H*;,,.~~~~~~~, Is ~~ ' 9.i 4j~4 ~ '~4'~4~t . ~. '9 4 V1,~~~~~~~~~~', 9. - w Z ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Republic of the Philippines Local Water Utilities Administration SEWERAGE AND SANITATION PROJECT WATER DISTRICT DEVELOPMENT PROJECT o . WORLD BANK ENVIRONMENTAL 1 X ~LUZON ASSESSMENT REPORT CALAMBA, LAGUNA / t ASAKAS X9YA MINDANAO 0 go~~~~~ August 1997 ______~~~~---------------- 0 TABLE OF CONTENTS Page EXECUTIVE SUMMARY 1 Chapter 1 INTRODUCTION 12 Chapter 2 BASELINE ENVIRONMENT - CALAMBA, LAGUNA 16 Section I Existing Environment 16 Section II Environmental Pollution 18 Chapter 3 PROJECT DESCRIPTsION AND ANALYSIS OF ALTERNATIVES 24 Section I Project Rationale and Objectives 24 Section H Sanitation 25 Section III Overall Sewerage Scheme 27 Section rV Recommended Project Design for Calamba, Laguna 40 Section V No Project Scenario 43 Chapter 4 ENVIRONMENTAL IMPACTS 46 Section I Beneficial Impacts of the Project 46 Section II Project Implementation Impacts 48 Section IH Summary 50 Chapter 5 ENVIRONMENTAL MANAGEMENT PLAN 51 Section I Mitigation Plan 51 Section II Monitoring Plan 53 Section III Implementing Arrangements 54 Appendices 1. Bibliography 2. Cimatological Normals (1961-1995) 3 Typical Noise Emissions of Construction Equipment 4. Expected Noise Levels at Various Distances from Construction Equipment 5. Environmental Quality Standards For Noise Maximum Allowable Noise lIevels 6. The Advanced Integrated Pond Svstem iA[PS) of Wastewater Treatment I:I7vIHflhtflenrai- I.'lxse.xvnielt tepnpt. ( 'alam7n a. ,'1tlv 1 4 I EXECUTIVE SUMMARY Introduction In the Philippines, the typical urban area/built-up area is characterized by a heavy concentration of activities, both commercial and industrial It is also the area where the di isity of population is at its highest. These areas are also the sites where the production and co.surnption of raw and processed materials could be found. Consequently the, pressure on the fife support systems in these areas are far higher than the suburban and rural areas. Adverse environmental conditions such as the generation and similarly the discharge of wastes into the environment is common in urban and built-up areas. Unfortumately, the amount, type and concentration of waste generated exceed the capacity of the local environment to absorb and assimilate them The carrying capacity of the life support svstems are stretched to the hmits. The urgency of establishing collection and treatment mietlhods to prevent adverse imtpacts to the health and wefl-being of the residents, and to the ecological systems which sustain them cannot be ignored and overstated. Most urban centers in the Philippines rely on individual septic tank systems for the treatment and disposal of wastewater from domestic and commercial buildings. However, the designs for such systems is often inadequate. Facilities for land disposal of effluents from the septic tanks are generally absent. Hence, the partially treated septic tank effluents flow directly into storm drainage systems and other receiving bodies of water, thereby exacerbating an already grave pollution situation. There are several possible options for addressing this problem, including improving the design of the septic tank system with the installation of soil absorption systems. But an environmentally sound alternative that is cost-effective and captures economies of scale is to connect individual properties directly to a sewerage system for the collection, treatment and disposal of the urban wastes. The provision of a cost-effective centralized wastewater collection, treatment, and disposal is the primary objective of the proposed Water Districts Development Project. The proposed project will assist the local govemment units (LGUs) of Dagupan City, Calamba (Laguna), Cagayan de Oro City. Davao City and Cotabato City, in finding solutions to the problem of sanitation. Financing assistance will be partly provided by the World Bank (WB) which shall be conduited through the Land Bank of the Philippines (LBP). Over-all administration will be exercised by LBP's Project Management Office (PMO) with technical support provided by the Central Sewerage and Sanitation Program Support Office (CPSO) of the Local Water Utilities Administration (LWUA). /~/171'1r(,1lf7C',)IaI I. L'%"EfJ7f ILRpfrI ( ala ihn. /.'unu Better sanitary conditions will thus be achieved in the areas served by the sewerage, drainage and sanitation systems. This will reduce water-borne pollution and water-logging within the cities and in the surrounding water bodies, thereby bringing health benefits to local populations. The construction of the systems will protect shallow groundwater aquifers from contamination. Environmental Assessment Requirements This Environmental Impact Assessment Report for Calamba has been prepared in accordance with the Presidential Decree No. 1586 otherwise known as the Environmental Impact Assessment Law and Departmenit of Enivironment anid Natural Resources (DENR) Revise -' Administrative Order Nos. 36, the Revised Water Usage and Classification/Water Qualit Criteria and Revised Effluent Regulations of 1990 respectively; and World Bank's Operational Directive 4.01 on Environtmlenital Assessment. The revised Administrative Order 36 for Environmental Impact Statement System issued in 1996 is comprehensive and is compatible vith the World Bank's Operational Directive 4.01. It outlines the procedure to be followed by environmental critical projects (ECPs) and projects to be located in environmental critical areas (ECAs), in preparing environmental impacts statement (EISs)'. ECP and ECA are defined in the AO. It should also be noted that that local ordinances and regulations governing projects of such nature have been taken into consideration in preparing this report. Similar EIA reports are being prepared for the other 4 cities. This report has been prepared by a team of local consultants under the aegis of the LWUA and the Calamba Government. Much of the work relating to the environmental impact analysis was undertaken as part of the feasibility study done by C. Lotti and Associati. Consultation with the community is an on-going process. The sanitation component of the project wil be executed in a participatory manner, and detailed guidelines have been spelled out. Selection of Priority Cities T'he choice of the first batch of Philippine cities for sewerage investments was made after an initial screening at the national level of urban areas facing the most serious problem of pollution by untreated wastes. Of the five cities, Davao and Cagayan de Oro represent the largest class of provincial cities with current population estimates in the range of a million and half a million respectively. There are several major population concentrations in the city - each being a source of sewage contamination for nearby surface and ground water. However, the largest volume of sewage is generated by the largest consumers of piped water supply; in the Central Business District or Poblacion area. Untreated wastewater from this area has polluted low-lyiig coastal areas. and basically converted the principal rivers into open sewers. The scale of the pollutioll problem can be appreciated by the fact that about 90 per cent of the daily water supply of 140,000 cubic meters in Davao city and 76.000 cubic meters in Cagayan de Oro is being discharged as untreated or undertreated This is tihe term used by DENR and refers to the standard Environmental Assessment Report required by the World bank as per OD 4.01 1Fnvironn71uW0al . Ise.vsrnent Report: (Calamna. L.c?gfla wastewater. Outside the Poblacion areas, there are pockets of population concentrations polluting nearby streams, creeks and drainage channels. In the other three cities of medium size (Cotabato City, Calamba and Dagupan City), current population estimates are close to 200,000. While the scale of urban pollution problems are not comparable with Davao and Cagayan de Oro, these cities are located close to environmentally sensitive wetlands and water bodies. In Cotabato City, the urban area is actually below the mean sea leveL exposing inhabitants to frequent flooding and waterlogging during the monsoon months. Calamba is located on the shores of Laguna Lake, which has experienced a rapid deterioration in water quality over the last two decades. Dagupan city is close to a large estuarine zone with ecologically sensit 'e wetlands and fishponds. In each of these cities, Mayors and city officials have rc..ognized for some time that unless their complex environmental problems are tackled through a strategic plan of handling waste disposaL sustainability of urban growth could be seriously affected. Overall Project Approach The proposed project follows a demand-based approach in the sense that facilities will be constructed only if they conform with the preferences of local stakeholders, and services conform to their respective willingness to pay. The stakeholders represent the different tiers of organizations from the City/Municipal Council and Barangay (part of the formal LGU system), to the more informal purok, neighborhood and household levels. During project preparation, the idea of involving communities in the planning process was field- tested in three barangays of Davao city. and found to be quite successful. The basic decision-making process is as follows: For the capital-intensive trunk system, consisting of the main transportation sewers, primary drains and wastewater treatment facilities, the project design and implementation plan has to be approved by the City CounciL because the latter is responsible to repay the loan [see Annex 3 of the Staff Appraisal Report (SAR) for the Project on Financial Aspects]. For the feeder system, consisting of collector sewers, secondary drains and on-site sanitation facilities. barangays and local neighborhoods will be associated with the planning and implementation program. The design criteria have been simplified, so that the feeder system can respond to local preferences and willingness to pay, rather than be bound by any conventional sewer design criteria used in industriahzed countries. Detailed design will be conducted through a participatory process described in Annex 13 of the SAR. Given the capital-intensive natur-e of the investments, the proposed project is only the initial phase of a program to improve the sanlitation infrastructure through a strategic plannIing approach that involves a mix of on-site and off-site wastewater collection. treatment and disposal. Choice of initial service areas for sewerage lhas been confined to 1;flvr me7lntal . lx.soxLvnhient RJlepori ( 'alatnb. 3. the Central Business Districts or Poblacion areas because these are the major contributors to municipal wastewater pollution. The only exception made is in the case of Davao City, where a second area of high growth prospects (Toril) has also been included on the request of the LGU. The project wil construct a sewer network that wil discharge sewage to a vertically integrated pond system designed to treat both sewage and septage. In each of the cities, with the exception of Davao', the treatment site was selected in areas free from encumbrances. For the sanitation components, the entire municipality has been included in the project area, with final selections being made on the basis of demand. On-site treatment systems through the construction of VIP (ventilated improved pit) latrines, pit latrines, pour flush toilets and septic tanks will also be constructed if there is demand from property owners. For those properties with uncertain land tenure (as in squatter settlements), the project will finance the construction of communal toilets, to be managed by non-governmental organizations (NGOs) and/or the private sector. The specific locations of these facilities will be driven by the willingness to pay for the services by beneficiaries at the barangay leveL provided of course that these are technically feasible. Analysis of Alternatives T-he recommended solutions for wastewater treatment were arrived at after an intensive process of evaluating alternatives durinlg the project preparation in order to achieve cost effectiveness and acceptability. The alternatives considered were anaerobic/facultative ponds, modified lagoon systems and mechanical treatment. The evaluation of altematives indicated that the modified lagoon systems, despite having a higher operation & maintenance (O&M) costs compared to anaerobic/facultative ponds (as it requires mechanical aerators and recirculation pumps) was appropriate. The selected option met the following criteria the effectively: Minimize overall pond area required Mininize odor production Meet DENR effluent quality criteria, including fecal coliform reduction Minimize sludge production rate Maximize potential to use surounldinig land for recreational purposes If()flh'l?'Oi7 ,'17 I . e.sst'xxtne,U I?epo;i: ( R Clumnba. Lq Igwlla 4 Summary Information on Project Cities Davao Cagayan de Oro Cotabato Calamba Dagupan Pop7ulatien (1990) 849.947 339.598 127.065 173.453 128.000 Housmg 163,329 47.724 21.581 32.109 21.219 Size of Central 1.000 heaares 400 hectares 120 becares 95 heaares 50 hecares Business Disstric (CBD) Morbidit rateper 595for 733fordiarrbea 3050fordiarrbea 8l8forparasilism 528forgastro- 10.000 from diarrhea(third rank (third ranik) (first rank) (secnd rank) entaeritis (third rank) diseases among diseases) Water bodies at Davao rivar and all Cagayan river and About 50% of dty Laguna Lake About 50% of city risk because of beaches close to adjoitnng beaches area cossiats of experiencing area are wetlands, municipal city not fit for cn Macajalar Bay wetlands. fNis ponds mcrease in turbidity used for fish wastewater recreational unfit for and estuarine area and rapid farming pullution pUlpOSeS recreational euirophicaticx ptuposes because of fecal contaminatimn The urban area/built-up areas in the project cities are characterized by a heavy con- centration of commercial and industrial activities. It is the area where population density is highest. These areas also represent the bulk of economic activity in the informal sector - such as, the production and consumption of raw and processed food, light manufacturing activities and retail distribution. A large proportion of piped water supply from the local Water District is also consumed in the Central Business District (CBD). Consequently, the pressure from both solid and liquid wastes in these areas greatly extceed the capability of the land and water resources to absorb. assimilate and recycle them. Calamba Impact During Construction Phase The implementation of the project and its components is projected to produce only minimal adverse environmenital impacts. The socio-economic impacts will be beneficial, and will result in a better standar-d of living for the municipalities and cities concerned. In the short-term, the project will provide emplovment and livelihood opportunities to the population of the surrounding communities through the jobs generated during the construction phase. In the long-term, better sanitary conditions will reduce sicknesses caused by water-related problems. Thuts an improvement of the existing environmental conditions is expected. The project N\ill und(lertake iitigatilig measures to minimize, or i at all possible, eliminate adverse impacts. hn vi riJnmentul . I "sevmnn/1f I?e'pu ni ( 1r[ Clcnnhc,, Ic'mci i Air Quality. The implementation of the project will result in an increase in the ambient concentration of suspended particulates in the vicinity of the project site. This would be attributed to dust from land clearing and excavation activities, which expose soil to wind and vehicular traffic over unpaved road. Water Quality. Excavation activities in the project sites could also loosen soils and tiansport of these materials to any surface waters, thereby increasing siltation and turbidity. During the rainy season, surface runoff may increase total suspended solids, and cause temporary stress at the discharge points. However, the impact will be localized, and when the vegetative cover returns, impact on the receiving body of water caused by surface run- off will be eliminated. Noise. The noise impact during the construction stage is expected to be generally minimal and will not require any special noise abatement measare. The treatment plant sites shall have a setback away from residential clusters, which will definitely provide the necessary buffer to reduce noise impact during construction of the modified lagoon systems. During pipe-laying, some noise will be generated due to the construction activities and the temporary operation of heavy equipment. Noise from breaking concrete pavement and sidewalks may also pose a temporary problem. However, the noise level at the streets is expected to be within the ambient noise quality standards. Ecological Effects. As there are no rare. endemic species of flora and fauna in any of the project areas, project implementation has minimal impact on the terrestrial ecology. Vegetative covers are expected to be cleared, unavoidably, during civil works. Impacts During Opeiation Phase Air Quality. The operation of the wastewater treatment facility will have minimal impact on the air quality of the area. Aside from the occasional odor nuisance, it is not projected to have adverse effect at all. Water Qualitv. The implementation of the plroject will be beneficial to the general environment of participating cities and their environs. Discharging of untreated domestic waste water from the high volume consumers in each city's Central Business Districts into nearby bodies of water would thus be minimized or eliminated. However, operations and maintenance failures may result in occasional discharges. Socio-economic. The provision of sanitationi facilities in the project cities would undoubtedly benefit the general populace of these areas. The occurrence of epidemic- scale diseases caused by current unsanitary conditions will be reduced. This will result in a more healthy and productive population. .I:/?M l )e ,J / aIM/ . 1X%'e.Y.VM/e /?t IRep l:. ( 'a/atnha Ia;Kiina 6 Sludge Disposal. The recommended modified lagoon system or vertically integrated pond system of treatment will require sludge disposal at very infrequent intervals. The sludge in the anaerobic pond/s remains for an extended period continuously undergoing organic decomposition. This may take place over a 20-30 year period. One system in operation in the U.S. has not been desludged in thirty years. Recent testing of this system has indicated that the sludge is well-digested and very stable. If desludging does become due, arrangements can easily be made with the city environment office for disposal at the sanitary landfill. Mitigating measures to minimize, or if possible. eliminate adverse impacts will be implemented. Measures to enhance the existing environmental conditions in the project site shall be implemented to maintain the environmental sustainability of the area. The implementation of the project wil inevitably cause impacts, both adverse and beneficial. Table I shows the potential impacts, risks and the proposed mitigating actions. Enxn onmenral .-I.v. es.nnt ?Report. (alamha. Lagtwm Table 1: Mitigation Actions Construction Phase Potential Impact & Risks Mitigation Action . Poor quality of construction * Design and supervision contract will be separated from supply and installation contract as a means of assuring quality of construction. Works engineers, with a relatively independent source of information on construction progress, will be hired. Air Pollution * Careful construction planning and work phasing, specifications and construction methods to reduce the length of time that the * Construction equipment and soil is exposed to the environment. vehicles may cause higher * Provision of adequately and properly maintained storage for suspended particulates, odors and construction materials and equipment. fumes emissions - CO2. CO, NOx * Expeditious and prompt removal of excavated materials or dredged spoils from construction sites. . Exposure of fine-grain particles to . Regular and adequate sprinkling of water on dust-generating wind and vehicular traffic will mounds/piles resulting from earthmoving activities and civil likely result in a decrease in air works. quality. . Good housekeeping for all construction affected areas and workplaces. . Control of motor vehicle and equipment emissions. * Use of protective gear by all workers. Water Pollution and Soil Erosion . Provide temporary drainage and storage facilities for excavation soils, for fuel and oils needed for equipment. * Siltation * Careful and rational planning of construction and post- construction phase_ of the project. . Maintenance of adequate drainage system. . Noise from operation of construc- . Erect temporary sound barriers around the work sites; avoid tion equipment would be about 70- si.nultaneous use of heavy equipment; limit daytime work, 80 dBA at 10 m: 50-70 dBA at 30 vehicle speed at 20 kph: regular maintenance of equipment m. . Use of appropriate mufflers and sound proofing of construction machinery, equipment. and engines. Use of appropriate shock- absorbing mountings for machinery. ,* Establishment of buffer zones and noise zones. * Temporary Disruption of Traffic * To the extent possible, feeder and collection sewer lines will be Flow located along secondary streets. * Scheduling and increasing input resources so that penod of traffic disruption in primary roads are reduced. * Coordinate with the local traffic management office and the PNP Traffic Management Command . Clear directional signs and barriers in case traffic rerouting is needed. . Public information campaign. _____onment_l_ I_sess_nent Repo_rt_( ____ __n_ j. _________________ Operation Phasel Potential Impact & Risks Mitigation Action * Environmental hazards due to * Carefully designed post-construction maintenance. contingency accidents and man-made or natural and monitoring programs. disasters. * Well designed plan for detection of accident or natural events • Breakdown or malfimction of the mcluding precautionary and remedial measures to be sewer lift station will increase taken/observed. level of polution at the San Juan . Adequate plans for environmental rehabilitation. clean-up, River near the center of the city as restoration, and disposition of temporary structures and facilities raw sewage will have to be installed during the construction phase. dumped directly. __| Water Pollution * Upgrade laboratory facilities of the Calamba Water District (CWD) to be able to undertake wastewater analysis. * The effluent discharge may well * Following the bubble concept, wastewater discharged into the affect the condition of receiving San Juan River shall, in the long-term, conform to the water bodies of water. quality standards established by the Department of Environment and Natural Resources as set forth in DAO No. 34 and 35, Revised Water Usage and Classification/Water Quality Standards and Revised Effluent Regulations of 1990, respectively. * A dispersion/dilution modeling study will be conducted to prior to locating the outfall. Treated effluent discharge into the San Juan River shall be timed based on tidal conditions. The adoption of the AIPS process for the treatment plants should result mto attainment of effluent standards. * Noise would be at about 65-85 * Establishment of buffer zones and noise zones. dBA. principally coming from septage trucks unloading at the treatment plant. . Odors (organic and sulfur com- * Maintenance of greenbelt zones and vegetation. pounds mainly from the trucks * Provision of landscaped open spaces which will improve the unloading septage) aesthetics in the area by planting the green strips with appropriate plant or tree species. Management and O&M of the System Institutional: * Management Contract with CWD which has proven utility * Poor maintenance of pumps management and operations capacity. . User consultation at detailed engineering design stage to ensure * Low number of connections connection. l Sewerage surcharge should be sufficient to provide incentives for CWD to maintain system. * Require M&E reporting to the DENR and LWUA. * Explore feasibility of BOO/BOT contracts for recreational activities in unused lands at treatment sites. * Provide adequate training of CWD and municipal staff. Regulatorv: * Require compulsory connection for all commercial, industrial and high domestic water users. l Utilize Public Performance Auditing system being set up by DENR to monitor adverse impacts. Technical * Provision of adequaite maintenance equipment and spares with CWD. Anvir1o )menLa?tlP . I vsve.%.v7men Reprtr ( 'uanmh o.i n,' 9 Monitoring and Implementation Arrangements Construction Phase Ambient air quality measurements will be undertaken near construction sites. This will be mostly near locations where sewer network is being laid and treatment plant sites. When selecting sites due consideration will be given to sensitive receptors like schools, hospitals. houses etc. Total suspended particulates (TSP) will be measured once a fortnight, for 8 or 24 hours, over the construction period. Noise will measured at the same locations as TSP. Leq and Lgo values will be measured and recorded. Operation Phase Receiving water quality will be monitored by the DENR through its regional offices which is monitoring the status of San Juan River on a periodic basis. The PMO will collect information on present conditions, observed changes in pollution loads etc. It should be noted that all the pollution load will not be removed but the proposed sewerage infrastructure will greatly reduce the problem. Once the plan becomes operational, the treatment plant operator, vis-a-vis, the local Water District concerned would be required to set up a laboratory and measure the effluent quality. TIhe Treatment Plant Operator will institute a monitoring program to measure effluent discharges. Daily representative values of PH, 5-day BOD, COD, Total Nitrogen and Total Phosphorus will be measured during the start-up period. Once the plant operations stabilize, weekly measurements (24-hourly basis) will be taken. Quarterly reports showing the trends of effluent discharge and receiving water quality will be reported to the PMO and DENR Regional Office. Implementation of the Monitoring Plan The PMO. with the assistance of LWUA-CPSO and consultants to be engaged in the project. would monitor compliance with the ECC and carry out the requisite data collection. Monitoring reports would be submitted to DENR/EMB and the World Bank periodically. While responsibilities for the various mitigation activities have been identified. the PMO will ensure that the requirements are complied with: in addition. feedback from communities. city officials. NGOs. etc. will be pro-actively sought through the city public affairs programs, regular monthly meetings of barangay captains and other methods. Finally. DENR, through its planned PPA system, would also periodically nionitor and audit compliance with the ECC. assisted by independent contractors. Table 2 summarizes the responsibilities and timetable for the Monitoring Plan. 1,nivronnenat1. Is.-essfllmw(1m eurr; ( alamtia. 1,vlm2,1a I0 Table 2 Summary of Responsibilities and Timetable for the Monitoring Plan Activity Responsibility Start Completion Secure ECC clearance from DENR. CPSO-LWUA Decanber 1996 Septanber 1997 Collect reference ambient air parameters City PMI 1t. Lh DENR September 1997 June 1998 around the proposed treatment plant sites at regional office project cities Ensure that the bid documenrts include PMO Januarv 1998 August 1999 provisio;ts for mutigatirm under the respmsibi- htN of the ctractor: review ccmtractor's work plans to easure compliance with en- vircmmantal mitigatico plan provisions Trait qerators cm O&M practice & handling PM() and CPSO-LWUA Jamuarv 1999 June 2000 etnergency situatirns. Assess and upgrade the laboratorv facilites of IProject Citv PMIJ ad local March 1998 June 2000 the Calamba Water District Water District Ccxduct user c tnsuiatiuns and infornatiun Projedt C itv PMt J. with January 1998 June 2000 carnpaigtt asssLance fNGC() Mmitor and report om cotnpliance. PMO Bi-amnual basis Bi-annual basis G229- 1A:?mr oncnŽnMntal. Issevvmen'nt Recpoy,r. ( almnha. J.ugv1na 1o I I 1. INTRODUCTION In the Philippines. the typical urban area/built-up area is characterized by a heavy concentration of activities, both commercial and induistrial. It is also the area where the density of population is at its peak. These areas are also the sites where the production and consumnption of raw and processed materials could be found. Consequently the, pressure on the life support systems in these areas are far higher than the suburban and rural areas. Adverse enviromnental conditions such as the generation and similarly the discharge of wastes into the environment is comnnon in urban and built-up areas. Unfortunately, the amount, type and concentration of waste generated exceed the capability of the local environment to absorb and assimilate them. The carrying capacity of the hfe support systems are stretched to the limits. The urgency of establishing collection and treatment methods which will prevent adverse impacts to the health and well-being of the residents, and to the ecological systems which sustain them cannot be ignored and overstated. The provision of a cost-effective centralized wastewater collection, treatment, and disposal is the primary objective of the proposed Water Districts Development Project (WDDP). The proposed project will assist the local governments of Dagupan, Calamba , Laguna, Cagayan de Oro, Davao City and Cotabato Cit. in finding solutions to tbe problem of sanitation. Most urban centers in the Philippines rely on individual septic tank systems for the treatment and disposal of wastewater from domestic and commercial buildings. However, the designs for such systems is often inadequate. Facilities for land disposal of effluents from the septic tanks are generally absent. Hence the partially treated septic tank effluents flow directly into storm drainage systems and other receiving bodies of water, thereby exacerbating an already grave pollution situation. There are several possible options for addressing this problem, including improving the design of the septic tank system with the installation of soil absorption systems. But an environmentally sound alternative that is cost-effective and captures economies of scale is to connect individual properties directly to a sewerage system for the collection, treatment and disposal of the urban wastes. Better sanitary conditions will thus be expetienced in the areas served by the sewerage, drainage and sanitation systems. This wNill reduce water-borne poUlution and water-logging within the cities and in the sunToundilng water bodies. thereby bringing health benefits to local populations. In Davao, Cagayan de Oro and Calamba cities, pollution from human wastes have affected recreational areas, such as beaches and lake front areas. Project investments in wastewater collection and treatment will also have positive benefits in terms of improving prospects of saving the r emaininig beaches for the city residents. The { nv nrnmentaI .xsessmcnr ?eport: (alamha. Laguna .1 construction of the systems will protect shallow groundwater aquifers from contamination [particularly in Tori area, in the case of Davao City, where the aquifer underneath is a major source of the city's water supply system]. Overall Approach of the Proposed Project The proposed project follows a demand-based approach, in the sense that facilities will be constructed only if they conform with the preferences of local stakeholders, and services conform to their respective willingness to pay. The stakeholders represent the different tiers of organizations from the Municipal Council and Barangay (part of the formal LGU system), to the more informal purok, neighborhood and household levels. During project preparation, the idea of involving communities in the planning process was field-tested in three barangays of Davao city, and found to be quite successful. The basic decision- making process is as follows: (a) For the capital-intensive trunk system, consisting of the main transportation sewers, primary drains and wastewater treatment facilities, the project design and implementation plan has to be approved by the City CounciL because the latter is responsible to repay the loan [see Annex 3 of the Staff Appraisal Report (SAR) for the project on Financial Aspects]. (b) For the feeder system, consisting of collector sewers, secondary drains and on-site sanitation facilities, barangays and local neighborhoods will be associated with the planning and implementation progranm The design criteria have been simplified, so that the feeder system can respond to local preferences and willingness to pay, rather than be bound by any conventional sewer design criteria used in industriahzed countries. Detailed design will be conducted through a participatory process. Given the capital-intensive natur-e of the investments, the proposed project is only the initial phase of a program to improve the sanitation infrastructure through a strategic planning approach that involves a mix of on-site and off-site wastewater collection, treatment and disposal. Choice of initial service areas for sewerage has been confined to the Central Business Districts or Poblacion areas because these are the major contributors to municipal wastewater pollution. The only exception made is in the case of Davao City, where a second area of high growth prospects (Toril) has also been included on the request of the LGU. The project will construct a sewer network that will discharge sewage to a vertically integrated pond system designed to treat both sewage and septage. In each of the cities (with the exception of Davao). the treatmenit sites selected are in areas free from encumbrances. For the sanitation components, the entire municipality has been included in the project area, wnith final selections being made oni the basis of demand. On-site treatment systems 117llronniUen/l .:ssexsnien7t Report (Calamba. Laguza 13 through the construction of VIP latrines, pit latrines, pour flush toilets and septic tanks will also be constructed if there is demand from property owners. For those properties with uncertain land tenure (as in squatter settlements), the project will finance the construction of communal toilets, to be managed by NGOs and/or the private sector. The specific location of these facilities will be driven by the willingness to pay for the services by beneficiaries at the barangay level, provided of course that these are technically feasible. The recommended solutions for wastewater treatment were arrived at after an intensive process of evaluating alternatives during the project preparation in order to achieve cost effectiveness and acceptability. The alternatives considered were anaerobic/facultative ponds, modified lagoon systems and mechanical treatment. In all the five cities, the evaluation of alternatives indicated that the modified lagoon systems, despite having a higher O&M costs compared to anaerobic/facultative ponds (as it requires mechanical aerators and recirculation pumps) was more appropriate. Details are available in project files. The selected option met the following criteria the effectively: (a) Minimize overall pond area required (b) Minimize odor production (c). Meet DENR effluent quality criteria, including fecal coliform reduction (d) Minimize sludge production rate (e) Maximize potential to use surrounding land for recreational purposes Environmental Impact Assessment This Environmental Impact Assessment Report for Calamba has been prepared in accordance with the Presidenitial Decree No. 1586 otherwise known as the Environmental Impact Assessmenit Lawv and Departmetit of Environmnenit anld Natural Resources Revised Administrative Order Nos. 36, the Revised Water Uscage anid Classification/Water Qualit, Criteria and Revised Effluent Regulations of 1990 respectively; and World Bank's Operationial Directive 4.(01 oni Enivironmental Assessment. The revised Administrative Order 36 for Environimental Impact Statement Svstem issued in 1996 is comprehensive and is compatible with the World Bank's Operational Diirective 4.01. It outlines the procedures to be followed by environmental critical plrojects (ECPs) and projects to be located in environmental critical areas (ECAs). in preparing environmental impacts statement (zelSs)'. ECPs and ECAs are defined in the AO. It should also be noted that that local ordinances and regulations governing projects of such nature have been taken into This is the term used by DENR and refers to thie standard Environmental Assessment Report required by the World bank as per OD 4.01 Z zlo /X/teste! >ssus:t79so c>wn S* C/alawba, LWunz/a 14 consideration in preparing this report. Similar EIA reports are being prepared for the other 4 cfties. This report has been prepared by a team of local consultants under the aegis of the Local Water Utilities Administration (LWUA) and the Calamba Municipal Government. Much of the work relating to the environmental impact analysis was undertaken as part of the feasibility study done by C. Lotti and Associati. Consultation with the community is an on-going process. The sanitation component of the project will be executed in a participatory manner, and detailed guidelines have been spelled out. o8 1fl-U i jcr (fHICH 1 0X) :ivlr0lme(u1en - ix. I.sse.sinent Rcporl ( Cu/limh/I. icgwiUiI 15 2. BASELINE ENVIRONMENT - CALAMBA, LAGUNA Introduction [his chapter is in two sections. Section I profiles the existing environmental situation in Calamba, Laguna and Section II analvses water pollution impacts (historical) of uncontrolled sewage discharge. Section I - Existing Environment 2.1 Land Resources and Use Calamba, Laguna is a progressive municipality occupying a total land area of 14,480 ha. Situated at the southem tip of Laguna de Bay it lies at coordinates 140 13' east latitude and 12 10' I north longitude. Calamba is bounded on the east by Laguna de Bay, on the north by the Municipality of Cabuyao, on the south by the Municipality of Los Bafios and on the west by Sto. Tomas Batangas. It is located 57 km south of Metro Manila and by land, serves as the gateway towards the south particularly to the provinces of Batangas, Quezon and the Bicol Region through the South Expressway. [Figure 2.1] Calamba is comprised of forty eight (48) barangays, twenty five (25) of which are classified as urban covering an area of 3,351 ha or 23% of the municipalitys total land area. The rest are classified as rural with an aggregate area of 1 1,129 ha or covering 77% of the total land area. Total arable area is estimated at 10.780 ha comprising about 75% of the municipahiy s total land area. Total land area cultivated is estimated at onlv about 5,182 ha. Crops predominantly cultivated include rice. sugarcane and vegetables. Inldustiial activities is highly concentrated at Barangay Canlubang in terms of the number of existing firms. although Barangays Mayapa, Paciano RizaL San CristobaL ReaL Makiling, Tulo and Turbina have also their share in the industrial growth. Heavy manufacturing industries are mostly located in Barangays Maklling, Tuo and Turbina. while light and medium industries are found in Barangays Canlubang. ReaL Sirang Lupa and San Cristobal. [Figure 2.2] 2.2 Physiographv and Geology Calamba is part of the volcanic plain of Mount Makiling and Taal. It has a gently to steeply telTain towards the Makiling Forest Reserve. The soil of Calamba particularlv Barangay Real is of the Lipa Loam Type with 0 to 2.5°% slope. The plroposed site for the wastewater treatment plant in Bgy. Sampiruhan is relatively flat and fertile and highly suitable for h1U7r'1 t U/ XVh1 1 .1.Vet.NVflt A'e/7 i RCI)I-1. ( c lli/l /I." 16 agricultural production.. The area is characteristic of a floodplain being inundated most of the year. The Banadero site is also flat and is currenwiy being cultivated to rice. The area is also being serviced by irrigation facilities of the National Irrigation Admiistration. Both sites have land available in excess of the requirements of the project. As gathered from the municipal planning officials, both sites are being earmarked or have a potential for development as residential areas. The volcanic plain of Mount Makiling and Taal was created during the pleistocene and recent times. Pyroclastic deposits underlying the basin appears to have been expelled from tall volcano vents. Clastic rocks composed principally oftuffaceous sedimentary detritus which includes waterlai and re-worked sandy tuffs generally bedded and well-stratified in places intercalated with beds of fine tuff Physiographic features of Calamba include lakes and r ivers such as the Laguna de Bay in its east side, the San Cristobal River forming its northem boundary, the San Juan River and Cauacauang River, as well as numerous streams and creeks. Natural hot and cold springs also abound in the area. Forests and woodlands occur in the hilly and mountainous areas southeast of the municipality. 2.3 Climate Calamba is located in an area classified as Type I ofthe Coronas Classification of Philppine Climate. This type is characterized by two pronounced season. dry and wet. The dry season starts from December to April sometimes lasting until May while the wet season occurs for the rest of the year with maximrnum rain period from June to September. Regions of this chmate type include those on the western part of the Islands of Luzon, Mindoro, Negros and Palawan. TIhese areas are exposed to the southwest monsoon and get a fair share of the rainfall brought about by the tropical cyclones occurring especially during the maximum rain period. Appendix 2 shows the climatological nonnals for the period 1947-1994 from the PAGASA Synoptic Station at Ninoy Aquino International Airport (NAIA), Pasay City. The information from this station, which is the nearest to the project site with complete climatological data, was used to characterize the local climate in the project area. February is the driest month with 3.1 mm monthly rainfall while August is the rainiest with an average monthly rainfall of 389.0 mm. The annual mean temperature is 27.4° C with January being the coldest month with a mean of 25.6°C and May the warmest with a mean of over 29.50 C. Annual mean maximum and minimum temperature is 31.7 ° C and 23.2°C. The average daily relative humidity is 76% and ranges from 71%, in February to 83° for Augu.st and September. The wet or rainy season is considered to be humid with relative lhumlidity gr-eater than 80%. The average daily sky coverage is about 5 octas which means that 5 out of 8 parts of the sky is covered with clouds. Cloudy months are from June to September with observed cloudiness of at most 6 octas. Relatively clear skies occur duttlng tlhe monthls of February to May while partially cloudy skies occur during,- the monitlhs of October to December. l ll s /fiene7tI . i. 'XeNflW.flI Re..'pcwt ('alainbae. I.agwisa / 2.4 Hydrology and Water Quality Calamba is principally drained by two (2) major rivers namely the San Cristobal River and the San Juan River. The San Cristobal River forms part of the northern boundary of the municipality. The San Juan river and ultimately the Laguna Lake will be the receiving bodies of water for the WWTP at Bgy. Banadero. It is officially classified as Class C waters as per the Department of Environment and Natural Resources Classification. The San Juan River is being utilized for irrigation purposes. 2.5 Vegetation and Wildli- Situated in built-up areas, the two proposed sites for the wastewater treatment plant has minor vegetative cover. The Sampiruhan site is covered mostly of fast growing grass species. The Banadero site, however, is planted to rice. There are no rare or endangered floral species in the area. The vegetative cover of the site is mostly palay and other cash crops. There are also no rare wildlife species reported or sighted in the proposed site or its vicinity. The wildlife population in the area may have been significantly limited by human interference and the absence of forest cover. Faunal species include domesticated anirmals such as dogs, cats, goats, chicken owned by nearby residents. Bird species were also sighted within the vicinities of the proposed sites. 2.6 Socio-economic Aspects As projected, based on the 1990 NSO Population Data, the population of Calamba in 1995 was placed at 199,467, with an average density of 11.98 person/hectare. The most populous barangay on the projections is the Poblacion, with a 1993 population of 27,194, and average density of 166 persons/ hectare. Section II - Environmental Pollution As in most other major cities, the urban area/built-up area in Calamba is characterized by a heavy concentration of commercial and industrial activities. It is also the area where population density is highest. These areas are also the sites where the production and consumption of raw and processed materials could be found. Consequently, the pressure on the environment in these areas are far higher than the suburban and rural areas. Adverse environmental conditions such as the generation and discharge of wastes onto the environment are common in urban and built-up areas. Unfortunately, the amount, type and concentration of waste generated exceed the capability of the local environment to ab- sorb and assimilate them. The carrying capacity of the life support systems are stretched to the limit. Aa,'lr)n?~nrnai ,lsx.exsflh.lt Report: (alamha. I.aguna I 8 2.7 Existing Sanitation Conditions A wilingness-to-pay survey had been conducted for Calamba (CDM, 1993) where it was determined that 40 percent of those surveyed were "very satisfied" with their present system. and 56 percent were "somewlhat satisfied." Onily 4 percent indicated dissatisfaction. Those 70 percent of houseliolds with water-flushed toilets for their exclusive use probably account for most of the "very satisfied" and half of the "somewhat satisfied" respondents. The relatively high degree of reasonable satisfaction with their existing systems could indicate that heads of households believe they have already provided for reasonable on-site toilet facilities. However, practically, all households are disposing their wastes to drains or canals whic' poses risk to public health of the people of Calamba. 2.8 Health Problems Faced by Calamba Residents As in the other project cities, sewage contamination is a prime cause of water-borne and water related diseases in Calamba. The municipal Health and Tourism Department (HTD) maintains records of morbidity and mortality in the municipality. HTD records indicate that among the ten leading causes of morbidity and mortality in 1991, water-related diseases such as parasitism, gastro-iiitestiiial disorders and fever were ranked second, sixth and eighth in the list of morbidity, but 11o mortality. 2.9 Existing Environmental Conditions at the Adjacent Laguna Lake The rapid growth of urbanization and industrialization in Metro Manila has spread out into the outlying cities and municipalities in the provinces of Cavite, Laguna, Batangas, Rizal and Quezon (known as the CALABARZON Region). Calamba is part of the CALBARZON priority development area which addresses the impacts of development brought about by rapid changes through expanding urban concentrations and industrial activities in the Metro Manila region. Although the impacts of these developments could be viewed as highly beneficial economically, the environomental consequences to the lake have been serious. The information available at this time substantiates that the urbanization and industrialization in the basin are causing significant environmental degradation of the lake. 2.10 Reduced Opportunities for Cominiecial Development Accelerated high-rise construction and sharp increases in property values have accompanied the installation of sewerage in the Makati district of Manila and the central business district of Jakarta. Indonesia. In some Latin American cities, central-city propertv values are reported to have increased by as much as 20% after sewerage was installed. It would not be surprising to see similar results in Calamba if sewerage were installed in the Poblacion district. Cilamba is well-positioned to become a commercial hub for its regioni. and the municipal leadership clearly aspires to this role for the An v7i ,n 0nmsi.tai71t1/ -. t.%'tsL9nmeI7; 1?epnr:els ( alcunhao1. I.iagi,,act 19 municipality. Rapid expansion of high-rise commercial activity in Poblacion seems very unlikely unless the area is served by a sewer svstem. 2.11 Summary of Findings on the Existing Environment Environmental conditions in the municipality are unsatisfactory. Two activities constitute the principal sources of pollution: Excreta and Wastewater Disposal. As noted above, about 4 percent of the population are without satisfactory on-site sanitation facilities, and most of the wastewater from those with acceptable facilities finds its way inito the municipality's rains and water courses. These deficiencies are the major contributing factor for the p Jr environmental conditions of Calamba. Solid Wastes. Solid wastes are collected from only 21 percent of the total area of the municipality, and not much of the wastes generated in those areas are actually collected. Disposal of uncollected wastes is unsatisfactory and large amounts of such wastes are littered casually at the places where these are generated. Much of these wastes find their way into the municipal drainage system, hampering the drains from conducting runoff during rains and contributing to flooding and general uncleanliness. Wastes collected are improperly disposed of atan open dumpsite where the uncovered wastes are burned. Health-related problems related to sewage contamination are of uncertain magnitude, but are an important consideration for the city leadership. Waterbome and other sanitation related diseases continue to be a major public health problem in the country. The advent of urbanization and induistrializationi has resulted into the development of urban and industrial centers outside the already saturated Metro Manila region. This present trend in urban sprawl and industrial development has catapulted population growths and accelerated industrial activities to outlving cities and municipalities such as Calamba. This growth and development however. has resulted into some environmental setbacks, among them the degradation of the municipality's water bodies, San Juan and San Cristobal Rivers and more notably Laguna Lake. Findings show that one of the main causes of this adverse condition is the organiic loadings from domestic solid and liquid wastes resulting from improper sanitation facilities and wastewater discharges from markets and other commercial establishments. This environmental situation makes imperative the implementation of sanitation and sewerage project in Calamba in order to promote sustainiable development that will not sacrifice the environment. Apart form thie project's contribution in minimizing domestic wastewater pollution form the munLicipality. it also addresses thie deficit in sanitation which will significantly improve health and living conditiolns. An x'ir00s1sP1onn?en In .- 7en1t ItMet ( /wha ,L,g,,,,,, 20 The municipality's water bodies appear to be in seriously deteriorated conditions. San Juan and San Cristobal Rivers which drain the municipality are both heavily polluted. These rivers function as natural drainage systems by r eceiving and conveying the municipality's liquid wastes and storm surface runoff to the nearby Laguna Lake. Laguna Lake which is located at the eastern edge of Calamba is not spared from this environmental situation. The lake is obviously under severe ecological stress. This is evident from the rapidly deteriorating water quality of the lake, declining fish production and the loss of its other present and intended beneficial uses. Commercial development in the Poblacion is repressed I ' the absence of sewerage. Installation of a system would permit high-rise construc )n and a significant increase in property values. LWUAqcr cnmhpr'.doc G08) 99? An,)-ronmenta/ .-Is.essment Rep'r (Calaniba. .li,gw, 2/1 IV~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~I . - - 'M\< ' 'V- 11 1 ' '' '' '\-" - '' ' . I, ~~~~~~~~~~~~~~~K o^tr ^urlxl ICM iAz1 llm~~2 -, %~~~~~~~~~~~~~~~~ Ok~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~2 -C- I A TlIA ~~~~~~~- + - . - 4i°d'2 2t 0~~~~~~~~~~~~~~~~~~~~~~MLIS *2f^s ;.,,,\ { ." "''';- ' - '44r' ' -- '..$f PROVINCE O F L A GU N A I, - -~~~~~ ~~ L ' / L EGENO~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Z a~~~ ~~ . I. -*-- ~~~~~~~~~ ? ~ ELPM A AN OFFPEN PC 04Fiue.. N / ~~~~~~~AN UE/A NATONL RBA SWEAG AN SNIATIN TRrEor ( oium/1lba ;.,Qz7aob1 3 time in this anaerobic zone and corresponding rise velocity is variable by design and nature of the waste stream. Treatment of soluble waste continues in the overlving aerobic zone, comprised of aerobic bacteria and algae. These organisms are maintained in an oxygenated state by photosynthesis, recirculation and surface aeration. The nature of the surface aeration creates a circular motion over the entire pond surface area which in turn ensures an oxygen rich colntiniuitv. Soluble wastewater componenlts undergo aerobic oxidation and further degradation in this zone. Thus, two nonnally seemingly incompatible biological wastewater treatment processes can be made to coexist uninterrupted in the same earthwork reactor. The horizontal velocity of the circular motion is reduced over secondary deepened zones as a result of the added volume, allowing the aerobic solids to settle by gravity into a secondary digester for further decomposition and stabilization. A sludge blanket is formed in this area and remains suspended over this zone. The surface aerobic circulation pattern reliably controls odors. The further fumction of the isolated reducing anaerobic zones includes denitrification, precipitation of heavv metals and fi-actionization of toxic compounds to a less toxic state. Seasonal, (temperature) and wind or wave action driven turnovers of the ponds is prevented by placement and design geometry of the internal cells and suppression of the thermocline. Turnovers are a complex phenomena of temperature changes, wind action. pond depths and configuration of the ponds. The advanced pond design features and method of cell integration serves to maintain the integrity of the system thus preventing potential pond turnovers. Sludge in the anaerobic cell(s) remains for an extended period continuously undergoing organic decomposition. This may take place over a 20 - 30 year period. One system in operation has not been desludged in thirty years. Recent testing of this system has indicated thiat the sludge is well digested and very stable. The second pond in the series is similar in nature to the first with the exception that the size and number of internal cells differ depending oni the design and type of waste treated. Recirculation of the hiahly oxygenated water from this second pond is introduced to the surface of the primnary faciultative pond to provide an oxygen rich overlay of this pond. This oxygeni quickly acts to oxidize reduced gases emerging from the fermentation cell and tluls mitigate possible migrating odors. Algae in the recycled water tend to adsorb heavy metals that may be present in the incominig waste stream. These algae tenid to settle in the primary pond. Thus a f nv ironnzL'nrat i.- .vaA:s.nL'7 /epornY: C*aamha. Laguna 33 significant fraction of heavy metals can be removed from the primary pond effluent in the form of reduced metal sulfides or as attached to algae solids. The modified lagoon system is proposed and an appropriate treatment method for a variety of wastewater treatment applications. These include normal discharges as well as variable hydraulic flows and organic loadings, particularly where there may be limited industrial pretreatment and source control of high strength unbalanced wastes and toxic and heavy metal discharges. The design elements provide for flow equalization, buffer capacity and recirculation capabilities to achieve secondary and advanced treatment for municipalities, agriculture and industry. The design criteria for the process is as follows: * Basic Design: Three ponds in series to meet coliform requirement < 1.00011 00mi - Primary Facultative with anaerobic cells - Secondary Facultative with following anaerobic cell - Tertiary - maturation pond * All systems designed with parallel facultative ponds. * Detention period: Primary pond - 5 days Secondary pond - 3 days Tertiary pond - 3 davs Note: Could use 4 ponid series with 5.2,2, 1 dazvs detention to achieve higher percentage coliform removal. * Pond design depths: Primary and Secondaiv - anaerobic sections - 4 m - aerobic sections - 3.5 m Tertianr Pond - 3.5 in * Supplemental aeration included for circulation and BOD requirements because of reduced area requirements. * Recirculation from Secondary pond to Primary included for media reinforcement and as a source of oxygen. * Land requirements low because of short detention and pond depths. * Combination of anaerobic and aerobic in same reactor improves efficiency. * Berm width - 3.64 m in all cases. 1 'ni ronmental .- lx.?stnzen1t Rteport: ('alun1ha. /lguWan 3 3. Mechanical Activated Sludge Plant The treatment plant would be constructed of reinforced concrete tankage and would have the following major components: - Illet Works: mechanical screens: glit removal: flow measurement - Priniary Settling Tanks - Aeration Tanks - Final Settling Tanks - Anaerobic Sludge Treatment Together with associated control building/laboratory, pump stations and maintenance buildings, partial standby power generation capability would be required. Based on international experience, mechanical activated sludge plants, although requiring smaller land area, are more expensive than any lagoon system in terms of capital as well as operation and maintenance expenditures. Furthermore, skilled staff is required to operate the plant. Therefore, the construction of a mechanical activated sludge plant is not considered a viable alternative for the municipality. Consequently, design criteria have not been developed. 4. Recommended Treatment Process A previous feasibility report (CDM. 1994) selected the anaerobic/facultative ponds for the initial septage treatment facilitv and for identifying the land area requirement for the deferred sewage treatment plant. However, the process has raised concerns as to its ability to operate satisfactorily without upset. In fact, with the reduced detention times, it is unlikely that any reduction in fecal coliform wil be achieved, which is a major requirement for the protection of the rivers and the gulf. Any upset to the system has the potential for the production of odors. Unless sufficient land is available, large buffer zones between the lagoons and inhabitants should be provided to reduce the level of odor reaching the nearby inhabitants. On the other hand, based on interniationial experience. the adoption of mechanical activated sludge plants, althoLugh1 requiiilng smaller land area, will be more expensive than anv lagoon system in temns of capital as well as operation and maintenance costs. Furthermore. skilled staff is required to operate the plant. Therefore, the use of a mechaniical treatmenit plant is considered not a viable optioii. The modified lagoon system utilizes mechanical aerators and recirculation pumps and, thus, has higher O&M costs compared to anaerobic/facultative lagoons. However. the modified lagooni svstem has the ability to treat variable strength fnvlronmlL'ntul. Ivxessmenem RIeport. (alan7ha. Lagwowci 35 flow; minimize odor production. meet effluent quality criteria, including fecal coliforn reduction; and has a minimal sludge production rate. These features allow the modified lagoon system to address the concerns related to the anaerobic/facultative ponds As a result of the above analysis, taking into account the quality of effluent after treatment, the availability of land as well as capital and operating costs, the modified lagoon system is recommended for all the WWTP to be included in the alternative schemes identified for Calamba. Comparison of Alternatives The alternative schemes identified are briefly described as follows: Alternative Scheme Description Stage I Service Area I The system will drain the sewage of the whole area (Poblacion and Eastern Area) to the WWTP (modified lagoon system) located at the Sampiruhan site. 2 The system is divided in two areas: the sewage flow of Poblacion will be pumped into the WWTP (modified lagoon system) located at the Banadero site; while the sewage flow of the Eastern Area will drain to the WWTP (modified lagoon system) located at the Sampiruhan site. 3 The sewage flow of the Eastemi Area will be pumped into the Poblacion system. The combinied flow of the two areas will then drain to the WWTP (modified lagoon system) located at the Banadero site. Stage I Expanded Service Area 4 The same as Alternative I. except that it includes a larger Eastern Area. 5 The same as Alternative 2. except that it includes a larger Eastern Area. 6 The same as Alternative 3, except that it includes a larger Eastern Area. Stage I Service Area (Poblacion only) 7 The same as Alternative 2 with the exclusioni of the Eastern Area. Therefore, the Poblacion sewage flow will be ptumped into the WWTP located in Banadero site. /.J?\IrI me7h?J?LI/ . esiXLXneml? ReporIIt. C( a b I/I/Lc /L/gl//L 36) 1. Design Assessment of Alternatives Specific design parameters for the treatment plants to be considered for five alternatives are as follows (schemes 3 and 6 had been discarded because of their much higher capital and O&M costs compare to the other five): Alternative WWTP Connected Total Flow BOD Loading Schemes Location Population (cu.m/d) (kg/d) Sampiruhan 19,020 1 - Sewage 4,394 761 - Septage 130 650 Total 4,524 1,411 Sampiruhan 2,956 - Sewage 683 118 - Septage 130 650 2 Total 813 768 Banadero 16,064 - Sewage 3,711 761 - Septage Total 3,711 761 Sampiruhan 23.134 4 - Sewage 5,347 926 - Septage 130 650 Total 5,477 1,576 Sampiruhan 7,070 - Sewage 1.633 283 - Septage 130 650 5 Total 1,763 933 Banadero 16.064 - Sewage 3,711 925 - Septage Total I 3,711 925 Banadero 16,064 7 Sewage 3,711 643 - Septage 130 650 Total I 3,841 1,293 Assumptions: - Flow 213 I/cap/d - BOD 40 g/capid - 60% of the population is connected to the sewerage system. - Septage BOD 5.000 n111f f:lii'/ '(,AlkfR7L'}leJ / i. I A%L'.%/1,e, t I?ep */ ( -ii il;'/!/, ,' {. 0/!I7C3 2. Financial Assessment of Alternatives As discussed above, seven altemnative sewerage schemes have been evaluated. A cost comparison of the seven sewerage schemes in terms of capital and O&M costs, has proved that the cost of Alternatives 3 and 6 are much higher than the others because too many pumping stations are needed. Therefore, the two altemnatives have been discarded and for which no further evaluations were made. Comparison of the remaining five alternatives is as follows: (i) Capital Cost To evaluate the altemative schemes, a set of construction unit costs were developed on the basis of costs derived from the Feasibility Report and other relevant studies and data gathered by the consultant. For fuirther information, reference should be made to the Feasibility Report (C. Lotti, 1996). Comparing capital costs as follows: Capital Cost of Alternatives' Facility (P milion) _ 1 2 4 5 7 I. Collection2 42.64 42.64 67.36 67.36 26.74 2. Property Connections3 25.96 25.96 28.96 28.96 21.93 3. Transportation System 33 48 1 9.73 39.13 25.63 11.91 4. Pump Stations - 7.85 - 6.42 7.85 5. Land for Pump Stations -0.09 0.09 0.09 6. Forcemains - 1.16 - 1.16 1.16 7. Outfall 5.04 1.51 5.04 1.51 _ 8 WW1TPs 23.22 2'4.7; 26.58 28.17 17.50 9. Land for WWTPs 8.00 10.60 9.60 12.00 7.60 10. Resettlement - - Total 138.34 134.25 176.66 171.30 94.79 Notes: Capital costs include 5% phvsical contingencies plus 15% for engineering and training. At a cost per hectare of P261,625 (includesfor contingencies, engineering, etc.) as developedfrom tvo studA' areas in Davao and Dagupan. Collection sewers proposed are "condoinimal ", that is, they are r outed through private property to optimize the sewer length and ennimize cost of connection to the transportation sewer. Property owners have to be consulted and agree to the condomeinal sewer design. 3 The cost of a house connection to a seiverfor an existing property, requiring the abandoning of a septic tank, has been estimated at P9,726 (includesfor contingencies, engineering, etc.). Assumes 60% of the v'ear 2001 population connected to the sewerage system. Ik'nvirnwnie (a l . l.ssessL7Iem e!)pf)ri. ( 'lai a'et. I,a' ,la 3S (ii) O&M Costs The O&M costs will increase in relation to the number of connections. Annual O&M costs have been computed for each alternative firom the vear 2001 (starting of operation) to the year 2015. The following table shows a compaiison of the O&M costs for the year 2001 and 2015. Alternatives Annual Cost 2001 Annual Cost 2015 (F million) (P million) 1 1.91 2.61 2 2.69 3.34 4 2-07 3.35 5 2.73 3.44 7 1.90 2.59 (iii) Net Present Value The above capital and O&M costs have then be used to determine the net present value (NPV) at 15% discount rate. Since the alternatives drain different areas, the corresponding sewage flows are also different. Therefore the net present value (NPV) of each alternative has been determined as the ratio between capital and O&M costs and the volume of sewage flows, at 15% discount rate. The result of the analysis is as follows: NPV Alternatives (P /cu.m) 1 21.28 2 21.45 4 21.22 5 21.20 7 17.84 (iv) Conclusion The above NPV clearly shows that Alternative 7 is the most economic and,.therefore. is recommended for implementation. The recommended alternative is for a collection and transportation sewer network, in the Poblacioni area. discharging to a single WWTP located at the Banadero site. The WWTP WOLuld use the modified lagoon treatment process and would treat both sewage and septage. The treated effluent would be discharged into the San Juan River. I nlvirounmenltal .1 .sse.vvn7eflI Report: (Calamha. I.C(agIMR 39 Section IV - Recommended Project Design for Calamba, Laguna Description and Components The recommended plan will include the following components: (i) on-site and communal sanitation facilities; (ii) sewerage systems in Poblacion; (iii) maintenance equipment, tools and spare parts for the operation and maintenance of installed sewerage infrastructures; and (iv) institutional support. Sanitation Facilities The sanitation component will include the constr-uction of 395 VIP latrines and 395 pour- flush toilets with septic tanks which will benefit about 4,150 residents as well as 17 communal toilets which will benefit about 4.250 residents in the municipality. I he on-site sanitation facilities include: "VIP latrine and pit" and "pour-flush toilet and septic tank". The demand for on-site facilities will, therefore, be established by public consultation concerning rented dwellings and owner occupied houses. Communal sanitation facilities to be provided under the project may be either on-site or off-site, connected to the sewerage system, depending on teclnical feasibility. The choice between individual and communal facilities will be driven by technical feasibility and demand by key stakeholders, and not by tenure status. However. in slum areas and squatter settlements, the demand will be ascertained not only from the tenants, but also from land owners and from local government officials representing public interest. The communal toilets will be constructed in areas where, through public consultation, there is an established demand and willingness to pay for the service. Seweraze Svstem The sewerage systems will include: (i) house connections; (ii) feeder sewers for the collection of wastewater in neighborhioods. puroks and barangays; (iii) trunk sewers and pumping systems for wastewater conveyance from baranlavs to treatment plants: and (iv) sewage and septage treatment plants. The connection of properties to sewers will be made under the project in order to ensure good workmanslhip and timely connectioni of houselholds to installed sewer systems. Recovery of house connection costs will be spread over a period consistent with demand. Feeder sewers will consist of simplified and condomi-nial sewers. Where condominial sewers are used, communities will be given a choice between location of the sewers in back-yards and locating them in front of tlheir properties. Simplified sewers will be used for trunk and maini transportationi sev\ers. i nZwlronm?entl .-lssvXint Reptnrt- ( alamha. Laguna 40 A modified lagoon system will be used for the treatment of both sewage and septage. Its principal unit is a deep vertically integrated pond with an anaerobic pond below a facultative pond system. The geometry prevents turnovers, thereby mrinimizing odor problems as well as sludge accumulation. The project proposes the construction of sewerage facilities in the Poblacion of Calamba. In the Poblacion, the Stage I sewerage system will cover a service area population, in 2015, of about 26,770 of which about 16.060 (or 60%) will be served. The Stage I system proposes the construction of a sewer network that will discharge sewage to a single vertically integrated pond system designed to treat both sewage and septage:. The treatment plant is located at the Banadero site and the treated effluent will be discharged to the San Juan River. In Poblacion the system (see Figure 3.2) wiUl include the following facilities: * collection sewers covering an area of 102 ha; * transportation sewers with a total length of 3,740 meters and diameter from 150 to 400 mm; * one pump station with a capacity of 5,566 cu.m/d and a land requirement of 173 sq.m; - a force main with a length of 700 meter s with diameter of 250 mm, - a WWTP with a capacity of 3,841 cu.m/d and a lanid requirement of 3.8 ha; a total of 2,049 connections in the year 2001. The additional 723 connections up to the year 2015 will have to be constructed by the CWD. Maintenance Equipment and Snares Equipment will be provided to the CWD including vehicles. machinery and tools needed for proper operation and maintenance of the sewerage and pumping facilities. Spare parts for critical equipment will also be supplied. It should be noted that the sewerage systems will, after con sti-tction, be turned over to the CWD not only for operation and mainteniaince but also for construction of additional connections. It is envisaged that the cost of new conniectionls will be paid up-front by the users at the moment they request to be connected to the system. This will surely constitute a constraint and mav restrain the users firom beillg connected. To minimize this problem in the first one-two years of CWD operation, it is proposed to include in the project the procurement of stored material (pipes. fittings, etc.) necessary for the coinections. This would reduce the up-front amount required from the users and the cost of material could be charged monthly on the water bill by the CWD. A nv 0nzen1aI . Ixve.ssnwn I? 'Report. (alamiha. Lagu1a 4/ Institutional Support The project will include: (i) consulting services for detailed design, consultation of beneficiaries and construction supervision; and (ii) training of CWD staff responsible for the operation and maintenance of installed sewerage infrastructures. The consulting services required are detailed in Section 6.5 of the Feasibility Report (C. Lotti & Associati, 1996). The services to be provided by the consultant also include the training of staff for the operation and maintenance (O&M) of the sewerage systems and particularly of ponding systems. The consultant will have to prepare an O&M manual and train the operators on basic ponding treatment concepts as well as familiarity with the O&M manual. The training program should also include an overseas visit to a country where the adopted treatment method is already in operation. Cost Estimates Based on the estimates, the capital cost of the Calamba project has been estimated at P111.34 million (US$4.24 million) excluding price contingencies and interest during construction. The cost is composed by P37.14 million (US$1.41 million) of foreign component and P74.20 million (US$2.82 million) of local component. By including price contingencies and interest during construction, the total project cost is P167.64 million (US$6.38 million). -The project cost by component is as follows: Comronent } (P million) SANITATION Construction of facilities 12.45 Land 0 Pnrce contingencies 2.20 Interest during construction 5 93 Tota Sanitation 20.68 SEWERAGE I Construction of facilities 75.74 Land and resettlement 7.69 Maintenance equipment & spares 4.00 Institutional support 11.36 Price contingencies 12.38 Interest during construction 35.79 Total Sewerage 146.96 Total Investment Total interest during constructionC 41 .72 Total Project Cost 167.64 I.mvirontmeinal >1Sl'SXflWflt Report (alamha. Lagima 42 Section V' - No Project Scenario Chapter 2 has vividly described the worsening environmental and health situation resulting from poor sanitation and uncontrolled discharge of sewage. Though the proposed project will cover only a small portion of the population, the project is seen as an important and significant first step in a long term program to provide Calamba (and the nearby cities and municipalities as well) the required sanitation and sewerage infrastructure. The project is anticipated to contribute to the gradual improvement of the municipalty's environment and improvement of the conditions of its San Juan and San Cristobal Rivers and the nearby Laguna de Bay. LWUAijcr c,pch,rc.do G299- IŹii LIr(Jfl)/7tL'17tu!/ .I I.s% '. :171UhfI? 1˘v9( l- ( a/ai/"17! a5. I. aŹ,'.,m11171 43 \~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -I LEGEND: EJ STAG E 2 WA GE 3 ;,^ N C~~~~~~~~~~ v IAWSf PAN1t SITES t _ - AmANCAW DORINVARtY \ *F^NCLYCOtlNDM' -Figure3.1 - ( .,Li/tn n'n i.l-',r a 52 Section II - Monitoring Plan Construction Phase Ambient air quality measurements will be undertaken near- constr'uction sites. This will be mostly near locations where sewer network is being laid and treatment plant sites. When selecting sites due consideration will be given to sensitive receptors like schools, hospitals, houses etc. Total suspended particulates (TSP) will be measured once a fortnight, for 8 or 24 hours, over the construction period. Noise will measured at the same locations as TSP. Leq and Lgo values will be meas ed and recorded. Operation Phase Receiving water quality is to be monitored by the DENR through its Regional Office which has been periodically monitoring the status of the San Juan River and estuarine water quality. The PMO will collect information on present conditions, observed changes in pollution loads etc. It is to be recognized that all the pollution load will not be removed yet it is also expected that the proposed sewerage infrastructure will greatly reduce the problem. Once the plan becomes operationaL the Treatment Plant Operator, vis-a-vis the Calamba Water District would have to set-up a laboratory and institute a monitoring program to measure the effluent discharge. Daily representative values of PH, 5-day BOD. COD, Total Nitrogen and Total Phosphor-tts will be measured durling the start-up period. Once the plant operations stabilize. weekivl measuremenlts (24-hourlv basis) will be taken. Quarterly reports showing the trends of effluent discharge and receiving water quality will be reported to the PMO and DENR Regional Office. 1`171-IMMY2071 XX.'A:1s,l7J 1 R r 1 ( IS1NONA, I .,v f .53 Section III -Implementing Arrangements The WDDP-PM-U, with the assistance of LWUA-CPSO and consultants, would monitor comphance with the ECC and carry out the requisite data collection. Monitoring results would be submitted to DENiVEMB and the World Bank periodically. While responsibility for the various mitigation activities have been identified, the WDDP-PMU shall ensure that the requirements are complied with. In addition, feedback from communities, city officials, NGOs, etc. will be proactively sought through the city public affairs programs, regular monthly meetings of barangay captains and other methods. DENR, through its planned PPA system, would also periodically monitor and audit compliance with the ECC, assisted by independent contractolrs. Summary of Responsibilities and Timetable for the Monitoring Plan Acdvity Responsibility Start Completion Secure ECC clearance from DENR Ci'S( )-LWIJA December 1996 Septanber 1997 Collect reference ambient air paramders arotnd the Citv PMU. with DENR September 1997 June 1998 proposed treatment plant sites at project ctties regional o tricc Ensuretsat the bid documtits inclUdepros-isi,st for jiilt- I'MO Jantia 1998 August 1999 gaticm under the respomsibiLitv of the contracl¶or: l is | canuacLor s work plans to ensure lceipnance wvith w- virounmctal m tigat io plas provisiots. Train perators au O&M praclice & handling emergeucv PMO amid CPSO-LWI1A January 1999 June 2000 situatious. Assess and upgrade the laboratorv faaitiLsofthic jl'ro;cat Citv PMUm mid local Mardi 1998 Jue 2000 Calamba Water Distrnct Water Distrnic Cdiduct user ceusultatimus and information campaigu. Pro1ect Citv PMI k. with January 1998 June 2000 { asstsance of NGiO. Mcuitor and repmrt on comphance. I'M) Bi-annual basis Bi-annual basis LRtLA icr G91 99- Anvzl r(onmenltal 9.;e/7l Rejsni': ( a,a,,,hc: /'.uiglll1( .5 Appendices 1. Bibliography 2. Climatological Normals 1947-1994 from the PAGASA Synoptic Station at NAJA, Pasay City (PAGASA Station nearest to Calamba, Laguna) 3. Typical Noise Emissions of Construction Equipment 4. Expected Noise Levels at Various Distances from Construction Equipment 5. Environmental Quality Standards For Noise Maximum Allowable Noise Level. 6. The Advanced Integrated Pond System (AIPS) of Wastewater Treatment Appendix I BIBLIOGRAPHY C. Lotti & Associati, 1996, Updating Feasibility Reports for Sanitation Investments in Five Cities, Final Report, Vol. 4, Calamba, Laguna, November C. Lotti & Associati, 1996, Updating Feasibility Reports for Sanitation Investments in Five Cities, Final Report, Vol. 1, Main Report, November CDM Intemational 1994, First Stage Feasibility Report for Sanitation and Sewerage: Calamba, Laguna, Philippines, January CDM Intemational 1993, Household Willingness to Pay for Improved Sanitation Services: Calamba, Laguna, June Environmentally Sustainable Development (ESD) Vice Presidency, World Bank, 1994, Water Supply, Sanitation and Environmental Sustainability, The Financing Challenge WASH, 1990, Health Benefits from lmprovements in Water Supply and Sanitation: Survey and Analysis of Literature of Selected Diseases. Technical Report No. 66, July Vfhittington, Dale, Donald Lauria and KyeongAe Choe, 1993, Households' Willingness to Pay for Improved Sanitation Services in Davao, Philippines, July Whittington. Dale, et. al., 1995, Economic Benefits of Surface Water Quality Improvements: Davao CV Study (mimeo.) Yhiiguez, Cesar, 1996, Urban Sanitation UJser Demand Study: Technical Consultant's Report. May Lee. E. W., 1990, Ponding Systems Treat Wastewater Inexpensively, USEPA Small Flows. October Oswald, W. J.. 1990. Advanced Integrated Wastewvater Pond Systems, 1990 ASCE Convention Proceedings. Am. Soc. of Civil Engilleers. New York SOA, Inc., 1996, Advanced Integrated Pond Systems: Innovative and Alternative, Environmentally Sound and Low Cost Solutions for Wastewater Treatment into the 21st Century, (Hand-out) I Appendix 2 (Clim2latological Nornials at PAGASA NAIA SNynoptic Station, Pasay City (1947-1994) Amnt. of No. of = = Tern erature (C) RH MSL Wind Cloud Days w/ Days w/ Montlh Rainfall Rainy Max Min Mean Dry Wet Dew Vapor (%) Press. Speed Dir. Cover Thunder Light- (ilmm) Days _ Bulb Bulb Point (mbs) (mbs) (octa) storm ning Januarv 8.6 3 30.2 20,9 25.6 25.2 21.8 20.3 23.8 74 1,013.5 2 E 4 0 0 February 3.1 2 31.2 21. I 26.2 25.9 21.9 20.2 23.7 71 1,013.5 3 E 3 0 0 March 6.4 2 327 22.4 27.6 27.4 22.8 20.9 24.7 68 1,012.7 4 E 3 0 .April 11.6 2 34.2 24.0 29.1 29.0 23.9 22.0 26,3 66 1,011.2 4 E 3 1 5 Mav 113.5 8 34.2 24.9 29.5 29.3 24.8 23.2 28.5 70 1,009.4 3 SE 4 7 17 JuLnc 263.4 17 32.4 24.4 284 281 24.9 23-8 29.6 78 1,008.8 2 W 6 12 17 Juk1v 362.0 19 31.3 24.1 27.7 27.4 24.7 23.8 29.5 81 1,008.3 2 W 6 12 17 Auigtust 389.0 20 30.8 24.0 27.4 27.1 24.7 23.8 29.6 83 1,008.0 2 W 6 9 10 Scptcniiber 310.2 IX 31.1 24.0 27.5 27.2 24.7 23.9 29.7 83 1,008.8 2 W 6 11 15 Octobcr 227.1 14 31.1 23.5 27.3 26.9 243 23.3 28.7 81 1,009.8 2 E 5 6 1 1 Novembcr 119.5 1 I 31.0 22.8 26.9 26.6 23.6 22.5 27.4 79 1,010.9 2 E 5 2 4 Dcccmbcr 42.9 6 30.3 21.7 26,0 25.7 22.7 21.5 25.6 78 1,012.5 2 E 5 0 Annlual 1,857.4 122 31.7 23.2 27.4 27.1 23.7 22.4 27.3 76 1,010.6 3 E 5 60 98 So* ree: PA (GA.SA I Appendix 3 TYPICAL NOISE EMISSIONS OF CONSTRUCTION EQUIPMENT Typical Sound Pressure Levels Equipment at 15 m from Source [in dB (A)] Air Compressor 75-87 Backhoe 71-92 Compactor 72 Concrete Mixer 75-88 Concrete Pump 82 Cranes 76-88 Front Loader 72-81 Generator 72-82 Grader 80-93 Jack Hammer 81-97 Paver 87-88 Pile Driver 95-105 Pumps 70-90 Tractors, Bulldozers 78-95 Trucks 83-93 Vibrator 68-81 Appendix 4 EXPECTED NOISE LEVELS AT VARIOUS DISTANCES FROM CONSTRUCTION EQUIPMENT [in dB (A)] Equipment 30 60 120 240 meters _ _ ___ _ . .meters meters meters Air Compressor 69-81 63-75 57-69 51-63 Backhoe 65-87 59-81 53-75 47-69 Compactor 66 60 54 48 Concrete Mixer 69-82 63-76 57-70 51-64 Concrete Pump 76 70 64 58 Cranes 70-80 64-74 58-68 52-62 Front Loader 66-75 60-69 54-63 48-57 Generator 66-76 60-70 54-64 48-58 Grader 74-87 68-81 62-75 56-69 Jack Hammer 75-91 69-85 63-79 57-73 Paver 81-82 75-76 69-70 63-64 Pile Driver 89-99 83-93 77-87 71-81 Pumps 64-84 56-78 50-72 44-66 Tractors, Bulldozers 72-89 66-83 60-77 54-74 Trucks 77-87 71-81 65-75 59-69 Vibrator 62-75 56-69 50-63 44-57 Appendix 5 ENVIRONMENTAL QUALITY STANDARDS FOR NOISE MAXIMUM ALLOWABLE NOISE LEVELS [in dB (A)] Class Area Day Morning/Evening Mght AA Hospital/School 50 45 40 A Residential 55 50 45 B Commercial 65 60 55 C Light Industrial 70 65 60 D Heaxy Industrial 75 70 65 Note: The divisions of the 24-hour period shall be as follows: Morning 5:00 AM - 9:00 AM Daytime 9:00 AM - 6:00 PM Evening 6:00 PM - 10:00 PM Nightime 10:00 PM - 5:00 AM I Appendix 6 THE ADVANCED INTEGRATED POND SYSTEM (AIPS)' of WASTEWATER TREATMENT Preface. The Sewerage and Sanitation Component of the World Bank-assisted Water District Development Project has proposed the adoption of the modified lagoon system vis-a-vis the Advanced Integrated Pond System (AIPS) as the processfor treating collected wastewater (and septage). The following describes the technology and benefits of the aforesaid treatment system. The ALPS is an integrated, multi-stage biological reactor system trepting wastewater. The system utilizes compacted earthen construction to reduce costs. Tb system optimizes natural biological processes to reduce power requirements and neea for chemical additives. The concept is to minimize bio-solids production rather than to maximize aeration solids resulting into minimal power requirements and solids management. AEPS consists of a series of at least four ponds, each designed to best perform one or more of the basic treatment processes. First is the primary biological reactor or a facultative pond with an aerobic surface and extremely anoxic intemal pit for sedimentation and fermentation. The pond reactor has three discrete and isolated biological zones integrated into a single unit: a deep anaerobic pit at the bottom, a sludge blanket suspended within the deep pit, and an overlying aerobic comprised of aerobic bacteria and algae oxygenated by photosynthesis, supplemented by horizontal mechanical aerators when needed. Anaerobic microbes in the pit are protected by surrounding wails or berms from the intrusion of cold surface water containing dissolved oxygen. Raw sewage is introduced directly into the pits where sedimentation and methane feTmentation occur. Overflow velocity in the pits is maintained so low that suspended solids removal approaches 100% and biochemical oxygen demand (BOD) removal approaches 70%. The overflow velocities of one to two meters per day are less than the settling velocities of helmninth ova and parasite cysts so most of these remain in the pit and consequently are permanently removed from the effluent. Solids at the bottom of the deep anaerobic pits remain for very long periods of time, continuously decomposing. Due to the large pit volume and its depth, and the reducing environment, settled solids ferment there to a point where only ash remains. Thus minimizing the generation of bio-solids, hence sludge removal is seldom if ever required. The oldest plant in operation treating domestic wastewater from the city St. Helena in California, USA, has not had to remove bio-solids for nearly 30 years. The second pond is a high rate pond where microalgae grow profusely releasing oxygen from water by photosynthesis. Algae produced are highly settieable and after Oswald, W. J, Advanced Integrated Wastewater Pond Systems. 1990 ASCE Proceedings, Am. Soc. of Civil Engineers, New York .-ppendix 6: 71e. ldvuancedne Integratedl PoiidS .Svstem(4IPS) of 11Wavtewater Treatment I sedimentation, the remaining water has a BOD that is generally less than 20 mg/L Recirculation of algae bearing water from the High Rate Pond to the Facultative pond provides an oxygen-rich cap on the facultative pond. This oxygen quickly oxidizes reduced gases emerging from the fermentation pit thus mitigating odors. The third pond provides for sedimentation of algae. Algae which settle tend to hibernate and thus do not immediately decompose and produce nuisance. The waters emerging from the settling ponds are sufficiently low in BOD and suspended solids. They can be percolated readily into the ground or used for irrigation. They still however high E-coli count of more than 1000 MPN per 100 ml. and therefore may require storage prior to disposal or reuse. Then comes the fourth pond which has a dual purpose of added disinfection and storage for irrigation or other uses. Performance: Following algal removal, the degree of pollutant removal in the ALPS is equivalent to that of mechanical secondary plants but as is to be emphasized at a much lower capital and operation & maintenance costs. The treatment action of the AIPS is very similar to and realizes the advantages of an upflow anaerobic sludge blanket (UASB) reactor. The AIPS however does not inherit the rigorous operation and maintenance problems like clogging and sludge handling inherent to UASB reactors. There now more than 85 operational treatment plants in the US and in other countries. Notable among them is the wastewater treatment plant for the city of St. Helena, in California, USA. The St. Helena system has been recognized as the Plant of the Year by the California Water Pollution Control Association for 5 MGD plants in 1994 and was likewise accorded by the California Energy Commission the "Energy Efficiency Showcase Award" also in 1994. The St. Helena plant treats domestic wastewater at a peak capacity of 2 MGD. Performance data indicate that for the period of 1990 to 1995: average influents of BOD of 290 mg/l and TSS of 263 mg/I were treated to 24 mg/l BOD (92% removal) and 34 mg/A TSS (87% removal), respectively. A treatment plant in Hollister, California, USA, with capacity of 2 MGD, exhibited similar removal efficiency, reducing an influent BOD of 194 mg/l to a mere 7 mg/l after treatment. Performance of AiPS plants can be expected to reduce pollutants in the following ranges:' * BOD 95-97% * COD 90-95% * Total Nitrogen 90% * Total Phosphorus 60% * MPN - E-coli 99.999% - Lee, E.. "'Ponding Systems Treat Wastewater Inexpensively", USEPA Small Flows. October, 1990 tppen1djx 6 7Y .elid iancedl )t!egratebl oI7nd . 'aIem(-A!P.S/ of lf ashteater 7reatment2 On sludge management, the earthwork digesters (fermentation pits in the facultative ponds) can be made large to permit complete digestion and thus reduces sludge generation to the extent that sludge handling is eliminated for many years. The St. Helena plant in 27 years of continuous operation, accumulated less than 1 meter of residue or just 3 centimeters per year! Thus daily or frequent sludge removal is eliminated thus attaining cost and energy savings. The Hollister plant also showed the same very low rate of accumulation in 12 years of operation. Because the sludge undergoes full fermentation, the sludge or residue resulting from the process is relatively inert and stable, and the volume is small. Disposal then should not be a major operation problem. In terms of costs, Oswald compares the cost of a conventional treatment of $350 to $700 per cu. mn. (1990) to that of the ALPS which would cost less than $5 per cu. in. (1990), 100 times cheaper. In essence, the AIPS of treatment has the following advantages: * Efficient organic pollution reduction and nutrient removal comparable if not better to secondary and tertiary treatment. * Energy efficient -- the design provides for reduces oxygen requirements on the front end * Less construction cost, as compared to AEPS: * Oxidation Ditch .5 times more expensive * Trickling Filters 4 • Activated Sludge 4.5 * Stabilization Pond 1.4 e Less operation cost * Oxidation Ditch 3 times more expensive * Trickling Filters 3 - Activated Sludge 3.5 * Stabilization Pond 1.3 * Virtually no odor - odor production is naturally controlled. In the case of the St. Helena (CA, USA) treatment plant: A convalescent home is within 300 feet of the ponds. In Hollister (CA, USA), the treatment plant is practically within "sniffing distance" of a golf course and residences in the area. * No daily sludge handling. St. Helena's Treatment Plant has not removed sludge in 30 years of continuous operation. * Pond buffer capacity enables the system to handle effectively variable organic and hydraulic shock loads. IppendirX 6. 7 e .- IdvWL;. I In/eV-ated Pfondc .>tem(.-1I'. ) o/11U as.eiater Tretment 3 Selected Bibliography: Lee, E. W., Ponding Systems Treat Wastewater Inexpensively, USEPA Small Flows, October, 1990 Oswald, W. J., Advanced Integrated Wastewater Pond Systems, 1990 ASCE Convention Proceedings, Am. Soc. of Civil Engineers, New York, 1990 SOA, Inc., Advanced Integrated Pond Systems: Innovative and Alternative, Environmentally Sound and Low Cost Solutions for Wastewater Treatment into the 21st Century, (Hand-out) * Further relevant information and reference materials on the AEPS are attached for reference. lppLendXr 6 The Advancedlnteg'ratedlPondS.'Yxtem (A P.N) oJ Ifasrex,ater Treatment v ADVANCED INTEGRATED POND SYSTEM (ALPS) Natural, Biological Wastewater Treatment for Municipalities, Agriculture and Industry - 3 ', ;, - .'-Innolva ive and Alternative, EEiivikronfe4ta fly Sound and low Cost ~"' rSolutions For Wastewater Treatment Into the 21st Centulry .~~~~~~~~~~~~~A . _ 1340 Amold Drive, Suiie 11)0 Martinez, CA 94553 510-228-5NO1 Faxc 51G-228-5804 I SOA, Inc. Martine-t AIPS llighlights > 1Efficient pollution control El recive organic reduction and nutrient removal for secondary and tertiary treatment. Energy Efficiency with AIPS The integrated, multi-stage anaerobic and aerobic reactor design reduces oxygen r equirements (and energy requirements) on thefrontendofthe system. St. Helena f lv,ssteiu'ater treatment planit was awarded the California Energy Commission Efficiency Showv Case.4 ward in 1994 and 1994 Plant of the YearAward by Calffornia Water Pollutior Control Association. Construction Cost Savings Oxidation Ditch 3.5 tfimes more expensive than AIPS Trickling Filters 4 times more expensive than AIPS Activated Sludge 4.5 times expensive than AlPS S(abilatio,i Iond 1.4 limes more expensive than AIPS Operating Cost Savings Oxidlation D)it'ch 3 times more expensive than AIPS 7)-ickling Filters 3 times more expensive than AIPS i1ctivated Sludge 3.5 times more expensive than AIPS Stabilization PIond 1.3 times more expensive than AIPS Virtually No odors Odors are controlled naturally. Winery Treatment Plant is wilhin 300feet of a convalescent /hosuital in the City of St. Helena, Calfornia. No daily bio-solids handling St. llelena's If W7 has not removedsludge in 30years of continuos operation; for industrial plantis shludge removal every 7-10years, depending on waste characteristics. lPond buffer capacity to accommodate variable organic and hydraulic sh(ck loads lf inerv organic variability rangesfrom 100 to 20,000 mg/ of BOD int one week. Advanced Water Treatment Achievable with AIPS Nuitrient removal...Denitrification in anaerobic zone and algal uptake in aerohic zone. PihovlhownLv oxidizes in the aerobic zone, assimilated with algae, naturally co-precipitated. tnd then .settled biy gravity. * litential for Enhanced Habitat for Wildlife & Recreational Benefits Notwral integration with constructed wetlands and habitat restoration. Landiscape pond-, contublwe bu aesthetic value and can provide recreational use. Redluicedl Fiscal Impact on Ratepayers Less cost to ratepc -er due to reduced life cycle costs because of lower consh t lion cosrs V NI) opera iitn v & maintenance costs and long term replacement. Martinrz 51') 2?S-<18.i Fax: 510-228-5804 1 Inc. Miartinez, CA~ ., INC ; '' hlanme; CA. AlPS 'lechnology All'S ulili4tes conipacted earthen construction practices to reduce construction costs. The system optinizes na.tural biological processes to reduoe power ruiremcnts and need for chemical additives. The design concept is to minimize bio-solids production rather Ihan to maximize aerationi solids and as a result minimize power requirements and solids management. i:; jcp 7f AlPS is an integraedt, multi-stage biological reactoisystem treating municipal, agricultural and industrial wastewa -r. The reactors are relatively deep and constructed as an open surface pjind of compacted earth. Tl..; biological reactor has three discrete and isolated biological zones integrated into a single unit: deep anaerobic pit(s) at the bottom of the reactor, a sludge blanket suspen(led within the deep pit, and ati overlying aerobic zone comprised of aerobic bacteria ad algae and oxygenaled by photosyntiesis, supplemented by horizontal mechnical aerators when needed. In nmost case:;, thc piit nary reactor is followed by a second reactor operating in series, will; tht: capability to t circulate, (lepend(jing on site specific conditions; Recirculation provides flexibility and slhock absorption abilities for variable hydraulic or organic loadings, or where there is th1e potenial fior toxic spikes. 'lhe intiilieit wastewaler enters the deep anaerobic pit at the bottom of the reactor where setlable solids are deposited arowid the inlet and where acid fer,mentation and methane generation occurs. The rising gases anid up-welling of wastewater flow through the thick anaerobic sludge blmnket that is fonned within ilte deep pit. The overlying aerobic zone is comprised of aerobic bacteria and algae arid kept oxygenialedi by h(irizontal surface aeratoum and photosynthesis.- The aerobic zone reliably controls o(lors and soluble wastewater components ndergo aerobic oxidation and firther degradation. 1'lie horizonlal acralors also create a circular motion over the whole surface area; the bacteria and algae circullate over the far end of the reactor where a second deep anaerobic pit is located. The horizontal velocity of the reactor is rediicetd while circulating over the second pit and the aeration solids are settled by gravity into this pit wvhere the solids are decomposed and stabilied , Solids at the botlomi of the deep anaerobic pits remans for very long periods of time. continuously deconmposingl. 'itus. biosolids minimization is accomplished. The oldest plant in operatiotn, treating domiestic waslewater, has not had to remove biosolids for nearly 30 years. Seasonal turnover of' thie ponds is prevented by isolation of the deep anaerobic pits. AlPS's design features and cell gometry maiiLiin tle initegrity of the system thereby suppressing turnovers. AIPS is appiolinat fiJr wastewater applications for nornal flow situations as well as where there are variable htydiatilic flows and organic loadings, parficularly where there may be limnited indusirial pre- treatinent and horurce control of toxic contaminants and heavy metals. AIPS design elements providle floNw .(Imalii aloin, buffer capacity and recirculation capabilities to achieve secondaty anid ailvantcd treatuiicitt r,i- nmiuicipalilies, agriculture and industry. !i i,4 . Marnt r-7: 5 (t.- 2 -S XO Fax: 510-228-5804 2 .,nc. Marinez, CA AIPS Technology AIPS utilizes compacted earthen construction practices to reduce construction costs. The system optimizes natural biological processes to reduoe power requirements and need for chemical additives. The design concept is to minimize bio-solids production rather than to maximize acration solids and as a result minimize power requirements and solids management AlPS is an integraled, multi-stage biological reactor system treating municipal, agricultural and industrial wastewater. The reactors are relatively deep and constructed as an open surface pond of compacted earth. The biological reactor has three discrete and isolated biological zones integrated into a'single unit: deep anaerobic pits) at the bottom of the reactor, a sludge blanket suspendled within the deep pit, and an overlying aerobic zone comprised of aerobic bacteria and algae and oxygenated by photosynthesis, supplemented by horizontal mechnical aerators when needed. In most cases, the primary reactor is followed by a second reactor operating in series, with the capability to iwcirculate, depend(ing on site specific conditions. Recirculation provides flexibility and shock absorption abilities for variable hydraulic or organic loadings, or where there is the potential for toxic spikes. Thie influent wastewater enters the deep anaerobic pit at the bottom of the reactor where settlable solids are deposited around the inlet and where acid fermentation and methane generation occurs. The rising gases and up-welling of wastewater flow through the thick anaerobic sludge blanket that is formned within the deep pit. The overlying aerobic zone is comprised of aerobic bacteria and algae and kept oxygenated by horizontal surface aerators and photosynthcsis. The aerobic zone reliably controls odiors and soluble wastcwater components undergo aerobic oxidation and futher degradation. T'he horizontal aerators also create a circular motion over the whole surface area; the bacteria and algae circulate (iver the far end of the reactor where a second deep anaerobic pit is located. The horizontal velocity of the reactor is reduced while circulating over the second pit and the aeration solids are settled by gravity into this pit where the solids are decomposed and stabilized. Solids at the botnom of the deep anaerobic pits remains for very long periods of time, continuously decomposing. 1Thus, biosolids minimization is accomplished. The oldest plant in operation, treating l domestic wastewater, has not had to remove biosolids for nearly 30 years. Seasonal turnover ol the l ponds is prevented by isolation of the deep anaerobic pits. AlPS's design features and cell geometry |, mainLain the integrity of the system thereby suppressing turnovers. U AIPS is appropriate for wastewater applications for normal flow situations as well as where there are variable ltydiaulic flows and organic loadings, particularly where there may be limited industrial pr,- treatmenl an,l source control of toxic contaminants and heavy metals. AlPS design elements provide flow ecualiaation, buffer capacity and recirculation capabilities to achieve secondary and advanict d treatmenit for municipalities, agriculture and industry. Martinez: 51O-229-5X0l1 Fax: 510-228-5804 2 SOA, Inc. Marfinez,:a Acceptance and Support. AIPS is a state-of-the-art pond-based wastewater treatment system. * Proven * Reliable * Inherent Buffer Capacity for hydraulic and organic shock loading anid toxic spiking * Advanced Microbiology j'^' - * Energy Efficient * Minimizes Sludge ProductionWManagement/Handling * Maximizes Natural Photosynthetic Oxygenation * Minimizes Power Requirements:, - O&M Costs are low when compared to Activated Sludge, Oxidation Ditch, Trickling Filters or conventional Stabilization Ponds. SOA, Inc. is a design engineering firm, 25 years old and specializes in the conceptual to dctailed design of innovative and allemative, low cost, simple to operate wastewater treatnent systems. SOA also providts start-up and training services, and on-going consulting services. SOA has experience in designing innovative and low cost municipal wastewaler treatment systems funded by die World Bank and other international agencies. * California Water Resources Control Board supports AIPS technology. * ~Califomia Water Quality Control Boards' supports AIPS technology. AIPS Plant Overview: ; * City of St. Helena, California Wastewater Treatment Plant 1994 Plant of the Year Award - Redwood Empire Region -- by Califiwmia Water Plollution Control Association (Under 5 MOD Category) California Energy Commission's Energy Efficiency Showcase Award, 1994 * City of Hollister, Califomia Wastewater Treatnent Plant * 1-lollister Industrial WastewaterTreatment Plant (Cannery Wastes) * Industrial -Winery WastewaterTreatment Plants, California * IRodney Bay WastewaterTreatment Plant, St. Lucia, West Indlies Mantinez: 510-223-5X)I Fax: 510-22-504 3 i SLar ' - Ee- a //- . . .s' AIPS .s an irntagrated Mr,uti-StGg3 bo!ogical reat_or sistein Itreailng m-iiicip,. ariculitural ar.d indus'rial wastewaters. Tihe reactors rc.-aiingWinds - r consist of lthee discrete aildisolated bioiogical zones: deeo ,jit k L anaerobic pits at the bottom of the reactor. a sludge bt3n:-\t suspence over the deep pit and an over!,.inc 2-rcbc zone coa..rsed of aerctc ' actaria 3nd algae ah;ct issusrsauratad with ax'1gen produced by algae and rTechanicai aerators. AN! wcather roadway All weather roadway s Aerobiczone 3 & A . i . / zs~~~~~econdarv ~ _, v utp ::.' ',, ZtoneiX / ,,,,,,, ,, \ Primar,y . n Fere nt/ t l,n z ^ w Settling ^ . \ zOtte e - 4, - ~~~~~~~~~Discbarge to aditioali . - . -: \ Zone / \,_J ~~~~~~~~~~~~~~~~~~~~ponds operanng in series and 10 r dDv Si1 M t4 5g1e 0 - -1 F 1pa02l Rmo vrasrvater Ina \ ~~~~blanket / \A aemobic/ zone 4 l. Aerobic 0xidon J - t~~~~~2 Phoh*yne ic Oxygenabon 3. Orga ii Acid Formabon 4. fleanp, Fermernvaon SO3A, Inc. . 1340AmoldDrive,Suite110 Martinez,CA 94553 510-228-5801 Fax:510-228-5804 Rerri,eted fri-" Sr,vpri n4t e rind u- . ,- !Ut! Apr Six 5j111,in r. i F.. ., a i,rs: AI Aippiyug Water and Savillig the Environrnent ADVANCED INTEGZA TED \ASTEW%ATEI' S. STL-S for Six Bt giIlioil Pt(3nQle viliam i Oswald. F. ASCE ABSTR ACT By incorportating special environments for methane fermentation and photosynthetic oxvgenation, advanced integrated ponding svytems attain high degrees of primary and secondary treatment and signiricant degrees of tertiary and Pt)ccirtJirqs af seksletd sessions from Ihc 1990 ASLr Convenlion s in pquaternary treatment of sewage and organic industrial wastes. When properly FtocccLiflqs CA electedsesslonsfrorri te 1990 SCE Convtil Iondesigned in appropriate locations. tht svstems virtuallv eliminate sludge disposal, minimize power use, require less land than conventional ponds. and are much more Sponsoreas by tnie reliable and economical than mechanical systems of equ3l cap3city. Environnsental Esigineering Divisin - - ; - - O * * Irr4slion anld Drainage Divisi t"v - -. X .INTR.ODUC.N Z Water Resources Pianning and Management Olvision . . : As is welt known to Environmental Engineers, wastewater treatment to the ol the American ofcur Or Ciil tn-inecrs -; . , ~ 2_f . . t ** secondary degree involves removal and digestion of settleable and floatable organic ;o~ty neers *. >;*;t . : . - :solids (primary treatment) followed by removal and digestion of microbial solids produced during aeration of the primary effluent (secondary treatment). Such - San franicisco. Calllornli-. - treatment traditionally has been done in reinforced concrete and/or steel structures i Mowvrmber 5-8. 1990 7 -- - with materials moved by motorized pumps and aeration provided by mechanical means. Sometimes for economy and simplicity in small communities. ponds are rdiled ly Udai e~ Singh and Otlo J. fel1weg used to repltrace mechanical systems. The greatest advantages of ponds are their Ed2MitebyUaFSigan OttoM J.i StelwegUIesl simplicity, economy, and reliability. their greatest drawbacks are their high land CHt2212 tflLL M%:riphits State Univers-ity use. their potential for odor, and their tendency to eutrophy or fill in with sludge Emcryvilice CA Memphis. TM and to become less effective with age. Our research, devoted to maintaining the advantages of ponds while mitigating their draawbacks, has led to the development of Advanced Integrated Wastewater Pond Systems (AIWPS). These require much less capit3al energy. operation and maintenance than mechanical systems and require less land. produce less odor. and fill in or age much more slowly than ordinary ponds. In this paper I wish to introduce AIWPS as a system worthy of considetation for many waste treatment applications. Due to space limitations. howe%er. only a brief description of AIWPS design and performance can be made herein. Sore detailed information is i2;laNle in the dissertations teaching sv!-!c Ip npdaen and engineering reDorts quoted in the reierence section (Oswald. 199i. tHE SYSTE!N1 In their most effective, reliable and economical form AIWx consist of a series of at least four ponds, each designed to nest perform onC or more or he >7j7 'Professor of Environmental Engineering and Public Health, Department of Civil tfuboished by the Engineering. 659 Davis Hall, University of California. Berkeley, C31ifornia 947 0. Anrrictn 5exiely ol Civil CnqinctiS S4*s ftast 4 -.In StSeet Mtew Yurk Merw t&ek 1017.2NYd SUPPIAN(; WATER AND SAVING ENVIRONNMENT j vasic Ireatment processes (see Figure I . First is 3 Facultative pond vith an c- aerobic surface 3nd an extremelv anoxic internal pit for sedimentation Jnd fermentation. Annerohic microbes in the pit are protected by surrounding wa!:s or r * ,::C .t lerms from the intrusion of :old surface water containing dissolved oxygen. Raw M$Sg r'H'OL sewage is introduced directly into the pits where sedirhentation and methane a :crmentation occur. Overflow velocity in the pits is maintained so low (see Figure l that suspended solids removal approaches 100% and biochemical oxygen demarnd at I BODU removal approaches 7O%. The overflow velocities of one or two meters per da- 3r- !re!! than the se:tlin; velc:ities of helminth ova and parasite .ysts so most *- *e-e re rna3 n .he pit and consequently are permanently remoned from inc ijL u5S effluent. \ X~~~~~~~~ _ i; - Pond Systems . X r i.iI. 11 Advanced In concept and simple in design, a new^ waste water treatment 1pp;t~i .ttII~ . 1 I2 Ir technology may offer a solution for communilt es beset b.y i ilensifying cost constraints and water quality regulations. Why not build n sewage trcatment thinking. In cr .in6 oItim sl plants, for facility tilat ust_s much lfss energy exampiv. acr af ii (it 1 ii constimes ihani a coni'enlional otne and produces 60. or in vi l h * e i'lt rical energy nto odors, especially if construction, usedl iii n asfrirvalr -xiclzament. In con- operation, and maintenance costs are trast, mmiroail lic in an All system alsoldrantatically lower?niis question provide dIi,.s(eo.lvd g.n thrrough iaily occtir 1t many who have visited photosyuil rsi.. * tilriantially reduc- tlie Waslw-tvater T'reatment anid Kiecta- ing ele( Irical nmon uition. Not sur- mati(mn I'lant in St. 11elena, California, prisinghi lIles'- sSunis ate optimal particularly to visitors from commoiliu- for suilthclt * omnilnluilmle. nities f eliug pressure front federal 4 I mi~r0 fin anid state environimenital regulations. "At St. I leleim. % eve proven this a .~ l . .t Pw 1 .,,,-. k.nl lehil 1 1ttil ;l*techninuloyy wilh , in nirmkable quality ,,, . " ,1:I , Itttt11 -s111" K ., rI" 14 Ite, C1,i, /#wt oq ,I *doi."r,,I liased on tile concept of Advanced of treatnw .iv" -vav, t .teinnge Milaneq, 'in,, iiHg . no:,r ' art,n ineovwflf ie : Integrated lPond (AlP) systems (see chief opie alr iit t ic plfant. "The eco- '.*,nl t..rl tic niiry:lglg pt, . 5 for description), the St. I lelena nOmics (if Whal it tilla[i to put one of t to itin d cmii r r,nlh,r thfirs 'I plant marks a radical departure from these togVtlrr1r jLP.I ma kes good finan- *-riifirct d r otnt ni. conventional wastewater treatment cial sense. Tis SIIhoultl really be the technologv of (honict ltI smaller com- munitivN of 2(1110 to ill)l people." "All' tn'nirrrnn)tg i; t it limilted to 'k . g7 4. Sflilll , Iiiriiiiiiiii' '%, liIZ\; (.\ Ct'. Co}st 'I ,~~~~~~~~~~~~~~~~~~~~~~~~~o.,v l,cs . ->* ,. * gt;-S, i; ' ^- - compari.;nAs ' ithi othel treatment metlo(lq lenid to [nivor AlP systems in manv lirger w,lnTirrrmities as well," says S;aintly XValk'r, I )it uctor of ! eI .iiSp ri'al t! tlit '* lt' ': a comrr PlVF'irinI( ri',l m d- gi . f1' i iF i iri ~~~ r . ~~~~~~MrimiA It *x aftirtios t" "O uwi~~~~~~~~~~~~~nAl', c, I:^ I sy I9 I,'! sz I{ -II t Constiuction and I Energy Costs /rlI'dfl˘t slZolull I Maintenance Costs I ~~~~~~~~~~~A propezrly dclsig,nd All' ltaifn ( t?71'1Sflt1't} fol}l~ii I C- } (Good financial sense begin,s with sioil (I (onsuLnes ablolt one-quarter to facility costs. lkCause solar a.enated oine-fiftli eli teergr of ca(oitveiitionii quatirler to) omll -fifll file ponds are built of fornied earthi ratlier medclanical w-sfJv%vater treatment I than of reinforced concrete, iliev cost planl I his tramnslates directly into Efi"S of ii ( tJi'viltional about PY) times less to build per cosi sa% ings. One significant soLurce -~tCtl!flfl icut wes i i'it'eie'r ctubic fool of containnment than do of savings lies in us;ing solhr energy convc'ltiollal Ireatment plil reac- rather than eOltlic il energy for aera tors. The total pond area needed is i ti(on. Conventional plants aerate by til'ifl~ii) t /lltnfltI II IS mucih la rlger thian that needed for a ushing, e-lectrical encrgy to blow or mix frarnslaltcs dIirectjl iUo conventional plant, but ponds should air bubble'; into the wastewater. In an still cost oinly one-third to one-half as All' ss;sten, alg ie use solar energy 'iiiticli Io lbuild, according 14) William an(d tihotosvnthsis to supersaturate O ()swald, who designed St. I leiena's thie wlt'atsr willh 01' toxygen thiat system in the early 1960s Os:vald is a microbes need IIn break down waste. prolfessol emeritis at [lie University of California, Berkeley (UC-Berkeley) "For peopli' wvh b1asv always and inventor of the AIP system. thought in tel In I 'i . nventional treatienit, il's It ind to understand P'roponenits of the technology believe that you cm an i alt' willotit any I that maintenance costs for the new mechlnifl .vst t'ni," .oay.; Oswald. plantis ate also lower because such "Usiiig mn' el mcdl ;iraltion, yotu Coa;i of a Convetmlional Plant plantis niiimize the use of mechani- need about I kltu..',tt-liour of elec- ts. an AIP Plant cal eqjuipmentand require a smaller tricity lor 'at h kil(olgan of dissolved .olfivs thrvitsands inventory of spare parts and supplies, oxygen-l. In an AIl' Psvtvm in a good _ $i __ __ ____| | Operatioin costsare reduced because climatv: vtiu gel af,tir] 20 kilogranms uffl I' I | I the plants can be run with smaller (44 pou1.nd11;) oif lxgier kilowatt- staffs hour, b uls' nour elnnergy is essen- tially frev. h1ai ne rg y is solar Another important advantage of AIP energy. I . j: 4__ . .. .... _ plants is the small amount of sludge they prodtiuce. In these ponds, sludge St. F lelnii;'s plant still uses more -- !t .; . ... . _ _ (fermenits until nothing is left but a energy th in anl oiiniatl, up-to-date '! smii voilunic of residue. I:ur exam- All' plod woiultd w(e ire. Tlat's pie, durinig 27 years of opieration, St. because s'. I ieltlo;i's plalnt, designed $2;, % l 1) lelena's wastewater treatment plant 30 years ago, uies t oiiventionial I; - t l has miever had to remove residue. A ptimls to circulate water in tile pond t, I 51ll -----_ _ _ recent measurement at St. Helena whereaeralion lakes place. Calcula- showed tlhat in nearly 3 decades, ss l tions tI il nowv shlo Ite five-to-one -- X il ;!;R9 t90l 8 than I meter (328 feet) of residue had energy advantage of an All; plant, S257 2 acctmitilated at the bottom (f the are bas('d on designs using paddle i__ll ____ d j (leelp digesler pil 1iis rep(rsntrts a whetels f(or circtulation. PIaddle wheels j Captiat Arnnual; Stlsubstanilti,al benetgfit inl zte-ils of nwet- aIe llev: a priimy lp c Imtinology com- cost operatngecst iing environmentaldregulations f r mrh used in comnercial algac- 1 1.cnventional pfanl t 6 AIP planin| . . I 'rivernlcttial pt-.5 SOA MttC I,4- CA res-idue disposal. gro( ing operation;. P'addle whleel -g evi tal relationfricirctviimtic nhass end inctptnted in Show7n anliny iS t i ncst c meit1t#nrn o an All ' sy,stem lhat l iC-Berkeiev is of cr.tilr'Ff jn IatetrQ lt 7' n,rillir, desiggiiig foi- a '.; I lerl'a-sized Iitt',-l I I ,niih,n, tptl.,,t.,I,, wastPt.alel ara *it P l antiCali- on at-f ri-twit'S .7qil" 14,1,t. ifl,, fornia;' Central Vai hey. St. lelena .wst om.1ymm{a k inl *1r, ˘ wfiday isak,lughi comnbustion of andl wlthln!:T511( LNIs MI tin aimage aqulatic ; methlane-could eliiminate electrical ecolsy.,lemis hilt) v.:hi ihl effluent may zltwer cosits coimpletely. Metlilatie can be !isc h. r-d All p\1llants are better ibe prduxced by fermentiig algae har- thani com-enelimaIl plants at removing vested from the plant's settlitig pond. these imriuiit,; Nilmgen removal (KCItIIS ill lh(- dligi I;fionl phase in the Conventional plants typically install facultativ ll(l In addition nitro- large taniks, known as digesters, in gen and p hosphorts are taken up which sluditge and efflutenlt solids fer- anri contain-d by algae in the high- iiient to ptrdutic methallne. In an All' rate pnul. ( )sw,ldi champions the use 8pliaint methane from ntattiuil fermen- of algav baui v'tedl Irorm AW plants as taltilon in the digester pit could Ie cap- ferfili/vr I-uecati;' the nutrients con- ture(d at thie surface of t[ie facultative tainfmd in a igav wnuldl be released ponI. I Dev vloping a goxdl conmi'n rcial molle -l4Viv Ihian would the water- I met thane( captutre system l10r All' sys- soluble hirmims in chemical fertilizers eileis ilntuler wav. Ihe lEnvironmiuen- and ths b I is likely to retur to t.1l I lingi m e-iing and1(1 1 Iz le,ulIlu ?&iz ene ' I.t akc , ait tlill-c'anu in rtinoff. saLboratory (UC-Btrkeley) in Rich- minmond. California, is working oiil that de1h* p 1 lenl wvith ftiunds frnm the ( alilornia l:nrgy C((immi.,sion and tle C alitornia liistittite for I lerlgy iIIiiu ienlzy. All' Psxstcmris ilo (,-emeed ch,nvu,,ti. r,al , it't (li. tlt'sIiPn ii ;iiitirit illcr Ia- prfimm}ll .mid v-ti ndary tleatmnlllt ingly slrimlolwll 1t) l,tfB ' !S p'lin.t t killig patlkhogenlls betail..' of says(;ir'i "'fotlc -w2itii'i 2 It() natliural disirituction by higii alkalillity 3Ul)t'Y, nt f (v r coil"s nil Ilic fio(nt (nd al1nd tiltraviollt I.L)V) expostire. With w With s,,,, (eugr(o (d I''rtti'r Ililrv a i- out a\li tilte tiuatrillent,efftlucut ternail i,itintiriuit il th,, lairgain, ito. fr(onl a tour-pond All' plant sliiiildl mal,' ha, r mrtwu% to put intr U!V tie stifficivitt to mnect the moost iecttnt disinfection (r dis,,olv(d air flotation I't'i"n.. tie r'wlZsr(r! XWorld licalth Organization rcnco- . and still o tnut mialld (of ilt I,, r i(-fl/i a rr"nw, t, ,dtiu, m Illv-ldatlolll (