watershed must be informed on the impact of construction works
on transportation and consulted for the best alternative routes to bring and sell their produce outside
the watershed area. Alternative route and fish and boat landings must be identified and ready for use
by the local folks prior to commencement of construction activities.
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5.4.9 Community Health and Safety
The health and safety of the community/public will be at high risk during construction. These people
will be exposed to cross‐cutting threats from the impacts on air quality, generated noise and vibration,
traffic, accidental spills of hazardous substances during transport, reckless drivers of construction‐
associated vehicles, potential fire and explosion, and lack of awareness on the hazards posed by
subproject implementation on health and safety.
Communicable and transmittable diseases may potentially be brought into the community by
construction workers.
Impact to community health and safety relating to road safety is anticipated, especially during
construction phase. The Ipo road is about 10km from Bigte portal to Ipo dam compound. The road is
characterized with some curves, very few road signs and no speed limit. At the onset of the tunnel
construction, it is expected that there will be an increase in traffic due to the transport of heavy
equipment and construction materials and hauling of spoil to temporary disposal areas. With the
influx of traffic and residential plots which have encroached in road ROW, road accidents may occur.
The preconstruction community IEC will be designed to ensure sufficient awareness of the community
on the health and safety hazards that will come with construction works, particularly with the blasting
operations and entry of workers in the community. Implementing measures to mitigate noise and
impacts on air and water quality and traffic would mitigate health and safety hazards.
5.4.10 Workers’ Health and Safety
The drill and blast method of tunnel construction will involve explosives. This poses salient threat to
the worker’s safety. Inadequate supply of safe/potable water in construction sites, sanitation facilities;
poor sanitation practices on site, poor housing conditions, handling and operation of construction
equipment; handling of hazardous substances, exposure to extreme weather and non‐observance of
health and safety measures pose additional threats to the health and safety of construction. Workers
may also be potentially exposed to communicable and transmittable diseases in the community and the
workforce.
The provision of adequate basic services in the workers’ camp/s and at the construction sites,
enforcement of use of protective wears, conduct of pre‐mobilization orientation workshop to include
health and safety hazards, training on emergency response and evacuation procedures and having a
well‐trained first‐response team on site are among the measures to mitigate workers’ health and safety
hazards.
Mitigating the potential adverse impacts of drill and blast in tunnel construction shall be the
responsibility of D&B Contractor. The D&B Contractor should secure related explosive permits from
PNP prior to blasting activities. The Contractor shall consider the position, erection, security fencing,
maintenance, licensing, and subsequent removal of proper explosive and detonator magazines
required for the satisfactory performance. The design and construction of the magazines shall comply
fully with relevant statutory requirements.
The D&B contractor shall also be responsible for the guarding of magazines in terms of any regulations
which may be in force or come into force. The Contractor shall ensure that only authorized, licensed
and competent persons are allowed access to the magazines
5.4.11 Waste Disposal
Waste generated during construction includes spoil, solid waste and hazardous waste. An estimate of
150,000 m3 excavated material expected to be generated due to tunnelling works. This is about
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190,000m3 loose volume. The core samples are reported not to have heavy metal content as shown in
the soil analysis done. The spoil is likely not to have nutrient content and not advised to be disposed in
the productive area.
The spoil can be re‐used as concrete materials for the tunnel lining or road backfill. The 6.5km tunnel
is estimated to require 11,000m3 or spoil material. Community roads of Brgys. Bigte and San Mateo
that need backfill require about 49,000m3 of excavated material. About 130,000m3 spoil of loose volume
has to be managed by D&B Contractor for final disposal.
Contractor will be required to implement solid and hazardous waste management that involves
minimization, re‐use, segregate, safe storage and prompt disposal to legitimate landfills.
5.5 Impacts during Operation
Potential impacts during operation are perceived insignificant. Low impacts are likely on water
quality, community health and safety during maintenance and repair.
It is also extremely unlikely that future developments will affect the tunnel. However, it would be
consistent with normal practice for significant new infrastructure or developments (including
excavations for quarries or mines) to be assessed for influence on the tunnel, prior to construction
permission being granted. The new tunnel will augment three existing, parallel, drill and blast,
partially lined, tunnels, constructed in the 1930s, 1970s and 1990s. It will run parallel to the existing
tunnels, with the potential to cross above the abandoned section of Tunnel 1 near Ipo dam. Table 28
presents the result of the Interaction Matrix during operation phase.
Environmental Items
Table 28: Interaction Matrix during Operation Phase
Alignment segment
Category
Description 1
Ipo dam site
2 San Mateo
rolling
3 AFP
housing
4 San Mateo grassland
5 Road ROW
6 Grassland
7 Bigte
terrain
A. Physical and Chemical Characteristics
Earth/Land Mineral
resources
soils
landform
unique physical features
Water surface low impact
quality
underground
temperature
recharge
Air quality
noise
climate
temperature
Processes floods
stability (slides,
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Environmental Items
Description 1 2
Alignment segment
3 4 5 6 7
Category
slumps)
stress-strain
(earthquake)
fire
air movements
Ipo dam site
San Mateo rolling terrain
AFP housing
San Mateo grassland
Road ROW Grassland Bigte
B. Biological Conditions
Flora trees, grass
microflora
Endangered
species
endemic
species
crops
fauna birds
endangered
species
endemic
species
insects
benthic
organism
microfauna
low impact
Biological Interactions
ecological relationships, ecosystem based processes, food chains
C. Cultural Factors
Landuse wilderness
wetlands
forestry
peatlands
agricultural
residential
commercial
industry
Recreation hunting
fishing
boating
swimming
camping and
hiking
resorts
Aesthetics scenic views
and vistas
open space
parks and reserves
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Environmental Items
Description 1 2
Alignment segment
3 4 5 6 7
Category
unique physical
features rare and unique
ecosystems historical or archeological sites and objects
Ipo dam site
San Mateo rolling terrain
AFP housing
San Mateo grassland
Road ROW Grassland Bigte
Cultural Status Cultural
patterns (lifestyle) health and
safety low impact low impact
employment
population density
Manufactured facilities and activities
transportatio n network
(movement, access) utility
networks waste disposal
low impact low impact
structures low impact low impact low impact low impact low impact low impact low impact
government activities
low impact
5.5.1 Transportation Networks and Utilities
During operation phase, it is anticipated that the transportation network will be affected due to the
slight increase of some vehicles travelling to Ipo dam site for maintenance and operation. Residential
plots alongside the roads have encroached the road ROW. An increase in residential infrastructure
built within the road ROW may result in slower journey times, higher accident risks, dirt on the roads
from the vehicles, and driver stress.
5.5.2 Impacts on Natural Water Flow and Flooding Patterns
Potential impact during the operation phase may include impacts on the natural water flow of Angat
river. Tunnel 4 construction is expected to augment the supply to Aqueducts 5 and 6 to their full
capacities. This entails abstraction and conveyance of additional volume of water from Angat river.
The riparian flow of Angat River will be affected if the water supply to AQ5 and AQ6 will be
maintained.
An increase in the number of days of wet season is anticipated from 2006 to 2035 compared to the
baseline from 1971 to 2000 as projected in the study made by DOST‐PAGASA. This forecast
reciprocates water requirement conveyed though the system.
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5.6 Project Benefit, Positive Impact and Outcome
The Project will offer opportunities for local employment and increased earnings of local enterprises
during construction. When completed and become operational, the Project will have improved and
expanded the raw water transmission system, increasing reliability and security of raw water
transmission and ensuring sustainable water supply services to Metro Manila.
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6 Environmental Management Plan
6.1 Introduction
The environmental management plan (EMP) will serve as the framework for the Project’s
environmental management, commencing before the procurement process for D&B Contractor up to
the operation. This will be updated by the OSP‐AWTIP based on the detailed design, with technical
assistance from the Environmental Specialists of the Project Implementation Support (PIS) Team. The
EMPs will be mainly implemented by the OSP‐AWTIP, D&B Contractor and the Concessionaires. The
EMP features the Environmental Mitigation Plan, Environmental Monitoring Plan, Implementation
Arrangements and Performance Indicators.
6.2 Environmental Mitigation Plan
The recommended mitigation measures consist of actions, activities, plans and documents that need to
be undertaken, observed, obtained, prepare to prevent and/or mitigate the Project’s adverse
environmental impacts. The broad measures are outlined below while the specific measures are
presented in the Environmental Mitigation Plan (Table 29, Table 30, and Table 31: ):
a) Ensure incorporation in the detailed design of adequate considerations and conditions relative
climate change and other natural hazards to sustain the structural integrity and effective
operations of completed works.
b) In the event of design deviation, such as shift of alignment resulting in tunnel being located
outside the MWSS ROW, change in inlet structure location and/or change in the method of
construction, ensuring to: (i) seek the advice of EMB Central Office if such design deviation
warrants an ECC amendment; and (ii) inform ADB should EMB advise for ECC amendment
and finally, (iii) seek ADBʹs clearance/concurrence for an IEE revision and/or EMP updating.
c) Ensure engagement of an environment‐responsible D&B Contractor by incorporating the SPS‐
compliant EMP for this Project (hereinafter referred to as the EMP) into the bidding documents,
as basis in the preparation of the Contractor’s EMP (C‐EMP) by D&B Contractor, addressing as
minimum the requirements of EMP. C‐EMP to be quantitatively and qualitatively evaluated
against the EMP by OSP‐AWTIP and cleared by ADB prior to the commencement of any work
onsite. The contract for civil works to explicitly stipulate the obligation to institute the
mitigation measures properly and carry out environmental monitoring according to the C‐EMP.
The Contract to stipulate some tie‐up of progress payment and collection of performance bond
with the performance in C‐EMP implementation.
d) A C‐EMP that ensures good and environment‐friendly engineering practices that avoid first,
and (if unavoidable) mitigate, adverse impacts; and commitment from D&B Contractor to fully
implement the C‐EMP.
e) Quality construction supervision and environmental monitoring by the OSP‐AWTIP.
f) Conduct of engineering investigations of built structures after every seismic, extreme weather
and other natural hazard events during construction and operation and full disclosure of
investigation reports. Prompt action to correct damages.
g) Sufficient funds for sustained quality of operation and maintenance.
h) Observance of the grievance redress mechanism and prompt action/ resolution of lodged
grievances.
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Table 29: EMP prior to Construction Phase
Potential
Possible approach/ Mitigating Measures
Cost of Mitigation/
Responsible
Performance Standard
Guarantee
Impact Enhancement
Required permits/ clearances
Obtain the following prior to Notice of Award:
a) ECC b) MOA between DENR RO 3, NPC and
MWSS c) Permit to cut tree d) Permit to use explosives for construction
a) PhP 500,000.00 b) none c) part of construction cost d) part of construction cost
a) MWSS b) MWSS c) D&B
Contractor d) D&B
Contractor
Permits/clearances obtained prior to Notice of Award
Employer’s requirement document
Preparing relevant communities
Conduct intensive social and environmental awareness program at least one month prior to Notice of Award, covering (i) communicable/ transmittable diseases that may be brought with the entry of workers; (ii) potential social conflicts between communities and workers; (iii) other health and safety hazards and impacts during construction and during maintenance and repair of completed works; and (iv) the grievance redress mechanism.
Included in OSP-AWTIP’s budget
OSP-AWTIP
Affected barangays
Ensuring environmentally responsible procurement
Include an SPS-compliant EMP in the bidding documents.
Not applicable OSP-AWTIP SPS-compliant EMP included in eth bidding documents
Append EMP to the Contract for basis in the preparation of the C-EMP.
OSP-AWTIP EMP appended in Contract
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In Contract, require D&B Contractor to submit monthly and semi-annual environmental monitoring report.
OSP-AWTIP Requirement stated in Contract
Stipulate in Contract the tie up of progress payment and collection of performance bond with the performance in C-EMP implementation.
OSP-AWTIP Stipulation in Contract
Prepare C-EMP that addresses as minimum the requirements of the EMP.
D&B Contractor Presence of a C-EMP based on EMP
Evaluate the C-EMP quantitatively and qualitatively against the EMP.
OSP-AWTIP Evaluation undertaken quantitatively and qualitatively
Clear the C-EMP before the start of any activity/work on site or establishment of any construction-related facility on site by D&B Contractor.
ADB C-EMP cleared prior to
start of any mobilization activity on site by D&B Contractor
Table 30: EMP for the Construction Phase
Potential Impact Possible Approach/ Mitigating Measures Cost of Mitigation/
Enhancement
Responsible
Implement Monitor
Performance Standard Guarantee
Physical (Land) Environment
Soil and Erosion due to:
soil disturbance
vegetation clearing
Location: Inlet structure and relevant work sites
Confine soil disturbance and/or vegetation clearing to pre-defined and planned area that includes project footprint and needed easements
Part of project development cost
D&B Contractor OSP-AWTIP CEMP
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Potential Impact Possible Approach/ Mitigating Measures Cost of Mitigation/
Enhancement
Responsible
Implement Monitor
Performance Standard Guarantee
Stabilize exposed soils with temporary seeding, mulches, mats, non-chemical-based soil binders.
Protect slopes with any one or combination of bonded fiber matrices, erosion control blankets, silt fence, fiber rolls, and keeping stormwater off the slopes through diversion channels and/or berms.
Re-vegetate disturbed soils/slopes as soon as possible after completion of the construction works.
Replacing vegetation that died during the defects liability period.
At the active work sites,
Provide temporary drainage with sedimentation tank or filters such as block and gravel, prior to discharge to watercourses
Impact on surface water quality due to/ from:
Contaminants from materials used and construction activities and processes
Siltation from soil erosion, spoil disposal area, drill and blasting, dewatering excavations, etc
At the active work sites
Mitigating contaminants
Provide adequate sanitation facilities and water supply at work sites and workers’ camp. Enforce observance of good sanitation practices by workers.
Implement solid waste management that
minimizes, re-uses, properly segregates and promptly and properly disposes of generated solid wastes.
Implement hazardous waste management
that minimizes, properly segregates and promptly and properly disposes of generated
Part of project (construction) cost
D&B Contractor OSP-AWTIP Water Column. Parameters to characterize the physico- chemical and biological status of the water column to include but not limited to: temperature, salinity, total suspended solids, turbidity, dissolved oxygen and bacteriological parameters.
Refer to DAO 34 and 35 for water quality standards
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Potential Impact Possible Approach/ Mitigating Measures Cost of Mitigation/
Enhancement
Responsible
Implement Monitor
Performance Standard Guarantee
hazardous wastes.
Store hazardous construction materials in appropriately contained and elevated area and at least100 m away from surface water bodies.
Have equipment clearly leaking oil repaired
off-site immediately. No vehicle/equipment maintenance, repair and refuelling to be allowed at the sites.
Treat construction water before discharge.
Install settling pond for water generated during tunnel boring. Allow water through grease trap or oil/collector and/or filters such as rock filled bags, block and gravel.
Implement corrective action, when trigger
thresholds of water quality are reached.
During construction, the contractor shall take corrective action to reduce concentration to below the standard.
Mitigating sedimentation
Build cofferdams when constructing inlet
structure
Use any combination of perimeter controls at spoil disposal areas or stockpiles of aggregate materials, e.g., silt fences, sediment basins, sandbags, earth bern/bund.
Minimize / control dewatering or extraction of
tunnel water by storing and re-using pumped-
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Initial Environmental Examination – Output 2
Potential Impact Possible Approach/ Mitigating Measures Cost of Mitigation/
Enhancement
Responsible
Implement Monitor
Performance Standard Guarantee
out water from the tunnel.
Extraction of water from the dam site (inlet) and creek (near the outlet) to be used as coolant during construction
Use efficient tunnelling technology that recycles tunnel drainage water to minimize extraction of water.
Part of project (construction) cost
D&B Contractor OSP-AWTIP If significant amount of water is to be used, a permit from the National Water Resources Board may be necessary.
DAO 34 and 35 for water quality standards
Impact on groundwater:
b) deteriorating water quality due to:
In all active work sites
Site temporary stockpile of excavated soils in flat areas, away from main surface drainage routes,
Part of project (construction) cost
D&B Contractor OSP-AWTIP DAO 1994- 26A for Philippine drinking water quality standards
Silt/sediments limit to maximum of 2 m high. Solid waste
Provide silt fences, silt traps, or sand bags, at Hazardous stockpiles of aggregate materials.
materials and waste Dispose of residual soil/spoil as soon as possible,
to the disposal areas, or as free backfilling materials for LGU/barangay roads.
Avoid stockpiling more aggregates than necessary.
c) lowering of water level of wells in nearby communities due to tunnelling, pumping/extracting of tunnel drainage water
Monitor for potential groundwater depletion in existing wells in the vicinity. Provide interim measures to avoid disrupting water supply to affected households. Investigate for proper corrective action.
Part of project (construction) cost
D&B Contractor OSP-AWTIP
Air Quality and Noise
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Initial Environmental Examination – Output 2
Potential Impact Possible Approach/ Mitigating Measures Cost of Mitigation/
Enhancement
Responsible
Implement Monitor
Performance Standard Guarantee
b) Deterioration of ambient air quality due to dust and gas emissions from:
Earthworks and
other construction processes;
At the project area, locate emission sources away from sensitive receptors, e.g., concrete batching and rock crushing plants at least 500m upwind of sensitive receptors.
In active work sites:
Part of project (construction) cost
D&B Contractor OSP-AWTIP Maintain air quality within national air quality standards, or if these are not available, internationally accepted air quality standards, such as WHO Air Quality Guidelines Global Update, 2005
D&B Contractor Scope of Work
D&B Contractor’s C-EMP
tunnelling (drill and blast);
Use of blast curtains / nets to capture dust from blasting
Parameter Averaging
Period
Guide
µg/m3
stockpiling of aggregates and Apply dust suppression techniques, e.g., watering
SO2 24 hrs 20
spoils, and conveyance of spoils to disposal areas;
increased transport activities in the construction areas and along Ipo Road;
burning of vegetation and wastes; and
operation of mechanical equipment
with bowsers, sheeting particularly at Bigte area
Water dry unpaved/exposed surfaces, stockpiles of sand and excavated materials, at least twice daily, or as necessary.
Protect aggregate stockpiles with sheeting to restrict the movement of dust.
Use of blast curtains / nets to capture dust from blasting.
Require trucks, particularly those hauling aggregates, to have secure covers.
Limit engine idling to 5 minutes.
Prohibit open burning of vegetation and other waste in the project area
Ipo Road, main access road, other roads in the Project area area,
Llimit speed of all construction vehicles to max. of 40 kph on the access road to, and max. 30 kph in, the site.
NO2 1 year
1 hour
PM10 1 year
24 hrs
PM2.5 1 year
24 hrs
40
200
20
50
10
25
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Initial Environmental Examination – Output 2
Potential Impact Possible Approach/ Mitigating Measures Cost of Mitigation/
Enhancement
Responsible
Implement Monitor
Performance Standard Guarantee
Noise and vibration in the project area from
drill and blast activities, vehicle and equipment operations
Use only equipment that emit least noise and vibration and are well maintained.
Use facility layout to minimize noise propagation e.g. using topography / existing buildings as barriers, where possible locate noisy activities away from local communities.
Control noise at source, e.g. low noise plant,
Part of project (construction) cost
D&B Contractor OSP-AWTIP Adopt national standards for construction sites and residential areas if available. Alternatively use internationally accepted standards such as WHO.
D&B Contractor Scope of Work
D&B Contractor’s C-EMP
muffling, acoustic screening, switch off Reference / Ambient
campaigns. Jurisdiction Standard
Restrict use of noisy and highly vibrating equipment from 8AM-5PM. Necessary overtime work should: a) not go beyond 9:00PM; b) observe regulated noise and vibration levels; c) not use noisy and highly vibrating equipment; and d) should be coordinated with the barangay and affected households.
Manage the ins and outs of hauling trucks. Spread out the schedule of material, waste and spoil transport in the day (off-peak hours).
Enforce the rule of no blowing of horns.
Strictly enforce upon workers the compliance with wearing of ear mufflers, especially those who are operating equipment.
Guidelines for Community Noise, WHO, 1999
International
Receptor: Residential; institutional; educational
Daytime (07:00- 22:00): 55dBA
Nighttime (22:00- 07:00): 45dBA
Receptor: Industrial; commercial
70dBA throughout the day
Biological Environment
Loss of vegetation due to:
vegetation clearing and potential trampling of trucks/equipment
Institute measures to avoid impacting on habitats and wildlife, such as:
minimize vegetation clearance at Bigte and especially at the intake
fence off vegetation to be retained
provide environmental training for workforce
Part of project (construction) cost
D&B Contractor OSP-AWTIP Minimal number of trees applied for tree cutting permit from DENR
Tree cutting permit
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Initial Environmental Examination – Output 2
Potential Impact Possible Approach/ Mitigating Measures Cost of Mitigation/
Enhancement
Responsible
Implement Monitor
Performance Standard Guarantee
beyond project footprints
enforce site rules and sanctions to discourage workforce from hunting, fishing and poaching.
Confine all construction activities to previously disturbed areas, to the extent practicable, e.g., workers’ quarters/camps.
Use existing roads for project activities. Minimize new road construction.
To avoid unnecessary clearing, mark/delineate areas to be cleared of vegetation, e.g. by fencing.
Rehabilitate cleared areas to their pre-project conditions, unless otherwise agreed with the landowner.
Re-vegetate construction sites using local, indigenous species.
Re-vegetate watershed target sites especially in areas identified by the Watershed Management Plan.
Limit any collection of wood for charcoal to exotic i.e. non-native species.
Disturbance to wildlife due to
Implement measures to mitigate noise, vibration and dust.
Part of project (construction) cost
D&B Contractor PMO Record of number of poaching and illegal
N/A
Construction noise, vibration, dust, lighting, presence/movement of people, etc.
flying debris from blasting
Strategically place nets at the tunnel portals to prevent flying debris.
Water to minimize dust accumulation and spreading.
trading of wildlife by workers
Socio Economic
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Initial Environmental Examination – Output 2
Potential Impact Possible Approach/ Mitigating Measures Cost of Mitigation/
Enhancement
Responsible
Implement Monitor
Performance Standard Guarantee
Traffic due to:
inadequate capacity of Ipo Road (access road)
expected volume of truck movement
Institute prior coordination with the Barangay and Municipality for the formulation of a traffic management and safety plan and for clearing of structures encroaching into access road ROW.
Prior to construction, clear easement of encroaching structures, most of them being temporary.
Strategically post billboards informing the public about the expected increase in volume of traffic in the influence area due to Project implementation. Post at least two weeks prior to mobilization.
Coordinate with the Barangay for assistance in traffic management.
Strategically post traffic flagmen along Ipo Road, equipped with two-way radio.
Post sufficiently legible (reflectorized) traffic safety notice and signage at strategic locations along the entire stretch of the access road.
Limit speed to 40 kph along Ipo Road, and 30 kph at construction sites and unpaved haulage roads.
Part of project (construction) cost
D&B Contractor
Zero road accident and related incidents
D&B Contractor Scope of Work
D&B Contractor’s C-EMP
Potential damage of existing roads used as access roads due to movement of heavy equipment and vehicles
Coordinate with DPWH regarding the use of Ipo Road.
Restore access roads within the MWSS compound to the pre-construction condition or better.
Part of project (construction) cost
D&B Contractor D&B Contractor Scope of Work
D&B Contractor’s CEMP
Restricted access to the existing fish landing sites in Sitio Consultant (identified area as the
Inform affected communities living in Ipo Watershed on the impact of construction works on transportation and consult them for the best alternative route. Have alternative route and fish
Part of project (construction) cost
D&B Contractor D&B Contractor
Scope of Work
D&B Contractor’s
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Initial Environmental Examination – Output 2
Potential Impact Possible Approach/ Mitigating Measures Cost of Mitigation/
Enhancement
Responsible
Implement Monitor
Performance Standard Guarantee
Contractor’s Work Area) and boat landing at Sitio Ipo
and boat landing sites ready for use prior to commencement of construction activities.
CEMP
Community health and safety hazards
Inform local residents of the timing of blasting and prohibit entry of local residents into the construction area.
Secure project area, including associated facilities particularly the storage for explosives, from unauthorized entry.
Implement measures to mitigate impacts on air and water quality, noise, traffic.
Part of project (construction) cost
D&B Contractor D&B Contractor Scope of Work
D&B Contractor’s CEMP
Workers’ health and safety hazard
Mitigating impacts from blasting:
Include H&S protocols in the C-EMP on the safe procedures in the storage, handling and use of explosives during construction.
Control the blasting by using small charges.
Evacuation procedures in tunnel prior to setting charges.
Set up a sufficiently equipped emergency first- response and health care team, linked to an ultimate response team.
Provide safe housing with adequate basic services.
Enforce use of protective wears when at work.
Conduct pre-mobilization orientation workshop on health and safety and emergency response and evacuation procedures.
Handling and storage of explosives
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Initial Environmental Examination – Output 2
Potential Impact Possible Approach/ Mitigating Measures Cost of Mitigation/
Enhancement
Responsible
Implement Monitor
Performance Standard Guarantee
Magazine storage should be far from
residential areas, roads, transmission
lines, dams and their appurtenant works.
Site should be well-drained and sloping,
accessible by road., at least 100 m from
overhead power transmission lines.
Detonators should not be stored
together with explosives.
Maintenance should follow the
prescribed instructions for the
explosives.
Inside of all magazines should be kept
thoroughly clean.
Cigarettes and matches should not be
taken into Explosives should be used
according to date of manufacture
magazines. Its keeper should ensure
this.
Explosive boxes should be of wood or
soft non-ferrous metal, e.g., brass,
copper.
Magazine should be securely locked,
when not attended.
Detailed records of outgoing and
incoming stocks should be kept
Magazines should be kept free from
bushes and vegetation.
Empty boxes, loose packing material or
cotton waste should not be kept on the
magazine premises.
Do not open magazines during or on the
approach of a thunderstorm. No person
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Initial Environmental Examination – Output 2
Potential Impact Possible Approach/ Mitigating Measures Cost of Mitigation/
Enhancement
Responsible
Implement Monitor
Performance Standard Guarantee
should remain in the vicinity of the
magazine during such storm
Generation of spoil and spoil disposal. More than 150,000m
3 is
expected to be generated due to tunnelling works, which
is about 190,000 m3
loose volume.
Prepare and implement a plan for the preparation of the spoil disposal areas.
Minimise the volume of spoil to be disposed of by re-use in backfilling of roads, and by offering as free filling materials to government projects needing backfill materials.
Disposal area must be confined to solid ground, of low ecological and agricultural value.
Disposal area must not occupy drainage lines and streams, and create an obstacle to streams or induced flooding.
Spoil heaps must be designed and shaped with stable side slopes and suitable drainage.
Spoils heaps must be compacted during the earthworks.
On complete, the spoil heaps must be covered with the original top soil from the site and re- vegetated
Part of project development cost
MWSS
DED Consultants
D&B Contractor
Detailed Engineering Design (DED) Scope of Work
Detailed Engineering and Design Plans
Solid waste Implement an eco-friendly solid waste management at work sites and workers’ camp/s, which minimizes, re-uses, segregates and promptly disposes of generated solid waste.
Part of project (construction) cost
MWSS
D&B contractor
D&B Contractor Scope of Work
D&B Contractor’s C-EMP
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Initial Environmental Examination – Output 2
Potential Impact Possible Approach/ Mitigating Measures Cost of Mitigation/
Enhancement
Responsible
Implement Monitor
Performance Standard Guarantee
Hazardous waste Locate stationary ground storage for hazardous waste at least 100 m away from water bodies, raised to min 1 ft above high flood level. Or, use mobile storage but should not be parked near water bodies.
Secure storage areas appropriately. Storage facilities must be able to contain spillage.
Dispose of waste promptly and appropriately.
The contractor shall be required to implement an appropriate hazardous waste management program.
Storage of oil and grease used for the maintenance and operation of heavy equipment shall be properly built and maintained, to include bunded storage for the capacity of the containers plus 10%, and oil traps on drainage outfalls.
Part of project (construction) cost
D&B contractor Construction D&B Contractor Scope of Work D&B Contractor’s C- EMP
Public safety as related to future development and activities along the ROW
MWSS must secure the ROW. Existing above ground infrastructure along ROW should be limited. The public must not be allowed to encroach onto the ROW by constructing any buildings or farming the land.
MWSS
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Table 31: EMP for the Operations Phase
Initial Environmental Examination – Output 2
Potential
Possible approach/ Mitigating Measures
Cost of Mitigation/
Responsible
Performance Standard
Guarantee Impact enhancement
Public safety as related to future development and activities along the ROW
MWSS must secure the ROW. Existing above ground infrastructure along ROW should be limited. The public must not be allowed to encroach onto the ROW by constructing any buildings or farming the land.
Part of project maintenance cost
MWSS
CPF (represented by 2 water
concessionaires - MWCI and
MWSI)
Concession agreement
Changes in hydrology along Angat River during dry season
During the operation phase, flows shall be monitored downstream of Ipo dam.
As practice in the Philippines, Ipo dam should maintain 10% riparian flow downstream of Ipo dam. This flow aims to allow migration of fish species and to maintain natural characteristics of the river downstream of Ipo dam.
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Initial Environmental Examination – Output 2
6.3 Institutional Arrangement
6.3.1 Existing Arrangement
The MWSS organization includes an Office of Special Project (OSP) that looks after the implementation
of its special projects. The OSP falls under the Office of the Deputy Administrator for Engineering and
Operations. This project will be managed by the Office for Special Project ‐ Angat Water Transmission
Improvement Project (see Figure 25). The OSP‐AWTIP includes the project manager and his
administrative support staff, a construction group as technical staff, the contractor, and the
construction supervision consultant.
There is no Environmental Unit at MWSS to oversee general environmental concerns and issues of its
projects.
The Resettlement Group within the Support Services Group under the Office of the Deputy
Administrator for Engineering and Operations includes 3 ROW and ECC Officers as shown in .
MWSS has five consultants overseeing the implementation of the Watershed Management Plan for Ipo
watershed. The Consultants were previously employed by Bantay Kalisan, a non‐government
organization of ABS‐CBN Foundation, which was contracted by MWSS to manage the Ipo watershed
and draft the community‐based Watershed Management Plan. The implementation of the Ipo
Watershed Management Plan includes tree planting, patrolling and organizing the People’s
Organization in the watershed. The People’s Organization is predominantly composed of the
Dumagats, the indigenous group in Ipo watershed. The People’s Organization is funded by both
Concessionaires through MWSS.
The two concessionaires, Manila Water Company Inc (MWCI) and Maynilad Water Services Inc
(MWSI), both have their own Environmental Department within their respective organizations. These
departments generally oversee environmental concerns of the operation of their respective companies,
including corporate social responsibility (CSR) activities.
The Common Purpose Facility (CPF) is composed of staff from MWCI and MWSI. The CPF manages
all infrastructures from Ipo dam, tunnels from Ipo to Bigte, Bigte portal Basins and aqueducts from
Bigte to La Mesa dam. The concessionaires’ staffs, assigned in the CPF, take turns in being the head of
the CPF. There is no clear environmental unit within the CPF that looks after the environmental
concerns of infrastructure or projects managed under the CPF.
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Initial Environmental Examination – Output 2
Figure 25: MWSS Organizational Structure
6.3.2 Proposed Arrangements for Environmental Management
For a more‐focused management of social and environmental safeguard concerns of the project, it is
proposed that a Safeguards Group (SG) be set up within the AWTIP OSP. The SG will have its own
social safeguard officer and Environmental Officer (EO) which the MWSS envisioned to provide for
this project. The EO will handle the project’s environmental safeguard concerns/ environmental
management. Qualified representations from the two concessionaires in the SG will be required at least
3 months prior to operation.
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Initial Environmental Examination – Output 2
Figure 26: MWSS Office of Special Projects
6.3.2.1 Proposed Arrangements for Environmental Management
The following institutions are the key players for the environmental management of the Project
a) The MWSS, as the Executing Agency (EA) and the Implementing Agency (IA), for the project
will be responsible for setting up of PMO; engaging an environmental officer for the PMO;
organizing the Multipartite Monitoring Team (MMT) as required by DAO 03‐30; and ensuring
an environment responsible procurement of a D&B Contractor.
b) The Office of Special Project for AWTIP (OSP‐AWTIP), as the project management office,
specifically the EO of its SG, will be responsible for overseeing the implementation of the
Environmental Management Plan (EMP) and conditions prescribed in the Environmental
Compliance Certificate. The TOR for the Environmental Officer is presented in Appendix 6.1.
c) Environment Specialist for project implementation support will provide technical assistance
and guidance to the AWTIP OSP, particularly its EO, in the implementation of the EMP and
ECC conditions.
d) ADB will clear and approve any necessary revisions of the IEE and its EMP. ADB will
clear/concur with any necessary IEE revision and/or EMP updating. Consequently, it will
review environmental monitoring reports and undertake missions to review the environmental
performance of the Project.
e) D&B Contractor incorporates the EMP prescribed environmental considerations in design and
implements the EMP during detailed engineering design and during construction.
f) Concessionaires (MWCI and MWSI), as operators, will provide qualified environmental
officers to work closely with the AWTIP OSP, commencing at least 3 months prior to
construction, and implement the EMP and ECC conditions.
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Set up the OSP-AWTIP. Engage an Environmental Officer for
the OSP-AWTIP. Organize the Multipartite Monitoring
Team (MMT) Sign MOA with DENR and NPC on
Angat Watershed and Forest Range Protected Area
Ensure an environmentally responsible procurement of a D&B Contractor.
Ensure an environmentally responsible maintenance policy
Review and endorse the C-EMP and the spoil management plan to ADB for approval.
Decide on environmental management matters requiring senior management intervention/actio n/ resolution.
Decide on environmental management matters requiring senior management intervention/action/ resolution.
Update IEE and EMP, as necessary.
Coordinate with D&B Contractor to ensure the incorporation of updated findings and mitigation
Measures in design and bidding documents.
Ensure EMP is part of the bidding documents, EMP clauses are incorporated in bidding documents, contracts.
Ensure DENR’s approval of EIS is granted prior to Notice of Award of D&B Contract.
Review D&B Contractor’s EMP (C- EMP) against EMP and the spoil management plan.
Endorse the C-EMP and spoil management plan to MWSS Management Team for ADB approval.
Conduct IEC, together with the Social Safeguard Officer in the OSP-AWTIP, for social preparation.
Ensure D&B Contractor has obtained permits for tree-cutting and use of explosive for
Conduct inspections and spot checks to monitor the performance of the D&B Contractor in implementing the C-EMP/EMP
Review Monthly and semi-annual EMRs of D&B Contractor.
Prepare the Project’s Semi- Annual EMRs for submission to ADB.
Conduct inspections and spot checks to monitor the Performance of the Operator in implementing the EMP.
Review Monthly and Annual EMRs of Operator.
Prepare the Project’s Annual EMR for submission to ADB, until loan closure or as agreed.
Initial Environmental Examination – Output 2
g) DENR/EMB Central Office will review and approve, respectively, the Project’s EIS and conduct
review of the monitoring reports from the AWTIP OSP and MMT.
h) MMT will conduct the periodic monitoring prescribed in DAO 03‐30.
i) Local Government Units, namely the Municipality of Norzagaray (through its Municipal
Planning and Development Office and Municipal Environmental and Natural Resources
Office) and Barangays Bigte and San Mateo will provide representations in the MMT.
Table 32: Institutional Responsibilities
Institution Prior to construction During construction During operation
MWSS
OSP- AWTIP
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Initial Environmental Examination – Output 2
Institution Prior to construction During construction During operation
construction not later than 3 days after receipt of Notice of Award.
Environment Specialist
Provide technical assistance and guidance to OSP-AWTIP in the: - Update of IEE and EMP, as
necessary - Review of bidding documents * - Incorporation of environmental
criteria and weights in the evaluation of bids *
- Review of environmental aspects of bid documents *
- Review of C-EMP against the SPS-compliant EMP
Provide technical advice/assistance e.g, preparation of Semi-annual EMR for ADB, review of results of environmental effects monitoring.
ADB Review and clear updated IEE/EMP, if applicable
Approval of the Spoil Management Plan and the C-EMP
Review Semi- annual EMR.
Review Annual EMR.
Design and Build (D&B) Contractor
Incorporate mitigation measures in design and bidding documents.
Incorporate EMP as part of bidding documents, EMP clauses in bidding documents, contracts.
Prepare a Contractor’s EMP that addresses as minimum the requirements of the EMP.
Obtain Tree-Cutting Permit and Permit to Use
Explosives for Construction not later than 3 after receipt of Notice of Award.
Implement mitigation measures and conduct internal EMP implementation monitoring.
Conduct environmental quality monitoring as prescribed in SPS-compliant EMP. (If an independent Licensed Laboratory will not be engaged)
Prepare Monthly and Semi-annual EMRs.
Operators (MWSI and MWCI)
Ensure an environmentally responsible maintenance policy in congruence to MWSS maintenance policy
Perform maintenance works in accordance with the maintenance policy
Implement mitigation measures and conduct internal EMP implementation monitoring.
Prepare Monthly and Annual EMRs.
DENR Review and approve Project EIS. Review MMT reports.
MMT Conduct environmental monitoring in compliance With DAO 03-30.
Municipality and Barangay
Facilitate social preparation. Participate in the MMT activities.
Participate in the monitoring of the performance of D&B Contractor in
Participate in the monitoring of the performance of Operator in EMP implementation.
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Initial Environmental Examination – Output 2
Institution Prior to construction During construction During operation
EMP implementation.
Facilitate (and participate in)public consultation/s and information disclosure
Review EMRs. Assist in ensuring
the observance of
Facilitate (and participate in)public consultation/s and
information disclosure Review EMRs. Assist in ensuring the
observance of the GRM.
the GRM.
6.3.3.1 Implementation Schedule
Environmental management will be implemented from the detailed design phase through to
construction and operation. Table 33 presents the indicative time frame of key EMP activities in
relation to Project implementation schedule.
Table 33: Environmental Management Implementation Schedule
Activity Indicative Time Frame
PROJECT IMPLEMENTATION
D&B Contractor’s Mobilization Q1 Y1
Surveys and Investigations Q1 Y1
Detailed Design Q1 Y1 – Q2 Y1
Design Review and Approvals Q1 Y1 – Q3 Y1
Construction Q2 Y1 – Q2 Y5
Maintenance Period Q2 Y5 – Q2 Y6
ENVIRONMENTAL MANAGEMENT
Overall
1. Engagement of Environmental Specialist for project implementation support
2. OSP-AWTIP's submission of Environmental Monitoring Report (EMR)
- Monthly EMR for Project's Monthly Progress Report
- Semi-Annual EMR during D&B for submission to ADB
Y0 (in place at least 2 months prior to bidding process for D&B starts)
8th day after effective month
8th day after effective 6-mo. period
- Annual EMR for submission to ADB 8th day after effective year
- Self monitoring report (DAO 03-30) 8th day after effective 6-mo. period
Prior to Notice of Award (NOA)/Notice to Proceed (NTP)
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Initial Environmental Examination – Output 2
Activity Indicative Time Frame
3. Secure MOA (in place of SAPA) Y0 - prior to EIS submission
4. Submit EIS for EMB CO review & secure approval from DENR CO
Y0 - prior to ICC application
5. Secure Tree Cutting Permit Y0 - post-EIS submission, prior to NoA
6. Secure licenses for use of explosives during construction prior to NTP
Y0 – post-NOA, prior to NTP
BETWEEN NTP & PRIOR TO CONSTRUCTION MOBILIATION
7. Inclusion of the EMP in the bid documents; obtaining ECC
8. Finalization of EMP, (if applicable) revision of IEE
9. ADB review and approval of revised IEE and EMP.
10. Community preparation (IEC, including disclosure of Final IEE and its EMP)
11. Preparation of C-EMP by selected D&B Contractor, review of C-EMP against SPS- compliant EMP, clearance from ADB
Construction Period (Mobilization to Demobilization)
1. Implementation of mitigation measures and conduct of environmental effects monitoring following the C-EMP.
2. Submission of Environmental Monitoring Report (EMR)
Q4 Y0 (prior to Notice of Award)
Q1 Y1 (ADB’s concurrence required prior to revision)
Q1 Y1
Q1 Y1
Q1 Y1, before start of works on site or establishment of construction- related facilities.
Q2 Y1 – Q2 Y5
Q3 Y2 – Q2 Y3
- Monthly, by D&B Contractor 5th day of the month following the effective month
- Semi-annually, by D&B Contractor 5th day of the month following the effective 6-month period
- Self-monitoring Report (DAO 03-30 compliance), by OSP AWTIP
- Monitoring Report (DAO 03-30 compliance) by MMT
Operation Period (potentially could start even before Maintenance Period is over)
1. Implementation of mitigation measures and monitoring activities as specified in the EMP
8th day after effective 6-month period
Week 2 after the effective 6-month period
Starting Q2 Y6
2. Submission of EMR Starting Q2 Y6
- Monthly, by Concessionaires 5th day of the month following the effective month
- Yearly, by Concessionaires 5th day after effective year
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Initial Environmental Examination – Output 2
6.4 Environmental Monitoring Plan
Two types of monitoring are required ‐‐ environmental and compliance/ performance monitoring.
Environmental effects monitoring will cover: (1) ambient air quality; (2) noise levels; (3) surface water
quality; (4) groundwater quality; (5) community health and safety prior to construction and during
construction and operation; and (6) workers’ health and safety during construction and operation
(maintenance and repair). Compliance monitoring will monitor and evaluate the performance of the
D&B Contractor, Concessionaire, and OSP‐AWTIP in complying with, or adhering to, the C‐EMP/EMP.
A draft Environmental Monitoring Plan is presented as Table 34.
6.4.1 Monitoring Mechanism
A hierarchy of monitoring teams is presented below.
a) The base layer of monitoring will be done by the D&B Contractor to ensure that construction
impacts on environment and its personnel are within the acceptable limits set in the D&B
Contractor Environmental Management Plan (CEMP).
b) The second layer is the internal monitoring of CPF and MWSS. The monitoring is intended to
provide information useful in promoting consistency and compliance with the Environmental
Management Plan (EMP) and compliance with the ECC conditions and continued update of
the EMP for sustained responsiveness to project construction, operations and impacts.
c) The third layer is an external monitoring by the multipartite monitoring team, which is
composed of representatives of MWSS, CPF, Bgry San Mateo LGU, Bgry Bigte LDU, EMB CO,
relevant government agencies.
d) The fourth layer is an external monitoring by DENR. The monitoring is intended to check
compliance to the ECC conditions and effectiveness of environmental measures
e) The fifth layer monitoring will be undertaken by ADB. This layer of monitoring is intended to
ensure that construction and operation activities comply with ADB policies and safeguards.
f) Independent Monitoring Team is an external independent team to undertake independent
audit and evaluate effectiveness of the environmental measures implemented by the contractor
and the project’s operators (the concessionaires – MWCI and MWSI) to mitigate the
environmental Project Impacts referred to in this IEE. The independent monitoring of the
environmental measures shall be undertaken during construction phase and for the first five
years of operation.
Table 34 summarizes the proposed environmental monitoring plan, which identifies the main
environmental aspects, the potential impact arising, the key parameters to be monitored, and the
sampling and management plan. The monitoring plan focuses on the construction period as no
significant environmental impacts were identified for the operations phase. Currently, MWSS carries
out daily observations of the raw water quality at the inlet structure. Hence, it would not be necessary
to have the same during the operation of Tunnel 4.
Existing conditions have been measured during the conduct of this IEE. The results may be adopted
as the baseline conditions against which results of environmental effects monitoring during
construction will be evaluated. The environmental monitoring plan covers water quality, air quality,
construction noise, and vegetation monitoring.
The monitoring plan should be updated to reflect the DENR recommendation specified in the ECC.
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The bid documents for the procurement of D&B Contractor should include implementation of
environmental measures and drafting of the C‐EMP. This shall be submitted to MWSS for review and
approval.
Table 34: Environmental Monitoring Plan
Key environmental
aspect Potential impact
Key parameters to be monitored
Sampling and measurement plan
During Construction and During Major Repair of Completed Works
Water quality Deterioration of water quality in Ipo Dam and Bigte river Tributary during construction
Physico-chemical parameters including: temperature, pH, conductivity, total suspended solids, dissolved oxygen, BOD, oil and grease, and total faecal coliforms
Method: refer to DAO 1990 -34
Frequency:
Daily observations of water quality
(a) Quarterly water quality sampling to include wet and dry seasons
(b) After every accidental spillage event
Locations:
Angat River Upper Reach
1. Upstream Ipo dam 2. Ipo dam site (in the vicinity of
construction area, near the intake of Tunnel 1,2 and 3)
3. Downstream Ipo Dam
Bigte
4. Upstream Bigte tributary 5. Sitio settling 6. Bigte River 7. Sta Maria River
Air quality Deterioration of ambient air quality during construction
Dust deposition Method: see recommended methods for sampling in testing of ambient air parameters stated in DAO 2000-81
Frequency:
(a) Pre-construction monthly dust deposition monitoring
(b) Monthly monitoring during construction
Location: Ipo Dam site, Bgry Hall of San Mateo, MWSS Bigte Portal, and any haul routes on unpaved roads
Where haulage traffic exceeds 200 heavy goods vehicles (HGV) per day
NOx Method: see recommended methods for sampling in testing of ambient air parameters stated in DAO 2000-81
Frequency: Monthly analysis while construction traffic exceeds 200HGVs / day
Location: At a sample of villages along haul
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Initial Environmental Examination – Output 2
Key environmental
aspect Potential impact
Key parameters to be monitored
Sampling and measurement plan
roads carrying more than 200 HGVs / day
Air quality in the tunnel
Oxygen and carbon monoxide
Method: BS6164 Construction:2011
Frequency: throughout the tunnelling construction period
Continuous monitoring of oxygen with equipment conforming to BS EN 50104
Direct monitoring of carbon monoxide
Construction Noise
Increase noise levels due to (a) blasting, (b) general construction activities, and (c) haulage traffic
Average ambient noise levels LAeq
Maximum noise levels LAeqmax
Method: Direct read out
Frequency:
Minimum of 15 minute measurements at different times of the working day and at night in the event of night-time working.
(a) Pre-construction baseline at all the construction sites and main haul roads and a selection of potential receptors nearby
(b) Monthly monitoring at all the construction sites, including camps, spoil disposal areas, and along the main haulage roads and a selection of potential receptors nearby.
(c) Following complaints from local communities at the complainant’s property and on the nearby construction sites.
Loss and damage to terrestrial vegetation
Over-clearance and damage to vegetation around the construction sites
Frequency:
(a) pre-construction survey of vegetation at construction sites an stake out / fence off vegetation to be retained
(b) weekly monitoring of vegetation cover around construction sites,
(c) monitoring of revegetation of temporary construction sites in accordance with the C- EMP requirements for the restoration of temporary construction sites.
Location: construction areas where vegetation clearance is done
During Operation
Water quality Deterioration of water quality in Ipo Dam and Bigte river Tributary during construction
Physico-chemical parameters including: temperature, pH, conductivity, total suspended solids, dissolved oxygen,
Method: refer to DAO 1990 -34
Frequency:
Daily observations of water quality
(a) Quarterly water quality sampling to include wet and dry seasons
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Initial Environmental Examination – Output 2
Key environmental
aspect Potential impact
Key parameters to be monitored
BOD, oil and grease, and total faecal coliforms
Sampling and measurement plan
(b) After every accidental spillage event
Locations:
Angat River Upper Reach
1. Upstream Ipo dam 2. Ipo dam site (in the vicinity of
construction area, near the intake of Tunnel 1,2 and 3)
3. Downstream Ipo Dam
Bigte
1. Upstream Bigte tributary 2. Sitio settling 3. Bigte River
Sta Maria River
6.5 Performance Indicators
This Section presents the preliminary set of environmental performance indicators to evaluate the
effect of Project implementation on the environment, i.e., whether or not Project is enhancing,
sustaining or deteriorating the state of the environment. The indicators are directed on two
environmental areas that will be impacted by Project implementation: (i) the natural resources and (ii)
health and safety of the concerned communities and Project workers. The selected indicators are
limited to only those that can be measured/ gauged from activities during Project implementation and
that can be tracked over a defined period.
Table 35: Performance Indicators
Indicator
Output / Impact
Baseline Level
Scenario
Target Outcome Performance
Data Source
During Construction and Operation (Major Maintenance/Repair Works)
1. Air
emissions
- Pre-construction
ambient level does not exceed the more stringent limit between national standard and WHO Guidelines
- Pre-construction
ambient level does not exceed the less stringent limit between national standard and WHO
- Level should be equal or less than the more stringent limit between national standard and WHO Guidelines.
- Level should be equal
or less than the less stringent limit between national standard and WHO Guidelines.
- No. of parameters that exceeded, and percentage of excess/es of each over, the more stringent limit/s between national standard and WHO Guidelines
- No. of parameters that exceeded, and percentage of excess/es of each over, the less stringent limit/s between national standard and WHO
- Results of air quality monitoring during construction
- Results of pre- construction air quality monitoring
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Initial Environmental Examination – Output 2
Indicator
Output / Impact
Baseline Level
Scenario
Target Outcome Performance
Data Source
Guidelines. Guidelines
2. Noise
3. Vibration/
ground shaking
4. Surface
- Pre-construction
ambient level exceeds the less stringent limit between national standard and WHO Guidelines.
- No valid complaint lodged on air emissions caused by Project.
- Pre-construction
ambient level does not exceed the more stringent limit between national standard and WHO Guidelines.
- Pre-construction ambient level does not exceed the less stringent limit between national standard and WHO Guidelines.
- Pre-construction ambient level exceeds the less stringent limit between national standard and WHO Guidelines.
- No valid complaint lodged on noise arising from Project
- Pre-construction
level exceeds the applied Guideline.*
- Pre-construction
level does not exceed the applied Guideline.*
- No valid complaint lodged on vibration caused by Project.
- Pre-construction
concentration
- Level should not exceed the pre- construction ambient level.
- No valid complaint
lodged on air emissions caused by Project.
- Level should be equal or less than the more stringent limit between national standard and WHO Guidelines.
- Level should be equal
or less than the less stringent limit between national standard and WHO Guidelines.
- Level should not
exceed the pre- construction ambient level.
- No complaint lodged
on noise during Project implementation
- Level should be equal
or less than the pre- construction level.
- Level should be equal or less than the applied Guideline.*
- No valid complaint
lodged on vibration during Project implementation.
- Concentration should
be equal or less than
- No. of parameters that exceeded, and percentage of excess/es of each over, the pre-construction ambient level/s.
- % of total HHs in main area of influence that lodged valid complaint on severe air emissions caused by Project.
- % of excess over the more stringent limit between national standard and WHO Guidelines
- % of excess over the
less stringent limit between national standard and WHO Guidelines
- % of excess over pre- construction ambient level
- % of total HHs in main
area of influence that lodged valid complaint on noise during Project implementation
- % of excess over the pre-construction level.
- % of excess over the
applied Guideline.*
- % of total HHs in main area of influence that lodged valid complaint on vibration during Project implementation
- % of excess over pre- construction
- Grievance Redress Mechanism records/ report
- Results of noise monitoring during construction
- Results of pre- construction noise monitoring
- Grievance Redress Mechanism records/ report
- Results of vibration
monitoring during construction
- Results of pre- construction vibration monitoring
- Grievance Redress
Mechanism records/ report
- Results of noise
monitoring during
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Initial Environmental Examination – Output 2
Indicator
Output / Impact
Baseline Level
Scenario
Target Outcome Performance
Data Source
water quality
exceeds national standard limit.
the pre-construction construction - Results of pre-
problem in Angat River and Bigte Creek
5. Groundw
ater quality problem
6. Constructi on-related vehicle road accidents
- Pre-construction concentration does not exceed national standard limit.
- No valid complaint lodged on surface water quality caused by Project.
- Pre-construction
concentration does not exceed the more stringent limit between national and WHO Drinking Water Guidelines
- Pre-construction concentration does not exceed the less stringent limit between national and WHO Drinking Water Guidelines
- Pre-construction concentration exceeds the less stringent limit between national and WHO Drinking Water Guidelines.
- No valid complaint lodged on groundwater quality caused by Project.
- No road accidents
involving Project- associated construction vehicles.
- No accident should result in long-term or permanent injury or fatality.
- Concentration should not exceed national standard limit.
- No valid complaint lodged on deteriorating surface water quality during Project implementation.
- Level should be equal or less than the more stringent limit between national and WHO Drinking Water Guidelines.
- Level should be equal
or less than the less stringent limit between national and WHO Drinking Water Guidelines.
- Level should not
exceed the pre- construction concentration.
- No valid complaint
lodged on groundwater quality during Project implementation.
- None and 0% of
construction days with road accidents involving construction vehicles.
- No accident should result in long-term or permanent injury or fatality.
- % of excess over national standard limit.
- % of total HHs in main area of influence that lodged valid complaint on deteriorating water quality during Project implementation
- % of excess over, the more stringent limit/s between national and WHO Drinking Water Guidelines.
- % of excess over the
less stringent limit between national and WHO Drinking Water Guidelines.
- % of excess over pre- construction level.
- % of total HHs in main
area of influence that lodged valid complaint on groundwater quality during Project implementation.
- Number and % of total construction days with road accidents involving construction vehicles.
- Number and % of total construction days with accident that caused serious injuries and/or fatalities
construction noise monitoring
- Grievance Redress Mechanism records/ report
- Results of groundwater quality monitoring during construction
- Results of pre- construction groundwater quality monitoring
- Grievance Redress
Mechanism records/ report
- D&B Contractor's and OSP-AWTIP's EMRs
- D&B Contractor's Safety Team's records
- Grievance Redress Mechanism records/ report
- Records/reports of LGU/ Barangay, local police/traffic authorities
7. Other
environme ntal
- No other valid
environmental complaint lodged
- No other valid
environmental complaint lodged
- % of total HHs in main
area of influence that lodged other valid
-
- Grievance Redress Mechanism records/ report
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Initial Environmental Examination – Output 2
Indicator
Output / Impact
Baseline Level
Scenario
Target Outcome Performance
Data Source
complaints on Project. during Project implementation
environmental complaint during Project implementation.
8. Workers' health and safety hazards(A ccidents, injuries, fire, explosion, landslide caused by earthwork s, social conflicts involving workers, crimes involving workers)
9. Damage
during earthquak e or extreme weather event
- No Project- associated vehicles involved in road accidents.
- No Project-
associated on-site accident or emergency (e.g., fire, explosion, landslide, ground collapse, etc).
- No road accident and on-site accident/
- No Project worker
involved in social conflicts or crime.
- No such events with Project.
- No incident of Project-associated vehicles involved in road accidents.
- No incident of on-site accident or emergency (e.g., fire, explosion, landslide, ground collapse, etc)
- No worker involved in Project- accident/emergency that caused injuries and/or fatalities.
- No worker involved in social conflict or crime.
- No damage during earthquake or extreme weather event.
- Number of incidents of: - Project-associated
vehicles involved in road accidents.
- on-site emergency (e.g., fire, explosion, landslide, ground collapse, etc).
- Number of workers: - injured - met long-term injury - lost lives.
- Number of workers
involved in social conflicts or crimes.
- Number of events inflicting damage on works during construction.
- Number of events with major damage requiring temporary stop of construction.
- Number of events inflicting damage on completed works during construction.
- Number of events with major damage requiring temporary closure of Tunnel 4 operations for repair.
- Progress and monitoring reports of OSP-AWTIP and D&B Contractor's emergency response team.
- Grievance Redress Mechanism Record or Report
- Record and report of the D&B Contractor's
- Records and reports of LGU/ Barangay, local police
- Hospital records
- Operator's field investigation report
- Field spot checks and random interviews by OSP-AWTIP.
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Table 36: Performance Monitoring Indicators
Output / Impact
Baseline Level Scenario
Indicator
Target Outcome Performance
Data Source
During Construction and Operation (Major Maintenance/Repair Works)
1. Air
emissio ns
2. Noise
- Pre-construction
ambient level does not exceed the more stringent limit between national standard and WHO Guidelines
- Pre-construction
ambient level does not exceed the less stringent limit between national standard and WHO Guidelines.
- Pre-construction
ambient level exceeds the less stringent limit between national standard and WHO Guidelines.
- No valid complaint lodged on air emissions caused by Project.
- Pre-construction
ambient level does not exceed the more stringent limit between national standard and WHO Guidelines.
- Pre-construction ambient level does not exceed the less stringent limit between national standard and WHO Guidelines.
- Pre-construction ambient level exceeds the less stringent limit between national standard and WHO Guidelines.
- Level should be equal or less than the more stringent limit between national standard and WHO Guidelines.
- Level should be equal
or less than the less stringent limit between national standard and WHO Guidelines.
- Level should not exceed the pre- construction ambient level.
- No valid complaint
lodged on air emissions caused by Project.
- Level should be equal or less than the more stringent limit between national standard and WHO Guidelines.
- Level should be equal
or less than the less stringent limit between national standard and WHO Guidelines.
- Level should not
exceed the pre- construction ambient level.
- No. of parameters that exceeded, and percentage of excess/es of each over, the more stringent limit/s between national standard and WHO Guidelines
- No. of parameters that exceeded, and percentage of excess/es of each over, the less stringent limit/s between national standard and WHO Guidelines
- No. of parameters that exceeded, and percentage of excess/es of each over, the pre-construction ambient level/s.
- % of total HHs in main area of influence that lodged valid complaint on severe air emissions caused by Project.
- % of excess over the more stringent limit between national standard and WHO Guidelines
- % of excess over the
less stringent limit between national standard and WHO Guidelines
- % of excess over pre- construction ambient level
- Results of air quality monitoring during construction
- Results of pre- construction air quality monitoring
- Grievance Redress Mechanism records/ report
- Results of noise monitoring during construction
- Results of pre- construction noise monitoring
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Initial Environmental Examination – Output 2
Output / Impact
Baseline Level Scenario
Indicator
Target Outcome Performance
Data Source
3. Vibration/
ground shaking
4. Surface water quality problem in Angat River and Bigte Creek
5. Groundw ater quality problem
- No valid complaint
lodged on noise arising from Project
- Pre-construction
level exceeds the applied Guideline.*
- Pre-construction
level does not exceed the applied Guideline.*
- No valid complaint lodged on vibration caused by Project.
- Pre-construction
concentration exceeds national standard limit.
- Pre-construction concentration does not exceed national standard limit.
- No valid complaint lodged on surface water quality caused by Project.
- Pre-construction
concentration does not exceed the more stringent limit between national and WHO Drinking Water Guidelines
- Pre-construction concentration does not exceed the less stringent limit between national and WHO Drinking Water Guidelines
- Pre-construction concentration exceeds the less stringent limit between national and WHO Drinking Water Guidelines.
- No valid complaint lodged on
- No complaint lodged on noise during Project implementation
- Level should be equal
or less than the pre- construction level.
- Level should be equal or less than the applied Guideline.*
- No valid complaint
lodged on vibration during Project implementation.
- Concentration should
be equal or less than the pre-construction
- Concentration should
not exceed national standard limit.
- No valid complaint
lodged on deteriorating surface water quality during Project implementation.
- Level should be equal or less than the more stringent limit between national and WHO Drinking Water Guidelines.
- Level should be equal
or less than the less stringent limit between national and WHO Drinking Water Guidelines.
- Level should not
exceed the pre- construction concentration.
- No valid complaint
lodged on
- % of total HHs in main area of influence that lodged valid complaint on noise during Project implementation
- % of excess over the pre-construction level.
- % of excess over the
applied Guideline.*
- % of total HHs in main area of influence that lodged valid complaint on vibration during Project implementation
- % of excess over pre- construction
- % of excess over
national standard limit.
- % of total HHs in main area of influence that lodged valid complaint on deteriorating water quality during Project implementation
- % of excess over, the more stringent limit/s between national and WHO Drinking Water Guidelines.
- % of excess over the
less stringent limit between national and WHO Drinking Water Guidelines.
- % of excess over pre- construction level.
- % of total HHs in main
area of influence that
- Grievance Redress Mechanism records/ report
- Results of vibration
monitoring during construction
- Results of pre- construction vibration monitoring
- Grievance Redress
Mechanism records/ report
- Results of noise
monitoring during construction
- Results of pre- construction noise monitoring
- Grievance Redress Mechanism records/ report
- Results of groundwater quality monitoring during construction
- Results of pre- construction groundwater quality monitoring
- Grievance Redress
Mechanism records/
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groundwater quality caused by Project.
No road accidents involving Project- associated construction vehicles.
No accident should result in long-term or permanent injury or fatality.
No other valid environmental complaint lodged on Project.
No Project-
groundwater quality during Project implementation.
lodged valid complaint on groundwater quality during Project implementation.
report
- None and 0% of - Number and % of total - D&B Contractor's and construction days construction days with OSP-AWTIP's EMRs with road accidents road accidents - D&B Contractor's involving construction involving construction Safety Team's vehicles. vehicles. records
- No accident should result in long-term or permanent injury or fatality.
- Number and % of total construction days with accident that caused serious injuries and/or fatalities
- Grievance Redress Mechanism records/ report
- Records/reports of LGU/ Barangay, local police/traffic
authorities -
- No other valid - % of total HHs in main - Grievance Redress environmental area of influence that Mechanism records/ complaint lodged lodged other valid report during Project environmental implementation complaint during
Project implementation. - No incident of - Number of incidents of: - Progress and
associated vehicles Project-associated - Project-associated monitoring reports of involved in road vehicles involved in vehicles involved in OSP-AWTIP and accidents. road accidents. road accidents. D&B Contractor's - on-site emergency emergency response (e.g., fire, team. explosion, - Grievance Redress landslide, ground Mechanism Record collapse, etc). or Report
No Project- associated on-site accident or emergency (e.g., fire, explosion, landslide, ground
- No incident of on-site accident or emergency (e.g., fire, explosion, landslide, ground collapse, etc)
- Number of workers: - injured - met long-term injury - lost lives.
- Record and report of the D&B Contractor's
- Records and reports of LGU/ Barangay, local police
- Hospital records
Initial Environmental Examination – Output 2
Output / Impact
Baseline Level Scenario
Indicator
Target Outcome Performance
Data Source
- 6. Constructi
on-related vehicle road accidents
-
7. Other -
environme ntal complaints
8. Workers' health and safety hazards(A ccidents, injuries, fire, explosion, landslide caused by earthwork s, social conflicts involving workers, crimes involving workers)
-
-
collapse, etc).
- No road accident and on-site accident/
- No Project worker
involved in social conflicts or crime.
- No worker involved in Project- accident/emergency that caused injuries and/or fatalities.
- No worker involved in social conflict or crime.
- Number of workers involved in social conflicts or crimes.
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Output / Impact
Baseline Level Scenario
Indicator
Target Outcome Performance
Data Source
9. Damage
during earthquak e or extreme weather event
- No such events with Project.
- No damage during earthquake or extreme weather event.
- Number of events inflicting damage on works during construction.
- Number of events with major damage requiring temporary stop of construction.
- Number of events inflicting damage on completed works during construction.
- Number of events with major damage requiring temporary closure of Tunnel 4
- Operator's field investigation report
- Field spot checks and random interviews by OSP-AWTIP.
operations for repair.
6.6 Reporting
Environmental monitoring activities and findings shall be documented for reporting, recording,
verification, referral and evaluation of the environmental performance of the Project. The
documentation shall also be used as basis in correcting and enhancing further environmental
mitigation and monitoring.
Environmental Monitoring Reports (EMRs) shall be prepared as follows:
a) Monthly, by the D&B Contractor during detailed design and construction and by the
Concessionaires during operation, to be submitted to the OSP‐AWTIP, to include, at least: (1)
physical progress of the Subproject; (2) mitigation measures implemented in line with the C‐
EMP/EMP; (3) grievances received, resolved, closed and those directed to other mechanisms;
and (4) if any, engineering investigation and corrective actions after a seismic or extreme
weather event. The monthly EMRs will be submitted to the OSP‐AWTIP.
b) Quarterly, by the OSP‐AWTIP, incorporating the monthly reports of D&B Contractors or
Concessionaires into the overall quarterly progress report of Project. In addition, to include: (i)
feedbacks from informal random interviews with affected communities; (iii) findings from
regular inspections and unannounced spot checks; and assessment of the environmental
performance of D&B Contractors or Concessionaires.
c) Semi‐annually during detailed design and construction and annually during operation until
loan closure or as agreed, by the OSP‐AWTIP to be submitted to the ADB to fulfill the
environmental agreement in the loan. The Semi‐Annual and Annual EMRs will not only report
on the progress and results of environmental monitoring and compliance of the C‐EMP/EMP
implementation but also: (1) assess the effectiveness of instituted measures; (2) point out
violation/s, if any; (3) assess/recommend corrective actions; and (4) cite any coordination made
for corrective actions and, if applicable, certifications for having instituted them effectively. It
shall also feature any innovative mitigation measures applied by the D&B Contractor or
Concessionaires, and other lessons learned in C‐EMP/EMP implementation. These will be
useful in adjusting the C‐EMP/EMP to adapt to real ground situations. (Proposed adjustments/
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Initial Environmental Examination – Output 2
enhancement of the C‐EMP/EMP must have prior ADB clearance.)
A draft outline for the Semi‐Annual and Annual EMRs is presented as Appendix 9. The monthly
EMRs by the D&B Contractor, Operator and PIU may adopt the outline, as applicable, to facilitate the
preparation of the Semi‐Annual and Annual EMRs.
In compliance with the Revised Procedural Manual for DAO 03‐30 and addressing the conditions of
ECC, the environmental monitoring reports shall be prepared as follows and submitted to EMB CO:
a) OSP‐ AWTIP shall prepare and submit Self Monitoring Report to EMB CO on semi‐annual
basis following the outline prescribed in the Revised Procedural Manual for DAO 03‐30.
b) MMT shall prepare Compliance Monitoring and Validation Report as the MMT Report Form
on quarterly basis.
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7 Public Consultation, Information Disclosure and Grievance Redress Mechanism
7.1 Public Consultation
The public consultation was carried out during the early stage of preparation for the feasibility study
and after the results of the preliminary surveys on air quality, water quality, vegetation, wildlife and
aquatic resources were known. The consultation meetings were held with the communities and
barangay councils of Brgy. San Mateo and Brgy. Bigte, NCIP, Dumagat leaders and communities at Ipo
watershed and CPF. The information about the project’s environmental issues and concerns and
technical data of the project were discussed in Tagalog, a dialect which the locals and indigenous
peoples (IP) can understand. In addition to the public consultation, focus group discussions were held
with the IP communities.
The following issues were raised during the consultation with Brgy. San Mateo, Brgy. Bigte and
Dumagat communities.
Table 37: Summary Matrix of Issues Raised at Public Consultation
Key issues and concerns Response/ comments
a) Lack of domestic water supply in Brgys. Bigte and San Mateo.
b) Identification of affected person (APs),
especially the residents along MWSS ROW. Concerns on the process of demolition of properties (with land titles and illegal resettlers) along MWSS ROW.
c) Impacts on road safety due to increase in traffic and transportation of spoil from the construction site to temporary spoil disposal. Identification of the roads likely to be affected especially during the construction phase.
d) Employment opportunities for the local
population (Brgys. Bigte and San Mateo).
e) Generation and management of spoil. Residents requested whether they could take the spoil for their personal use, e.g. as backfill material in their house plots. Spoil can also be used as community road backfill especially in dirt roads.
Other MWSS project is underway and looking at the feasibility of treated water distribution in Bulacan.
MWSS assures to have proper survey of the tunnel ROW before project commences. Affected residents will be compensated if relocation is needed
The residents are aware that their houses and/ or their house plot fences have encroached in the RROW. The 1m road easement on both sides of the road is recognized by the residents.
Mitigating measures on the potential impacts caused by the transportation of spoil will be included in the EMP. Possible mitigating measure
The community will be prioritized for jobs suitable to their acquired skills and capability.
The residents’ request for spoil may be course through the barangay council and such consolidated request will be forwarded to MWSS/ D&B Contractor.
f) Commencement of the project construction. The project is expected to start in 2014. For the project to push through, several approvals are needed and release of loan from ADB.
g) The barangays are keen to having another consultation/ discussion on the project implementation prior to start of construction.
h) Determination of alternative routes and fish landing at Sitio Ipo.
Consultation meetings with affected communities will be done by MWSS prior to construction.
Alternative route and boat landing should be identified prior to commencement of tunnel
construction. Potential boat landing site was
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Initial Environmental Examination – Output 2
identified near the mouth of Sapang Munti, a tributary of Angat River which is near the dam site.
7.2 Information Disclosure
Results of the surveys undertaken were discussed with Brgy. San Mateo, Brgy. Bigte and IP community
at Sitio Ipo in Brgy. San Mateo. Public consultation meetings apart from the meetings held as reported
in this IEE should be conducted with the potentially affected communities in Brgy. Bigte and Brgy. San
Mateo in the Municipality of Norzagaray. The meeting should engage the stakeholders and discuss
monitoring activities, implementation of the EMP that may require community collaboration, grievance
redress mechanism as described in this IEE. Suitable communication method should be used.
7.3 Additional Public Consultation and Information Campaign
To keep the directly impacted barangays aware of the progress of the project and necessary
contribution, additional public consultations should be carried out after the detailed engineering
design documents have been submitted by the D&B Contractor and approved by MWSS.
Stakeholders must be invited and encouraged to participate in community discussions. The OSP‐
AWTIP, D&B Contractor and Concessionaires will be easily accessible to contact by the public on
matters concerning project progress, adverse impacts, mitigation measures, environmental monitoring
and grievances. The PMO, in coordination with the concerned Barangays of San Mateo and Bigte, will
be responsible for organizing public consultations. Specifically, the conduct of the following:
a) At least one month prior to the start of construction mobilization, a joint social and
environmental information campaign by the OSP‐AWTIP on the project’s social and
environmental impacts with emphasis on health and safety concerns should be carried out to
communities in Brgy. San Mateo and Brgy. Bigte;
b) During construction, informal interviews by the OSP‐AWTIP to monitor environmental
concerns of the same communities to be able to address them; and
c) During operation, in the first two years, periodic random interviews by the Concessionaires to
continue to monitor the communities’ environmental concerns.
During entire project implementation, the final IEE and its EMP, as well as the GoP‐approved EIS will
be made available in the PMO and MWSS for the reading of the interested parties. Copies may be
made available upon formal request.
7.4 Grievance Redress Mechanisms
Grievances raised on environmental impacts are critical to the health, wellness and safety of affected
persons (APs). Hence, the proposed mechanism intends to be easily accessible and promptly
responsive to APs’ environmental complaints. The proposed formal grievance redress mechanism
(GRM) for the Project is presented below in Figure 27: Grievance Redress Mechanism Diagram. It
shows an integrated social and environmental mechanism. For environmental complaint, an AP may
also opt for an informal approach to have his/her grievance addressed. The subsequent sub‐section
describes the approach for environmental complaint.
7.4.1 Informal Approach
TA 8196-PHI: Angat Water Transmission Improvement Project
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Initial Environmental Examination – Output 2
Informally, APs can lodge complaints directly to the D&B Contractor during construction or CPF
(Common Purpose Facility) during operation. The D&B Contractor/CPF shall document and assess the
complaint immediately. If assessment validates the complaint as within the scope of the GRM/eligible,
the D&B Contractor/CPF shall act on the complaint within three days from receipt of complaint. If
assessment invalidates the complaint (i.e., reveals the complaint as ineligible or not associated with the
Project’s environmental performance), the D&B Contractor/CPF shall direct the AP to the Grievance
Committee for confirmation, triggering the formal approach.
The Contractor/CPF shall report the following to the OSP‐AWTIP within 2 days from receipt of
complaint: (i) complaint received, eligible or ineligible, duly referenced; and (ii) actions to be taken/
taken including timeline. The OSP‐AWTIP shall obtain a written confirmation of satisfaction from the
AP, 7 days from completion of resolution by Contractor/CPF.
7.4.2 Formal Approach
If complaint lodged informally is eligible but is not acted on within three days from receipt of
complaint, or if AP is not satisfied with the resolution undertaken by the Contractor/CPF, he/she can
access the formal approach. A Project Grievance Committee (GC) will be set up to consist of the
Barangay Council (or IP Chieftain and Council for IP complaints), Contractor, CPF and MWSS as
follows:
Step 1 Lodging a Complaint (Day 1)
AP lodges complaint with the OSP‐AWTIP or the Barangay.
Step 2 Documentation and Registration of Complaint (Day 1)
OSP‐AWTIP or Barangay registers lodged complaint and makes sure these are duly
referenced and provides AP with a copy of referenced complaint.
The Barangay forwards a copy of the referenced complaint to the OSP‐AWTIP.
Step 3 Screening (Day 1)
OSP‐AWTIP or Barangay screens if complaints relates to Tunnel 4.
AP is informed if the grievance relates or does not relate to Tunnel 4.
The Tunnel 4 Grievance Committee (GC) is also informed of the screening result.
If screening ruling is not acceptable to the AP, he/she may re‐lodge his/her complaint with
the Grievance Committee, which will properly document the complaint.
Step 4 Complaint Investigation (Day 1‐3)
The GC conducts investigation of the complaint to determine if actions are required or not.
The AP is informed of the findings/ruling.
If actions are required, AP is informed of the expected action timelines as set out in the
established mechanism. Agreement on actions and measures and time involved are made
with the AP. Agreement is properly documented and filed. OSP‐AWTIP, Barangay
Council (or IP Chieftain and Council), Contractor/CPF and AP are furnished copies.
If actions are not required and GC ruling is not acceptable to the AP, AP may file the case
with the Municipal Local Government Unit.
Step 5 Implementing the Agreed Action
For minor action required: (Day 4‐5)
The Contractor/CPF implements agreed on action within 2 days.
TA 8196-PHI: Angat Water Transmission Improvement Project
116
Initial Environmental Examination – Output 2
If AP is not satisfied with the completed action or if action is not started within 2 days from
GC ruling, AP may file case with the Municipal LGU.
For major action required: (Day4/5‐Day 8/9)
The Contractor/CPF provides agreed interim measure and starts work on the final action
within 5 days from the GC ruling.
If AP is not satisfied with the completed action or if action is not started within 5 days from
GC ruling, AP may file case with the Municipal LGU.
Step 6 Acceptance of Resolution (1 week after completion of action)
If, according to the AP, the impact has been resolved satisfactorily, OSP‐AWTIP will obtain
a written confirmation of satisfaction from the AP. This confirmation will signify closure
of grievance and will form part of the grievance documentation. The GC, Barangay
Council (or IP Chieftain and Council), Contractor/CPF and AP are furnished copies.
Step 6 Monitoring and Evaluation (for 1 week after completion of action)
The OSP‐AWTIP shall monitor the effectiveness of the resolution for at least a week after
completion of action.
Monitoring and evaluation shall be properly documented and included in the
Environmental Monitoring Report (EMR).
The mechanism prescribes that the OSP‐AWTIP shall inform the ADB of: complaints evaluated as
major issues; and any appeal raised by dissatisfied AP.
The AP wishing to make a claim must first make an appeal to his respective barangay or to the IP
leaders for the case of the Dumagats. The claim must be made in writing and should include brief
details including factual background; issues; and AP’s position on the issue/s raised. The barangay
must review the case within the context of existing policy, regulations, procedures and valid
entitlement of the AP as provided in relevant implementing plans. The barangay council should
respond within five days of receipt of the complaint. Should the grievance case cannot be resolved, the
AP can file complain to the municipal level.
TA 8196-PHI: Angat Water Transmission Improvement Project
Initial Environmental Examination – Output 2
Figure 27: Grievance Redress Mechanism Diagram
117
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Initial Environmental Examination – Output 2
8 Findings
The main impacts will occur during construction and these can mostly be mitigated within acceptable
levels.
The construction work area (CWA‐Ipo) of about 1ha area called “Consultant/Workers Area” in Ipo dam
site would entail vegetation clearing prior to construction. This would sacrifice some 67 trees/ha in the
area, although most are low diameter and non‐timber, non‐commercial species. The same is true for
Bigte tunnel outlet construction site where there will also be clearing and where several mature rain
trees will be affected. This can be mitigated by replacing the species that will be cut with the same
species and plant the same in the open portions of the property. Also, a planned clearing of vegetation
and keeping the vegetation clearing to a minimum will need to be done. The loss of vegetation is
considered to be a low adverse impact, given the small area affected, the absence of rare and
endangered species.
There are two river systems draining a seemingly separate watershed areas that are the immediate
impact areas of the project: the tunnel inlet construction may potentially impact on the Angat river
system, and the tunnel outlet construction will impact the Bigte‐Sta. Maria River system. During
construction, there will be potential for temporary, short‐term, reductions in water quality due to the
construction activities. The main pollutants are likely to be elevated levels of suspended solids in
channel works and site drainage, and oils and grease from leakage from machinery and accidental
spillages. These can be controlled to a large extent through good site practice, to minimize in‐channel
works, control soil erosion and runoff, and avoid accidental spillages. It should also be noted that high
turbidity is normal during the wet season. High coliform content of the water in Ipo dam/Angat river
waters and the Bigte‐Sta. Maria channel may be due to human and animal (domesticated) waste being
thrown to the river waters. Immediate contact with these waters may produce medical/health concerns
with the people. Turbidity and siltation of these water systems are prevalent, especially during the wet
season.
Aquatic ecological studies indicate that the biodiversity of aquatic species in Angat river and Bigte
creek is low and had not identified rare species. Limited construction works may impact on the
plankton and benthos in localized areas during the construction period, but the aquatic system would
be expected to recover to current ecological status following construction. Noise, vibration and poor
water quality may disturb fish, which could find refuge elsewhere in the reservoir upstream. The
construction works may have a low, temporary, and highly localized effect on aquatic ecology. It
would be desirable, but not essential, to look at the dry season scenario of the macro‐benthic
communities in the various sites.
The water quality in Ipo dam/Angat river waters and the Bigte‐Sta. Maria channel showed exceedances
of bacteriological standards, which may be due to human and animal (domesticated) waste discharged
to the rivers. Direct contact with these waters may produce medical/health issues for the people. Care
must be taken in the siting of construction camps and the collection and handling of wastewaters that
the surface waters are not contaminated further as a consequence of the construction works.
The presence of mercury in the fish samples also may lead to health hazards the local population who
consume the locally caught fish. The project is not expected to change the situation.
There may be temporary disturbance to wildlife during the construction phase. The contiguous Angat
watershed will serve as the wildlife refuge while construction is ongoing and overall the impact of
construction on wildlife is considered to be negligible and no mitigation has been proposed. The initial
survey conducted during the wet season provides an indication of species present in the area and can
be used as baseline for the subsequent monitoring, especially in the construction area and adjacent
119
Initial Environmental Examination – Output 2
areas of Isla Puting Bato in Angat Watershed Area.
Defective housing units were observed in the AFP housing project in Brgy. San Mateo. It is unlikely that
construction of the tunnel would generate sufficient vibration to damage the property, given the depth
of the tunnel. Defects cannot be associated with tunnel construction.
The traffic management along Ipo road is poor. There are only few road signs. No speed limits are
enforced considering that the road is winding. Several houses were observed to encroach upon the
road ROW. These factors contribute to reported road accidents along Ipo Road.
Large volume of spoil will be generated and the spoil is considered a good construction material. There
are temporary spoil disposal site identified in the feasibility study and in this IEE Report. The
excavated materials are characterized to be very good construction materials that can be used during
tunnel construction, backfill of barangay roads and material to concrete mix products.
Operational impacts are minimal. It is anticipated that the transport network will be affected during
the operation due to slight increase some vehicles travelling to Ipo dam site for maintenance. Potential
impact may also include decrease in the natural water flow of Angat river especially during dry season
since Tunnel 4 is expected to augment water supply of AQs to their full capacities.
MWSS doesn’t have experience in environmental supervision and implementation of environmental
measures. Watershed unit is in place but it is not institutionalized and does not function as
environmental unit of MWSS.
120
Initial Environmental Examination – Output 2
9 Conclusions and Recommendations
The Project will improve and expand the raw water transmission system, increasing the reliability and
security of raw water transmission and ensuring sustainable water supply services to Metro Manila.
The IEE concludes that most of the environmental impacts associated with Tunnel 4 are expected to
arise during construction. Potential impacts will be localized and site‐specific. Most of the identified
impacts are low and temporary and if assessed carefully, it can be mitigated to an acceptable level
without difficulty through good site, engineering and construction practices. No significant adverse
impacts have been identified during operation phase.
The few impacts of high magnitude (without mitigation) during construction will not be distinct.
Tunnel 4 will be the fourth tunnel to be constructed in the MWSS ROW. These impacts will not be
sufficient to threaten the surrounding resources. During operation, low to moderate impacts will come
from maintenance and repair.
The wildlife and river ecology surveys were done during the wet season. There is a need to assess the
same parameters during the dry season, which is considered the baseflow period to provide a more
robust baseline data. The EMP should be updated whenever necessary.
More detailed infrastructure survey should be carried out and existing conditions of the infrastructure
should be noted. At the preliminary stage of Tunnel 4 project, it was observed that there were poorly
constructed housing units of the AFP subdivision. Such defects occurred prior to the tunnel
construction and cannot be associated as an impact of the tunnel construction activity.
During the detailed design phase, further consultation is required to address the concerns raised
during previous consultations to ensure that all public concerns are updated and publicly
acknowledged and incorporated into detailed designs and updated EMP.
Also, during the detailed design, environmental due diligence should be conducted on the key
associated facilities, namely: Ipo dam, Basin 3 and Aqueduct 5.
The EMP presented here should be updated during the detail design phase to:
a. Update the legislation and administrative arrangements,
b. Incorporate the results of further terrestrial and aquatic surveys, and land use surveys,
c. Update the impacts and mitigation presented herein,
d. Expand upon the mitigation and monitoring plans, and
e. Develop capacity building needs.
In the event of design deviation, such as shift of alignment resulting in tunnel being located outside the
MWSS ROW, change in inlet structure location and/or change in the method of construction, the MWSS
through its PMO should immediately: (1) seek the advice of EMB Central Office if such design
deviation warrants an ECC amendment; and (2) inform ADB should EMB advise for ECC amendment
and finally, (2) seek ADBʹs clearance/concurrence for an IEE revision and/or EMP updating.
The successful Contractor shall be required to prepare and implement a Construction Environmental
Management Plan based on SPS compliant EMP. The following specific sub‐management plans should
form part of the C‐EMP: chance finds recovery and removal; and include with the excavation subplan
placement of temporary berms and plastic sheeting between excavations and adjacent land, surface
waters, and property to prevent erosion, sedimentation, or contamination from excavation work, noise
control plan, dust control plan; and workers and staff health and safety plan.
121
Initial Environmental Examination – Output 2
Based on the above conclusion and recommendation, no further detailed EIA needs to be undertaken to
comply with ADB SPS. Under GOP policy an EIS is required. The EIS will be based on this IEE.
122
Initial Environmental Examination – Output 2
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