Philippines - Manila Second Sewerage Project : environmental impact assessment (Vol. 24 of 27) : Initial Environmental Examination of Project no. 22 ; Kalayaan communal septic tank, Quezon City

Metropolitan Waterworks and Sewerage System Manila Water Company, Inc. E94 Volume 24 Initial Environmental Examination of the Community Sanitation Project Manila Second Sewerage Project IBRD 4019 Project No. 22 Kalayaan Communal Septic Tank Quezon City, Philippines Prepared by: Manila Water Company, Inc. 489 Katipunan Rd, Balara, Quezon City December 2001  TABLE OF CONTENTS PAGE NO. Executive Summary 7 1.0 PROJECT DESCRIPTION 12 1.1 BASIC PROJECT INFORMATION 12 1.2 PROJECT LOCATION 12 1.3 PROJECT RATIONALE 14 1.4 DESCRIPTION OF PROJECT PHASES 16 1.4.1 Pre-Operational/Construction Phase 16 1.4.1.1 Construction Plan 16 1.4.1.2 Total Surface Development Block 16 1.4.1.3 Estimate of 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 19 Availability 1.4.1.8 Estimate of Total Cut Soil Volume 19 1.4.1.9 Total Manpower Requirement 20 1.4.2 Operational Phase 20 1.4.2.1 Project Operation Schedule and Duration 20 1.4.2.2 Process Technology and Activities 20 1.4.2.3 Waste Production Scheme 21 1.4.2:4 Manpower Requirement 23 1.4.3 Abandonment Phase 23 2.0 BASELINE ENVIRONMENTAL CONDITIONS 24 2.1 STUDY METHODOLOGY 24 2.2 LAND 24 2.2.1 Land Resource Utilization 24 2  2.2.2 Physiography and Geology 24 2.2.3 Vegetation and Wildlife 24 2.2.4 Land Acquisition Assessment 26 2.3 WATER 26 2.3.1 Inventory of Water Bodies 26 2.3.2 Water Quality (Surface/Ground) 26 2.4 AIR 27 2.5 PEOPLE 27 2.5.1 Population 27 2.5.2 Project Affected Persons 27 3.0 ALTERNATIVES 28 4.0 IMPACT ASSESSMENT 28 4.1 IMPACT IDENTIFICATION 28 4.1.1 Impacts During Construction Phase 30 4.1.2 Impacts During Operation Phase 31 4.2 IMPACT PREDICTION AND EVALUATION 33 4.3 UNAVOIDABLE AND RESIDUAL IMPACTS 34 5.0 ENVIRONMENTAL MANAGEMENT PLAN 34 5.1 IMPACTS MITIGATION/ENHANCEMENT PLAN 34 5.2 ENVIRONMENTAL MONITORING ACTION PLAN 38 6.0 . COMMUNITY CONSULTATION PROCESS 40 3  LIST OF FIGURES NO. FIGURE PAGE NO. Location Map of Kalayaan Communal Septic 13 Tank (CST) 2 Existing Sewerage System Layout 15 3 Proposed Implementation Schedule 17 4 Proposed Site Development Plan and Details 18 5 General Treatment Process Scheme 22 6 Photograph of STP site 25 4  LIST OF TABLES NO. TABLE PAGE NO. 1 Typical Analysis of CST Effluent Quality 14 2 Estimates of Soil Excavation Volumes 19 3 Influent Flow Characteristics 20 4 DENR Effluent Parameters for Class C Waters 21 5 Sources and List of Potential Environmental 28 Impacts Typical Noise Emissions of Construction 6 Equipment at Various Distances from Source in 31 dB(A) 7 Sludge Production of Various Wastewater 32 Treatment Processes 8 Summary of Assessment of Environmental 33 Issues/Impacts 9 Environmental Management Plan 34 10 Environmental Monitoring Action Plan 39 1 1 Institutional Monitoring 40 5  LIST OF ANNEXES Manila Water Company STARRT Card for Monitoring Construction Works 2 Wastewater Quality Monitoring Schedule Environmental Compliance Certificate (ECC) NCR-2001-03- 3 22-032-211 4 Manila Water PCO Report Format 5 Sample Monitoring Sheet for Effluent Quality 6 Endorsement from the Barangay Captain Draft Memorandum of Agreement (MOA) between the National 7 Housing Authority and Manila Water Company 6  EXECUTIVE SUMMARY The proposed project for the Kalayaan Communal Septic Tank (CST) 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 Pasig River by the more than three thousand (3,000) residential and commercial units within the service area of Kalayaan CST. The project involves the provision of secondary treatment to the CST effluent. Specifically, the project includes the construction and installation of a package sewage treatment plant (STP) within the CST compound. A Memorandum of Agreement (MOA) between the National Housing Authority (NHA) and Manila Water Company is being processed. The Barangay Captain of Malaya has favorably endorsed the project. In conformity with the requirements of the Department of Environment and Natural Resources (DENR), an Environmental Compliance Certificate (ECC) NCR-2001-03-22-032-211 pursuant to P.D. 1586 was secured for the project. I. BASELINE ENVIRONMENTAL CONDITIONS The sewerage system of the project service area was developed in the 1960s by the then Philippine Homesite and Housing Corporation (now National Housing Authority). The service area is situated in the southern portion of Quezon City in Metro Manila and is bounded by Malamig, Matimtiman and Masinsinan Streets in the north, Kalayaan Avenue in the west, Maginhawa Street in the east and by the Botocan Transmission Line in the south. The service area has a total land area of 109 hectares, about 90% of which are residential areas and the remaining 10% are commercial areas. Floral population within the CST service area constitutes ornamental plants and trees which were planted by the residents. 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 village 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. 7  Existing Sewerage System The sewerage system was developed in the 1960s by the then Philippine Homesite and Housing Corporation (now National Housing Authority). The sewer network consists of 16.85 kilometers of concrete sewer pipes with diameters ranging from 200 mm to 375 mm. This network was designed so that the wastewater flows by gravity towards the communal septic tank (CST) located at Kalayaan Avenue near Kamias Road. The CST effluent flows to the drainage system which discharges to the Diliman Creek. At present, the Manila Water Company operates and maintains the sewerage system, including the communal septic tank. II. ENVIRONMENTAL IMPACTS AND MITIGATING MEASURES Potential Environmental Mitigating Measures Impact -_:-: CONSTRUCTION PHASE 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 e.g. 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 resulting from earthmoving activities and civil works. . Control of motor vehicle emissions . Dust accumulation will also be prevented through proper washing of construction vehicles prior to 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 8  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 a 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 . Public information campaign posting schedule of construction traffic flow within the . Scheduling of delivery materials and removal of excavated village material during non-rush hour periods OPERATIONAL PHASE 1. Environmental hazards . Carefully designed post-construction maintenance, due to accidents, man- contingency and monitoring programs made or natural . Well designed plan for detection of accident or natural events disasters e.g. accidental including precautionary and remedial measures to be spills, fire, seismic observed activity, earthquakes, a Provision of preventive and remedial procedural manuals at heavy rain/flooding and workplace design failure . Adequate plans for environmental rehabilitation and restoration of site and removal of temporary structures and facilities installed during the 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 mains to prevent discharge/seepage of untreated wastewater to the environment 3. Noise Pollution (STP . Use of appropriate mounting for machinery to minimize equipment) vibration . All mechanical/electrical equipment shall be installed inside enclosures . Motors shall be provided with soundproofing devices * Maintenance of greenbelt zones and vegetation with appropriate tree species 9  4. Solid Waste . Regular collection and disposal of solid waste generated within (generated within and by and by the STP the STP) * Disposal of generated sludge 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) . Provision of landscape which will improve the aesthetic of the area by planting green strips using appropriate plant or tree species * Provision of odor controi 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 * Regular maintenance works for the STP equipment (pumps of mechanical and motors) equipment (pumps . Adequate training of STP operators and motors) * Provision of adequate maintenance equipment and spares for * Connections the sewerage system facilities 10  Ill. ENVIRONMENTAL MONITORING PLAN Environmental monitoring will be the responsibility of Manila Water Company. _ _ _2 - Construction Phase Compliance with Manila . At STP site and its * On-the-spot daily inspection Water Company health and perimeter and monitoring will be safety policies (dust * Equipment and implemented by the Health emissions, good materials storage area and Safety Dept. of Manila housekeeping, noise, odors) Water Company using the Safety Task Analysis Risk Reduction Talk (STARRT) Card (Annex 1) Traffic . Ingress and egress to * Daily the construction site Operational Phase Effluent Water Quality . Effluent/Discharge * Annex 2 describes in detail the for parameters like pH, 5-day Point schedule of wastewater quality BOD, COD, Total coliform, monitoring. suspended solids, and oil and grease Odor . STP site and * Daily perimeter Sludge accumulation/clogging . At STP site . Weekly . Sewer network  1.0 PROJECT DESCRIPTION 1.1 Basic Project Information Name of Project KALAYAAN COMMUNAL SEPTIC TANK COMMUNITY SANITATION PROJECT MANILA SECOND SEWERAGE PROJECT Address : Kalayaan Avenue, near Kamias Road, Barangay Malaya, Quezon City, Philippines Contact Persons : Leonor C. Cleofas Manager, Engineering and Project Management Office Metropolitan Waterworks and Sewerage System Ground Floor, Engineering Building, MWSS Complex, 489 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 the Kalayaan Communal Septic Tank 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 MSSP. The service area covers the residential units and commercial establishments along Malamig, Matimtiman, Masinsinan, Mahinhin, Mahiyain, Magiting, Mabait, Maginhawa, Kalayaan Avenue, Matahimik, Malumanay, Mapagkawanggawa, Mahabagin, Maalalahanin, Malingap, Masambahin, Maningning, Madasalin, Matipid, Maimpok, Malihim, Matino, Anonas Extension, Mapagkumbaba, Mapagsangguni, Matipid, Masunurin, Maamo, Makadios and V. Luna Extension. The STP site is easily accessible from Kalayaan Avenue. Figure 1 presents the location map of the project. 12  Figure 1 LOCATION MAP 03 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 and commercial establishments 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 come from domestic discharges. 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 of Kalayaan CST. Table 1 shows a typical analysis of the effluent quality of septic tanks in other project sites. Figure 2 shows the existing sewerage system of the project service area. The project will help reduce public health risks and environmental pollution from untreated/partially treated domestic wastewater by providing a sustainable sewerage facility. It will also serve as a good illustration of proper sanitation especially to the neighboring communities near Diliman Creek. Table 1 Typical Analysis of Septic Tank Effluent Quality Parameter Ljmit(s) Septic Tank -aaeeDENR-EMB Effluent pH 6.5-9 7.3 @ 27.90C Suspended solids, mg/L 70 - Dissolved Oxygen, mg/L 0.00 Biochemical Oxygen Demand 50 . 250 ' (BODs), mglL Chemical Oxygen Demand, mg/L 100 ....2.300 3O . Total Coliform Count, MPNIIOO ml 10,000 W Fecal Coliform Count, MPN/100 ml - S t>106107;" 14  Figure 2 Existing Sewer Network 15  1.4 DESCRIPTION OF PROJECT PHASES 1.4.1 Pre-Operational / 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 September 2002 (210 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 109 hectares and is estimated to have a current population of more than 18,000. The project will serve about 3,000 residential and commercial establishments within the service area. 1.4.1.3 Estimate of Total Land Area to be Opened for Civil Works Civil Works will include the construction of an aboveground STP. The STP will be located in an 800 square-meter area in the CST compound which is owned by the NHA. Figure 4 shows the proposed site development plan and details. 1.4.1.4 Major Openings and Construction Activities The civil works to be implemented are as follows: * Site clearing * Earthworks - Excavation and handling - Dewatering - Backfill and compaction - Lean concrete/gravel bedding * Concrete Works - Shoring and soil protection - Formworks - Concreting * Electro-mechanical - Internal and extemal pipeworks - Mechanical installation - Electrical installation * Site restoration * Clearing/miscellaneous activities 16  Figure 3 Proposed Implementation Schedule for the KALAYAAN CST Community Sanitation Project Week No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 PenTisand Clearanoes;W FTF X Install Treatrment Equipment Instail Be eical and Purmbing Tostintg. Accoptanco and Turnovor 17  Figure 4 Proposed Site Development Plan and Details Manila Water EXISTING SEPTIC TANK EFFLUENT LINE (MAY BE USED) KP st WEP = ,n ~~~~~~~~~~~~~~~~~~~~EXISTING SEPTIC TANK * / :9 \ t ~~~~~~~~~~~~~~~~TO REMAIN EXISTING FENCE TO REMAIN ST- 1 S- x \ EXISTING TEMPORARY HOUSE EXISTI G FENCE TO EMAI LL AVAILABLE AREA FOR STP 0 CEP MH I-I J 18  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: * UPVC Pipe * Polyethylene . Fiberglass * Ductile Iron Pipe * Cast Iron Soil Pipe The contractor can choose from any of the above pipe materials. 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 the NHA and/or any other party will be made by the contractor. 1.4.1.8 Estimate of Total Cut Soil Volumes Table 2 presents the estimated dimension, depth and excavation volume of each project component. Table 2 Estimates of Soil Excavation Volumes Estimated Average Average Dimensions Excavation Depth Volume (m x m) (m) (cu.m.) STP 22 x 8 1 176 19  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 210 calendar days. The contractor wil! provide skilled and unskilled workers to carry out the scope of works as detailed in the bid documents. The general scope of works includes: * site clearing * detailed engineering design and construction/installation works for the STP and its appurtenances * landscaping of the STP site and its vicinity + abandonment activities (road restoration, etc.) * STP start-up operations 1.4.2 Operational Phase 1.4.2.1 Project Operation Schedule and Duration Completion of construction is expected by September 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: * Domestic 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 pipe sizes and capacity of the STP. * The influent flow characteristics were based on laboratory analysis of a sample of septic tank effluent as well as samples from the other project sites. The influent quality assumptions are shown in Table 3 below: Table 3 Influent Flow Characteristics TSS BOD5 COD Oil and. (mg/l) (mg/I) (mg/l) Grease (mg/I) pH 100 200 350 50 6-9 TSS = Total Suspended Solids BOD5 = 5-day biochemical oxygen demand at 20