Philippines - Manila Second Sewerage Project : environmental impact assessment (Vol. 11 of 27) : Initial Environmental Examination of Project no. 9 ; Philippines Centennial Cillage, Taguig, Metro Manila

E94 Volume 1 1 Metropolitan Waterworks and Sewerage System Manila Water Company, Inc. Initial Environmental Examination of the Community Sanitation Project Manila Second Sewerage Project IBRD 4019 Project No. 9 Philippine Centennial Village (Centennial Village) Taguig, Metro Manila Prepared by: Manila Water Company, Inc. 489 Katipunan Rd, Balara, Quezon City Decembei 2001 FILE COPY  TABLE OF CONTENTS PAGE NO. Executive Summary 7 1.0 PROJECT DESCRIPTION 1.1 BASIC PROJECT INFORMATION 1 1 1.2PROJECT LOCATION 12 1.3PROJECT RATIONALE 14 1.4 DESCRIPTION OF PROJECT PHASES 1.4.1 Pre-Operational/Construction Phase 1.4.1.1 Construction Plan 16 1.4.1.2 Total Surface Development Block 16 1.4.1.3 Estimate Total Area to be opened for Civil Works 16 1.4.1.4 Major Openings and Construction Activities 16 1.4.1.5 Types of Equipment to be Used 19 1.4.1.6 Source of Construction Materials and Facilities 19 1.4.1.7 Support Services and Facilities Requirements and Availability 20 1.4.1.8 Estimate of Total Cut Soil Volume 20 1.4.1.9 Total Manpower Requirement 20 1.4.2 Operational Phase 1.4.2.1 Project Operation Schedule and Duration 21 1.4.2.2 Process Technology and Activities 21 1.4.2.3 Waste Production Scheme 22 1.4.2.4 Manpower Requirement 24 1.4.3 Abandonment Phase 24 2.0 BASELINE ENVIRONMENTAL CONDITIONS 2.1 STUDY METHODOLOGY 2.2 LAND 25 2.2.1 Land Resource Utii_ation 25  2.2.2 Physiography and Geology 25 2.2.3 Vegetation and Wildlife 25 2.2.4 Land Acquisition Assessment 26 2.3 WATER 2.3.1 Inventory of Water Bodies 26 2.3.2 Water Quality (Surface/Ground) 26 2.4AIR 27 2.5 PEOPLE 2.5.1 Population/Beneficiary 27 2.5.2 Project Affected Persons 27 3.0 PROJECT ALTERNATIVES 27 4.0 IMPACT ASSESSMENT 4.1 IMPACT IDENTIFICATION 4.1.1 Impacts During Construction Phase 30 4.1.2 Impact During Operation Phase 31 4.2 IMPACT PREDICTION AND EVALUATION 33 4.3 UNAVOIDABLE AND RESIDUAL IMPACTS 34 5.0 ENVIRONMENTAL MANAGEMENT PLAN 5.1 IMPACTS MITIGATION / ENHANCEMENT PLAN 34 5.2 ENVIRONMENTAL MONITORING ACTION PLAN 39 6.OCOMMUNITY CONSULTATION PROCESS 40 3  LIST OF FIGURES __S11 1 Location Map of BLC 13 2 Existing Sewer Network Layout 15 3 Proposed Implementation Schedule 17 4 Proposed Sewer Collection Layout 18 5 General Treatment Process Scheme 23 6 Photograph of STP site 26 4  LIST OF TABLES I Typical Analysis of Septic Tank Effluent Quality 15 2 Estimates of Soil Excavation Volumes 20 3 Influent Flow Characteristics 21 4 DENR Effluent Parameters for Class C Waters 22 5 Sources and List of Potential Environmental 29 Impacts 6 Typical Noise Emissions of Construction 31 Equipment at Various Distances from Source in dB(A) 7 Sludge Production of Various Wastewater 32 Treatment Processes 8 Summary of Assessment of Environmental Issues 33 / Impacts 9 Environmental Management Plan 34 10 Environmental Monitoring Action Plan 39 11 Institutional Monitoring 40 5  LIST OF ANNEXES 1 Manila Water Company STARRT Card for Monitoring Construction Works 2 Wastewater Quality Monitoring Schedule 3 Environmental Compliance Certificate (ECC) NCR-2000-12- 11-0268-211 4 Manila Water PCO Report Format 5 Sample Monitoring Sheet for Effluent Quality 6 Endorsement from the Barangay Captain 7 Memorandum of Agreement (MOA) between Manila Water Company and the Bases Conversion Development Authority 6  EXECUTIVE SUMMARY The proposed project for Philippine Centennial Village (Centennial Village) is one of the twenty-three (23) sub-projects of the Community Sanitation Project Phase 1, which is a component of the World Bank-assisted Manila Second Sewerage Project (MSSP). The project is intended to reduce the current wastewater pollution discharged to the Laguna Lake by the one thousand one hundred and forty (1,140) residential units in Centennial Village. The project involves the improvement and rehabilitation of the sewerage system in the compound. Specifically, the project includes the installation of sewer lines to intercept sewage flows from existing communal septic tanks as well as raw wastewater flows from buildings without septic tanks. An underground centralized sewage treatment plant (STP) will be constructed to treat the wastewater flows. A Memorandum of Agreement (MOA) between Manila Water Company and the Bases Conversion Development Authority (BCDA) will be executed for the project. In conformity with the requirements of the Department of Environment and Natural Resources (DENR), an Environmental Compliance Certificate (ECC) NCR-2000-12-11-0268-211 issued pursuant to P.D. 1586 was secured for the project. I. BASELINE ENVIRONMENTAL CONDITIONS Philippine Centennial Village was developed for the housing needs of the population affected by the disposition of portions of the Fort Bonifacio military reservation. Completed in 1997, Centennial Village occupies a 67,201 square meter land bounded by the C5 Road in the North, SSB Village in the east and EP village in the south. Centennial Village consists of thirteen (13) multilevel buildings with a total of 1,140 units and an estimated population of 7,980. Floral population within Centennial Village constitutes ornamental plants and a few trees. Faunal population is limited to household pets and stray animals. The area is characterized by a relatively even distribution of precipitation during the year. Like in most parts of Metro Manila, the community has two distinct seasons: the dry season during the months of November to May and the wet season during the months of June to October.  Existing Sewerage System The sewerage system serving the 7,980 population of Centennial Village is made up of sewer pipes with diameters ranging from 150-200 millimeters. The sewer lines collect wastewater from each of the thirteen buildings and are directed to five communal septic tanks. From the septic tanks, settled wastewater flows to the local drainage system. From the drainage system, untreated/partially treated wastewater flows to an unnamed creek which discharges to the Laguna Lake. The current BOD5 of the Laguna Lake ranges from 2-5 mg/L which falls within the BOD5 for Class C waters. DENR Administrative Order 34 (DAO 34) describes Class C water as that suitable for the following: 1. Fishery Water for the propagation and growth of fish and other aquatic resources; 2. Recreational Water Class II (Boating, etc.); 3. Industrial Water Supply Class I (For manufacturing processes after treatment). II. ENVIRONMENTAL IMPACTS AND MITIGATING MEASURES Potential Mitigating Measures Environmental Impact 1. Poor quality of . Manila Water Company will monitor the supply and installation construction contract to assure quality of equipment and construction. Site Managers and Engineers with experience in construction management shall approve all materials and equipment to be used and installed at the site. * The contractor will be required to post a performance bond for the Design and Construction Contract of the sewerage system.  2. Air pollution * Efficient construction planning and work scheduling (suspended particulates, . Formulation of appropriate work plans, work scheduling, work odor and fumes, vehicle specifications and work methodologies emissions eg. C02, CO * Provision of properly maintained storage area for keeping NO,) stocks of construction materials and equipment * Prompt and fast removal of excavated materials or dredges spoils from construction site * Sprinkling of water on dust-generating mounds of resulting from earthmoving activities and civil works. * Control of motor vehicle emissions . Dust accumulation will also be prevented through proper washing of the vehicles prior to its departure from the site * Development and enforcement of strict health and safety pollution control regulations specific for the project site - Good housekeeping of workplace and construction affected areas - Use of Protective Gear by all workers 3. Water pollution due to . Provide temporary drain systems and storage facilities for wastewater, oil excavation soils, fuel and oils needed for equipment leakage/spills * Cautious and sensible planning for construction and post- construction phases of the project . Provision of a routine chemical and oil spill clean-up plan * Formulation of a monitoring program 4. Noise pollution from . Establish temporary sound barriers around the work site operation of construction . Proper scheduling and phasing of high-noise activities equipment * Use of appropriate mufflers and sound proofing for construction machinery, equipment and engines . Use of Personnel Protective Equipment by all workers 5. Temporary disruption of a Public information campaign posting schedule of construction traffic flow within the . Provision of a liaison officer from the residents of the compound compound to assist the information dissemination regarding inevitable changes in schedule of operations . Provision of temporary alternative routes, including visible traffic warning signals . To the extent possible, sewer lines, manholes and lift station will be constructed in common areas not used for pedestrian or vehicular traffic . Scheduling of delivery materials and removal of excavated material during non-rush hour periods. 9  OPERATIONAL PHASE 1.Environmental hazards * Carefully designed post-construction maintenance, due to accidents, man- contingency and monitoring programs made and natural disasters . Well designed plan for detection of accident or natural events eg. accidental spills, fire, including precautionary and remedial measures to be seismic activity, observed earthquakes, heavy . Provision of preventive and remedial procedural manuals at rain/flooding and design workplace failure . Adequate plans for environmental rehabilitation and restoration of site and removal of temporary structures and facilities installed during construction phase 2. Water Pollution (effluent . Wastewater discharged by the STP shall conform with the discharge) Effluent Standards set forth in DENR Administrative Order 34 and 35 for Class C waters . Regular monitoring of wastewater effluent by the Manila Water Company Central Laboratory . Regular check on sewer lines to prevent discharge/seepage of untreated wastewater to the environment . Quality of civil work on the STP facility shall be enforced during construction to avoid seepage 3. Noise Pollution (STP . Use of appropriate mounting for machinery to minimize equipment, lift station) vibration * All mechanical/electrical equipment shall be installed inside enclosures * If appropriate, motors shall be provided with soundproofing devices . Maintenance of greenbelt zones and vegetation with appropriate tree species 4. Solid Waste . Solid waste generated within the STP facility will be minimal (generated within the facility but provision will be made for garbage collection and by the facility) * Disposal of sludge generated will be in accordance with established procedures of relevant authorities (disposal of sludge for use as soil conditioner) 5. Odors (organic and sulfur . Maintenance of greenbelt zones and vegetation with compounds coming from appropriate tree species raw wastewater and during . Provision of landscape which will improve the aesthetic of the desludging of septic tanks) area by planting green strips using appropriate plant or tree species . Provision of odor control mechanisms (deodorizer/adsorbent/masking agent) to prevent malodorous emissions) 6, Maintenance and . Regular asset condition monitoring by Manila Water Company Operation of the System personnel * Poor maintenance of . Regular maintenance works for STP equipment (pumps and mechanical equipment motors), sewer network and septic tanks (pumps and motors) . Adequate training of STP operators * Connections . A liaison officer from the Community will assist the STP operator in assuring the facility's efficiency in operation . Provision of adequate maintenance equipment and spares for the- sewerage system facility 10  111. ENVIRONMENTAL MONITORING PLAN Environmental monitoring will be the responsibility of Manila Water Company. i - Jo - -e - Construction Phase Compliance with Manila . At STP site and its * On-the-spot daily Water Company health and perimeter inspection and safety policies (dust . Pipe laying area monitoring will be emissions, good * Equipment and implemented by the housekeeping, noise, odors) materials storage area Health and Safety Dept. of Manila Water Company using the STARRT Card (Annex 1) Traffic . Ingress and egress to * Daily the construction site Operational Phase Effluent Water Quality . Influent * Annex 2 describes in for parameters like pH, 5-day . Samples from detail the schedule of BOD, COD, Total coliform, Treatment stages wastewater quality suspended solids, and oil and . Effluent monitoring. grease. Odor * STP site and . Daily perimeter Sludge * -At STP site accumulation/Clogging * Sewer network . Weekly a Communal septic tanks  1.0 PROJECT DESCRIPTION 1.1 Basic Project Information Name of Project PHILIPPINE CENTENNIAL VILLAGE COMMUNITY SANITATION PROJECT MANILA SECOND SEWERAGE PROJECT Address PHILIPPINE CENTENNIAL VILLAGE, Barangay Western Bicutan, Taguig, Metro Manila Contact Persons : Leonor C. Cleofas Manager, Engineering and Project Management Office Metropolitan Waterworks and Sewerage System Ground Floor, Engineering Building, MWSS Complex, Katipunan Road, Balara, Quezon City 1105 Tel No. (632) 920-5413; (632) 920-5521 to 40 locals 3570/3569; Telefax: (632) 922-2568 Ma. Fiorella De Los Reyes-Fabella Wastewater Project Development Manager Manila Water Company, Inc. 489 Katipunan Road, 1105 Balara, Quezon City, Philippines Tel No. (632)981-8147; (632)926-7999 loc2032 Fax (632) 981-8106 1.2 PROJECT LOCATION The proposed project for Centennial Village is a sub-project of the Community Sanitation Project, which is a component of the World Bank-assisted MSSP. The service area is the entire Centennial Village. The project site is along C5 Road. Figure 1 presents the vicinity map of the project. 12  Figure 1. Location Map 0 EL1 02 j Project Area v Water Bodies 13  1.3 PROJECT RATIONALE In Metro Manila, untreated/partially treated domestic wastewater is the major source of pollution of inland waters. Most residential houses in Metro Manila treat their wastewater by means of septic tanks, which do not provide adequate treatment to satisfy the DENR requirements for wastewater effluent standards. Moreover, majority of septic tanks in Metro Manila is not properly maintained. This situation has led to the deterioration of the Pasig River and other inland waters. The DENR has estimated that around 60% of the pollution load to Pasig River, which empties to Manila Bay and Laguna Lake, come from domestic discharges. In the case of Laguna Lake, 65% of the pollution loading is attributed to domestic waste. There is therefore an urgent need to establish collection and treatment methods that will help reduce the pollution load to inland waters. The provision of an efficient and cost-effective sewage collection, treatment and disposal is the primary objective of the Community Sanitation Project under the MSSP. This project specifically aims to address the problems of inadequate wastewater treatment and disposal in Centennial Village. Figure 2 shows the existing sewer layout in Centennial Village. Inadequate treatment of wastewater in septic tanks is indicated by the typical analysis of the effluent quality of septic tanks in other project sites (see Table 1 below). The project will help reduce public health risks and environmental pollution from untreated/partially treated domestic wastewater by providing a sustainable sanitation and sewerage facility. It will also serve as a good illustration of proper sanitation especially to the neighboring communities near Laguna Lake. Table 1 Typical Analysis of Septic Tank Effluent Quality Parameter Limit(s) Septic Tank DENR-EMB Effluent PH 6.5-9 7.3(27.90C Suspended solids, mg/L 70 90-120 Dissolved Oxygen, mglL 0.00 Biochemical Oxygen Demand 50 150-5 (BOD5), mgIL Chemical Oxygen Demand, mg/L 100 200-M300" Total Coliform Count, MPN1100 ml 10,000 i06-107 Fccal Colif,rm Count, MPNI100 m! _ -107. 14  Figure 2 Existing Sewer Network Layout Manila Water BOX CULVERT 15  1.4 DESCRIPTION OF PROJECT PHASES 1.4.1 Pre-Operational I Construction Phases 1.4.1.1 Construction Plan The project is scheduled for bidding in December 2001. Construction is expected to commence in March 2002 and project completion is targeted in October 2002 (240 calendar days). Figure 3 shows the implementation schedule for the project. Manila Water Company will undertake the project implementation. 1.4.1.2 Total Surface Development Block The service area is approximately 6.7 hectares and is estimated to have a current population of 7,980. The project will serve all the residential units in Centennial Village. Any increase in population is not considered because there are no further planned development within the compound that would significantly affect the quality and/or quantity of wastewater discharges. 1.4.1.3 Estimate of Total Land Area to be Opened for Civil Works Civil Works will include the STP construction and the laying of sewer lines to connect sewerage system to the STP. The STP will be located underground in a 200 square-meter lot. Sewer lines totaling 297 meters will be opened for civil works. Figure 4 shows the sewer network layout plan for the project. 1.4.1.4 Major Openings and Construction Activities The complete sewerage system will include the following components: * Collection sewers (diameter=150 to 200 mm) with a total estimated length of 297 meters to connect the 5 communal septic tanks and buildings without septic tanks to the STP * Nine (9) sewer manholes and junction boxes with depth less than 1.5 meters * Underground STP with a design capacity of 1,277m3/day and land requirement of 200 m2 * Sewer line (diameter=200 mm) with a total estimated length of 20 meters from STP discharge point to existing storm drainage 16  Figure 3 Proposed Implementation Schedule for the Centennial Village Community Sanitation Project .eek No. 1 2 3 4 5 6 7 8 9 1 0 11 1 2 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 Cleearanscaesd 2 1 all_______ ___ __ _ Testing jf Sewer Lines 17  Figure 4 Proposed Sewer Collection Layout Manila Water BOX CULVERT PLAYG |UNOSEWER LtNE FROM SMH-9 UP TO STP ANO STP EfFLUENT X L D 0. PIPELINE UP To DISPOSAL POINT SHALL BE BY STP CONTRACTOR  Civil works to be implemented are as follows: For STP/Lift Stations For Pipelaying * Site clearing * Pavement cutting * Earthworks * Shoring and removal - excavation and handling * Excavation and handling - dewatering * Dewatering - backfill and compaction * Pipelaying - lean concrete/ gravel bedding * Backfill and compaction * Concrete Works * Testing pavement restoration - shoring and soil protection * Clearing / miscellaneous activities - formworks - concreting * Electro-mechanical - internal and external pipeworks - mechanical installation - electrical installation * Site restoration * Clearing/ miscellaneous activities 1.4.1.5 Types of Equipment to be Used The civil works contractor will provide equipment which include, but is not limited to, the following: * backhoe/loader * dewatering equipment * concrete mixer/concrete pump * welding machine * compactor * jackhammer and air compressor * generator * dump trucks 1.4.1.6 Source of Construction Materials and Facilities The following alternative type of pipe materials will be permitted for sewer mains: * UPVC Pipe * Polyethylene * Fiberglass Pipe * Ductile Iron Pipe * Cast Iron Soil Pipe The contractor can choose trom the above pipe materials. 19  1.4.1.7 Support Services and Facilities Requirements and Availability Support services and facilities will be tapped from the available utilities on site. Arrangements with locators in Centennial Village and/or any other party will be made by the contractor. 1.4.1.8 Estimate Total Cut Soil Volume (for pipelaying) Table 2 presents the total system length, average excavation depth of the sewer pipes and area of the project. Table 2 Estimates of Soil Excavation Volumes Estimated Average Excavation Average Dimensions Depth (m) Excavation (sq.m) Volume (cu. m.) STP site 200.00 6.0 1,200.00 Sewer line 0.45 x 166 1.5 112.05 150mm0 Sewer line 0.50 x 131 1.7 111.35 200mm0 _ TOTAL 1,423.40 *Estimated dimension of pipe (sq.m.)= [(pipe diameter +0.3) x total length of pipe required] 1.4.1.9 Total Manpower Requirement The project will be bid out based on World Bank procedures. The winning bidder will provide contractual work for a period of around 240 calendar days. The contractor will provide skilled and unskilled workers to carry out the scope of works as detailed in the bid documents. The scope of works includes: * site clearing * installation works for the sewer network * detailed engineering design and construction/installation works for the STP and its appurtenances * landscaping of the STP site and the vicinity * abandonment activities (road restoration, etc.) * STP start-up operations 20  1.4.2 Operational Phase 1.4.2.1 Project Operation Schedule and Duration Completion of construction is expected by October 2002. Start-up operations will begin immediately after project completion. 1.4.2.2 Process Technology and Activities The project will be bid on the basis of performance specifications for the STP Treatment Process: * Wastewater flows were computed on the basis of a per capita water demand of 200 liters per day and a 70% wastewater discharge. Storm infiltration was estimated at 10% of the total flows. A peak factor of 1.5 was added in the computation of design flows to determine pipes sizes and capacity of STP. * The influent flow characteristics were based on random laboratory analyses of septic tank effluent in representative sites. The influent quality assumptions are shown in Table 3 below: Table 3 Influent Flow Characteristics TSS BOD5 COD Oil and pH (mg/I) (mg/I) (mg/I) Grease (mg/I) 100 200 350 50 6-9 TSS = Total Suspended Solids BOD5 = 5-day biochemical oxygen demand at 200C COD = chemical oxygen demand * Wastewater discharged by the STP shall conform with the Effluent Standards set forth in DENR Administrative Order 34 and 35 for Class C waters as shown in Table 4 below: * Wastewater treatment will reduce the BOD5 from 200 mg/L to 50 mg/L, at the minimum. This illustrates an STP treatment efficiency of at least 75%. 21  Table 4 DENR Effluent Parameters for Class C Waters Color PCU 150 pH 6-9 COD mg/L 100 Settleable solids mg/L 0.5 5-day 20