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- w Z ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Republic of the PhilippinesLocal Water Utilities Administration

SEWERAGE AND SANITATION PROJECTWATER DISTRICT DEVELOPMENT PROJECT

o .

WORLD BANK

ENVIRONMENTAL1 X ~LUZON

ASSESSMENTREPORT

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 16Section II Environmental Pollution 18

Chapter 3 PROJECT DESCRIPTsION AND ANALYSIS OF ALTERNATIVES 24

Section I Project Rationale and Objectives 24Section H Sanitation 25Section III Overall Sewerage Scheme 27Section rV Recommended Project Design for Calamba, Laguna 40Section V No Project Scenario 43

Chapter 4 ENVIRONMENTAL IMPACTS 46

Section I Beneficial Impacts of the Project 46Section II Project Implementation Impacts 48Section IH Summary 50

Chapter 5 ENVIRONMENTAL MANAGEMENT PLAN 51

Section I Mitigation Plan 51Section II Monitoring Plan 53Section III Implementing Arrangements 54

Appendices

1. Bibliography2. Cimatological Normals (1961-1995)3 Typical Noise Emissions of Construction Equipment4. Expected Noise Levels at Various Distances from Construction Equipment5. Environmental Quality Standards For Noise Maximum Allowable Noise lIevels6. The Advanced Integrated Pond Svstem iA[PS) of Wastewater Treatment

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4

I

EXECUTIVE SUMMARY

Introduction

In the Philippines, the typical urban area/built-up area is characterized by a heavy concentrationof activities, both commercial and industrial It is also the area where the di isity of populationis at its highest. These areas are also the sites where the production and co.surnption of rawand processed materials could be found. Consequently the, pressure on the fife supportsystems in these areas are far higher than the suburban and rural areas. Adverse environmentalconditions such as the generation and similarly the discharge of wastes into the environment iscommon in urban and built-up areas. Unfortumately, the amount, type and concentration ofwaste generated exceed the capacity of the local environment to absorb and assimilate themThe carrying capacity of the life support svstems are stretched to the hmits. The urgency ofestablishing collection and treatment mietlhods to prevent adverse imtpacts to the health andwefl-being of the residents, and to the ecological systems which sustain them cannot be ignoredand overstated.

Most urban centers in the Philippines rely on individual septic tank systems for thetreatment and disposal of wastewater from domestic and commercial buildings. However,the designs for such systems is often inadequate. Facilities for land disposal of effluentsfrom the septic tanks are generally absent. Hence, the partially treated septic tank effluentsflow directly into storm drainage systems and other receiving bodies of water, therebyexacerbating an already grave pollution situation.

There are several possible options for addressing this problem, including improving thedesign of the septic tank system with the installation of soil absorption systems. But anenvironmentally sound alternative that is cost-effective and captures economies of scale isto connect individual properties directly to a sewerage system for the collection, treatmentand disposal of the urban wastes.

The provision of a cost-effective centralized wastewater collection, treatment, and disposal isthe primary objective of the proposed Water Districts Development Project. The proposedproject 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 ofsanitation. Financing assistance will be partly provided by the World Bank (WB) which shallbe conduited through the Land Bank of the Philippines (LBP). Over-all administration will beexercised by LBP's Project Management Office (PMO) with technical support provided by theCentral Sewerage and Sanitation Program Support Office (CPSO) of the Local Water UtilitiesAdministration (LWUA).

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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-loggingwithin the cities and in the surrounding water bodies, thereby bringing health benefits tolocal populations. The construction of the systems will protect shallow groundwateraquifers from contamination.

Environmental Assessment Requirements

This Environmental Impact Assessment Report for Calamba has been prepared in accordancewith the Presidential Decree No. 1586 otherwise known as the Environmental ImpactAssessment Law and Departmenit of Enivironment anid Natural Resources (DENR) Revise -'Administrative Order Nos. 36, the Revised Water Usage and Classification/Water QualitCriteria and Revised Effluent Regulations of 1990 respectively; and World Bank'sOperational Directive 4.01 on Environtmlenital Assessment. The revised Administrative Order36 for Environmental Impact Statement System issued in 1996 is comprehensive and iscompatible vith the World Bank's Operational Directive 4.01. It outlines the procedureto be followed by environmental critical projects (ECPs) and projects to be located inenvironmental critical areas (ECAs), in preparing environmental impacts statement(EISs)'. ECP and ECA are defined in the AO. It should also be noted that that localordinances and regulations governing projects of such nature have been taken intoconsideration in preparing this report. Similar EIA reports are being prepared for the other 4cities.

This report has been prepared by a team of local consultants under the aegis of the LWUA andthe Calamba Government. Much of the work relating to the environmental impact analysis wasundertaken as part of the feasibility study done by C. Lotti and Associati. Consultation withthe community is an on-going process. The sanitation component of the project wil beexecuted 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 afteran initial screening at the national level of urban areas facing the most serious problem ofpollution by untreated wastes. Of the five cities, Davao and Cagayan de Oro represent thelargest class of provincial cities with current population estimates in the range of a millionand half a million respectively. There are several major population concentrations in thecity - 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 pipedwater supply; in the Central Business District or Poblacion area. Untreated wastewaterfrom this area has polluted low-lyiig coastal areas. and basically converted the principalrivers into open sewers. The scale of the pollutioll problem can be appreciated by the factthat about 90 per cent of the daily water supply of 140,000 cubic meters in Davao city and76.000 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 Reportrequired 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 concentrationspolluting 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 pollutionproblems are not comparable with Davao and Cagayan de Oro, these cities are locatedclose to environmentally sensitive wetlands and water bodies. In Cotabato City, the urbanarea is actually below the mean sea leveL exposing inhabitants to frequent flooding andwaterlogging during the monsoon months. Calamba is located on the shores of LagunaLake, which has experienced a rapid deterioration in water quality over the last twodecades. Dagupan city is close to a large estuarine zone with ecologically sensit 'ewetlands and fishponds. In each of these cities, Mayors and city officials have rc..ognizedfor some time that unless their complex environmental problems are tackled through astrategic plan of handling waste disposaL sustainability of urban growth could be seriouslyaffected.

Overall Project Approach

The proposed project follows a demand-based approach in the sense that facilities will beconstructed only if they conform with the preferences of local stakeholders, and servicesconform to their respective willingness to pay. The stakeholders represent the differenttiers of organizations from the City/Municipal Council and Barangay (part of the formalLGU system), to the more informal purok, neighborhood and household levels. Duringproject 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 basicdecision-making process is as follows:

For the capital-intensive trunk system, consisting of the main transportationsewers, primary drains and wastewater treatment facilities, the projectdesign and implementation plan has to be approved by the City CounciLbecause the latter is responsible to repay the loan [see Annex 3 of the StaffAppraisal Report (SAR) for the Project on Financial Aspects].

For the feeder system, consisting of collector sewers, secondary drains and on-sitesanitation facilities. barangays and local neighborhoods will be associatedwith the planning and implementation program. The design criteria havebeen simplified, so that the feeder system can respond to local preferencesand willingness to pay, rather than be bound by any conventional sewerdesign criteria used in industriahzed countries. Detailed design will beconducted through a participatory process described in Annex 13 of theSAR.

Given the capital-intensive natur-e of the investments, the proposed project is only theinitial phase of a program to improve the sanlitation infrastructure through a strategicplannIing 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

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the Central Business Districts or Poblacion areas because these are the major contributorsto 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 therequest of the LGU.

The project wil construct a sewer network that wil discharge sewage to a verticallyintegrated 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 fromencumbrances.

For the sanitation components, the entire municipality has been included in the projectarea, with final selections being made on the basis of demand. On-site treatment systemsthrough the construction of VIP (ventilated improved pit) latrines, pit latrines, pour flushtoilets 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 projectwill finance the construction of communal toilets, to be managed by non-governmentalorganizations (NGOs) and/or the private sector. The specific locations of these facilitieswill be driven by the willingness to pay for the services by beneficiaries at the barangayleveL provided of course that these are technically feasible.

Analysis of Alternatives

T-he recommended solutions for wastewater treatment were arrived at after an intensiveprocess of evaluating alternatives durinlg the project preparation in order to achieve costeffectiveness and acceptability. The alternatives considered were anaerobic/facultativeponds, modified lagoon systems and mechanical treatment. The evaluation of altemativesindicated that the modified lagoon systems, despite having a higher operation &maintenance (O&M) costs compared to anaerobic/facultative ponds (as it requiresmechanical aerators and recirculation pumps) was appropriate. The selected option metthe 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

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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 hecaresBusiness 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 cityrisk 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 fishwastewater recreational unfit for and estuarine area and rapid farmingpullution pUlpOSeS recreational euirophicaticx

ptuposes because of fecalcontaminatimn

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 densityis 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 manufacturingactivities and retail distribution. A large proportion of piped water supply from the localWater District is also consumed in the Central Business District (CBD). Consequently, thepressure from both solid and liquid wastes in these areas greatly extceed the capability ofthe 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 onlyminimal 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. Inthe short-term, the project will provide emplovment and livelihood opportunities to thepopulation of the surrounding communities through the jobs generated during theconstruction phase. In the long-term, better sanitary conditions will reduce sicknessescaused by water-related problems. Thuts an improvement of the existing environmentalconditions is expected. The project N\ill und(lertake iitigatilig measures to minimize, or i

at all possible, eliminate adverse impacts.

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Air Quality. The implementation of the project will result in an increase in the ambientconcentration of suspended particulates in the vicinity of the project site. This would beattributed to dust from land clearing and excavation activities, which expose soil to windand vehicular traffic over unpaved road.

Water Quality. Excavation activities in the project sites could also loosen soils andtiansport of these materials to any surface waters, thereby increasing siltation andturbidity.

During the rainy season, surface runoff may increase total suspended solids, and causetemporary stress at the discharge points. However, the impact will be localized, and whenthe 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 minimaland will not require any special noise abatement measare. The treatment plant sites shallhave a setback away from residential clusters, which will definitely provide the necessarybuffer 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 thetemporary operation of heavy equipment. Noise from breaking concrete pavement andsidewalks may also pose a temporary problem. However, the noise level at the streets isexpected to be within the ambient noise quality standards.

Ecological Effects. As there are no rare. endemic species of flora and fauna in any of theproject 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 impacton the air quality of the area. Aside from the occasional odor nuisance, it is not projectedto have adverse effect at all.

Water Qualitv. The implementation of the plroject will be beneficial to the generalenvironment of participating cities and their environs. Discharging of untreated domesticwaste water from the high volume consumers in each city's Central Business Districts intonearby bodies of water would thus be minimized or eliminated. However, operations andmaintenance failures may result in occasional discharges.

Socio-economic. The provision of sanitationi facilities in the project cities wouldundoubtedly 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 amore healthy and productive population.

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Sludge Disposal. The recommended modified lagoon system or vertically integratedpond system of treatment will require sludge disposal at very infrequent intervals. Thesludge in the anaerobic pond/s remains for an extended period continuously undergoingorganic decomposition. This may take place over a 20-30 year period. One system inoperation in the U.S. has not been desludged in thirty years. Recent testing of this systemhas indicated that the sludge is well-digested and very stable. If desludging does becomedue, arrangements can easily be made with the city environment office for disposal at thesanitary landfill.

Mitigating measures to minimize, or if possible. eliminate adverse impacts will beimplemented. Measures to enhance the existing environmental conditions in the projectsite shall be implemented to maintain the environmental sustainability of the area. Theimplementation 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 supplyand installation contract as a means of assuring quality ofconstruction. Works engineers, with a relatively independentsource of information on construction progress, will be hired.

Air Pollution * Careful construction planning and work phasing, specificationsand 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 forsuspended 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 civillikely 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 excavationsoils, 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; avoidtion 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 equipmentm. . 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 beFlow located along secondary streets.

* Scheduling and increasing input resources so that penod of trafficdisruption in primary roads are reduced.

* Coordinate with the local traffic management office and the PNPTraffic Management Command

. Clear directional signs and barriers in case traffic rerouting isneeded.

. 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. contingencyaccidents 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 besewer 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 facilitiesraw 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 theaffect the condition of receiving San Juan River shall, in the long-term, conform to the waterbodies 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 QualityStandards and Revised Effluent Regulations of 1990,respectively.

* A dispersion/dilution modeling study will be conducted to priorto locating the outfall. Treated effluent discharge into the SanJuan River shall be timed based on tidal conditions. Theadoption of the AIPS process for the treatment plants shouldresult mto attainment of effluent standards.

* Noise would be at about 65-85 * Establishment of buffer zones and noise zones.dBA. principally coming fromseptage trucks unloading at thetreatment 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 theunloading 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.

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Monitoring and Implementation Arrangements

Construction Phase

Ambient air quality measurements will be undertaken near construction sites. This will bemostly near locations where sewer network is being laid and treatment plant sites. Whenselecting 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 or24 hours, over the construction period.

Noise will measured at the same locations as TSP. Leq and Lgo values will be measured andrecorded.

Operation Phase

Receiving water quality will be monitored by the DENR through its regional officeswhich is monitoring the status of San Juan River on a periodic basis. The PMO willcollect information on present conditions, observed changes in pollution loads etc. Itshould be noted that all the pollution load will not be removed but the proposed sewerageinfrastructure will greatly reduce the problem. Once the plan becomes operational, thetreatment plant operator, vis-a-vis, the local Water District concerned would be requiredto set up a laboratory and measure the effluent quality.

TIhe Treatment Plant Operator will institute a monitoring program to measure effluentdischarges. Daily representative values of PH, 5-day BOD, COD, Total Nitrogen andTotal Phosphorus will be measured during the start-up period. Once the plant operationsstabilize, weekly measurements (24-hourly basis) will be taken.

Quarterly reports showing the trends of effluent discharge and receiving water quality willbe 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 theproject. would monitor compliance with the ECC and carry out the requisite datacollection. Monitoring reports would be submitted to DENR/EMB and the World Bankperiodically. While responsibilities for the various mitigation activities have beenidentified. the PMO will ensure that the requirements are complied with: in addition.feedback from communities. city officials. NGOs. etc. will be pro-actively sought throughthe city public affairs programs, regular monthly meetings of barangay captains and othermethods. Finally. DENR, through its planned PPA system, would also periodicallynionitor and audit compliance with the ECC. assisted by independent contractors.

Table 2 summarizes the responsibilities and timetable for the Monitoring Plan.

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Table 2Summary 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 1998around the proposed treatment plant sites at regional officeproject cities

Ensure that the bid documenrts include PMO Januarv 1998 August 1999provisio;ts for mutigatirm under the respmsibi-htN of the ctractor: review ccmtractor's workplans to easure compliance with en-vircmmantal mitigatico plan provisions

Trait qerators cm O&M practice & handling PM() and CPSO-LWUA Jamuarv 1999 June 2000etnergency situatirns.

Assess and upgrade the laboratorv facilites of IProject Citv PMIJ ad local March 1998 June 2000the Calamba Water District Water District

Ccxduct user c tnsuiatiuns and infornatiun Projedt C itv PMt J. with January 1998 June 2000carnpaigtt asssLance fNGC()

Mmitor and report om cotnpliance. PMO Bi-amnual basis Bi-annual basis

G229-

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I I

1. INTRODUCTION

In the Philippines. the typical urban area/built-up area is characterized by a heavy concentrationof activities, both commercial and induistrial. It is also the area where the density of populationis at its peak. These areas are also the sites where the production and consumnption of raw andprocessed materials could be found. Consequently the, pressure on the life support systems inthese areas are far higher than the suburban and rural areas. Adverse enviromnental conditionssuch as the generation and similarly the discharge of wastes into the environment is comnnon inurban and built-up areas. Unfortunately, the amount, type and concentration of wastegenerated exceed the capability of the local environment to absorb and assimilate them. Thecarrying capacity of the hfe support systems are stretched to the limits. The urgency ofestablishing collection and treatment methods which will prevent adverse impacts to the healthand well-being of the residents, and to the ecological systems which sustain them cannot beignored and overstated.

The provision of a cost-effective centralized wastewater collection, treatment, and disposal isthe primary objective of the proposed Water Districts Development Project (WDDP). Theproposed project will assist the local governments of Dagupan, Calamba , Laguna, Cagayan deOro, 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 thetreatment and disposal of wastewater from domestic and commercial buildings. However,the designs for such systems is often inadequate. Facilities for land disposal of effluentsfrom the septic tanks are generally absent. Hence the partially treated septic tank effluentsflow directly into storm drainage systems and other receiving bodies of water, therebyexacerbating an already grave pollution situation.

There are several possible options for addressing this problem, including improving thedesign of the septic tank system with the installation of soil absorption systems. But anenvironmentally sound alternative that is cost-effective and captures economies of scale isto connect individual properties directly to a sewerage system for the collection, treatmentand 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-loggingwithin the cities and in the sunToundilng water bodies. thereby bringing health benefits tolocal populations. In Davao, Cagayan de Oro and Calamba cities, pollution from humanwastes have affected recreational areas, such as beaches and lake front areas. Projectinvestments in wastewater collection and treatment will also have positive benefits interms 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 amajor 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 beconstructed only if they conform with the preferences of local stakeholders, and servicesconform to their respective willingness to pay. The stakeholders represent the differenttiers of organizations from the Municipal Council and Barangay (part of the formal LGUsystem), to the more informal purok, neighborhood and household levels. During projectpreparation, the idea of involving communities in the planning process was field-tested inthree 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 maintransportation sewers, primary drains and wastewater treatment facilities,the project design and implementation plan has to be approved by the CityCounciL because the latter is responsible to repay the loan [see Annex 3 ofthe Staff Appraisal Report (SAR) for the project on Financial Aspects].

(b) For the feeder system, consisting of collector sewers, secondary drains andon-site sanitation facilities, barangays and local neighborhoods will beassociated with the planning and implementation progranm The designcriteria have been simplified, so that the feeder system can respond to localpreferences and willingness to pay, rather than be bound by anyconventional sewer design criteria used in industriahzed countries. Detaileddesign will be conducted through a participatory process.

Given the capital-intensive natur-e of the investments, the proposed project is only theinitial phase of a program to improve the sanitation infrastructure through a strategicplanning 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 tothe Central Business Districts or Poblacion areas because these are the major contributorsto 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 therequest of the LGU.

The project will construct a sewer network that will discharge sewage to a verticallyintegrated 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 fromencumbrances.

For the sanitation components, the entire municipality has been included in the projectarea, 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 tankswill also be constructed if there is demand from property owners. For those propertieswith uncertain land tenure (as in squatter settlements), the project will finance theconstruction of communal toilets, to be managed by NGOs and/or the private sector. Thespecific location of these facilities will be driven by the willingness to pay for the servicesby beneficiaries at the barangay level, provided of course that these are technicallyfeasible.

The recommended solutions for wastewater treatment were arrived at after an intensiveprocess of evaluating alternatives during the project preparation in order to achieve costeffectiveness and acceptability. The alternatives considered were anaerobic/facultativeponds, modified lagoon systems and mechanical treatment. In all the five cities, theevaluation of alternatives indicated that the modified lagoon systems, despite having ahigher O&M costs compared to anaerobic/facultative ponds (as it requires mechanicalaerators and recirculation pumps) was more appropriate. Details are available in projectfiles. 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 accordancewith the Presidenitial Decree No. 1586 otherwise known as the Environmental ImpactAssessmenit Lawv and Departmetit of Environmnenit anld Natural Resources RevisedAdministrative Order Nos. 36, the Revised Water Uscage anid Classification/Water Qualit,Criteria and Revised Effluent Regulations of 1990 respectively; and World Bank'sOperationial Directive 4.(01 oni Enivironmental Assessment. The revised Administrative Order36 for Environimental Impact Statement Svstem issued in 1996 is comprehensive and iscompatible with the World Bank's Operational Diirective 4.01. It outlines the proceduresto be followed by environmental critical plrojects (ECPs) and projects to be located inenvironmental critical areas (ECAs). in preparing environmental impacts statement(zelSs)'. ECPs and ECAs are defined in the AO. It should also be noted that that localordinances 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 Reportrequired 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 4cfties.

This report has been prepared by a team of local consultants under the aegis of the Local WaterUtilities Administration (LWUA) and the Calamba Municipal Government. Much of the workrelating to the environmental impact analysis was undertaken as part of the feasibility studydone by C. Lotti and Associati. Consultation with the community is an on-going process. Thesanitation component of the project will be executed in a participatory manner, and detailedguidelines have been spelled out.

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: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 inCalamba, Laguna and Section II analvses water pollution impacts (historical) ofuncontrolled 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 and12 10' I north longitude. Calamba is bounded on the east by Laguna de Bay, on the north bythe Municipality of Cabuyao, on the south by the Municipality of Los Bafios and on the westby Sto. Tomas Batangas. It is located 57 km south of Metro Manila and by land, serves as thegateway towards the south particularly to the provinces of Batangas, Quezon and the BicolRegion through the South Expressway. [Figure 2.1]

Calamba is comprised of forty eight (48) barangays, twenty five (25) of which are classified asurban covering an area of 3,351 ha or 23% of the municipalitys total land area. The rest areclassified 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 totalland area. Total land area cultivated is estimated at onlv about 5,182 ha. Crops predominantlycultivated include rice. sugarcane and vegetables. Inldustiial activities is highly concentrated atBarangay 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 theindustrial growth. Heavy manufacturing industries are mostly located in Barangays Maklling,Tuo and Turbina. while light and medium industries are found in Barangays Canlubang. ReaLSirang 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 steeplytelTain towards the Makiling Forest Reserve. The soil of Calamba particularlv Barangay Realis of the Lipa Loam Type with 0 to 2.5°% slope. The plroposed site for the wastewatertreatment plant in Bgy. Sampiruhan is relatively flat and fertile and highly suitable for

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agricultural production.. The area is characteristic of a floodplain being inundated most of theyear. The Banadero site is also flat and is currenwiy being cultivated to rice. The area is alsobeing serviced by irrigation facilities of the National Irrigation Admiistration. Both sites haveland available in excess of the requirements of the project. As gathered from the municipalplanning officials, both sites are being earmarked or have a potential for development asresidential areas.

The volcanic plain of Mount Makiling and Taal was created during the pleistocene and recenttimes. Pyroclastic deposits underlying the basin appears to have been expelled from tallvolcano vents. Clastic rocks composed principally oftuffaceous sedimentary detritus whichincludes waterlai and re-worked sandy tuffs generally bedded and well-stratified in placesintercalated with beds of fine tuff

Physiographic features of Calamba include lakes and r ivers such as the Laguna de Bay in itseast side, the San Cristobal River forming its northem boundary, the San Juan River andCauacauang River, as well as numerous streams and creeks. Natural hot and cold springs alsoabound in the area. Forests and woodlands occur in the hilly and mountainous areas southeastof the municipality.

2.3 Climate

Calamba is located in an area classified as Type I ofthe Coronas Classification of PhilppineClimate. This type is characterized by two pronounced season. dry and wet. The dry seasonstarts from December to April sometimes lasting until May while the wet season occurs for therest of the year with maximrnum rain period from June to September. Regions of this chmatetype 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 broughtabout by the tropical cyclones occurring especially during the maximum rain period.

Appendix 2 shows the climatological nonnals for the period 1947-1994 from the PAGASASynoptic Station at Ninoy Aquino International Airport (NAIA), Pasay City. The informationfrom this station, which is the nearest to the project site with complete climatological data, wasused to characterize the local climate in the project area. February is the driest month with 3.1mm 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 of25.6°C and May the warmest with a mean of over 29.50 C. Annual mean maximum andminimum temperature is 31.7 ° C and 23.2°C. The average daily relative humidity is 76% andranges from 71%, in February to 83° for Augu.st and September. The wet or rainy season isconsidered 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 iscovered with clouds. Cloudy months are from June to September with observed cloudiness ofat most 6 octas. Relatively clear skies occur duttlng tlhe monthls of February to May whilepartially cloudy skies occur during,- the monitlhs of October to December.

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2.4 Hydrology and Water Quality

Calamba is principally drained by two (2) major rivers namely the San Cristobal River and theSan Juan River. The San Cristobal River forms part of the northern boundary of themunicipality. The San Juan river and ultimately the Laguna Lake will be the receiving bodiesof water for the WWTP at Bgy. Banadero. It is officially classified as Class C waters as per theDepartment of Environment and Natural Resources Classification. The San Juan River is beingutilized for irrigation purposes.

2.5 Vegetation and Wildli-

Situated in built-up areas, the two proposed sites for the wastewater treatment plant has minorvegetative cover. The Sampiruhan site is covered mostly of fast growing grass species. TheBanadero site, however, is planted to rice. There are no rare or endangered floral species in thearea. The vegetative cover of the site is mostly palay and other cash crops. There are also norare wildlife species reported or sighted in the proposed site or its vicinity. The wildlifepopulation in the area may have been significantly limited by human interference and theabsence 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 theproposed sites.

2.6 Socio-economic Aspects

As projected, based on the 1990 NSO Population Data, the population of Calamba in 1995was placed at 199,467, with an average density of 11.98 person/hectare. The most populousbarangay on the projections is the Poblacion, with a 1993 population of 27,194, and averagedensity 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 aheavy concentration of commercial and industrial activities. It is also the area wherepopulation density is highest. These areas are also the sites where the production andconsumption of raw and processed materials could be found. Consequently, the pressureon 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 theenvironment are common in urban and built-up areas. Unfortunately, the amount, typeand 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 stretchedto the limit.

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2.7 Existing Sanitation Conditions

A wilingness-to-pay survey had been conducted for Calamba (CDM, 1993) where it wasdetermined that 40 percent of those surveyed were "very satisfied" with their presentsystem. and 56 percent were "somewlhat satisfied." Onily 4 percent indicateddissatisfaction. Those 70 percent of houseliolds with water-flushed toilets for theirexclusive use probably account for most of the "very satisfied" and half of the "somewhatsatisfied" respondents. The relatively high degree of reasonable satisfaction with theirexisting systems could indicate that heads of households believe they have alreadyprovided for reasonable on-site toilet facilities. However, practically, all households aredisposing their wastes to drains or canals whic' poses risk to public health of the people ofCalamba.

2.8 Health Problems Faced by Calamba Residents

As in the other project cities, sewage contamination is a prime cause of water-borne andwater related diseases in Calamba. The municipal Health and Tourism Department (HTD)maintains records of morbidity and mortality in the municipality. HTD records indicatethat among the ten leading causes of morbidity and mortality in 1991, water-relateddiseases such as parasitism, gastro-iiitestiiial disorders and fever were ranked second, sixthand 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 intothe outlying cities and municipalities in the provinces of Cavite, Laguna, Batangas, Rizaland Quezon (known as the CALABARZON Region). Calamba is part of theCALBARZON priority development area which addresses the impacts of developmentbrought about by rapid changes through expanding urban concentrations and industrialactivities in the Metro Manila region. Although the impacts of these developments couldbe viewed as highly beneficial economically, the environomental consequences to the lakehave been serious. The information available at this time substantiates that theurbanization and industrialization in the basin are causing significant environmentaldegradation of the lake.

2.10 Reduced Opportunities for Cominiecial Development

Accelerated high-rise construction and sharp increases in property values haveaccompanied the installation of sewerage in the Makati district of Manila and the centralbusiness district of Jakarta. Indonesia. In some Latin American cities, central-citypropertv values are reported to have increased by as much as 20% after sewerage wasinstalled. It would not be surprising to see similar results in Calamba if sewerage wereinstalled in the Poblacion district. Cilamba is well-positioned to become a commercialhub for its regioni. and the municipal leadership clearly aspires to this role for the

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municipality. Rapid expansion of high-rise commercial activity in Poblacion seems veryunlikely 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 constitutethe principal sources of pollution:

Excreta and Wastewater Disposal. As noted above, about 4 percent of the population arewithout satisfactory on-site sanitation facilities, and most of the wastewater from thosewith 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 conditionsof Calamba.

Solid Wastes. Solid wastes are collected from only 21 percent of the total area of themunicipality, 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 arelittered casually at the places where these are generated. Much of these wastes find theirway into the municipal drainage system, hampering the drains from conducting runoffduring rains and contributing to flooding and general uncleanliness. Wastes collected areimproperly disposed of atan open dumpsite where the uncovered wastes are burned.

Health-related problems related to sewage contamination are of uncertain magnitude, butare an important consideration for the city leadership. Waterbome and other sanitationrelated diseases continue to be a major public health problem in the country.

The advent of urbanization and induistrializationi has resulted into the development ofurban and industrial centers outside the already saturated Metro Manila region. Thispresent trend in urban sprawl and industrial development has catapulted populationgrowths and accelerated industrial activities to outlving cities and municipalities such asCalamba.

This growth and development however. has resulted into some environmental setbacks,among them the degradation of the municipality's water bodies, San Juan and SanCristobal Rivers and more notably Laguna Lake. Findings show that one of the maincauses of this adverse condition is the organiic loadings from domestic solid and liquidwastes resulting from improper sanitation facilities and wastewater discharges frommarkets and other commercial establishments.

This environmental situation makes imperative the implementation of sanitation andsewerage project in Calamba in order to promote sustainiable development that will notsacrifice the environment. Apart form thie project's contribution in minimizing domesticwastewater pollution form the munLicipality. it also addresses thie deficit in sanitation whichwill significantly improve health and living conditiolns.

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The municipality's water bodies appear to be in seriously deteriorated conditions. SanJuan and San Cristobal Rivers which drain the municipality are both heavily polluted.These rivers function as natural drainage systems by r eceiving and conveying themunicipality'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 thisenvironmental situation. The lake is obviously under severe ecological stress. This isevident from the rapidly deteriorating water quality of the lake, declining fish productionand 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 inproperty values.

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3. PROJECT DESCRIPTION AND ANALYSIS OFALTERNATIVES

Introduction

This chapter begins with an explanation of the rationale of the proposed project and thengoes onto describe the project. The main components - sanitation and sewerage schemesare described separately. Description includes the analysis of alternatives considered inarriving at the final choice. The chapter concludes with the recommended design and plan.

Section I - Project Rationale and Objectives

Chapter 2 describes the existing enviromnental situation Calamba, and illustrates theworsening health impacts caused by the uncontrolled discharge of sewage. There isnegligible piped sewerage in the municipality. There are no treatment and disposalfacilities for septage removed from septic tanks. Septic tank overflows and soakawaysenter the drains and the groundwater.

T;he proposed project is, therefore, aimed at addressing the problems of inadequatesanitation and sewerage in Calamba by providing sustainable sanitation and seweragefacilities. thereby reducing public health irisks and environmental pollution fromwastewater sources. The project is designed also to provide a learning experience forfuture expansion of sustainable sanitation services for the municipality as well as for otherurban areas. The selection of final project design is driven by: (i) demand-based approach;(ii) level of wastewater treatment to be achieved; and (iii) the need for protecting theenvironment.

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Section 11 - Sanitation

Proposed Facilities

The sanitation component will include the construction of 395 VIP-latrines, 395 poor-flush toilets and 17 commrunal toilets over the entire municipality. The sanitation workswere based upon an identified deficit of sanitation facilities of 4%. The choice betweenindividual and communal facilities will be driven by technical feasibility and demand by keystakeholders and not by tenure status. The location of the individual as well as commrunaltoilets is not defined yet and will depend o01 the consultationi of potential beneficiaries.The areas to be served by the communal toilets may include public areas such markets andlow-income squatters or blighted areas.

The possibility to construct on-site facilities is site specific. As the majority of squattersare located on government owned property, that is, along river banks and shoreline it isunlikely that communal toilets, with on-site disposal will be technically feasible. At theselocations, communal toilets will only be feasible if there can be a direct discharge to aproposed sewer. The sizing of the facility is dependent upon the depth to groundwater, thepermeability of the ground and the availability and cost of land.

The on-site sanitation facilities include: "VIP latrine and pit" and "pour-flush toilet andseptic tank." The recommended on-site system would be for a two-cell septic tankdischarging to a soakaway. Ideally, there would be two soakaways, allowing for onesoakaway to rest after 12 months of operation. Though ideal, it is unlikely that such asystem would meet the affordability criteria/demand of the customers. The demand foron-site facilities will be established by public consultation concerning both renteddwellings and owner occupied houses. Only then. the actual willingness of individualhouseholds to avail of the proposed loan system from the LGU in the amount needed toconstruct the facility, will be established.

The communal toilets will be constncted itn areas where, through public consultation.there is an established demand and willinigess to pay for the service. Arrangements forconstruction and operation could take many forms such as:

(i) Municipality constructs and operates:

(ii) Municipality constructs and contr acts out the operations either to a privatecompany or to the local communlitv the facility is serving through a leasingarrangement:

(iii) Construction and operation contracted throughl a concession arrangement.

It is recommended that arrangemenit (ii) be giveni pr eference over the others, particularly ifthe local community is willing to operate the facility.

An't ironnzL'7t. .Iss.?s.mRent Icporr: ('alam7ha. I.agLma 25

The different arrangements should be examinied followinig consultation between themunicipality and users, in order to implemenit the preferred option. Then following amonitoring period, the more successful operation can be repeated. A balance has to besought between affordability to construct (the quality) and willingness to pay. The facilityhas to be made "attractive" to the users and provide the service they require and,therefore, in selecting the option the following aspects should be considered:

* Site - central location to proposed users (designed to serve 250 users, orapproximately more than 40 properties):

- proximity to a proposed sewer line, if any, of the land area required(including for septic tank/soakaway)

- availability of water supply;

- availability of power supply;

- area not prone to flooding.

* Services - need for inclusion of showers/launldry facilities.

* Design - attractive to users;

- clean, odor/insect free;

- well lit; good security:

- facilities designed for intenise usage: need to be functional and durable.

Cost Estimates

4. Capital Cost

The capital cost for the sanitation componenlt is as follows:

Facility (P million) [ Betieficiaries

On site facilities 7:28 4.148Conmmunal Toilets- Construction 5 27 4.250- Land 0Total r 12.45 _ _

The construction cost includes 5°lo pllYsical continigenicies. The cest of engineering hasnot been considered on the assumption that thie design and( conistruction supervision can behandled directly by the concerned municipal department because of the simplicity of thestructures.

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B. Operation and Maintenance Cost

Annual O&M costs for each communial toilet has been estimated at P 192,780. This wouldrequire an user fee of about P1.20-1.40 per visit on the assumption of 250 persons usingthe facility twice daily. It is intended that the cost of O&M plus the operator's fee have tobe covered by the users.

Implementation Schedule

It has been assumed that the 395 VIP latrines, 395 poor-flush toilets and 17 communaltoilets will be constructed during a period of three years. Therefore, an average of 132VIP latrines, 132 poor-flush toilets and 5-6 communal toilets would be constructedannually including the required time for consultation and design. However, as may benecessary, the construction of the sanitation component could be extended over the five-year implementation period of the project.

Section III - Overall Sewerage Scheme

Classification

Sewerage refers to the collection and treatment, at a single location, of water-borne waste(sewage) discharged from individual properties. It includes the collection and treatment of"domestic" sewage only and not for any "industrial" waste discharge.

The sewage is collected and transponted thjrough a network of underground pipes, orsewers. to a wastewater treatment plant (WWTP). wher-e the sewage is treated to producean effluent that can be discharged to a receivinig water body (river, sea, etc.). Sewageflows along the sewers by gravity, that is, the pipes are laid at a slope or gradient which issufficient to ensure that the sewage will flow without causing blockage.

To minimize depth of excavation, sewers, generallv. should follow the slope of theground. that is, they go downhill. If the depth of a sewer becomes too deep (greater than5 m) a pump station would be used to elevate the sewage, either to another sewer or tothe WWTP. The sewers are divided into two classifications:

* collector sewers - sewers comiecting an individual property or group of severalproperties to a sewer located in the street or right-of-way;

* transportation sewers - those sewers receiviing the sewage flow from the-collection" sewers and transporting the sewage to the WWTP.

The transportation sewers can be considered as the -main road". with the collector sewersactinig as the "feeder roads".

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Selection of Service Areas

The Poblacion area is considered a priority area for the following factors:

* increasing population density and limitations for on-site sanitation;

* presence of large commercial establishments. and institutions such as schools,colleges, governrment offices and hospitals;

* health hazard and risk posed by the increasing wastewater flow on the municipaldrainage system;

* high level of urban development with a population density capable of payingwastewater service charge;

* biological degradation of rivers and Laguua de Bav which have been found to bepolluted with human excreta and positive for fecal coliforms. Disposal of septictanks effluent to the drainage system contributes to aggravate this pollution problen.

The identified Initial Service Area (ISA) comprises a total of 15 barangays with an area of1,176 ha and a total population of about 64,700 in 1995 projected to increase to about102,200 in 2015. The ISA is bounded on the north by the San Juan River, on the west byBarangay Parian, on the east by Barangays San Juan and San Jose, and on the south byBarangay Lecheria.

As shown in Figure 3.1, the ISA is subdivided into three stages of implementation.

The Stage I Service Area has been outlined to include those areas which can provide thehighest impact in terms of improvements to the environment as well as to the social andeconomic conditions of the Municipality. The areas included are:

* the Poblacion's center where commercial and institutional establishments, such as.hospitals, and offices are located;

* the barangays that are highly urbanized and densely populated of the Eastem Areawhich is adjacent to the Poblacion. The Easterm Area, however, has a lowerpopulation density thani Poblacion.

An Expanded Stage I Service Area has also been outlined to include additional fourbarangays of the Eastern Area.

The Stage I Service Area includes:

Service Area Population(v) 2001 2015

Poblacion 102 19.720 26,770Eastemn Area 6 1 3.630 4.930

Total 163 23,350 31,700

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The Expanded Stage I Service Area includes:

Service Area Population(Ia) 2001 2015

Poblacion 102 19,720 26,770Eastern Area 155 8,680 11,790

Total 257 28,400 38,560

The population which will connect to the system has been estimated at 60% of the servicearea population. At the starting of operations, in the year 2001, the system will serveabout 11,830 users, with 2,049 connections, projected to increase to about 16,060 users in2015 with 2,782 connections.

The figure that 60% of service area population will connect to the system is based on theassumption that 85% of the population (year 2015) would be connected to the CWDsapply system, and of those, 70% would be coimected to the sewer. Expansion of thesystem would be dependent upon the number of sewer connections and the sewage flowfrom each connection. The capacity of WWTPs and pump stations would have to beincreased on^e the 60% design flow is reached. This may or may not correlate to theactual connected population.

Potential Treatment Plant Sites

The strategy to identify potential treatment plant sites for Stage I was:

* take advantage n the availability of small parcel of lands with minimal number ofsettlers, if not totally vacant;

- divide the system into smaller catclhmeut areas considering the potential treatmentplant sites, as well as topogr-aplhy and drainage characteristics.

In consultation with the Municipality the following potential sites were identified:

* Sampiruhan (identified by the previous Feasibilitv Report [CDM, 1994])* Banadero

The Sampiruhan site is subject to flooding by Laguna de Bay and is being used for limitedfarmning. The Banadero site is currently farm-led. Thlere are no requirements for therelocation of inhabitants on both sites. A land valtie of P200/sq.m has been used for theWWTP sites and P530/sq.m for the pump station site in the Poblacion, as indicated by theMunicipal Planning Department.

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Treatment Process Options

For the treatment of sewage to be collected from the Stage I service area, three processoptions were assessed, as follows:

* anaerobic/facultative lagoons;

* modified lagoons:

* mechanical activated sludge.

1. Anaerobic/Facultative Lagoons

This system comprises of two or more ponds in series: the initial anaerobic pondfollowed by facultative pond(s). Each pond is defined as follows:

* Anaerobic Pond - used primarily as a pre-treatment process for high-strengthwastewater. They may be used for septage, night-soil, and high-strengthdomestic sewage. The advantages of using anaerobic ponds are that theyeffectively decrease the land requirements of subsequent facultative andaerobic ponds and the accumulation of large sludge banks in subsequenttreatment ponds is avoided.

- Facultative Pond - are the most common type used for wastewater treatment.Raw wastewater enters at one end of the pond and suspended solids settle tothe pond bottom. Over a period of time, a sludge layer develops that is voidof dissolved oxygen. The bottom sludge decomposes anaerobically. Abovethe sludge layer, the pond has a facultative layer that alternates from aerobic.during daylight hour, to anaerobic at light. The upper layer of the pond isaerobic at all times due to oxygen supplied primarily by photosynthesis andwind action. Facultative pond effluent would have to be further treated forthe removal of suspended solids before discharging to the receiving water tomeet the effluent discharge standalrds.

A previous Feasibility Report (CDM. 1994) selected this process for the initialseptage treatment facility and for identifyinig the land area requirement for thedeferred sewage treatment plant.

The design criteria for the process is as follows:

* Anaerobic Ponds

- Dual ponds; depth of 4.0 m; side slopes of 3: 1; rectangular with length of 1.5to 2 x width.

- Organic loading of 0.3 kg of BOD/dav per cu.m of pond volume.

- Deteution time at least 1.5 davs.

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- Pond volume to be determined bv the higher value.

- Assumed BOD removal for subsequent treatment of 65%.

Facultative Ponds

Dual ponds in series; depth 1.5 m; side slopes 3: 1; rectangular shape, withlength 2 x width.

- Organic loading rate of 400 kg of BOD/day per hectare of pond surface area(based on 40 g of BOD per capita and 10,000 persons per ha). Loading rate tobe applied to residual BOD in effluent from anaerobic ponds.

- Detention time to be 6 days, total for all ponds in series.

- Pond volume to be determined by the higher value.

- Estimated BOD removals of 70% of influent BOD (overall BOD removalsestimated at 90%).

While providing a treatment system that has a reduced land take (compared toa complete facultative lagoon system) and utilizes no mechanical equipment,there are concems as to its ability to operate satisfactorily. Concerns raisedinclude:

Anaerobic Pond

Will produce odors - particular ly if sulfates are present in the influent.

Sometimes difficult to manage if pH valies on1 the acid side. Processeffectiveness decreases or fails completely. Short detention period tends toreduce buffer capacity. Once the system becomes acid, it must be treated withlime or some other chemical to neutralize the system.

Removal of sludge required. Frequently depelnds otl severity of the solids -BOD loading and nature of composition (sludge disposal was not addressed inthe Feasibility Report).

Ability to treat low strength domestic sewage and variable rates of flow.

Facultative Pond

Shallow ponds at depths of 1.5 to 1.75 meter-s subject to turnover because oftemperature variations or wind and wave action. Temperature not as much ofa factor in areas of low fluctuationls.

iAnaerobic and aerobic processes tend to be in state of flux and vacillatebetween stages reducinig treatdmielnt effectivelness.

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- Tends to increase land requirements because of the relatively shallow depth.

- Limited detention period will not ensure the removal of fecal coliforms to anacceptable level.

2. Modified Lagoons

The modified lagoon system, [e.g., the Advanced Integrated Pond System (AIPS),see Appendix 6] is a non-structural design which utilizes earthen constructionpractices to simplify and reduce construction costs. The system is designed tooptimize natural biological processes in order to improve treatment effectivenessand reduce power requirements and chemical additives while limiting landrequirements. The design concept is to minimize sludge production, eliminatedaily sludge handling and restrict desludging to a long term 20- to 30-year cycle.

The modified lagoon system is an integrated, multi-stage biological reactor systemtreating municipal, agricultural and industrial wastewater. The reactors may berelatively deep and constructed of compacted earth as open surface pond areas.The biological reactor has discrete and isolated biological zones integrated into asingle unit; a deeper anaerobic cell(s) at the bottom of the reactor, sludge blanketsuspended over the deepened zone and an overlying aerobic zone comprised ofaerobic bacteria, algae and a satur ated oxygen media provided by a combination ofalgae and surface aeration.

In many cases the initial reactor is followed by a similar second reactor operatingin series with the provision to recirculate to the first pond depending on conditionsand circumstances. Recirculation lends flexibility and buffer (shock loading)capacity and adsorption abilities with highly variable hydraulic or organic loadingsor where there is a potential for receiving toxic spikes.

TIhe primary facultative pond with an aerobic surface and extremely anoxic internalcells for sedimentation and fermentation is the initial treatment element in the seriestreatment train. In this element raw or screened wastewater is introduced directlyinto the bottom of a relatively deep internal cell(s) where settleable solids aredigested anaerobically. The overflow velocity in the cell is maintained at a lowrate such that the suspended solids and BOD5 r emoval efficiency approach 100 and65%. respectively. These rates are maintained at less than the settling velocities ofhelminth ova and parasite cysts. Consequeitlxv. the majority of these organismsremam in the cells and are permanenitly removed from the effluent. Settled solidsin the anoxic cells ferment to the extent that only ash remains due to the large cellvolume. Hence, sludge removal is seldom required.

The rising gases and upwelling of wastewater firom the anaerobic cell pass througha thicki anaerobic sludge blanlket. that is formed as a result of the fermentationprocess, and remains suspended above the anaerobic cell. . The hydraulic detention

fE7lrsl1e/lfl kseNsvinen1t ReP>or ( oium/1lba ;.,Qz7aob1 3

time in this anaerobic zone and corresponding rise velocity is variable by designand nature of the waste stream.

Treatment of soluble waste continues in the overlving aerobic zone, comprised ofaerobic bacteria and algae. These organisms are maintained in an oxygenated stateby photosynthesis, recirculation and surface aeration. The nature of the surfaceaeration creates a circular motion over the entire pond surface area which in turnensures an oxygen rich colntiniuitv.

Soluble wastewater componenlts undergo aerobic oxidation and furtherdegradation in this zone. Thus, two nonnally seemingly incompatible biologicalwastewater treatment processes can be made to coexist uninterrupted in the sameearthwork reactor.

The horizontal velocity of the circular motion is reduced over secondary deepenedzones as a result of the added volume, allowing the aerobic solids to settle bygravity into a secondary digester for further decomposition and stabilization. Asludge blanket is formed in this area and remains suspended over this zone. Thesurface aerobic circulation pattern reliably controls odors.

The further fumction of the isolated reducing anaerobic zones includesdenitrification, precipitation of heavv metals and fi-actionization of toxiccompounds to a less toxic state.

Seasonal, (temperature) and wind or wave action driven turnovers of the pondsis prevented by placement and design geometry of the internal cells andsuppression of the thermocline. Turnovers are a complex phenomena oftemperature changes, wind action. pond depths and configuration of the ponds.The advanced pond design features and method of cell integration serves tomaintain the integrity of the system thus preventing potential pond turnovers.

Sludge in the anaerobic cell(s) remains for an extended period continuouslyundergoing organic decomposition. This may take place over a 20 - 30 yearperiod. One system in operation has not been desludged in thirty years. Recenttesting 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 thatthe size and number of internal cells differ depending oni the design and type ofwaste treated. Recirculation of the hiahly oxygenated water from this second pondis introduced to the surface of the primnary faciultative pond to provide an oxygenrich overlay of this pond. This oxygeni quickly acts to oxidize reduced gasesemerging 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 theincominig 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 effluentin the form of reduced metal sulfides or as attached to algae solids.

The modified lagoon system is proposed and an appropriate treatment method fora variety of wastewater treatment applications. These include normal dischargesas well as variable hydraulic flows and organic loadings, particularly where theremay be limited industrial pretreatment and source control of high strengthunbalanced wastes and toxic and heavy metal discharges. The design elementsprovide for flow equalization, buffer capacity and recirculation capabilities toachieve secondary and advanced treatment for municipalities, agriculture andindustry.

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 higherpercentage 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 mediareinforcement 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 andwould 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 andmaintenance buildings, partial standby power generation capability would berequired.

Based on international experience, mechanical activated sludge plants, althoughrequiring smaller land area, are more expensive than any lagoon system in terms ofcapital as well as operation and maintenance expenditures. Furthermore, skilledstaff is required to operate the plant. Therefore, the construction of a mechanicalactivated 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 pondsfor the initial septage treatment facilitv and for identifying the land arearequirement for the deferred sewage treatment plant. However, the process hasraised 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 coliformwil be achieved, which is a major requirement for the protection of the rivers andthe 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 andinhabitants should be provided to reduce the level of odor reaching the nearbyinhabitants.

On the other hand, based on interniationial experience. the adoption of mechanicalactivated sludge plants, althoLugh1 requiiilng smaller land area, will be moreexpensive than anv lagoon system in temns of capital as well as operation andmaintenance costs. Furthermore. skilled staff is required to operate the plant.Therefore, the use of a mechaniical treatmenit plant is considered not a viableoptioii.

The modified lagoon system utilizes mechanical aerators and recirculation pumpsand, 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 fecalcoliforn reduction; and has a minimal sludge production rate. These featuresallow the modified lagoon system to address the concerns related to theanaerobic/facultative ponds

As a result of the above analysis, taking into account the quality of effluent aftertreatment, the availability of land as well as capital and operating costs, themodified lagoon system is recommended for all the WWTP to be included in thealternative schemes identified for Calamba.

Comparison of Alternatives

The alternative schemes identified are briefly described as follows:

AlternativeScheme Description

Stage I Service Area

I The system will drain the sewage of the whole area (Poblacion and EasternArea) to the WWTP (modified lagoon system) located at the Sampiruhansite.

2 The system is divided in two areas: the sewage flow of Poblacion will bepumped into the WWTP (modified lagoon system) located at the Banaderosite; 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 Poblacionsystem. 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 inBanadero 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 fivealternatives are as follows (schemes 3 and 6 had been discarded because of theirmuch higher capital and O&M costs compare to the other five):

Alternative WWTP Connected Total Flow BOD LoadingSchemes Location Population (cu.m/d) (kg/d)

Sampiruhan 19,0201 - Sewage 4,394 761

- Septage 130 650Total 4,524 1,411

Sampiruhan 2,956- Sewage 683 118- Septage 130 650

2 Total 813 768Banadero 16,064- Sewage 3,711 761- Septage

Total 3,711 761

Sampiruhan 23.1344 - Sewage 5,347 926

- Septage 130 650Total 5,477 1,576

Sampiruhan 7,070- Sewage 1.633 283- Septage 130 650

5 Total 1,763 933Banadero 16.064- Sewage 3,711 925- Septage

Total I 3,711 925

Banadero 16,0647 Sewage 3,711 643

- Septage 130 650Total 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

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2. Financial Assessment of Alternatives

As discussed above, seven altemnative sewerage schemes have been evaluated. A costcomparison of the seven sewerage schemes in terms of capital and O&M costs, has provedthat the cost of Alternatives 3 and 6 are much higher than the others because too manypumping stations are needed. Therefore, the two altemnatives have been discarded and forwhich 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 onthe basis of costs derived from the Feasibility Report and other relevant studies and datagathered by the consultant. For fuirther information, reference should be made to theFeasibility Report (C. Lotti, 1996). Comparing capital costs as follows:

Capital Cost of Alternatives'Facility (P milion)

_ 1 2 4 5 7I. Collection2 42.64 42.64 67.36 67.36 26.742. Property Connections3 25.96 25.96 28.96 28.96 21.933. Transportation System 33 48 1 9.73 39.13 25.63 11.914. Pump Stations - 7.85 - 6.42 7.855. Land for Pump Stations -0.09 0.09 0.096. Forcemains - 1.16 - 1.16 1.167. Outfall 5.04 1.51 5.04 1.51 _

8 WW1TPs 23.22 2'4.7; 26.58 28.17 17.509. Land for WWTPs 8.00 10.60 9.60 12.00 7.6010. 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.) asdevelopedfrom tvo studA' areas in Davao and Dagupan. Collection sewers proposed are"condoinimal ", that is, they are r outed through private property to optimize the sewerlength and ennimize cost of connection to the transportation sewer. Property owners haveto be consulted and agree to the condomeinal sewer design.

3 The cost of a house connection to a seiverfor an existing property, requiring theabandoning 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 seweragesystem.

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(ii) O&M Costs

The O&M costs will increase in relation to the number of connections. Annual O&Mcosts 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 year2001 and 2015.

Alternatives Annual Cost 2001 Annual Cost 2015(F million) (P million)

1 1.91 2.612 2.69 3.344 2-07 3.355 2.73 3.447 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, thecorresponding sewage flows are also different. Therefore the net present value (NPV) ofeach alternative has been determined as the ratio between capital and O&M costs and thevolume of sewage flows, at 15% discount rate. The result of the analysis is as follows:

NPVAlternatives (P /cu.m)

1 21.282 21.454 21.225 21.207 17.84

(iv) Conclusion

The above NPV clearly shows that Alternative 7 is the most economic and,.therefore. isrecommended for implementation. The recommended alternative is for a collection andtransportation sewer network, in the Poblacioni area. discharging to a single WWTPlocated at the Banadero site. The WWTP WOLuld use the modified lagoon treatmentprocess and would treat both sewage and septage. The treated effluent would bedischarged 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 communalsanitation facilities; (ii) sewerage systems in Poblacion; (iii) maintenance equipment, toolsand 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 17communal 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 andseptic tank". The demand for on-site facilities will, therefore, be established by publicconsultation concerning rented dwellings and owner occupied houses. Communalsanitation 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 betweenindividual and communal facilities will be driven by technical feasibility and demand by keystakeholders, 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 andfrom 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 thecollection of wastewater in neighborhioods. puroks and barangays; (iii) trunk sewers andpumping 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 ensuregood 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 condominialsewers are used, communities will be given a choice between location of the sewers inback-yards and locating them in front of tlheir properties. Simplified sewers will be used fortrunk 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. Itsprincipal unit is a deep vertically integrated pond with an anaerobic pond below afacultative pond system. The geometry prevents turnovers, thereby mrinimizing odorproblems 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, in2015, 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 dischargesewage to a single vertically integrated pond system designed to treat both sewage andseptage:. The treatment plant is located at the Banadero site and the treated effluent willbe 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 to400 mm;

* one pump station with a capacity of 5,566 cu.m/d and a land requirement of 173sq.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 tothe 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 neededfor proper operation and maintenance of the sewerage and pumping facilities. Spare partsfor critical equipment will also be supplied.

It should be noted that the sewerage systems will, after con sti-tction, be turned over to theCWD not only for operation and mainteniaince but also for construction of additionalconnections. It is envisaged that the cost of new conniectionls will be paid up-front by theusers at the moment they request to be connected to the system. This will surelyconstitute a constraint and mav restrain the users firom beillg connected. To minimize thisproblem in the first one-two years of CWD operation, it is proposed to include in theproject the procurement of stored material (pipes. fittings, etc.) necessary for thecoinections. This would reduce the up-front amount required from the users and the costof 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 ofbeneficiaries and construction supervision; and (ii) training of CWD staff responsible forthe 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 thetraining of staff for the operation and maintenance (O&M) of the sewerage systems andparticularly of ponding systems. The consultant will have to prepare an O&M manual andtrain the operators on basic ponding treatment concepts as well as familiarity with theO&M manual. The training program should also include an overseas visit to a countrywhere the adopted treatment method is already in operation.

Cost Estimates

Based on the estimates, the capital cost of the Calamba project has been estimated atP111.34 million (US$4.24 million) excluding price contingencies and interest duringconstruction. The cost is composed by P37.14 million (US$1.41 million) of foreigncomponent and P74.20 million (US$2.82 million) of local component. By including pricecontingencies 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)

SANITATIONConstruction of facilities 12.45Land 0Pnrce contingencies 2.20Interest during construction 5 93

Tota Sanitation 20.68SEWERAGE IConstruction of facilities 75.74Land and resettlement 7.69

Maintenance equipment & spares 4.00

Institutional support 11.36Price contingencies 12.38Interest during construction 35.79

Total Sewerage 146.96

Total InvestmentTotal 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 resultingfrom poor sanitation and uncontrolled discharge of sewage. Though the proposed projectwill cover only a small portion of the population, the project is seen as an important andsignificant first step in a long term program to provide Calamba (and the nearby cities andmunicipalities as well) the required sanitation and sewerage infrastructure. The project isanticipated to contribute to the gradual improvement of the municipalty's environmentand improvement of the conditions of its San Juan and San Cristobal Rivers and thenearby Laguna de Bay.

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FORCE "AET4 SEWERAGE SYSTEM

4. ENVIRONMIENTAL IMPACTS

Introduction

This chapter has three sections. Section 1 describes the beneficial impacts of the projecton the environment. Section II identifies and evaluates the different impacts of theproposed project on the environment. Section III summarized the environmental impacts.

Section I - Beneficial Impacts of the Project

T'he implementation of the sewerage and sanitation project for Calamba is foreseen toresult in positive impacts, namely:

* Health and Environment Benefits

On the short term, it is expected that the implementation of the sanitation and sewerageprogram in Calamba will improve the public health conditions especially the targetbeneficiaries. The provision of sanitary toilet facilities is anticipated to decrease thepossibilty of human contact with excreta which leads to a reduction of water bome andsanitation related diseases. This health benefit is most significant not only because of thehealth implications but also because the project will mostly be advantageous to lowincome groups which could not afford proper sanitation facilities.

Project impacts include the improvement of water quality particularly of the San Cristobaland San Juan Rivers. The effects of the project on these water bodies though will be longterm and not immediate like the health impacts. Furthermore, it should be emphasizedthat parallel improvements in solid waste management, drainage and industrial pollutioncontrol will have to be implemented to enilanlce environmental impacts, otherwise effectson water quality become marginal at best. If the water quality of both rivers (SanCristobal and San Juan) are improved, it is expected that to some extent, water quality inthe nearby Laguna Lake particularly at the outlets of the two rivers will likewise improve.

Also a potential impact is the decrease in the possibility of contamination of shallowgroundwater wells and springs in the area. In Calamba. the springs and creeks play a vitalrole in the municipality's tourism industry -- springs. creeks and groundwater provide thelocal resorts with ample supply of water neecledl by these tourist attractions.

I " n,wonmenial Isse.ssmeznt R1e1yort ( aolaomho 1 a I c a 46

* Increased Recreational and Economic Opportunities

On the long term, it is predicted that the consequenlt improvements in water quality of SanJuan and San Cristobal Rivers and most specially Laguna Lake, vwill bring about increasedeconomic opportunities for the municipality. Fish production in the lake will improve withthe reduced pollution coming from domestic sources. This benefit is significantconsidering that fishing is an important livelihood not only in Calamba but for most of thelake basin.

Also expectea. to benefit from the improved water quality and living conditions is the localtourism industry. Numerous tourist facilities in the municipality rely on good waterquality and ample supply of water coming fiom hot springs and creeks. Therefore,measures that will be undertaken to prevent their contamination and/or deterioration willensure the area's attractiveness to local and foreign tourists and the industry itself. Thisdoes not only boost the local economy but also provides recreational opportunities forCalamba residents.

With program implementation, not onlv will it be expected to generate local employmentduring the actual construction of sanitation and sewerage facilities, but it will also give riseto a new business activity in which the private sector will be encouraged to participate.For example, the collection of septage from existing septic tanks will entice privatedesludging contractors to work with the operator of the proposed sewerage facility.

* Increase in Productivity and Income

On the long term basis, the reduction in the incideuce of water borne and sanitation relateddiseases is foreseen to result to increased plroductivity of usually affected households.Since people become indisposed due to illness, the time lost is a potential for incomegenerating activities. The associated benefits include reduction in medical expenses whichincreases the money available for other household expenditures.

* Increased Property, Values and Commercial Attractitveness

The municipality's poblacion. the initial area to be served by the sewerage system, has astrong advantage in when it comes to property valuation and commercial attractivenessbecause it contains the Calamba's central business district. Sewera2e in the district wouldallow construction of high-r-ise office buildings, positively leveraging property values andtax collections. In addition, the central business district is the most visible area forpotential investors. A conservative impact estimate suggests that a sewerage projectcould be self-financing in the central buisiness district.

A.nv ironmental . I.scsssment Report. (alantba. Laguna 4 /

Section II - Project Implementation Impacts

As described above, the implementation of the project is expected to have beneficialimpacts in the long term. However, the constr-uctioni and operation of the system is boundto result in impacts that require mitigation. This section identifies such impacts andassesses the scale and magnitude.

Construction Phase

A. Air Quality

The implementation of the project will result in occasional, marginal and acute increase inthe ambient concentration of suspended particulates in the vicinity of the project site. Thiscan be attributed to land clearing and excavation activities wlhich expose soil to wind andvehicular traffic over unpaved road.

P. Water Oualitv

Excavation activities in the project sites could also loosen soils and transport of thesematerials to any surface waters will result in siltation or increase in turbidity.

During the rainy season, surface runoff will tend to increase total suspended solids and isexpected to cause temporary stress at the discharge points, but the impact is localized. Assoon as the vegetative cover of the site is re-established on open spaces. impact on thereceiving body of water caused by surface ntnl-offAwill be eliminated.

C. Noise

The noise impact during the construction stage is expected to be generally minimal andwill not require any special noise abatement measure. The treatment plant sites shall havea setback away from residential clusters. which will definitely provide the necessary bufferto reduce noise impact during construction of the treatment facilities.

During the pipe-laying, some noise will be temporarily generated due to operation ofheavy equipment and from breaking concrete pavement and sidewalks. In addition, sometraffic congestion may be expected on during pipelaying.

D. Ecological Effects

As there are no rare, endemic species of flora and fautna in the project area, projectimplementation has minimal impact on the terrestrial c.nd aquatic ecology. There will beclearing oftrees during actual construction wlher-e unlavoidably necessary.

1 n-ironniental .Is.swessx,nent Report: (C'almina. Laguna 4N

Operation Phase

E. Air Ouality

The operation of the wastewater treatment facility slhall have minimal impact on the airquality of the area. Aside from the occasional odor nuisance. it is not projected to haveadverse effect on the air quality. Odor production at the AEPS treatment plants iscontrolled by the natural processes employed by the system. In existing installations,residences, a convalescent home, and recreational areas like golf courses are within"sniffing distance" of the plant facilities.

F. Water OuaLitv

The implementation of the project will be beneficial to the general environment ofCalamba and its surroundings. The current practice of discharging untreated domesticwaste into nearby bodies of water would thus be reduced or eliminated. Diffusion effects -- the adoption of the modified lagoon system (or AIPS) treatment process should attainhigh rates of BOD, TSS, and coliform removals. Dischlarge to the receiving bodies ofwater should therefore pose no significant pollutioni risks. However, to fuirther eliminatethis risk, proper studies would be conducted on the mixing and dilution before locating theoutfall. In the unlikely event that projected r emoval r ates appear to be unattainable, thetreatment system particularly the maturation ponds can be designed for larger capacitiesand/or longer detention times to further enhance removal efficiencies and thereby negatethe risks of polluting receiving waters.

H. Socio-economic Aspects

The provision of sanitation facilities in Calamba would undoubtedly benefit the generalpopulace of these areas. The occurrence of epidemic-scale diseases as a result ofunsanitary conditions shall be minimized. This will make for a more healthy andproductive population.

1. Sludge Disposal and Management

The modified lagoon treatment system is designe(d antd actually performs so that solids atthe bottom of the deep anaerobic pits in thie facultative pond (first biological pond reactor)remain for very long periods of time. continitouslv decomposing. Due to large pit volumeand its depth, and its reducing environmlenit. settled solids ferment there to a point whereonlv ash remains. Thus minimizing the genier-ation of bio-solids, hence sludge removal isseldom if ever required.

Since sludge is retained in specially designle(d pit digester-s anld r emainis there indefinitely,daily transfer of sludge is not necessary ancl energy needs for sludge transfer areeliminated. Also because digestion proceeds over Nyears of time, heating and mixing (as inconventional sludge digesters) are not requir ed ther efore reducing costs of operation.

Repor,,.- Ualumba, 1.4~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~IZWW 4y~~~~~~~~~~

The oldest plant in operation treating domestic wastewater in the city of St. Helena inCalifornia, USA, has not had to remove bio-solids for nearly 30 years. (Recent testings ofthis system have indicated that sludge is well-digested and very stable.) Owing to itsstability, the sludge/residue, if desludging does become due, can be disposed ofX witharrangements with the municipality, at the municipality's sanitary landfill. Because of itsrelatively stable nature, desludged material could even be barged to the open sea fordisposal say once in every 15, 20 or even 30 years.

Section III - Summary

The implementation of the project and its components is projected to produce onlyminimal adverse environmental impacts. Moreover, there are socio-economic impacts thatwill essentially be beneficial and will provide employment and livelihood opportunities tothe population of surrounding communiities as jobs will be generated during the projectimplementation. In the long-term, better sanitary conditionis will result in the project areas.Consequently, an improvement and enhancement of the existing environmental conditionsin the project areas shall be experienced.

During project implementation, mitigation measur es will be incorporated to minimize, or ifat all possible, eliminate adverse impacts. Moreover. measures to enhance existingenvironmental conditions in the project site shall be implemented to maintain thesustainability of the area. The implementation of the project will inevitably produceimpacts, both adverse and beneficial. The mitigation actions are outlined in the nextchapter.

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5. ENVIRONMENTAL MLANAGEMENT PLAN

Section I - Mitigation Plan

Construction F iase

Potential Impact & Risks Mitigaton Action

* Poor quality of construction * Design and supervision contract will be separated from supplyand installation contract as a means of assuring quality ofconstruction. Works engineers. with a relatively independentsource of information on construction progress, wiU be hired.

Air Pollution . Careful construction planning and work phasing, specificationsand 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 forsuspended particulates, odors and construction materials and equipment.fumes emissions - C02 , CO, NO, * Expeditious and prompt removal of excavated materials or

dredged spoils from construction sites.* Exposure of fine-grain particles to * Regular and adeqtiate sprinkling of water on dust-generating

wind and vehicular traffic will mounlds/piles resultinig fi-om earthmoving activities and civillikely result m 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 excavationI soils. for fuel and oils needed for equipment.

* Siltation * Careful and rational planning of construction and post-construction phases of the project.

* Maintenance of adequate drainage system. -

* Noise from operation of construc- * Erect temporaiy sound bariners around the work sites: avoidtion equipment would be about 70- simultaneous use of heavy eqmupment: limit daytime work,80 dBA at 10 m: 50-70 dBA at 30 vehicle speed at 20 kph: regrulaf maincenance of equipmentm. . Use of appropriate mufflers and sound proofing of construction

imachinieries, equipment, and engmnes. Use of appropnate shock-absorbing mounilttings for machinery.

l Establishment of buffel zones and noise zones.

| Temporary Disruption of Traffic . To the extent possible. feeder and collection sewer lines will beFlow located alonig secondary streets.

l Schedtulinig and increasing input resources so that penod oftraffic disruption in primary roads are reduced.

* Coordinate with local traffic management office and the PNPTraffic Management Command

l Clear (irectionial signs andI barriers in case traffic rerouting isl needed,.

* Pnblic informationl campaigni.

hpiiLUifl'i ira!,77 -I se.'.s7aneo?t Rep,rt: ( a/(amh Icitglll7 5/

___________________________ Operation PhasePotential Impact & Risks Mitigation Action

* Environmental hazards due to . Carefully designied post-construction maintenance, contingencyaccidents and man-made or natural and monitoring programsdisasters. . Well designed plan for detection of accident or natural events

* Breakdown or malfunction of the including precautionary and remedial measurres to be taken/sewer lift station will increase level obseived.of pollution at the San Juan River * Adequate plans for- environmental rehabilitation, clean-up,near the center of the municipality restoration. and disposition of temporary structures and facilitiesas 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 undeitake wastewater analysis.

* Tbe effluent discharge may well . Following the bubble concept, wastewater discharged into theaffect the condition of receiving San Juan River shall, in the long-term, conform to the waterbodies 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 QualityStandards andc Revised Effluent Regulations of 1990,respectively.

* A dispersiorr/diltitiori modeling study will be conducted to pnorto locating the outfall. Treated effluent discharge into the RioGrande de Mindanao shall be timed based on tidal conditions.The adoption of the AlPS process for the treatment plants shouldresult into attairimerit of effluent standards.

* Noise would be at about 65-85 * Establishment of buffer zones and noise zones.dBA. principally coming fromseptage trucks unloading at thetreatment 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 theunloading septage) aesthetics in the area by planting the green strips with

i appropriate plant or tree species.

Management and O&M of the System Institutional:. Mtanagement 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.a Sewerage surcharge shouild be sufficient to provide incentives for

CWD to mainitain system.* Require M&E reporting to the DENR and LWUA.. Exploie feasibility of BOO/BOT contracts for recreational

activities in tunsecd lancis at treatment sites.Provide adeclnnate trailiigl of CWD and city staff

* j ~~~~~~~~~~~~Re'srlatorv =* Require compulsory connection for all conunercial. industnal

and high domestic water users.. Utilize Public Performance Auditing system being set up by

DENR to ImloniitoI adverse impacts.Teclhical:i Provision of adequate maintenance equipmenlIt and spares with

se;'U'D.

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Section II - Monitoring Plan

Construction Phase

Ambient air quality measurements will be undertaken near- constr'uction sites. This will bemostly near locations where sewer network is being laid and treatment plant sites. Whenselecting 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 or24 hours, over the construction period.

Noise will measured at the same locations as TSP. Leq and Lgo values will be meas edand recorded.

Operation Phase

Receiving water quality is to be monitored by the DENR through its Regional Officewhich has been periodically monitoring the status of the San Juan River and estuarinewater quality. The PMO will collect information on present conditions, observed changesin pollution loads etc. It is to be recognized that all the pollution load will not be removedyet it is also expected that the proposed sewerage infrastructure will greatly reduce theproblem.

Once the plan becomes operationaL the Treatment Plant Operator, vis-a-vis the CalambaWater District would have to set-up a laboratory and institute a monitoring program tomeasure 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. Oncethe plant operations stabilize. weekivl measuremenlts (24-hourlv basis) will be taken.

Quarterly reports showing the trends of effluent discharge and receiving water quality willbe 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 monitorcomphance with the ECC and carry out the requisite data collection. Monitoring resultswould be submitted to DENiVEMB and the World Bank periodically. Whileresponsibility for the various mitigation activities have been identified, the WDDP-PMUshall ensure that the requirements are complied with. In addition, feedback fromcommunities, city officials, NGOs, etc. will be proactively sought through the city publicaffairs programs, regular monthly meetings of barangay captains and other methods.

DENR, through its planned PPA system, would also periodically monitor and auditcompliance 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. Pro 1 ect Citv PMI k. with January 1998 June 2000{ asstsance of NGiO.

Mcuitor and repmrt on comphance. I'M) Bi-annual basis Bi-annual basis

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G91 99-

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Appendices

1. Bibliography

2. Climatological Normals 1947-1994 from the PAGASA Synoptic Station atNAJA, 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 IBIBLIOGRAPHY

C. Lotti & Associati, 1996, Updating Feasibility Reports for Sanitation Investments in FiveCities, Final Report, Vol. 4, Calamba, Laguna, November

C. Lotti & Associati, 1996, Updating Feasibility Reports for Sanitation Investments in FiveCities, 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 SanitationServices: Calamba, Laguna, June

Environmentally Sustainable Development (ESD) Vice Presidency, World Bank, 1994, WaterSupply, 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 toPay for Improved Sanitation Services in Davao, Philippines, July

Whittington. Dale, et. al., 1995, Economic Benefits of Surface Water QualityImprovements: Davao CV Study (mimeo.)

Yhiiguez, Cesar, 1996, Urban Sanitation UJser Demand Study: Technical Consultant'sReport. May

Lee. E. W., 1990, Ponding Systems Treat Wastewater Inexpensively, USEPA SmallFlows. October

Oswald, W. J.. 1990. Advanced Integrated Wastewvater Pond Systems, 1990 ASCEConvention 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 the21st 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 3TYPICAL NOISE EMISSIONS OF CONSTRUCTION EQUIPMENT

Typical Sound Pressure LevelsEquipment at 15 m from Source

[in dB (A)]Air Compressor 75-87Backhoe 71-92Compactor 72Concrete Mixer 75-88Concrete Pump 82Cranes 76-88Front Loader 72-81Generator 72-82Grader 80-93Jack Hammer 81-97Paver 87-88Pile Driver 95-105Pumps 70-90Tractors, Bulldozers 78-95Trucks 83-93Vibrator 68-81

Appendix 4EXPECTED NOISE LEVELS AT VARIOUS DISTANCESFROM CONSTRUCTION EQUIPMENT[in dB (A)]

Equipment 30 60 120 240 meters_ _ ___ _ . .meters meters meters

Air Compressor 69-81 63-75 57-69 51-63Backhoe 65-87 59-81 53-75 47-69Compactor 66 60 54 48Concrete Mixer 69-82 63-76 57-70 51-64Concrete Pump 76 70 64 58Cranes 70-80 64-74 58-68 52-62Front Loader 66-75 60-69 54-63 48-57Generator 66-76 60-70 54-64 48-58Grader 74-87 68-81 62-75 56-69Jack Hammer 75-91 69-85 63-79 57-73Paver 81-82 75-76 69-70 63-64Pile Driver 89-99 83-93 77-87 71-81Pumps 64-84 56-78 50-72 44-66Tractors, Bulldozers 72-89 66-83 60-77 54-74Trucks 77-87 71-81 65-75 59-69Vibrator 62-75 56-69 50-63 44-57

Appendix 5ENVIRONMENTAL QUALITY STANDARDS FOR NOISEMAXIMUM 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 PMEvening 6:00 PM - 10:00 PM Nightime 10:00 PM - 5:00 AM

I

Appendix 6THE ADVANCED INTEGRATED POND SYSTEM (AIPS)'of WASTEWATER TREATMENT

Preface. The Sewerage and Sanitation Component of the World Bank-assisted WaterDistrict Development Project has proposed the adoption of the modified lagoon systemvis-a-vis the Advanced Integrated Pond System (AIPS) as the processfor treatingcollected wastewater (and septage). The following describes the technology and benefitsof the aforesaid treatment system.

The ALPS is an integrated, multi-stage biological reactor system trepting wastewater. Thesystem utilizes compacted earthen construction to reduce costs. Tb system optimizesnatural biological processes to reduce power requirements and neea for chemicaladditives. The concept is to minimize bio-solids production rather than to maximizeaeration 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 ormore of the basic treatment processes. First is the primary biological reactor or afacultative pond with an aerobic surface and extremely anoxic intemal pit forsedimentation and fermentation. The pond reactor has three discrete and isolatedbiological zones integrated into a single unit: a deep anaerobic pit at the bottom, a sludgeblanket suspended within the deep pit, and an overlying aerobic comprised of aerobicbacteria and algae oxygenated by photosynthesis, supplemented by horizontal mechanicalaerators when needed. Anaerobic microbes in the pit are protected by surrounding wailsor berms from the intrusion of cold surface water containing dissolved oxygen. Rawsewage is introduced directly into the pits where sedimentation and methane feTmentationoccur. Overflow velocity in the pits is maintained so low that suspended solids removalapproaches 100% and biochemical oxygen demand (BOD) removal approaches 70%. Theoverflow velocities of one to two meters per day are less than the settling velocities ofhelmninth ova and parasite cysts so most of these remain in the pit and consequently arepermanently 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 reducingenvironment, settled solids ferment there to a point where only ash remains. Thusminimizing 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 inCalifornia, 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 oxygenfrom water by photosynthesis. Algae produced are highly settieable and after

Oswald, W. J, Advanced Integrated Wastewater Pond Systems. 1990 ASCE Proceedings, Am. Soc. ofCivil 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/LRecirculation of algae bearing water from the High Rate Pond to the Facultative pondprovides an oxygen-rich cap on the facultative pond. This oxygen quickly oxidizesreduced gases emerging from the fermentation pit thus mitigating odors.

The third pond provides for sedimentation of algae. Algae which settle tend to hibernateand thus do not immediately decompose and produce nuisance.

The waters emerging from the settling ponds are sufficiently low in BOD and suspendedsolids. They can be percolated readily into the ground or used for irrigation. They stillhowever high E-coli count of more than 1000 MPN per 100 ml. and therefore may requirestorage prior to disposal or reuse. Then comes the fourth pond which has a dual purposeof added disinfection and storage for irrigation or other uses.

Performance: Following algal removal, the degree of pollutant removal in the ALPS isequivalent to that of mechanical secondary plants but as is to be emphasized at a muchlower capital and operation & maintenance costs. The treatment action of the AIPS isvery similar to and realizes the advantages of an upflow anaerobic sludge blanket (UASB)reactor. The AIPS however does not inherit the rigorous operation and maintenanceproblems 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, inCalifornia, USA. The St. Helena system has been recognized as the Plant of the Year bythe California Water Pollution Control Association for 5 MGD plants in 1994 and waslikewise accorded by the California Energy Commission the "Energy Efficiency ShowcaseAward" 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 BODof 290 mg/l and TSS of 263 mg/I were treated to 24 mg/l BOD (92% removal) and 34mg/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 of194 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 facultativeponds) can be made large to permit complete digestion and thus reduces sludge generationto the extent that sludge handling is eliminated for many years. The St. Helena plant in 27years of continuous operation, accumulated less than 1 meter of residue or just 3centimeters per year! Thus daily or frequent sludge removal is eliminated thus attainingcost and energy savings. The Hollister plant also showed the same very low rate ofaccumulation in 12 years of operation.

Because the sludge undergoes full fermentation, the sludge or residue resulting from theprocess is relatively inert and stable, and the volume is small. Disposal then should not bea major operation problem.

In terms of costs, Oswald compares the cost of a conventional treatment of $350 to $700per 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 betterto secondary and tertiary treatment.

* Energy efficient -- the design provides for reduces oxygen requirements on thefront 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 theponds. In Hollister (CA, USA), the treatment plant is practically within "sniffingdistance" of a golf course and residences in the area.

* No daily sludge handling. St. Helena's Treatment Plant has not removed sludge in30 years of continuous operation.

* Pond buffer capacity enables the system to handle effectively variable organic andhydraulic 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 ASCEConvention 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 Treatmentinto the 21st Century, (Hand-out)

* Further relevant information and reference materials on the AEPS are attached forreference.

lppLendXr 6 The Advancedlnteg'ratedlPondS.'Yxtem (A P.N) oJ Ifasrex,ater Treatment v

ADVANCED INTEGRATED POND SYSTEM(ALPS)

Natural, Biological Wastewater Treatmentfor

Municipalities, Agriculture and Industry

- 3 ', ;,

- .'-Innolva ive and Alternative,EEiivikronfe4ta fly Sound and low Cost

~"' rSolutions

For Wastewater TreatmentInto the 21st Centulry

.~~~~~~~~~~~~~A . _

1340 Amold Drive, Suiie 11)0Martinez, CA 94553510-228-5NO1 Faxc 51G-228-5804

I

SOA, Inc. Martine-t

AIPS llighlights

> 1Efficient pollution controlEl recive organic reduction and nutrient removal for secondary and tertiary treatment.

Energy Efficiency with AIPSThe integrated, multi-stage anaerobic and aerobic reactor design reduces oxygen r equirements(and energy requirements) on thefrontendofthe system. St. Helena f lv,ssteiu'ater treatmentplanit was awarded the California Energy Commission Efficiency Showv Case.4 ward in 1994and 1994 Plant of the YearAward by Calffornia Water Pollutior Control Association.

Construction Cost SavingsOxidation Ditch 3.5 tfimes more expensive than AIPSTrickling Filters 4 times more expensive than AIPSActivated Sludge 4.5 times expensive than AlPSS(abilatio,i Iond 1.4 limes more expensive than AIPS

Operating Cost SavingsOxidlation D)it'ch 3 times more expensive than AIPS7)-ickling Filters 3 times more expensive than AIPSi1ctivated Sludge 3.5 times more expensive than AIPS

Stabilization PIond 1.3 times more expensive than AIPS

Virtually No odorsOdors are controlled naturally. Winery Treatment Plant is wilhin 300feet of a convalescent/hosuital in the City of St. Helena, Calfornia.

No daily bio-solids handlingSt. llelena's If W7 has not removedsludge in 30years of continuos operation; for industrialplantis shludge removal every 7-10years, depending on waste characteristics.

lPond buffer capacity to accommodate variable organic and hydraulic sh(ck loadslf inerv organic variability rangesfrom 100 to 20,000 mg/ of BOD int one week.

Advanced Water Treatment Achievable with AIPSNuitrient removal...Denitrification in anaerobic zone and algal uptake in aerohic zone.PihovlhownLv oxidizes in the aerobic zone, assimilated with algae, naturally co-precipitated. tndthen .settled biy gravity.

* litential for Enhanced Habitat for Wildlife & Recreational BenefitsNotwral integration with constructed wetlands and habitat restoration. Landiscape pond-,contublwe bu aesthetic value and can provide recreational use.

Redluicedl Fiscal Impact on RatepayersLess 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 systemoptinizes 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 andas a result minimize power requirements and solids management.

i:; jcp 7 fAlPS is an integraedt, multi-stage biological reactoisystem treating municipal, agricultural andindustrial wastewa -r. The reactors are relatively deep and constructed as an open surface pjind ofcompacted earth. Tl..; biological reactor has three discrete and isolated biological zones integrated intoa single unit: deep anaerobic pit(s) at the bottom of the reactor, a sludge blanket suspen(led within thedeep pit, and ati overlying aerobic zone comprised of aerobic bacteria ad algae and oxygenaled byphotosyntiesis, 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: capabilityto t circulate, (lepend(jing on site specific conditions; Recirculation provides flexibility and slhockabsorption abilities for variable hydraulic or organic loadings, or where there is th1e potenial fior toxicspikes.

'lhe intiilieit wastewaler enters the deep anaerobic pit at the bottom of the reactor where setlable solidsare deposited arowid the inlet and where acid fer,mentation and methane generation occurs. The risinggases anid up-welling of wastewater flow through the thick anaerobic sludge blmnket that is fonnedwithin ilte deep pit. The overlying aerobic zone is comprised of aerobic bacteria and algae arid keptoxygenialedi by h(irizontal surface aeratoum and photosynthesis.- The aerobic zone reliably controls o(lorsand soluble wastewater components ndergo aerobic oxidation and firther degradation. 1'lie horizonlalacralors also create a circular motion over the whole surface area; the bacteria and algae circullate overthe far end of the reactor where a second deep anaerobic pit is located. The horizontal velocity of thereactor is rediicetd while circulating over the second pit and the aeration solids are settled by gravity intothis pit wvhere the solids are decomposed and stabilied ,

Solids at the botlomi of the deep anaerobic pits remans for very long periods of time. continuouslydeconmposingl. 'itus. biosolids minimization is accomplished. The oldest plant in operatiotn, treatingdomiestic waslewater, has not had to remove biosolids for nearly 30 years. Seasonal turnover of' thieponds is prevented by isolation of the deep anaerobic pits. AlPS's design features and cell gometrymaiiLiin tle initegrity of the system thereby suppressing turnovers.

AIPS is appiolinat fiJr wastewater applications for nornal flow situations as well as where there arevariable 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 providlefloNw .(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 systemoptimizes 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 andas a result minimize power requirements and solids management

AlPS is an integraled, multi-stage biological reactor system treating municipal, agricultural andindustrial wastewater. The reactors are relatively deep and constructed as an open surface pond ofcompacted earth. The biological reactor has three discrete and isolated biological zones integrated intoa'single unit: deep anaerobic pits) at the bottom of the reactor, a sludge blanket suspendled within thedeep pit, and an overlying aerobic zone comprised of aerobic bacteria and algae and oxygenated byphotosynthesis, supplemented by horizontal mechnical aerators when needed.

In most cases, the primary reactor is followed by a second reactor operating in series, with the capabilityto iwcirculate, depend(ing on site specific conditions. Recirculation provides flexibility and shockabsorption abilities for variable hydraulic or organic loadings, or where there is the potential for toxicspikes.

Thie influent wastewater enters the deep anaerobic pit at the bottom of the reactor where settlable solidsare deposited around the inlet and where acid fermentation and methane generation occurs. The risinggases and up-welling of wastewater flow through the thick anaerobic sludge blanket that is formnedwithin the deep pit. The overlying aerobic zone is comprised of aerobic bacteria and algae and keptoxygenated by horizontal surface aerators and photosynthcsis. The aerobic zone reliably controls odiorsand soluble wastcwater components undergo aerobic oxidation and futher degradation. T'he horizontalaerators also create a circular motion over the whole surface area; the bacteria and algae circulate (iverthe far end of the reactor where a second deep anaerobic pit is located. The horizontal velocity of thereactor is reduced while circulating over the second pit and the aeration solids are settled by gravity intothis pit where the solids are decomposed and stabilized.

Solids at the botnom of the deep anaerobic pits remains for very long periods of time, continuouslydecomposing. 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 lponds 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 arevariable 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 provideflow ecualiaation, buffer capacity and recirculation capabilities to achieve secondary and advanict dtreatmenit 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 orconventional Stabilization Ponds.

SOA, Inc. is a design engineering firm, 25 years old and specializes in the conceptual to dctailed designof innovative and allemative, low cost, simple to operate wastewater treatnent systems. SOA alsoprovidts start-up and training services, and on-going consulting services.

SOA has experience in designing innovative and low cost municipal wastewaler treatment systemsfunded 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 Plant1994 Plant of the Year Award - Redwood Empire Region -- by Califiwmia WaterPlollution 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 reactorsrc.-aiingWinds - r consist of lthee discrete aildisolated bioiogical zones: deeo

,jit k L anaerobic pits at the bottom of the reactor. a sludge bt3n:-\tsuspence over the deep pit and an over!,.inc 2-rcbc zonecoa..rsed of aerctc ' actaria 3nd algae ah;ct issusrsauratadwith 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,nz ^ 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 1pa02lRmo vrasrvater Ina \ ~~~~blanket /

\A aemobic/ zone 4 l. Aerobic 0xidon

J - t~~~~~2 Phoh*yne ic Oxygenabon3. Orga ii Acid Formabon4. 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 andSavillig 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 andphotosynthetic oxvgenation, advanced integrated ponding svytems attain highdegrees 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 properlyFtocccLiflqs 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 moreSponsoreas 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 theol the American ofcur Or Ciil tn-inecrs -; ., ~ 2_f . . t ** secondary degree involves removal and digestion of settleable and floatable organic

;o~t y 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 mechanicalmeans. 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 theirEd2MitebyUaFSigan OttoM J.i StelwegUIesl simplicity, economy, and reliability. their greatest drawbacks are their high landCHt2212 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 theadvantages of ponds while mitigating their draawbacks, has led to the developmentof Advanced Integrated Wastewater Pond Systems (AIWPS). These require muchless capit3al energy. operation and maintenance than mechanical systems andrequire less land. produce less odor. and fill in or age much more slowly thanordinary ponds. In this paper I wish to introduce AIWPS as a system worthy ofconsidetation for many waste treatment applications. Due to space limitations.howe%er. only a brief description of AIWPS design and performance can be madeherein. 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 aseries 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 CnqinctiSS4*s ftast 4 -.In StSeetMtew 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 Jndfermentation. 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 perda- 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~~~~~~~~ _<t_9L Pam* VW V c\

4 _|0AI pe- la -so" ewm IL OO UIS Wk-_._ L_ *"__ * ___ _ _o___ ___it_ _W._ e _

ww IL St an w m ITO I _VA"UN vi - _

- CWMYCAL -ftOM -

902 30 so 6 70 Bo to 0o

. ' .* ws. r., .. . P151,20 2............ ABC? Ou-del. .. ?trfozt. SGtoetd Par Sedira*tation-. fI5r~ Tai xrf0MAV* Showing AIM~ OverflowRae

tgs 1. An Adsced h 4 mt s to w .:t.r ' -' -*9'. ". -

Pending Syst. (3_tlC -e)

TAOU I

Another potential benefit of anoxic pits is conversion of chlorinated SEDIMENTATION OF AL&L.8ACTEItAL SOUDOShydrocarbons to forms that may be biodegradable in an aerobic environment FROM A PAOOLE WHEEL MIXEO HM31m RATE PONO.(Bauer and McCany. 1933).4 k. at pit ,OIu uits reducing _ .ievrontnm#. l en s tor M sw u m whetre only ash reami, hence . Mit?In. e a Pw Atsh-Pet Ort Wam_

irst Dalplui eovlbttgbe required for over 25 years. A P N EFI,UENT 5UPFtNATA#T SEtEO

second AIWPS at Hollister. Californis. evidences little sludge build up after twelve JAN tts 0 I

years. FES 220 I 5 93mAR ISO I 0 I

The second pond of an ATWPS series is a paddle wheel mixed shallow APO a40 20 1

raceway called a High Rate Pond. In such a pond microalgae grow profusely MAr 203 2.

releasing oxygen from water by photosynthesis. This oxygen is immediately ' s a o 3S of

available to bacteria to oxidize most of the soluble and biodegradable DOD J.oL 2^ tO 3

remaining in the effluent from the facultative pond. Algae produced during 220eat at 1i220 j I 93

paddle wheel mixing are highly settleable (see Table I) (Eisenberg, 19S1) and. 2 . Is^ 1 Isar.ftr itgal removal by sedimentation. or dissolved air nlotation (Krofta and Wang. 125 I aS

1984), the remaining water has a BOD that is lenerally less than 20 mg/liter. ts 0 5 to

Recirculation of algae-bearing water from the High Rate Pond to the Facultative w 60.6

Pond provides an oxygen rich cap on the ftcultarive pond. This oxygen quickly Slo 0* 2

oxidizes reduced gaes emerging from the fermentation pit thus mitigating odors. 24 "M S _.a wwAft.. £lsme..eg ltI3ll

76 SUPPLYING WATER AND SAVING ENViRONMENT ; :'TCGRATED POND SYSTEMNS 77

_ 1600 1 1 l % \Vaters emerrgnir' tram the belfiing ponds are sufficiently low in BOD 3ndsuspended solids rto rercm:tte reaciiiN inio [he ground or to be used for irrigation-They will. however. iite;i ,uiaai,i ur, N;M'N greater than l000 per 100 ml andhence m3s recuirc - .iz! ::rc^,- prior to use. The rourth pond of an AIU PS14 Z often called a Nlatur3mion rond has the dual purpose of added disinfection 3nd

t_ i cnwtorage Ifor irria3tint. The use of ponj effiuents l'or irrigation is more fullyn) idiscussed elsewhere (OsA3ld. 1989; P3hren, 1985: Sheikh and Cooper, 1984i. A

c- | recent publication b% the World Het!th Organization outlines major concerns anII° 1200_ satety f3ctors related to the use of wastewater for irrig3tion (Shuval, 1989).r I Ac.crding to Shun' an t others the major danger in developing countries is0 Ni2 CO; frn; rransmission o.' neirnrh o%a. This is % irtually precluded bs the use of four ponds.U W _ , _ 1, in ,eres Added IO the need rfr four ponds in series should be an admonition5 ooo0 Facultative Ponds in against short circuiting which can only be avoided by alternating surface and

Series 50 Percentiles submerged intakes in pipes transferring water from one pond to another.

After Ramoni et.al.1975.2 00TABLE 2

PERAORMANCE OF ADVANCED INTEGRATEDC 600 - WASTEWATER PONDSO ST. HELENA (Annual Means) (I)

E 400 P-RA . pUNiTS STATION Percent

, -_ , ,i 2 t3'T et IS Removed.- ,; 'T. O ; _ z , giB0 DAYS 0 1 20 10 5 tN EF

.._.;.. .:COO M 438 124 7 O 32 3_- TOTAL C Mlhl 2tS .4. a dO 50 7t

i TOTAL N Mg/I 223 a G g a 4 eO

~~~~20O~. MUR NT I I@Cn0 ~~~~~~~~~~~~~~~~~TOTALN mail 40 -16 132 6 5 94INF POND I POND 2 POND 3 POND4 TOTALD aI +' 13 12

Figure 3. !:otal Chromtiumt Rtemoval Due ?o0 Alg&1 .(1) After M@t@i' 1570 HOLLISTER (Anntyol Means) (2)Grow-t. Mnd Sedizen't~ii0n In wastewa~ter Pondsa

PA___A ___ OArs I__STATION PercentAsscT- I * ikYS 0 32 lo 7

Algae in the rec\ led waters tend to adsort anv he3vv metals that may be present Soo I 'ii 0 I 7 _ I6in the incoming ~a'tte tnd to settie in :hc taculttative rnd. thus renoving most of T S0' J..the .insorbrm inet.L fr)em n.e faz settlet in n. efluent e Fieure t1 (Ramani nnd e0. S 'C^ rr 33 34 42Oswald. 19751.

The third pond of the AIWPS series provides for sedimentation of algae in (2) Atter 1012K,ar s96sthe effluent of the high rate pond. As noted atove a paddle wheei mixed nighn ratepownd tends *., seh:: for algae t2ha! are set!!eahte when not in a mixing rield (3) E. Col(Nurdogan. !9SI; a11ll. 101t. Algae which 5ettle tend to hibernate and thus do ' Approxinsits (Re3oen:e Tirme VaOes With Secson)not immediatelv decompose or produce nuisance. In fact if two settling ponds inparallel are used. Cae or the ot-her can bte drained and dried ever thr Stat,om Key 1. Intwcnt Sew .c *--..lollistors Scnlng Pond Ethree orusyears to remnove ==n mlraed algal Tludge-% Dried ailtaI sludge is rich in nitrogen. SttinKes IntuearitSee NobtesSeln Pn Elu.tIphosphorus, and potash and hence is an excellent fertiliier for fast growing plants 2. Fsuttive t e To Natural Ot avet PerolationtNle tting ;,nd Pine, 1c93S67). there is liStle echancC thatt dvired algae would contain 3. High Rats Ponoinfectious orga2nism'l but to he saf'e it shnuld only b used on ornarsicntals and 4 Statng Pono S ta There Is No Surtan E0luentcropsv n!e evten raw rCalifornia state, 19'8; Gunnersot et 2l_ 1984). 5- Metlration Pond

-R SUPI'LYING WATER AND SAVING E.NVIR0NMINI' .xv.s.'.E !Nf r`-_PA!' 'OND SYSTLN.M-

PERFOR\tI ̀ C, . the aerubic surface waters. rhe huh-hle then emerte and the Tartic!es .V!th the:ri.,hering anntst ha::er:a ire tree -,i gain wettu doawn through the . I--1 ris5ms

Table ' prescnts performance data trom the A,iA tc. a; St. Niita M-crtn. eo ot' nluent sewaze. In :nis was the entire raw 3ewaee ilow is pa,ed :hroueh a!9 ^' a-. 'lc'isser ht r t . it is clear from these data t,1at she ma:or %oluine of inten,e anoxic acti'ii% ,here cozh insoluble and soluble o maan: mntt:crfraction ol' i3OD remOVal o1ccurs in the facultatite punds atid. fro.n the Si. Iklena is adsorbed and ;on .erted io carb,n dioxide. water. methane anti nreenas.data. thit 1 mna or friction of the total nitrogen is removed in he f3cuitathe Pond. T'. -osit;ie action in derut XFP vits is verv similar ro that of the Acli knownil.,1li<"er'; hah inlatile disnived goli,is nriginamt fronm a paner eciarratio., vlant : itr!eniltx urtlow a.tot *c ittoe h'ankrt '!:?AS2' rracrer s --- v: - 5i-- .^-^ -'.lid& renriting heyond the f'tottltattve anri 4i&li -ite 7-ni i- ..- t-riv ' 1-n.o .,r It .NcQP, r -k -i-_;r I - ,-, ± -7 ±

t; )cthts annernbic and aerobic degradntion. Tht high rate ponds deo nott mrnin!tannce even for a *hort time. ire ne7i?!:red. ' -Sr, arW e 3c- roZ!-Sngrenmo%e a great deal of BOD but contribute oxygenation to the facultati,e ponds with rags. plastic bags and with compacted sludge or grit. anm hence requireana aid tn removal ot nitrogen. pnosphorus ana carcon. Following algal removal rigorous management inciuding f'aii sale pretreatment. freauent sluace removalthe degree of pollutant removal in AIMPS is equivalent to :hat if mechanical and orter rnarteicnane. In ;he casc Al'PS. sludge removal is not oi;cn required,ie-ranJry t.rltIas with the 3dded benefit of signtficant ntsroien and carbon cicg&zng :s impossiole and maintenance is ninimal. Thus the main principies andremoval (Table 2. St. Helena). removal of heavy inetals l-igure 3) .ant a dearee ot advantages _t U.%SB reactors are realized in mtd,anced facultati,e pi,,|ils with fewfail sat'e disinfection (Table 2. Hollister) (also sce Saritaya and Sartei. 19S7). of the disadvantages and with lower costs.

DISCUSSTON ~~~~~~~~~~~~~~~~~~~~~~~The helminth ova remoVial projected for fermentation pits is of particularinterest in developing countries where millions of children are weakened byNeither Hollister nor St. Helena are complete AIWPS because they lack parasites and consequently fall prey to childhood diseases.

paddle wheel mixing in the high rate pond. Also residence times in the high rateponds are excessive, exceeding the time required to aczumulate sufficient solar The economy of AIWPS results from a number of factors beyond operationenergv to release sufficient photosynthesic oxygen to meet the DOD. The high rate and maintenance. For example. consider the cost of reactor volume: reinforcedpond in Hollister is mixed with screw pumps and in St. Helena with propellar concrete reactors such as settling tanks and digesters are likely to cost S350 US.Spumps. Both are a waste of energy compared with paddle wheels. The data in . . l9901 to S700 US,LI990) per m _ On the {ther hand formed earth reactors areTable I is from paddle wheel mixed experimental 1;4 acre 10.1 hectare) ponds at : WsTr-fo cost less thai5tS W; IQrermn --att hundred-fold less. By usingRichmond. and indic3tes the excellent natural algal removal that results from earthwork ponds. large reictor volumes can be created very economicaily. Thegentle mixing. The interrelationship between paddle wheel mixing and algae . microbes involved in treatment are, of course. unaware of the cost of their reactorsedimentation was first noted in high ate pond studies in the Philippines (Otvald - and, provided the environment is suitable and constant, perform as welt it 4et a1. )978) and was confirmed in extensive subsequent studies at Richmond * . .earthwork ponds as they would in the most elaborate digesters. Alhossince they J(Eisenberg. 1981). Both Nurdogan (198) and Hall (1989) have studied the reasons - -- so little, eat"hwork digesters (fermentation pits) can be made iarge enough toror improvement in algal sedimentation following paddle wheel mixing. Nurdogan - nrmit complete digestion and thus the elimination of day by day sludgejhandinpI;has found a natural selection for larger algae which settle in a quiescent field and * - for many years.Hall has emphasized the natural filaments produced by algae and their tendency to ::cause agglomeration of cells with consequent improved sedimentation. Both CONCLUSIOphenomena appear to be important in natural separation. Neither is related to thephenomenon of auto flocculation that occurs due to high pH in poorly mixed Development of economical and reliable AIWPS is timely because of theponds resulting in precipitation of calcium carbonate. magnesium hydroxide, and problems small Communities now have with financing their treatment systems.calcium phosphate. This type of precipitation, as well as thermal stratification, is The past trend, under government and state subsidies. has been toward complexprevented by continuous mixing at a linear velocity of about 1/2 foot per second and expensive mechanical treatment plants. many of which work poorly and ari(IS cm per sec) (Oswald, 197 8). difficult to operate reliably in small communities and developing countrip- Now.

most government and state subsidies for sewage treatment are being 1J .reased orThe energy required to paddle wheel mix 3 shallow pond at a velocity of terminated and economy is becoming a major criterion in the selection or

i,2 ro.t per .econd is onlx about 5 kwhrs per lsecaur p.r Jay and e: ., in ihe upgrading Of 3 community's wastewater treatment system iiBsed on ourrele-se '.--rnm water of more thin fOl. kg of dissolved us g-n1-_- per het..:ttre per !2v-- experience 3a St. Helena 'nJ Hoilister. AIWv when m roperly designeo. are notthat ;s 29 kg !f oxygen per kilowatt hnur (kwhr!. This should be comp3red w:sh oniy economical and effecti;e. but alse attractive and tuisance free. Formechanical aeration which normally transfers one kilogram of oxygen per kwhr communities in the sunny part of the world. AIWPS can provide a new ooportunitvi.;ini:h, 1973), The energy savings is thus more than 10 fold. to ha'e adequate. sintple, reti3ale and nuisance tree waste water treatment wiht

signit'icant opprjrtu5ilties 1,or reo:,_iliation 3an environmental enhanc:ornent nan at aThe phenomena that occur in the fermentation pits of facuitative ponds are price most communities qhoXid be able to atfford.

3omewhat unique and deserve consideration. Quiescent sedimentation is oni: thetirsi reaction. Apparently then, in the intensely anoxi; *olume in a pit, surfa.es ACKNOWWLEDCi%FNTof all sorts of solid particlae that settle from raw sewage become populated by acidforming and methane producing bacteria. As gas is released otn their surfaces, the I am indebted to Rose Ann Nitzan for typing this manuscript and tosolid particles become buoyant and tend to rise due to the attached gas bubbles. If Patrick Oswald for preparing the tables.the pits are sufficiently deep (5-6 meters). the gas bubbles expand as they rise andusually will break away from their attachment to the particles before thev reach

(PP.'7;': . '-V TER N D S VId '1 !. I O.N 1: I) tWN \F I RATt.D i) N l S YSElt Is

P . R. C. C o! ferl ,in R S J-artteq 1 1S4 4'Wastcw,rter eff'!uen reuse ur

B,er. C. J.. and P. L. \ICirtv f !408i) Trmntform3tion of I - and S- carbon Rcu e..W..e..Re..e..m..sium...l Prc%-Ine2 5!-ulv. in 4 R i i- p S ii't;nr;-, Nre

halogen7.:ed atlrph:rti. 'rgan!c .omrounds un¢!er rneth3r. geni; olndiQ "s. \ atzrworks Assuciattun Research Foun.didJon. 6666 Q6uin. n:. '' em er,Fn, e! rr.onmentril Nfihobiouoiv. 45,,P. r.I86 Col;r3do. USA 30235.

1;^'!tntl *.r Iz4S i '.ash'water rCd3amtI:cn cri-ari. n A \C !'rnrnm :ne Shu.-i. Ili; !S R ::r-:l for. Fn bet7 er crnlilde!ines in Humnn Wi;Vteq HeltrhC ;I' r,.i m.,t,2i'.ir:fnve Code. T!tle O% L ;ion ,. DDi357 to ioj9. State Tt;` C t7 l: SC - :md a uidurA :8-1 ;OI"t '.i i) u'a.-

Ca i.r:; .. :. Cepr-rn_r., sf Herth Ser% ie'. S.nnivarv Fr- inŽern senn ! ... t 5. NIan P?SS. - p. i t. Ur! m. S!rsfe i m r .. .n ....laerkele\ WaVy. Berkeley. CA 94704. USA. Si;:. rland.

E' nhrem Din M1. (1981) Proauctivity HarveYtabiuit Sm Fermcn,_ , * Smith. Rohert I1973) E!e-tric31 Power Consumption for Wlstewater Treatment.Nlicro1:!e in Paddle V.heel Mixed High Rate Ponds. P.L.D. Dissertation, EP!i-R'- 3-`', pfge 79, N3tionali En% Res. Center. Oinc:nnrt,. F,ntiu !aS.Unt%erstix of CaliCornia. Berkeley, CA. S-i:.enb.rum. .like. ed. f1985) Anaerobic Treatment of SewAgt.' Nv. E.E,

Gunrertvn. C G H. 1. Shuval, and S. Arloscrof (!^.i. He:0!;h -tTe;; . r S.SS-5. Proceedings ot a Seminar Workshop neld June _ -: - atwaStew3ter irrigation ind their control in deve!!,pirvg :ountries. pp. :576- :cQ-. lj niersitv of Massachussetts at Amntterst. Amherst. NljssachuuKetn ui:03,in Future of W' ater Reuse in Water Reuse Symrcsi.rm Ill. proceedinpc. Vol. 3.American Waterworks Association. Research Founration. 6606 QuincvAvenue, Denver, Colorado. USA 80235.

Hall, T. W'. ( 19S5) Bioflocculation in high rate algal ponds--implemenintion of aninnovative wastewater treatment technology. Ph.D. dissertation. Universitv ofCalifornia. Berkeley.

KrOft3. M.. and L. K. Wang (1984) Development of innovative flotative filtrationsvstems for water treatment first-full sandfloat process in U.S. parts A.B.C. p.1;26-1:64 in Future of water Reuse, Water Reuse Svmposium fil. vol.. 3.American Waterworks Association Research Foundation. 6666 W. Quincv Ave.. ErrataDenver. Colorado. USA 80235. 2

NMeron. X. (1970) Stabilization Pond Systems for Water Quality Control. Ph.D. pg. 75 fig 2_1ower scale gal/ft /dayDissertation, University of California at Berkeley, pp. 318.

Metting, B., and J. W. Pyne (1986) Biologically Active Comrounds from .pg. 76, 3rd. ,to last lineC(Metting and Pyne 1986)Microalgae. Enzyme Microbiol. Technology 8, 386-94.

Mosquera.J. F. (1988) Performance of Advanced Integrated Ponding Systems. pg. 78 Discussion 4th line photosynthetic oxygenMaster of Engineering Thesis. Sanitary and Environmental Engineerine.Uni'ersitv of California. Berkeley, California. pp. 1-84.

Nurdogan. Y. 1988) NMicroalgal Separmtion from High Rate Ponds. Ph.D.Dissertation. University of California. Berkeley.

Oswald. V'. J. (1978) The engineering aspects of microalgae. In CRC Handbook ofmicrobiology. ed. A. 1. Laskins. pp. 519-52. Baca Raton: CRC Press.

Oswald. W.. J.. E. W. Lee. B. Adan and K. H. Yao (1978) New WastewaterTreatment Method Yields a Harvest of Saleable Algae. WHO CNronicle. 32.348-350.

Oswald. W.. J. (1988) Microalg3e and Wastewater Treatment. Chapter 12. pp. 305-3'. in \hicroralel Biotechnology. Borovitzk3 and Borowitzka Ed. CambrdigeUnimefs.r. Press, U.K.

Uswald. V. .1, 989) Use of Wastewater Effluent ;n Ari,u;i tu,c. Des2! nization'7. 7-S0. Elsevier Sctence Publishers. B. V Amsterdam. Netherlands.

Oswald. W. J. 11990) A SOllabtts of Waste Pnd Ftindamentals. EnvironmentalEngineering and Public Heaith, University of California, i erkelev.

Pahren. H. R. t 19S5) EPA's Research Program on Health Effects of W:!s!ew3rerR!-u,e fe.r Potable Purposes. Chapter 10 in Artificial Rechtarge ofGroundwater. TaKashi Asano Ed. pp. 319-3.28, Butrerworth.

Ranmant. R.. and VW. J. Oswald 11975) Studies of pond perf,:rmance and pilot i!3gaseparation at Napa sanitation district, report by CSO lnternationai to Napasanitation district, 950 Imola Ave. West, Napa. CA 94558.

Sarikava. H. Z.. and A. M. Saatci (1987) Bacterial die. otl' in waste stabiiizationponds. Journal of En'.ironment Engineering, Vol. 113, No. 2. p. 366-132, Env.Eng. Div. American Society of Civil Engineers.

Page 4 Smarl Flo e

1GECHNOLOGY.-.Ponding systems treat wastewater inexpensively

by Edwin IV. Let,. P.E.

Er,rii 'rtn : th:ie arrrh,r'rof dsrJilowsaricle aria sr fs.lmptpf dcondlconsulAphet |-en 'e'

and alsDr isflfiiiar'id ath 5wanson. Viswrrld) and AseJinatis in Marirntr. California. lc |e

previmly woired as an environmenstl eagineer with the US. Bureau o(Reclmaeieon inSacramento (Cobj.rnia. and as a sanitary engincer with the lorld ffealnh Organizati.nin the Philippnes. lie ret eived his bachelor's andnasr's degree in clriltsaniraryengtnntring from th Units ersity f Californioa t Berkle,. _ ,.

Tue integrated pondiing system is a low-cost advanced waste treatment process fot ;V. -`municipal sewage. oqgaic iindustrial waste. and organic atiturlat wate. red sinp-i_.ily. economy, and tla irros potential of the Advanced integrated Pondittg Syst,m(AIPS) nuke it atir2clive to those contmunihies wishing Iso tnsforn polluting wastes Into Adasseitsat nitrinslcost. low capitalcost. tigttrelibaltty. and lowspertion aind tuiote-nance cost favor the use of AIPS over conventional secndry nd advanced wattreattent wherevcr climate aid Isiid availability pernitr

As shown in Figute I. an AIPS Involves a selectd sequence of ponds ah pond issietifically designed to accomplish, by ntnural mesn. one or mre stall openitloas In -stgtedprocesseskadingupto advtncedevels@f te thab The n wgotgid antegration is selected tott ie the objectives of he site spedfic prt$ecl SeConday AtN sedet kedx AIPS Is 1ielssalr. CirntIei that svfens ealowns of 1e,0t0 aprot.ruttnent can be achitved with a deep faculitaive pond followed by secondary pOds h Ln Ay * as t r tige.ilsuient nmoval and bionitsss recl nation cmn be achieved withted lusrtlos Ofpeciracally designed ponds. etotstruction costs result aitnly (tone itic tsinitnizatiin of use of reinforced concfetc

loidge and grease tiovala1 are ccomnplished In deep fwslskatlve ponds wkh specdal bull- sasuawues by usIng tomned eafi.ideep pit di;ge,s T,ic,cnr,ot crlt,r and attain partianaleidton in thes pondssupple* Lower operation n maintenance clots resull tti,:emnry oxygen can tE iuitroduced by recircultilng highly-oxygenated efsTeir gmm * Elimitnai of day.by.ly sludge handling: Integrated powis are dsigned soallow, s(lowly ICciPcutitd algal ruv Ith units teured ttighb-t e ponds," the satndary reain sluge In dot deep In- ttnd dicssters est many yeass. Sludge volune Isits of the system. blirroscoiic algae in the hight-ae poWnd aseslarw enesgy to asntai- theeby educed to a minimunit in prolonigel digestiott. the residusl sludge isously accomplish ,rhosilrinfoelic oxtgel, production. high pil disinfection, atnd nnriet relaielyi enditsvolurme il Disitoeslisnotistajuoperaionalnotsovl Bacteria in the high-rate pttd use oxygen psoduced by algIaeooxIdtze alliota problem.

maon reicttcuy organic substances. Following itidatoi iin the high.teu poi bot * Decreased energy requiementcs Energy necds tot aeration, sludge sandling. an.e and bacteris biomass should be separted (to the keffluent digestion tamdecreued. Each pound of mticrorlgae selesses 1.6 prnwls rfoxygen.

which is dissolved In water and thus aviatly ssuable for bactetial uxidautitgal-bacterial sepanstions are accomplished in seftiasy ponds specially designtd to peimh of waste rgaic matter. An acre of algai culture will prodice 211 lbs. of useaAc,-ural sedimenualiwo of algae produced in the high-ate pond. Natural esedetraio Is dissolved oxyten each day. eqtuivalnt o ItErO horsepower hun of dcitanicalcletrted by a slf-indutcd bio(llcculationprocess. Remoalv aindretsuoapontiosf weratim T nakrstta encty requirement is 1/10 kilowats4our pet kiilgua tseifallac biomass msy be needed for seeding inte the primaury pond or higShbte pond BOB.rage of treated wster for controlled reuse is provIded in quatemnary ponds called * cras ettagy cost ht sludge handling: Since sludge is retained In spectiallyisuration" or siorage ponds." Storage ponds aay be used top te fish t designed pit digesters and renains thec indefinitely; daily transfer of sludgte Is snsi of aquatic life ildestred tlie wiitricoing liriif atsc i sahsffitclte necessaryondencrgy needs fr. stridgc trans(ie are eliminated. Also. becausi odfor uscrae hwpu gniolf- eirechaFe, ia gft or tdigstion pmrceeds over years of tine. helatig and miting of sludge Suc nwj

- ~~~-- .ii~~~~~~~ r~equired. fushe reducing energy requteiernrs.D tecrasd etmaoe requirenrents: hiirerniiationr of elecirmncchtaical

xonds of the integrsetd seqrares air designed to utilite aturl deconpstihlon equipment is an intertat part trf ite sysicin rlesign. Thir also minitriies tgclcrriealeases. W ). OsuaId. 11.!).. Uiivsity of Califomri s Sekeey. ha studied dtese persotnel required to operute and maintain equrpttns.esses and develrsped the tystern during more ihan 40 yean tof resech. Thle elinet lhealh -rltated tisk reduction advantages or Iniegratte ponds incttludsy attained In such pttx ling sysretass is comparable to the efLuent derived from * Minirio. f opportunities tir canyos cr ol Intestinal pats. ptlors.:nen planu incorporating compitc advanced treatment stagts costing severad tit ss hacerica ad vitat in effluent streams, liis is accomplislicd by providing hiig1. detention peiods for skidge In the pit digesetrs. shortcitcuri ssaeggutlds.tigh pt

mursuce of Alt'S can bc expected tD reduce poliutnrts in ihe following rangrtr levels ie secondwy ponds, snd efricient deprtion prceses.-Minimiztion or eliminatiotn of the neeilfrrr chersticrl dishinection of elfurrnts

BOD 95-97% whh & resultafn increase in reliability and a dkecase hi cost. Tic p.stmntist IISTaIarsCOD 90-95* of mutagen. eratogen. and carcinogtn pruduction in the final tifluent by consue-Total Nitrogen 90tional disinfection processes can be avoided.Total Phosphorus 60% * Removal of heavy etals though co-precipitation and sedlimentation.MPN - E. Coli 99.999% With regard to environtntail Impact, ihe mnajo obec*tion to waste stabilization ponds of

s#t advantages of Ieiterated ponds over conventional treatment processes result conventional design has been the produtiion of odors at certain times of the year. iheirfrom lowet construction costs and lower operation and maintenance coats. Low large land requirements, and the prmsence of suspended algae in their effluents Alps

USEPA Small Flows Oct. 1990

Oaober 1990 PagS5

FECHNOLOGY_

KEY TO NUMBERS ON FIGURE BELOW1 SCREENING & GRIT REMOVAL 7. PADDLE WHEEL MIXER 13. ALGAE HARVEST

2 DISTRIBUTOR S11. HlH RATE POND 14. LOW LEVEL TRANSFER

3. FERMEtlTATION PITS 9. HIGH LEVEL TRANSFER 15. MATURATION POND

4. FACULTATIVE POND 10. ALGAE SUBSIDENCE CHAMBERS 16. HIGH LEVEL TRANSFER

5. OXYGENATED WATER RETURN 11. ALGAE SETTLING PONDS 17. WATER REUSE

6. LOW LEVEL TRANSFER 12. SETIIED ALGAE RETURN IB. SUPPLEMENTARY AERATION

Figure 1Advanced Integrated Algal-Bacterl System for Lquid Waste Treatment and Oxygen, Water, atd Nttrieit Recovery or Reuse

:reome ihese objections to s considerablcextnt beca t they re designed to 5nLutinize Efiluesi lt t orn tge porame otten suital,le for aluaculturC developrent and itigadossize of the land for podis. to avoid objectionable odom md lo rtnsov lgae. oI forage cmps becase:

* hem (re of passite ova nd dependably low in coliformn and othaer enlrieland occupied ty properly designed ponds will: baclesii dut to high pH disinfeclion in the primary and high-atme pond and long

Prvide open space anid aitheWic views. considered essuenl In omtsr y de tiedru in to sysem.planning. * rhey are low In mhrogen and phosphorus and will not over-fenilize.

Permi development of aquiculture and wetland habitat.Be euily asd inexpensively tersimable, usualy at a highly pprcited land Mlmoalgae p ied ib egrsed ponds hove grenl Fotential for:

value, should future developmnts lead to altmadve compui tr eatrucem UetlhodS * Deveopne as a high-proein feed suppleFreslt far fish. ehicken. swine annaminantE

eciionable odors aue avoided in Inegicrted ponds by * tJse s a liquid or solid fetlilizer for rapidly-growing crs:* Assuring 1h1 onset of slialine fermentation, wehcs detits odor etmissm in eh * Use as a aubastte (or methane fennentation.primary ponds of the system, by controlled st1n1-p procedes. * Exscaiom of iL pims and colh ids.* fPtovirlitig *ttrpls lu°yi en. ut aell au algal seeding. trugh trecreultliort of high-rite pond ciluent to Ihe sumface of Irhe primary ponds. whenever low dissolved To ttnaanrze. a properly designed Advanced Integrated I'inding System can pguvideoxygen levels in the pinralry ponds indicite a need. wate managenwm and recmtion that is ne reliabl. econoarnical. and envimousnme-

tally-sound than conventionI sysnens.I harvesing is prnmoted by:

* Natural biofnoctiltior of algae in pmoperly designed tnd mised high.rate pords. Rtlertea* ligh utruent removals that enhnce sedinsentation ud retard additional sisal Oswald WJ. 1197)Larg-Scale AlgaeCullure Systems; Eiginetering Aspects. Ingrowth in receiving vaters. Micro-Algali iotechnolgy. Cbhaper 12. Borowitzki. it, anid orrowitija. L cii,. Cam.

rdvanced waste trtstment procsss should be considered for use by: bridge University Press. New York.* Any comniuriiy involved tsther in developing new waste treatme and disposl OCwald. WJ. (1981) The Role of Algae in Liquid Waste Trearnent and Reclanation.syems or in upgrading teir present itreatmtnt sysem. Choapter 12. pp. 255-281 In Miroo/ars andl humn Affairi. CA. Ianb and lR. Wual-; Comnmunities in aid or semi-aid arteas dsiring to pracice walewvalr reclama.- eds CAmobidge Univenirty Pns. New York.tion.

Oirgnic industries requiring independent waste disposal systems. Oswald. W.) (1989°91 Itoduction to Advanced Integrated Wastewater Pondin5 Sy3sems,* Animal feed lots dairies, and poultry fainu truiring waste imsgemstent nd Depainent of CIvil Esginieing. Univerity of Califomia. erkelty.nutrien recycle.- Comrunities wIth sufficicnl atmounus of available land.

!1 1, -Ii ld. Alternative VVastewaterTreatment:Advanced Integrated

;'!!F jj!> 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 ilensifyingcost constraints and water quality regulations.

Why not build n sewage trcatment thinking. In cr .in6 oItim sl plants, forfacility tilat ust_s much lfss energy exampiv. acr af ii (it 1 ii constimesihani a coni'enlional otne and produces 60. or in vi l h * e i'lt rical energynto odors, especially if construction, usedl iii n asfrirvalr -xiclzament. In con-operation, and maintenance costs are trast, mmiroail lic in an All systemalsoldrantatically lower?niis question provide dIi,.s(eo.lvd g.n thrroughiaily 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 optimalparticularly 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 thisa .~ 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 oft 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 treatmentmetlo(lq lenid to [nivor AlP systemsin manv lirger w,lnTirrrmities as well,"says S;aintly XValk'r, I )it uctor of! eI .iiSp ri'al t! tlit '* lt' ': a comrrPlVF'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 tofacility 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 treatmentI 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 aerators. 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 mixfrarnslaltcs 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 supersaturateO ()swald, who designed St. I leiena's thie wlt'atsr willh 01' toxygen thiatsystem in the early 1960s Os:vald is a microbes need IIn break down waste.prolfessol emeritis at [lie Universityof California, Berkeley (UC-Berkeley) "For peopli' wvh b1asv alwaysand inventor of the AIP system. thought in tel In I 'i . nventional

treatienit, il's It ind to understandP'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 kilogranmsuffl 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'spie, 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 oiiventionialI; - 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 wheelsj 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 isof 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,l<f coitisider-itiga (onve rsiot(li tI atnw in t .1 tl. -,, in padidlte wheelsAtlz ant, rit In frOrnalce I'flvt, playt.

Wasteivater: A flesou,ce,Nol a Waste

1 v,; ,tc ;ig Iiii (ouglier iegi;iatioiis

. *z,. | - I sliipi' Nh'hIt- and fl(i irlIlm their 1iplaits.

1 t 1 t 0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'1 II Itt1 III 11 VI II .tr(t8 IIIL 1I SS

! liii ~.t(1i 'I I I; i; vf1 t o,ne )IuI

,' _~~~~~~~~~~~~~~~~II .. 'tv ,I( _;\ rt(,l IOWntl @t11O1NiCl.iti; \S('

. s e<ilI", V, I _.I I 1I(\ Grven, a UC-

B_ ,rkeltv Ii i tii i aniige

t~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~~~~~~~~~~~~~~~l Jt II, ,t d II I, _l l .R nidI tojSIll.are hi' ! Idd ill Iallge

Keg' i~kn 'i ''I 'tricter hilnil!; un

adtitm, nll. 44 [i it heavy metal-s in

t tl Ii',' t.f I:t.r f il *t 1', airation sewi'gc' i 'r c1ar piriitat.d and remainr~ lf' re: i, fretiud. enil,erg toyyage it oart fr i r . . i tt. tt Wi a lo lyaaallsearralil uIl in Hi II L iilt ilive pond's

.l # o ! 1Sr. fIr tlarirl ilf tiril ! enrgy caii greatly red uce the elec- dilgestir p i ttricity cotmsunied by an AIP plant,anothetlr sour-e o f ellerg), ( (8-itvi-iciy- Futrficr, m lit ii-ni, 91mhl as nitrogengenieratimi iiiro>ughi comnbustion of andl wlthln!:T511( LNIs MI tin aimage aqulatic

; methlane-could eliiminate electrical ecolsy.,lemis hilt) v.:hi ihl effluent mayzltwer 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 removingvested from the plant's settlitig pond. these imriuiit,; Nilmgen removal

(KCItIIS ill lh(- dligi I;fionl phase in theConventional plants typically install facultativ ll(l In addition nitro-large taniks, known as digesters, in gen and p hosphorts are taken upwhich 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 use8pliaint methane from ntattiuil fermen- of algav baui v'tedl Irorm AW plants astaltilon 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 releasedponI. 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 fertilizerseileis ilntuler wav. Ihe lEnvironmiuen- and ths b I is likely to retur tot.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 thatde1h* p 1 lenl wvith ftiunds frnm the( alilornia l:nrgy C((immi.,sion and

tle C alitornia liistittite for I lerlgyiIIiiu 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 (ndal1nd 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 flotationI'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, mIllv-ldatlolll (<o ilnligation wlatur, il - gaile-."

Cordinig to ( )'v.ald. t tie St. I Iilellaf ! It ,:A !er r (.... ..,f !Pl I"

,,, ff ,,,;,V, * X ,,,,t ,,,! ,,,,, ,t plant is high ligliing tlie beneficial*I'( i et I ze Milii tit hcrr retuse (if its Ireclainied water by grow- ,

. f-it rf SI. firlr,' ilig pumnpkiiis, corn, melonis, flowers, Conclusioni',aIrr l)r,fentr,,f 1n,lit_ roses, and more ilian 0.8 hectares

(2 acres) of wine grapes. The St. I leh'na plant h os dermon-strated the All' cuncrept for nearly

S Still, not ev-en the most eIthusiastic 30 years Mm e l tiani W Ir/brid All'PrOponeiits ol All' systems claini tilat plants at iow cilr p mn ini elemenlts

1} i l li!21 the basic futir-stage system of ponds of the All' (or (chpt in tlhc Urnited

I 4 i ll ' ealone can producec effluent meeting States andt t hnr -m itn I i,'s Most ofI1 ' standards for drinkinig water or for them, lik'1t. I k hcl i, plant,edue

"unrestrirled" uses such as swimming very little vitidigi% Malaiv of them use ap pIo1s and irrigatioin 4of public parks. combination (it ninir ttnicail and solarAii All' system, like other treatment aeration, a nt.i' fit( thr' -till requires

'i uolncts, caln onily achieve these goals less electi it iiN tli il -; * univentionalby additional treatment (e.g., disin- treatmeni att if .I i I leia thankectioii, fillratiin, and solids removal), does a s)-slum a' I ;ra '~I. I lelena's.

____ _ _ _ - - ----- - -- - As the bvn(tliti (f All' wysi'insrig Adi ancedt Initorated Pond System Concepts In Your Community become mim v, v'I 11 l ii r fi, however,

the accepto ( t, o f iitli,; lm% -co (st treat-fit thll! sw7tolt elpmlients used in AlP high-rate pond can reduce the need or, or m cct Pin ititl Ii- Il -cowt a

o-o(ly I in be tr';nul in conpjimlrion substitute for, mechanical aeration equip- poltical t 'i it 'tt;ifv'In a*nIionaetl inn vrar*e'tatr a teltnenrrt mnent. The primary or secondary reactorsoology I, crealt a h1brids) stern. and mechanical aeration equipment are regulati(ln *11u1 a fi ., l climnate in

*liluitinr tlinse AlP elements allovws usually the most expensive and energy- wlhich coii-lrit' li *,i, im6fifunance,o achieve the "lnrst of both worlds" intensive elements of a conventional treat- and opr valii w ;'si; an' increasinglyI planiinn a wastewalter tieatinenit ment tacil,Ly. And because ol the long impportailt it fiAt 11 i,pt niayion. delention time of organic material in the prove t( i"' tihe it kt ,l Wit Irio'lFgy

echnology has benri arounfJ for facultative pond's digester pit, organic f(or use lbv nrml oical 'xa!tewaterI 40) years and htas beoll ap;plied in material is completely removed from the \\ manag,er-. ItuI 'it)ers. Worldwd ha ee happled in wastewater. This sludge undergoes con-;taleions are nolw using sof e ele- tinuous digestioni until only a small vol-!;iAllations lechn,tolr u cing soni ele ume of residue remains. Daily sludgedo All' lechnolfmne, tmh creating removal and disposal are eliminated, thus(I treatiment systems. Giveit the aheii olradeirysvnsisinq liscal pressitre on local govein- achieving dollar and energy savingss anti the high rapital costs of cont- Wastewater treatment managers are fac-i21l uastevtaler heatinent plaints, ing toughier state and federal regulationsIs believe interest in AIP concepts is alfecting the quality and handling ofJ Ircreasing. Yotn cnmmitnilv may sludge and elfluent lrom their plants.hat a hibrid appvwcli makes Ilre Using AIP technology to design hybridsens e. systems or complete AIP systems can

.~amnple, use of a t3 arultative p d help your conmtinity meet regulationsvnplow vusto (of e or e3lV 1iminte and save dollans arid energy-a win-win I

iloYw yc u to drawnsize or eiimtiinate IhPe situation.uyr or seorildary reactor. Use ol a

4

lfescli plioli ol an Advancei Inlegrated Pond SyslemAn Advanced Iniegrated Poni( (AlP) sys- ilrlriilpae 1hte rtl't+ (ov-wlh of al'gnt|Iem consists of four basic types of ponds, also raises tthe alkalinitv of the viater.interlinked arid working together. killinr., pathogens Berause tire algae

Facullative I'ond (Pond #1/supersaturate the hiuh-rri)e pondJ withi

Ihle facultttive pond consists of an open rer somule of this pondrs l ater isepond containiiij a digester pit. Sewage recirclated to te ite layer ientering thie system is injected at the bot- ractltatie pond to bolster ito ntoni of tire where ~~~~content. thuts redJuringq or eliniiirating.ton of the digester pit, where sludge is

i I. § l! 3 i | t permranenitly trapped and consutied by- 1 l i fermentation in newer AIP systeml Settling Pond (Pond #3)

designs, in which the water table is low Mote thcn lrait tile alfrie produced inenough. the taciultative pond is about the hiu(ll-rate pond( settle oult. Sufficienlt4- to 5-mieters (13- to 16.4-feet) deep. algae settle ii tfre hiIlih-rate pond to

I d c 1r I ic qr,v Ird I ipii zn. f-ir The pond lias an oxygen-rich upper layer meet tutal suspended solids dischargeI .. il. ni r t if. I. I i,Ocn a. a about 1-meter (3.28-feet) deep, which requireprenils

heips to oxidize any malodorous gases Maluration Ponds (Ponds #4 and f5)rising frorn the digester pit. Treated waler is enposed to tte sun's

High-Rate Pond (Pond #2) UV rats and stored iuc irrigation andWater from the facultative pond flows to dispo;althe hiight-rate pond, where aerobic bacte-ria break down dissolved organic matter.Oxygen is supplied photosynthetically by

IhiMgram 1f tJI. Helenia 's AIP System

Iecirculation of 3 L Ioxyqen-rict water . i :

l - T 1 i (- ) ( A~~~~~~~~~~f Ii tt

i ~ ~ - uud l - | | . J i .t" 1 ,S . ~~~~~~~~~~Fatulttre 1|llv1 't tq4

i Illi-rata pond 12 _ \f;bFj:1 1 e 1 1 ~~~~~~~~~MatilraHea II MaterotUon \i

_______'____ pond* 4 pond #5!~~~~~ - -- - -. l }*

I; ' Settling pond 93 Ef3uen t os rdIscharge durinirP

wealr

|~.. lmo irrigation

I