Metropolitan Waterworks and Sewerage System Manila Water Company, Inc. E94 Volume 18 Public Disclosure Authorized Initial Environmental Examination of the Community Sanitation Project Public Disclosure Authorized Manila Second Sewerage Project IBRD 4019 Project No. 16 Karangalan Village Pasig City Public Disclosure Authorized Prepared by: Manila Water Company, Inc. 489 Katipunan Rd, Balara, Quezon City Public Disclosure Authorized December 2001 FI CO TABLE OF CONTENTS PAGE NO. Executive Summary 7 1.0 PROJECT DESCRIPTION 1.1 BASIC PROJECT INFORMATION 13 1.2 PROJECT LOCATION 13 1.3 PROJECT RATIONALE 15 1.4DESCRIPTION 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 18 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 2.2LAND 25 2.2.1 Land Resource Utilization 25 2 2.2.2 Physiography and Geology 25 2.2.3 Vegetation and Wildlife 25 2.2.4 Land Acquisition Assessment 31 2.3 WATER 2.3.1 Inventory of Water Bodies 31 2.3.2 Water Quality (Surface/Ground) 31 2.4AIR 32 2.5 PEOPLE 2.5.1 Population/Beneficiary 32 2.5.2 Project Affected Persons 32 3.0 ALTERNATIVES 32 4.0 IMPACT ASSESSMENT 4.1 IMPACT IDENTIFICATION 4.1.1 Impacts During Construction Phase 34 4.1.2 Impact During Operation Phase 45 4.21MPACT PREDICTION AND EVALUATION 47 4.3UNAVOIDABLE AND RESIDUAL IMPACTS 48 5.0 ENVIRONMENTAL MANAGEMENT PLAN 5.1 IMPACTS MITIGATION / ENHANCEMENT PLAN 48 5.2 ENVIRONMENTAL MONITORING ACTION PLAN 53 6.0 COMMUNITY CONSULTATION PROCESS 54 LIST OF FIGURES . ;e . ;e_,5 1 Location Map of Karangalan Village 14 2 Proposed Implementation Schedule 17 3 General Treatment Process Scheme 23 4 Photographs of STP Sites 26-29 5 j Location Map of STP Sites 35-44 LIST OF TABLES 1 Analysis of Septic Tank Effluent Quality 15 2 Land Requirement for STPs 18 3 Design Capacities of STPs 18 4 Estimates of Soil Excavation Volumes 20 5 Influent Flow Characteristics 21 6 DENR Effluent Parameters for Class C Waters 22 7 Vegetative Cover 30 8 Sources and List of Potential Environmental 33 Impacts 9 Typical Noise Emissions of Construction 45 Equipment at Various Distances from Source in dB(A) 10 Sludge Production of Various Wastewater 46 Treatment Processes 11 Summary of Assessment of Environmental Issues 47 / Impacts 12 Environmental Management Plan 48 13 Environmental Monitoring Action Plan 53 14 Institutional Monitoring 54 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-2000-02- 19-0289-211 4 Manila Water PCO Report Format 5 Sample Monitoring Sheet for Effluent Quality 6 Endorsements from the Barangay Captains 7 1994 Memorandum of Agreement between NHA and MWSS 6 EXECUTIVE SUMMARY The proposed project for Karangalan Village is a sub-project of the Community Sanitation Project, 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 approximately six thousand (6,000) households in Karangalan Village. The project involves the improvement and rehabilitation of the sewerage system in the Village. Specifically, the project includes the rehabilitation of the existing sewer lines and lift stations, installation of new sewer lines to intercept sewage flows from the storm drain, as well as untreated wastewater flows from individual septic tanks and households without septic tanks. Sewage treatment plants (STP) will be constructed to treat the wastewater flows. In conformity with the requirements of the Department of Environment and Natural Resources (DENR), an Environmental Compliance Certificate (ECC) NCR-2000-02-19-0289-211 issued pursuant to P.D. 1586 was secured for the project. 1.0 BASELINE ENVIRONMENTAL CONDITIONS Karangalan Village belongs to the Third Urban Development Project (Urban Ill) of the National Housing Authority. Urban IlIl projects were funded through a loan secured in February 1980 by and between the Government of the Philippines and the International Bank for Reconstruction and Development. Karangalan Village was developed in 1985 on what used to be rice fields. The Village is located along Imelda Avenue. Based on municipal and barangay boundaries, portions of the Village belong to Barangays Manggahan and de la Paz in Pasig City and Barangay San Isidro in Cainta, Rizal. Karangalan Village is divided into nine phases. Phases IA, IB and IC are on the northwestern side while phases 2A, 2B1, 2B2, 2C1, 2C2 and 2C3 are on the southeastern side. The Village is bounded by Vista Verde Subdivision in the east, Pasig Greenpark Subdivision in the west and Metroville Subdivision in the south. Hakbangan Creek bounds the northern portion of the housing area. The Village is home to an estimated 6,000 households. Included in the estimate/projection are those from the newly constructed medium rise housing (MRH) units. The Karangalan MRH consists of 10 buildings, each with 60 residential units. Floral population within Karangalan 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: 7 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 estimated 42,000 population of Karangalan Village is made up of polyvinyl chloride (PVC) and concrete sewer pipes with diameters ranging from 150-250 millimeters. From each household, wastewater flows to sewer lines directed to nine (9) separate lift stations. The stations are equipped with pumps that lift wastewater to each of the nine (9) communal septic tanks (CST) serving each phase. Presently, the lift stations are non-functional. The septic tanks are typically designed with approximate dimensions of 9mxl 8mx3.5m (LxWxD). The septic tanks consist of a grit chamber, wet well and digestive chamber. The flow of raw wastewater to the grit chamber is controlled by two sluice gates. The influent is screened by a cast iron bar screen (25mmx30mm) before entry to the wet well. The digestive chamber is made up of three compartments. The septic tanks have different disposal points. The description and disposal points of the septic tanks are listed in the table below. Description of Communal Septic Tanks (CST) CST # Location and (Boundaries) Area Units Discharge (mi) Served Point 1 Block 31 (Kayumanggi/K-1 7/K- 406 846* Hakbangan 18/Karunungan), Phase IA Creek 2 Block 63 752 777* sewer (Kaayusan/Kalayaan/Karunungan), manhole Phase 1C 3 Block 84 (Kaayusan/Kabanalan/K- 925 961 Drainage 44/K-45), Phase 1B 4 Block 58 (Kabutihan/Katipiran/K-1 18), 470 945 Hakbangan Phase 2A Creek 5 Block 21 230 401 sewer (Kagalingan/Kapatagan/Kaalaman, manhole Phase 2B1 6 Block 128 900 318 sewer (Kaunlaran/Kakisigan/Kalakasan/Kasi- manhole nupan), Phase 2C1 7 Block 14 759 357 drainage (Kaalaman/Kapayakan/Katiyakan), Phase 2B2 8 Block 61 (Kaluwagan/Katimugan/KC- 447 742 sewer 25/KC-21), Phase 2C2 manhole 9 Block 61 (Kaluwagan/Katimugan/KC- 754 588 Drainage 125/KC-21), Phase 2C2 *elementary school not counted 8 Settled wastewater from CST #1 flows to a pilot wastewater treatment facility-a biomodule project of the Japan International Cooperation Agency (JICA). The biomodule was constructed in -1U9 1 and is currently operated and maintained by Manila Water. The biomodule has a design flow of 36-150 m3/day. In the biomodule system, the microorganisms in the activated sludge are stored in a string-type media installed in the aeration tank. Oxygen required for activation of the microorganisms is introduced by way of aeration pumps. From the disposal points listed above, all settled/treated wastewater flows to Hakbangan Creek which is a tributary of Balante Creek. This water body releases into the Marikina River which ultimately discharges into the Pasig River. During the rainy season, the BOD5 of Pasig River ranges from 3-5 mg/L. This loading reaches 7-10 mg/L during dry season. Pasig River water quality 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). Defective lift station pumps, substandard design and materials, and settled wastewater in the sewer lines are indicative of the need to rehabilitate and improve the existing sewer system. 2.0 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.