World Bank Document

E1288 v 5 Public Disclosure Authorized Environmental Impact Statement (EIS) for Manila Third Sewerage Project Public Disclosure Authorized Volume 5: Bio Solids Management Strategy February 11, 2005 (Revised Draft) Public Disclosure Authorized Public Disclosure Authorized Manila Water Company, Inc. Manila, Philippines Manila Water Company, Inc. Biosolids Management Strategy Options Study Report August 2004 Contents Executive Summary 1 Technical Acronyms and Abbreviations 4 1. Introduction 6 1.1 General 6 1.2 Project Objectives 6 1.3 Definition of Terms 6 2. Available Information 8 2.1 Data Sources 8 2.2 Required Data from Additional Testing and Monitoring 8 2.3 Assumptions 9 3. MWCI Operations 10 3.1 MWCI Service Area 10 3.2 Existing Facilities Related to Biosolids Generation and Management 10 3.3 Certifications and Licenses 10 3.4 On Going and Planned Projects 10 3.5 Key Issues in Establishing the MWCI Biosolids Strategy 10 4. Biosolids Quantity and Quality 10 4.1 General 10 4.2 Dried Sludge from Magallanes WWTP 10 4.3 Liquid Sludge from Operating WWTPs 10 4.4 Dewatered Sludge from MSSP Facilities 10 4.5 Sludge from MTSP Facilities 10 4.6 Liquid Sludge Generation from MSSP WWTPs 10 4.7 Septage 10 4.8 Filter Cakes from Proposed Septage Treatment Plants 10 4.9 Summary of the Expected Biosolids Quantity 10 4.10 Biosolids Quality 10 5. Planning Considerations 10 5.1 General 10 5.2 Review of Local Guidelines on Biosolids Management 10 71/10229/21017 Biosolids Management Strategy 2 Options Study 5.3 Review of International Guidelines on Biosolids Management 10 5.4 Review of US EPA Guidelines on Land Application of Domestic Septage 10 5.5 Global Trends 10 5.6 Carbon Credit Opportunities 10 5.7 Transport Alternatives 10 5.8 Planning Issues 10 5.9 Social Issues 10 6. Biosolids Reuse and Disposal Assessment 10 6.1 Potential Reuse 10 6.2 Disposal Options 10 6.3 Short-listing of Options 10 7. Biosolids Treatment Unit Processes 10 7.1 Introduction 10 7.2 Technology Options Overview 10 7.3 MWCI Technology Requirements 10 7.4 Short-listed Technologies 10 8. Enhancement of Existing Operations 10 8.1 Magallanes WWTP 10 8.2 Valle Verde Homes WWTP 10 8.3 Existing Karangalan Village WWTP 10 8.4 Diego Sillang WWTP Infrastructure 10 8.5 Lahar Application Practices 10 9. Proposed Strategy 10 9.1 Short-term (Current to 2005) 10 9.2 Medium-term (2005 to 2010) 10 9.3 Long-term (2010 onwards) 10 10. Risk Assessment 10 10.1 General 10 10.2 Project Risk Assessment 10 10.3 Discussion of the High and Extreme Risks 10 11. Preliminary Costing of Preferred Options 10 11.1 Basis of Cost Estimates 10 11.2 Short Term (Current to 2005) 10 71/10229/21017 Biosolids Management Strategy 3 Options Study 11.3 Medium Term (2005 to 2010) 10 11.4 Long Term (2010 onwards) 10 12. Conclusions and Recommendations 10 12.1 Conclusions 10 12.2 Recommendations 10 13. References 10 Table Index 1 Table 1 MWCI Concession Area Forecasted Population 10 Table 2 MWCI Sewerage Service Coverage Targets (% of 1 total population in area) 10 Table 3 MWCI Sanitation Service Coverage Targets (% of 1 total population in area) 10 Table 4 Existing Communal Septic Tanks 10 Table 5 Septic Tank Desludging Data (Number of individual 1 tanks serviced) 10 Table 6 On Going and Planned Wastewater Projects under the MSSP (Bio-contact Activated Sludge Process) 10 Table 7 On Going and Planned Wastewater Projects under the MTSP 10 Table 8 Estimated Biosolids Generation Rate for Existing * WWTPs 10 Table 9 Biosolids Generation from MSSP Projects 10 Table 10 Biosolids Generation of Wastewater Projects under the MTSP 10 Table 11 Biosolids Generation Rates of MSSP WWTPs 10 3 Table 12 STP Solids Generation Growth Rate in m /day 10 Table 13 Summary of Biosolids Generation in Terms of Source 10 Table 14 Summary of Biosolids Generation in Terms of Biosolids Type 10 Table 15 List of Controlled Contaminants 10 Table 16 Typical Properties and Composition of Various Sludge Types* 10 Table 17 Typical Septage Constituent Concentrations and Unit Loading Factors* 10 Table 18 Metro Manila Septage Characteristics 10 71/10229/21017 Biosolids Management Strategy 4 Options Study Table 19 Maximum Average Concentration of Heavy Metals for Land Application (mg/kg) 10 Table 20 Allowed Annual Loading Rates (kg/ha/yr) 10 Table 21 Comparison of US EPA Guidelines with MWCI Practices 10 Table 22 Comparison of Annual Greenhouse Gas Emissions for Management Options* 10 Table 23 Potential Biosolids Reuse Market Sectors 10 Table 24 Short-listed Biosolids Market Options 10 Table 25 Sludge Treatment Overview 10 Table 26 Qualitative Measures of Consequence or Impact of Any Single Incident 10 Table 27 Qualitative Measures of Likelihood 10 Table 28 Qualitative Risk Analysis Matrix 10 Table 29 Qualitative Risk Assessment – Identified Risks 10 Table 30 Classification Requirements for Biosolids Reuse 10 Table 31 Comparison of Various Composting Methods 10 Table 32 Short-term Storage Characterisations for Various Sludge Types 10 Appendices A Environmental Management Bureau Classification of Domestic Sludge and Septage B Review of International Guidelines on Biosolids Management C Processing Technology Review 71/10229/21017 Biosolids Management Strategy 5 Options Study Executive Summary GHD was commissioned by Manila Water Company, Inc. (MWCI) to undertake the planning and development of a robust and sustainable Biosolids Management Strategy to deliver efficient solutions and enhance MWCI’s reputation as a company with strong environmental values. MWCI operates a number of wastewater treatment and septage collection facilities that currently generate a significant volume of biosolids requiring treatment and disposal/reuse. Biosolids are the organic sludge produced from physical and biological treatment of wastewater and include treated septage, secondary sludge, and processed/stabilized sludge. Significant increases in the rate of biosolids generation are anticipated (from 95 m3/day to around 400 m3/day of dry solids), in line with a number of wastewater treatment plants and septage collection initiatives currently underway. This increased biosolids generation (to around 180 dry tonnes/day) will result in significant increases in operational costs for MWCI, unless the current management practices are improved and streamlined, particularly the transport and disposal/reuse options. The objectives of this project are to: ?? Develop a long-term Biosolids Management Strategy to provide a cost effective and environmentally sustainable solution for MWCI’s anticipated increase in septage and wastewater sludge generation. ?? Within this strategy, investigate measures to improve the efficiency and operability of the current biosolids management systems particularly: – Reducing the current operational costs of the system. – Identifying low capital cost improvement options with short payback periods (less than 3 years). – Reducing health and safety risks to operational staff. ?? Ensure that the septage treatment process selected for the Manila Third Sewerage Project (MTSP), Pasig River Rehabilitation Commission (PRRC) projects and other wastewater treatment plants is compatible with the downstream biosolids processing, reuse and final disposal options selected under the strategy. ?? Ensure that environmental performance in biosolids management promotes a positive corporate image for MWCI at an appropriate cost. The study concludes the following: ?? Biosolids produced from MWCI plants are unstabilised. The use of biosolids should be restricted and applied to land adapting internationally recognised practices. ?? Current vi able markets include the rehabilitation of the lahar fields, and in extensive agriculture in Pampanga, Tarlac, and other nearby provinces. ?? In the short term, management of the application of biosolids in these markets needs to be improved for health and safety reasons, and to avoid potential environmental harm in the long term. This should include reviewing current practice of distributing dried sludge to third parties. ?? The production of higher quality biosolids will create alternative markets. These markets are likely to be closer to Manila and transportation costs will be lower. Having a range of viable markets will reduce risks for MWCI in case the current options are restricted. 71/10229/21017 Biosolids Management Strategy 1 Options Study ?? Pilot scale evaluation of alternative stabilisation technologies will provide MWCI with an understanding of the technology and minimise the risks of a full-scale operation. ?? Storm events have the potential to limit the ability to continuously apply biosolids to land. Sufficient biosolids storage facilities are required to balance the production rates with practical application rates. ?? A landfill disposal option would play a significant role in contingency planning. This is a risk management option to protect against a potential disruption of operations due to climactic conditions and other unforseen circumstances. Based on the outcomes of this study, the following strategy is proposed: Short-term (Current to 2005) ?? Biosolids markets – Lahar application needs to be fully investigated. Lahar application dependent on surface and ground water monitoring, adsorptive capacity of lahar, and computed agronomic rates for application. – Extensive Agriculture. Improvements to the current practice of septage application on agricultural sites in accordance with the guidance of the US EPA Part 503 rule (Biosolids to be injected below the surface, or incorporated within 6 hours of application to the

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