1128 dhapa.assessment.report.4!27!10

8/20/2019 1128 Dhapa.assessment.report.4!27!10

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ASSESSMENT REPORT

D h a p a D i s p o s a l S i t eK o l k a t a , I n d i a

Prepared for:Kolkata Municipal Corporation

Prepared under the support of:U. S. Environmental Protection AgencyLandfill Methane Outreach Program

Prepared by:

File No 02205942 00


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D h a p a D i s p o s a l S i t e

Ta b l e o f C o n t e n t s

Section Page

1.0 Executive Summary................................................................................................................................ 1 2.0 Introduction.............................................................................................................................................. 2

2.1 Purpose of the Assessment Report ............................................................................................2 2.2 Data Sources.................................................................................................................................2

2.3 Project Limitations ........................................................................................................................3 3.0 Site Description....................................................................................................................................... 3

3.1 Waste Disposal Information ......................................................................................................4 Annual Waste Disposal Rates....................................................................................................4 Waste Composition Data ...........................................................................................................7

4.0 Landfill Gas Generation and Recovery Projections........................................................................ 8 4.1 Background on the SCS International LFG Model .................................................................8

4.2 Effects of Site Conditions on LFG Generation and Recovery..............................................9 4.3 Site Remediation Activities.........................................................................................................9 4.4 Model Parameters.................................................................................................................... 10

Model k Values ......................................................................................................................... 10 Methane Correction Factor .....................................................................................................10 Model Lo Values ....................................................................................................................... 10 Collection Efficiency..................................................................................................................11

4.5 Model Results............................................................................................................................. 12 5.0 Landfill Gas Project Options .............................................................................................................13

5.1 Electricity Generation...............................................................................................................13 5.2 Direct Use ...................................................................................................................................16 5.3 Flaring Only and Emissions Trading ...................................................................................... 17

6.0 Other Issues...........................................................................................................................................18 6.1 LFG Rights ..................................................................................................................................18

6.2 Security and Scavangers......................................................................................................... 18 7.0 Recommendations ................................................................................................................................18 7.1 Site Management......................................................................................................................18 7.2 Project Implementation............................................................................................................. 19

8.0 Conclusions ............................................................................................................................................20


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L i s t o f Ta b l e s

No. PageTable 1. Waste Disposal Estimates – Dhapa Disposal Site ................................................................ 5 Table 2. Waste Composition Data – Dhapa Disposal Site................................................................. 7

L i s t o f A t t a c h m e n t sAttachment A – Dhapa Waste Disposal SiteAttachment B - LFG Model Results


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ASSESSMENT REPORT – DHAPA LANDFILL, KOLKATA INDIA

1 . 0 E X E C U T I V E S U M M A RY

This assessment report for a landfill gas (LFG) utilization or flaring only project has been prepared by SCS Engineers (SCS) for the Dhapa Disposal Site in Kolkata, India. Theassessment was prepared based on the information provided by the Kolkata MunicipalCorporation (KMC) and observations made during a site visit on October 20, 2009.

The disposal site has served the City of Kolkata as an uncontrolled dumping ground since 1981.Based on site volume and waste density estimates, the site is estimated to have receivedapproximately 7 million metric tonnes (Mg) of municipal solid waste (MSW) as of the time ofthe site visit in October 2009, and has the capacity to receive another 4 million Mg of waste, fora total of 11 million Mg at closure. This future capacity estimate assumes a 10 hectare (ha)expansion occurs and that all disposal areas reach maximum height of 40 m (10 m above October2009 levels). Based on 2009 disposal rates (3,500 Mg per day) and an assumed growth rate oftwo percent, the site will be full by late 2012. At that time, either a new landfill site will need to

be ready for use, or disposal will need to continue outside of current disposal area boundariesand/or above reported maximum height limits.

Areas of the site targeted for installing LFG collection wells will require closure and remediation prior to development. Site remediation activities are already planned for the 8.1 ha WesternMound, starting in 2010. Remediation is assumed to be completed in the Western Mound in2011 to allow LFG project start-up in that disposal area in 2012. Remediation is also assumed tooccur in the remaining disposal areas to allow the project to collect LFG from the 13.3 haEastern Mound by 2013 and the 10 ha Expansion Area by 2014. Because site remediationactivities are expected to include grading and slope reduction, additional disposal areas will needto be acquired to accommodate expansion of the waste footprint,.

An LFG generation and recovery model was prepared based on the estimated waste disposalrates, waste composition, climate, site conditions, and estimated achievable collectionefficiencies. The model assumes site closure occurs in late 2012, followed by completion of siteremediation activities for the entire disposal site, and projects that an LFG project could yield atotal of about 771,000 Mg of CO 2-equivalent emission reduction credits (CERs) over a 10-year

period (2012-2021). Based on the projected quantities of recoverable LFG and a review ofil bl j i hi i di h h Dh Di l Si ld b


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2 . 0 I N T R O D U C T I O N

This assessment report for the Dhapa Disposal Site has been prepared by SCS Engineers (SCS)for the U. S. EPA’s Landfill Methane Outreach Program (LMOP), as part of the Methane-to-Markets Program, an international initiative to help partner countries reduce global methaneemissions in order to enhance economic growth, strengthen energy security, improve air quality,improve industrial safety, and reduce emissions of greenhouse gases.

2 . 1 P U R P O S E O F T H E A S S E S S M E N T R E P O RTThe overall purpose of the Dhapa Disposal Site Assessment Report is to perform an assessmentof potential LFG recovery rates and a preliminary evaluation of options for the utilization of theLFG. This overall purpose is achieved through the pursuit of the following objectives:

• Summarize and evaluate available information on the disposal site, including its physical characteristics, site management, and waste disposal data.

• Evaluate technical considerations for LFG project development, including estimatesof the amount of recoverable LFG over the project period.

• Examine available LFG utilization options, including electricity generation, directuse, and flaring only projects.

2 . 2 D ATA S O U R C E S

The following information which was used in the preparation of this report was (1) based onobservations by SCS personnel during the site visit performed on October 20, 2009; (2) provided

by Mr. Arun Sarkar, Principal Chief Engineer of the Kolkata Municipal Corporation (KMC)during a meeting on the day of the site visit; (3) provided in a data profile form completed by Dr.Suneel Pandey of KMC; or (4) provided by KMC via email (sent April 10, 2010 by ArpitaChatterjee to P.U. Asnani).

• Estimated site opening date (1981).• The size of the areas used for disposal, including a proposed expansion area.• Estimated maximum current waste depths.• Average waste disposal rates in 2008 and 2009 based on scalehouse data.


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2 . 3 P R O J E C T L I M I TAT I O N S

The information and estimates contained within this assessment report are based on the data provided by the Kolkata Municipal Corporation (KMC). Neither the U.S. EPA nor itscontractors can take responsibility for the accuracy of this data. Measurements, assessments, and

projections presented in this report are based on the data and physical conditions of the landfillobserved at the time of the site visit. No warranty, express or implied, is made as to the

professional opinions presented herein. Changes in the property use and conditions (forexample: variations in rainfall, water levels, site operations, final cover systems, or other factors)may affect future gas recovery at the disposal site. The U.S. EPA and SCS Engineers do notguarantee the quantity or the quality of the available landfill gas.

3 . 0 S I T E D E S C R I P T I O N

The Dhapa Disposal Site is located in Kolkata, India in the state of West Bengal. The climate inKolkata is tropical and rainy. The 24-hour average temperature is 26.6 degrees C (79.9 degreesF). Average annual precipitation in Kolkata is 1,625 mm (64 inches), of which over 95 percentfalls in the monsoon months of June through September. 1

The Dhapa Disposal Site is owned by the KMC. The disposal site has been operating as an opendump serving the City of Kolkata (estimated 2009 population of 5 million 2) since 1981. The sitecurrently accepts waste from both KMC’s public waste haulers and private haulers. Little or nosoil cover has been applied historically, and waste is deposited in an uncontrolled manner thathas resulted in steep, unstable slopes, leachate accumulation within the waste mass, and leachaterunoff into nearby water bodies (see Figure 1 below). Besides the creation of environmentalhazards, these conditions limit both LFG generation and the potential for efficient LFGextraction.

The disposal site property covers 34.2 hectares (ha), of which approximately 21.5 ha consists ofwaste disposal areas. The site has been divided into an eastern disposal area (“Eastern Mound”),which receives waste from KMC’s waste haulers, and a western disposal area (“WesternMound”), which receives waste from private haulers. A composting facility is located betweenthe two disposal areas and receives selected waste loads from organics-rich sources such as foodmarkets. The composting facility is privately owned and covers 12.2 ha of the disposal site

property. In addition, there are about 200 waste pickers at the site who scavenge through thewaste daily (see Figure 2). A schematic drawing of the site is provided in Attachment A, whichh h d l i l i f h i f ili d di l i l di


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immediately after availability of the land for new Engineered Landfill and the same is ready for

operation. At present Kolkata Municipal Corporation has no other alternative but to utilize theEast Mound and 10 Ha. Expansion area for waste disposal system within this period.” (Seediscussion of possible impacts of a delay in site closure on LFG recovery in a later section of thisreport.)

Wa s t e C o m p o s i t i o n D a t a

Waste composition and moisture conditions in a landfill are primary considerations when

estimating LFG model Lo and k values. This report applies waste composition data provided byKMC in a completed data form for the Dhapa site. Because the data was grouped into only fourwaste categories – food and garden/park waste combined (50.56%); wood (1.15%); paper andtextiles combined (7.94%); and all inert waste (29.60%) – details on the breakdown of inertwaste categories were developed using waste composition information developed for the GoraiLandfill Assessment Report. 4 The estimated waste composition percentages are summarized inTable 2.

Ta b l e 2 . Wa s t e C o m p o s i t i o n D a t a – D h a p aD i s p o s a l S i t e

Waste Material Estimated %

Food Waste 45.5%Garden Waste 5.1%Paper 4.0%Textiles 4.0%Wood 1.2%Plastics 3.3%Construction and Demolition Waste 29.6%Metals 0.5%Glass and Ceramics 0.3%

Other Organics 3.4%Other Inorganics 3.4%

Total 100.0%Organic Fraction (wet basis) 63.0%Organic Fraction (dry basis) 25.9%


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4 . 0 L A N D F I L L G A S G E N E R AT I O N A N D R E C O V E RYP R O J E C T I O N S

4 . 1 B A C K G R O U N D O N T H E S C S I N T E R N AT I O N A L L F GM O D E L

SCS has developed a proprietary international LFG model that employs a first-order decayequation for estimating LFG generation based on annual waste disposal rates, the amount ofmethane one tonne of waste produces (Lo value), and the rate that waste decays and producesLFG (k value). The model k and Lo variables are based on estimated waste composition andlocal climate information. Data used for developing model input parameters are discussed inlater sections of this report.

The SCS International Model uses the same input variables (k and Lo) and is generally similar tothe U.S. EPA’s Landfill Gas Emissions Model (LandGEM). The most significant difference

between the models is the assignment of multiple k and Lo values in the SCS InternationalModel. While the simple (single k and Lo) first order decay equation used in LandGEM isappropriate for modeling U.S. landfills, it is SCS’s opinion that LFG generation at sites indeveloping countries may not be adequately modeled using this approach, primarily due to thesignificantly different waste composition and site conditions which create different patterns ofwaste decay and LFG generation over time.

The SCS International LFG model employs separate modules with different k and Lo values thatseparately calculate LFG generation from the different waste components. This “multi-phased”first-order decay model approach recognizes that the significant differences in the types of wastedisposed in developing countries require changes to the model structure as well as to the valuesof the input variables. A similar approach has been adopted by the Inter-governmental Panel onClimate Change (IPCC), which released a landfill methane generation model in 2006 that appliesseparate modules for four different waste categories. 5

LFG generation estimates produced by the model are used to project LFG recovery followinginstallation of a collection system based on the estimated collection efficiency. Collectionefficiency, defined as the percentage of generated LFG that is recovered by the LFG extractionsystem, is affected by a number of factors, including: collection system design, extent ofwellfield coverage, waste depth, type of liner and cover, leachate management issues, landfillmanagement practices, and collection system operations.


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4 . 2 E F F E C T S O F S I T E C O N D I T I O N S O N L F G G E N E R AT I O NA N D R E C O V E RY

Site conditions at the landfill can impact LFG recovery either indirectly (by their effects on LFGgeneration) or directly (by their effects on achievable collection efficiency). Site conditionsimpacting LFG generation and recovery which were considered in the development of the modelestimates are summarized below:

• Moisture conditions. Annual average precipitation was used to evaluate moistureconditions at the site and to estimate appropriate model k values. According towww.worldclimate.com, annual average precipitation in Kolkata is approximately1,625 mm.

• Landfill management practices. As noted previously, the site has been operated as anopen dump throughout its active lifetime. Shallow and/or uncovered waste pilestypically experience aerobic conditions near the surface, that are toxic to methanegenerating bacteria. As a result, dump sites generate significantly less methane thanmanaged landfills that control the size of the active disposal area, compact waste, andapply soil cover on a frequent basis. This effect is accounted for in the model bymodifying the Lo values through the application of a “methane correction factor”(MCF) that is assigned based on the estimated fraction of waste which decaysaerobically and does not produce methane. The historically poor conditions at dumpsites also tend to contribute to low collection efficiencies.

4 . 3 S I T E R E M E D I AT I O N A C T I V I T I E S

Site remediation activities planned for the Western Mound would be expected to include at leastthe following: waste consolidation, re-grading, intermediate or final cover installation, andconstruction of stormwater drainage features. Site remediation will lessen environmentalimpacts of the disposal site, including water pollution from leachate runoff into nearby wetlands.Re-grading of the existing sloped areas to more stable (e.g. 3 to 1) slopes will require a larger

area than the disposal area currently occupies. Remediation of nearby wetlands may be requiredto offset possible expansion of the disposal area.

While environmental improvements would be the primary reason for site remediation, siteremediation also would make conditions more suitable for the installation and operation of anLFG collection system. Given the existing conditions (no soil cover, steep and unstable side


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Disposal areas must first stop receiving waste before beginning remediation activities. Any

delays in the assumed remediation schedule due to disposal areas continuing to receive waste past projected closure dates will cause delays in LFG system installation.

Even after an area is remediated, the long history of leachate accumulation in exposed wastewithout proper drainage will likely create leachate problems that can persist for years.Furthermore, the process of waste excavation and re-grading to stabilize slopes will expose

buried wastes to aerobic conditions and decrease methane generation.

Additional discussion of model inputs and assumptions that reflect the site conditions is provided below.

4 . 4 M O D E L PA R A M E T E R S

M o d e l k Va l u e s

Based on the precipitation rate and estimated waste moisture conditions at the disposal site, SCS

assigned the model k values of 0.360, 0.072, and 0.018 per year for the fast, medium, and slowlydecaying organic waste fractions, respectively.

M e t h a n e C o r r e c t i o n F a c t o r

Based on an assessment of the effects of historic site management practices and expectations ofdisposal area re-grading, a MCF of 0.7 was assigned to account for aerobic waste decay. Prior toremediation, waste areas would be expected to generate greater amounts of methane than

assumed in the model (i.e., a MCF of 0.8 would be appropriate based on the IPCC recommendedvalue for unmanaged disposal sites less than 5 m deep). However, since all disposal areas areassumed to eventually be remediated before wells are installed, a 0.7 MCF was applied to reflectthe impacts of site re-grading on average rates of aerobic decay. The MCF adjustment wasapplied to the Lo values.

M o d e l L o Va l u e s

Waste composition data was used to estimate Lo values for the fast, medium, and slowlydecaying organic waste categories, based on the dry organic content of the disposed waste (ascompared to average U.S. waste) multiplied by the estimated MCF. Separate Lo values werecalculated for the different organic waste categories which are as follows (after applying a MCFof 0.7):


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C o l l e c t i o n E f f i c i e n c y

As discussed above, conditions at the disposal site would be expected to limit the efficiency ofthe collection system to low levels and would require site remediation before system installation.Three LFG recovery scenarios were developed to reflect a range of achievable collectionefficiencies that vary depending on the level of effort and amount of resources available tooperate the collection systems. All three scenarios assume that the Western Mound would beremediated in 2010 and 2011, followed by installation of a collection system and system start-up

in 2012, and complete system coverage of the Western Mound by 2013. Site remediation andsystem expansion into the remaining disposal areas is assumed to occur from 2013 through 2015.Maximum collection efficiency levels will occur from 2015 onwards, when remediation, finalcover installation, and collection system installation in all disposal areas are assumed to becomplete. Any delays in the assumed schedule for site remediation and system installation (i.e.,if the East Mound and/or Expansion Area remain open past projected closure dates), would causesignificant decreases in projected collection efficiencies under all scenarios. The three recoveryscenarios are described as follows:

1. The low recovery scenario assumes that a moderate level of skill and effort isemployed in the operation and maintenance of the collection system (e.g., includingwellfield monitoring and adjustment about once per month). Collection efficiency isassumed to be 10 percent in the West Mound in 2012 and 35 percent starting in 2013.Collection efficiency in the East Mound is assumed to be 10 percent in 2013 and 35

percent starting in 2014. Collection efficiency in the Expansion Area is assumed to be 10 percent in 2014 and 35 percent starting in 2015. Using the above assumptions,site-wide collection efficiency is calculated to increase from 2 percent in 2012 to 35

percent in 2015. The Project Team considers the low recovery estimates to beconservative and should be employed only if a large margin of safety is needed.

2. The mid-range recovery scenario assumes that a moderately high level of skill andeffort is employed in the operation and maintenance of the collection system (e.g.,including wellfield monitoring and adjustment 2 to 3 times per month). Collectionefficiency is assumed to be 25 percent in the West Mound in 2012 and 50 percentstarting in 2013. Collection efficiency in the East Mound is assumed to be 25 percentin 2013 and 50 percent starting in 2014. Collection efficiency in the Expansion Areais assumed to be 25 percent in 2014 and 50 percent starting in 2015. Using the aboveassumptions, site-wide collection efficiency is calculated to increase from 6 percent in2012 to 50 percent in 2015. The Project Team considers the mid-range recoveryscenario to be its best estimates of likely recovery and recommends its use in the


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and 60 percent starting in 2014. Collection efficiency in the Expansion Area is

assumed to be 35 percent in 2014 and 60 percent starting in 2015. Using the aboveassumptions, site-wide collection efficiency is calculated to increase from 8 percent in2012 to 60 percent starting in 2015. The Project Team considers the high recoveryestimates to be ambitious and attainable only if the maintenance of an optimal LFGrecovery system is considered to be a top priority.

Note that, in addition to the potential variability in collection efficiency and the level ofoperation and maintenance, mathematical modeling of LFG is inherently uncertain. The Project

Team considered (and tried to account for) this modeling uncertainty in selecting the values forthe high and low recovery scenarios when projecting LFG recovery rates.

4 . 5 M O D E L R E S U LT S

LFG generation projections for the Dhapa Disposal Site are provided in Table B-1 and Figure B-1 in Attachment B. LFG recovery projections under alternative collection system efficiencyscenarios (low, mid-range, and high) are provided in Tables B-1 and B-2 and Figure B-1 inAttachment B.

As shown in Table B-1, projected LFG generation increases from about 5,250 m 3/hour in 2010 toa maximum of about 7,000 m 3/hour in 2013. LFG generation is projected to decline steeplythereafter, reaching about 4,100 m 3/hour in 2015, 1,500 m 3/hour in 2020, and 820 m 3/hour in2025.

Under the mid-range collection efficiency scenario, LFG recovery is projected to be about 400m3/hour in 2012, and to steadily increase to a maximum of about 2,070 m 3/hour in 2015 whencollection efficiency increases to maximum levels. After 2015, LFG recovery is projected todecline rapidly due to declining LFG generation. Table B-1 also shows that the potential for

power generation from LFG is estimated to exceed 1 MW over a 9-year period (2013-2021), andexceed 0.5 MW for a 17-year period (2012-2028), under the mid-range recovery projections.Certified emission reductions (CERs) achieved by this project through the combustion of landfillmethane under the mid-range recovery projections are estimated to exceed 770,000 tonnes ofcarbon dioxide equivalent (CO 2e) emissions for the 10-year period from 2012 through 2021.

Section 3.1 noted that the projected site closure date based on remaining volume would not applyas long as an alternative site for an engineered landfill is not available. If waste disposalcontinues past 2012, LFG recovery would be impacted largely by any changes to the assumedschedule for site closure, remediation, and LFG system development. Unless disposal moves


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5 . 0 L A N D F I L L G A S P R O J E C T O P T I O N S

LFG project options examined in this study include: (1) on-site electricity generation; (2) directuse for heating/boiler fuel (medium-Btu application), and (3) flaring only for obtaining emissionreduction credits (CERs) under the Clean Development Mechanism (CDM). Both utilizationoptions would require construction of new facilities, including an LFG-to-electricity (LFGE)

power plant in the case of the electricity generation option and an LFG processing and deliverysystem (pipeline) in the case of the direct use option. All three options would require operationof the LFG collection and flaring system and are expected to generate revenues from the sale ofCERs. The utilization options also would be expected to generate revenues from the sale ofelectricity or LFG.

Capital costs for a GCCS will depend to a large extent on LFG flows, landfill size, and wastedepth. A typical range for GCCS costs, including flare start-up and source test and engineeringand contingency costs, is about $70,000 to $120,000 (U.S.) per hectare of landfill area. AnnualGCCS operation and maintenance (O&M) costs typically average from 7 to 10 percent of capitalcosts, not including costs of electricity or system expansions.

5 . 1 E L E C T R I C I T Y G E N E R AT I O N

The projected LFG recovery rates under the mid-range recovery scenario indicate that thedisposal site could support approximately a 1 MW power plant from 2013 through 2021, and a0.5 MW power plant from 2012 to 2028, using reciprocating engines. To evaluate whether anelectricity generation project is economically feasible, the estimated project revenues,

construction costs (capital costs), and operating costs for the following alternatives should beconsidered:

• Selling generated electricity to a nearby end-user through a dedicated line.• Selling generated electricity to the power grid.• Utilizing generated electricity to offset electricity purchases for on-site uses.

The revenues produced by these project alternatives should be compared to the estimated projectconstruction and operating costs. Estimated revenues from electricity sales will depend on thequantity of electricity sold and the electricity sales price. Costs associated with an LFGE projectat the Dhapa Disposal Site will depend not only on the cost of constructing and operating the

power plant but also the cost of the electrical interconnection to the grid. All of the abovealternatives will require either a new interconnect or modifications to the existing interconnect.


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• Smaller projects require similar fixed cost investments as larger projects, including

electric transmission lines and interconnection infrastructure to the closest substation.• Smaller engine-generator units cost more per installed kW and have lower

efficiencies compared to larger units.

To offset the high investment costs, smaller electric projects typically require some kind of project “competitive advantage” such as:

• High on-site electricity usage paying high retail rates which can be offset by the project’s electricity generation.

• Existence of a high electricity tariff, renewable tariff, or renewable portfolio standard,and the existence of markets where the renewable attributes can be sold.

• Existence of a large electricity user close by paying high retail rates which candirectly take the power generated at the facility.

• Existence of an electric interconnect to the grid nearby which can be utilized withlittle additional infrastructure investment.

The Dhapa Disposal Site has some of the competitive advantages listed above, including theexistence of a fairly large electricity user on the site property (composting facility), and the

possible existence of three-phase distribution lines suitable for connecting to a small LFGE project close to the disposal site.

The composting facility located at the disposal site is expected to have significant electrical andthermal energy needs based on the observed size of the facility. The composting facility may beable to use both electricity and thermal energy from the LFG and would be an excellent facilityto approach regarding the use of LFG-based energy, given its close proximity. The composting

plant can be seen in Figures 3 and 4.


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The alternative to selling generated renewable electricity directly to a nearby end-user orutilizing the electricity for on-site load is selling renewable electricity to the electrical grid. Thiswould require an interconnect to the local power grid. During the site visit, a three-phasedistribution power line going to the landfill was observed. This line, which was used to supplyon-site power to the composting operations, may have adequate capacity to be used to connectthe electricity generation project to the grid, but a more detailed interconnect study would berequired to evaluate its suitability. If the existing distribution line is not adequate, an assessment

of the interconnection options and the suitability of nearby substations to accept the power would be required. Interconnection options may include upgrades to the existing line or constructing anew dedicated line to a nearby substation. Further study also would be needed to evaluate theregulatory requirements for renewable energy sources to connect to the state grid, as well as tosell power directly to a third party end user.

The National Electricity Policy of 2005 states that the purchase of electricity from non-conventional sources by distribution companies must occur through a competitive bidding

process. The Electricity Act of 2003 also provides guidelines for setting up generation tariffs forrenewable-based electricity, including a suggestion to link the generation tariff to the highest power purchase cost (fixed + variable) from the conventional plant in the state.

Although the Ministry of New and Renewable Energy (MNRE) 6 has stated that LFG is a sourceof renewable energy, to date no renewable energy tariff has been announced for waste-to-energy

projects, which include LFG recovery projects. However, the MNRE does offer financialassistance to waste-to-energy projects. For LFG recovery projects, financial assistance would be

provided under the scheme of “demonstration projects for power generation from MSW throughnew technologies,” and the project would receive financial assistance of up to 50 percent of the

project cost or a maximum of 3 million Rupees per megawatt of capacity.

In the State of West Bengal, the West Bengal Electricity Regulatory Commission (WBERC) hasdetermined the tariffs for electricity from renewable sources in the regulations for “Cogenerationand Generation of Electricity from Renewable Sources of Energy”. 7 This regulation establishesthat distribution companies in the State of West Bengal have a quota “of electricity to be

purchased … from cogeneration and renewable sources expressed as percentage of their totalconsumption of electricity in a year”. The quota varies depending on the established licenseeand increases on year by year basis. The regulation recommends that the tariff for the purchaseof electricity from cogeneration and renewable sources is agreed mutually between the licenseeand the supplier at a level not above the price cap for each type of source of energy specified inthis regulation The price cap for renewable energy from MSW is $4 50 Indian Rupees per kWh


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access to any transmission company system within the State of West Bengal, once payment has

been made for open access, transmission, wheeling, reactive energy, and other charges.Based on an estimated electricity sales rate of $0.097 per kW-hr, and assuming a 93 percentcapacity factor (percent of plant operating time) and a 7 percent parasitic load (percent ofgenerated electricity required to run the power plant), a 1 MW plant could generate revenues ofapproximately $730,000 per year. Based on the estimated construction and operating costs perkW of facility capacity, construction costs for a 1 MW LFGE facility at the Dhapa Disposal Sitewill likely exceed $2 million, and facility operating costs will likely exceed $175,000 per year.

These construction cost estimates do not include the cost of an electrical interconnect to a localsubstation, which could range substantially depending on the availability and suitability ofnearby distribution lines and/or substations.

5 . 2 D I R E C T U S E

The sale of LFG for direct use at a nearby industrial facility can generate significant revenueswhile requiring less initial facility costs than an electricity generating facility. The projectedLFG recovery rates under the mid-range recovery scenario indicate that the disposal site couldsupport a 1,000 m 3/hr direct use LFG project from 2013 through 2018, and a 400 m 3/hr direct useLFG project from 2012 through 2025. Project feasibility is largely determined by distances toend users. Unless the direct use client is located at a very short distance from the disposal site,an LFG transmission pipeline will be required. If the direct use project requires transporting theLFG a significant distance to the end user, it typically requires a gas compression and treatmentskid (filter, compressor or blower, de-hydration unit). LFG treatment requirements also aredriven by the equipment that will utilize the LFG. Gas compression and treatment skid costs will

be about $500,000 to $1 million, depending on the volume of LFG treated, distances to endusers, and end user delivery pressure requirements. Pipeline construction will be about $100,000

per km (assuming open trenching and not including payments for right-of-way easements).Annual O&M costs are estimated to be approximately $35,000 to $55,000 per year, dependingon the project size and labor costs.

The Dhapa Disposal Site is located in an isolated area, and no industries were observed near thedisposal site during the site visit, other than the on-site composting facility. Unless otherfacilities can be identified that are located nearby and could serve as potential end-users of LFG,an off-site direct use project does not appear to be a feasible option. The only potential optionfor utilizing recovered LFG appears to be on-site uses that do not generate revenues (only

potential cost savings). As discussed above, the potential for using LFG as a source of thermalenergy at the composting facility should be explored. Another potential on-site use for recovered


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fuel; (4) complexity and cost to convert existing systems to utilize LFG; and (5) quality of LFG

required by the end user for its processes.

5 . 3 F L A R I N G O N LY A N D E M I S S I O N S T R A D I N G

It is now possible to account for, and transfer, the reduction in greenhouse gas emissionsresulting from activities that reduce or capture any of the six main greenhouse gases. Becausemethane generated from solid waste disposal on land is one of the major sources of greenhousegas emissions, its capture and oxidation to carbon dioxide results in an environmental benefit.

This benefit may be measured and traded under a number of different emission reduction tradingschemes world wide, including the sale of CERs under the CDM.

In order to qualify for trading of emission reductions, normally a project must be able to provethat there is no requirement under law, or mandated by waste disposal licenses or otherregulations, to control the emission of the particular greenhouse gas relating to the project. Thisappears to be the case at the Dhapa Disposal Site.

While flaring is the normal method for thermal oxidation of LFG, any process which preventsthe emission of methane to the atmosphere would also qualify for tradable emission reductions.The carbon dioxide created by the thermal oxidation of methane is considered to be "short cycle"and the product of the normal carbon cycle, and therefore does not need to be accounted forunder the current methodologies.

If electrical energy production is also included, and that power is either exported to the localdistribution network or used to displace other usage of electricity generated by the combustion offossil fuels, it is possible to gain additional emission reductions as a result of the displacement offossil fuel use.

Although not a utilization option, flaring collected LFG would therefore produce significantenvironmental benefits and potential revenues from the sale of CERs. Because CERs aretypically the only source of revenues from a flaring only project, prices received for the emissionreductions will largely determine economic feasibility. A flaring only project would likely

produce lower revenues than the other project options but may be more economically feasible todevelop due to much lower capital investment costs. In addition, a flaring only project does not

preclude a landfill from subsequently developing and implementing an LFG utilization project.A phased approach can reduce project risk by allowing for the proving of LFG quantities that thelandfill can produce, recover the cost of the LFG collection system (and thus not burden theutilization project with having to fund the capital for the collection system), and provide a

b h l h d l d fi i f h ili i j I i


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6 . 0 O T H E R I S S U E S

6 . 1 L F G R I G H T S

For any LFG project to occur, the ownership of the gas rights needs to be clearly defined.Potential disputes over gas rights need to be settled before there can be decisions regarding

proceeding with a project, contract negotiations, or revenue sharing.

6 . 2

S E C U R I T Y A N D S C AVA N G E R SThe Dhapa Disposal Site currently does not block public access to the site, and a large number ofscavengers work the active disposal areas on a daily basis. To prevent theft and vandalism, LFGextraction equipment can only be installed in secured areas. Thus, security fencing will need to

be installed to protect any areas that are to be developed.

7 . 0 R E C O M M E N D AT I O N S

This section presents general recommendations aimed at improving the chances of developing asuccessful LFG utilization or flaring only project.

7 . 1 S I T E M A N A G E M E N T

Site Closure Plan . In order to develop a realistic plan for the implementation of the LFG

recovery system, the site should first prepare a closure plan. The following considerationsshould guide the preparation of the site closure plan:

• Closure plan : A site closure plan will give more certainty to the schedule forimplementing the LFG project and expanding the collection system to cover all disposalareas. This plan also will provide information to determine how the system coverage can

be maximized through the life of the LFG project. Current uncertainties regarding theclosure dates for the Eastern Mound and the Expansion Area make developing a closure

plan for the Dhapa Disposal Site difficult at present.• Side slopes : Side slopes should be at grades that are stable while providing adequate

drainage of stormwater. Historical disposal practices at the site have resulted in steep,unstable slopes that exceed 1:1 (horizontal to vertical) ratios in many places. Side slopesof approximately 3:1 are generally recommended, but a slope stability analysis should be


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• Access roads : Access to all areas of the site must be provided for heavy equipment such

as drilling rigs, backhoes, etc. potentially needed during the construction of the LFGsystem.

Active Disposal Area. The active disposal area should be minimized. Considering thatstormwater that infiltrates through the active disposal area becomes leachate, the smaller theactive disposal area the less leachate will be generated.

Stormwater Management . The site does not have any soil cover and does not use tarps to

prevent stormwater that falls on the landfill surface to infiltrate into the waste and turn intoleachate. The site remediation process should include final cover installation and provideadequate slopes and runoff features (ditches, benches, etc.) to avoid ponding of water andexcessive erosion.

Leachate Management . All landfills considering an LFG project must implement a leachatemanagement system that evacuates leachate from the waste mass, limits additional rainfallinfiltration, controls leachate runoff, and properly treats generated leachate. The site has no

bottom liner or leachate drainage system. High rainfall rates in the region and the lack of coverhave caused leachate accumulation within the waste and leachate runoff into nearby water

bodies. Leachate accumulation problems often are the primary cause of LFG projectunderperformance. Final cover installation and site remediation should help limit future leachategeneration and provide drainage, but dewatering of the site will likely take years to complete.

7 . 2 P R O J E C T I M P L E M E N TAT I O N

The following are recommended next steps for implementing an LFG utilization or flaring only project:

• LFG Rights : To clarify any potential uncertainty regarding the rights to the LFG,legitimate stakeholders should work together to equitably share the benefits anddocument any agreement. As a general guideline, we recommend that any benefitreceived resulting from the LFG should be commensurate with the level of risk incurred.

For example, the entity responsible for addressing environmental liabilities (includingincurring the costs of site closure and remediation) should also receive benefits from theLFG.

• Solicit Offers: The project owner should solicit offers to develop the LFG utilization project and/or a flaring only (GHG reduction) project. If the successful bidder is


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the PDD. Even if all the details are not known, a general utilization project concept

should be introduced to allow for the modification of the PDD in lieu of a complete PDDresubmission. Give the developer a reasonable timeframe to implement the utilization project; after that period, they would lose their rights to the project. If the developer doesnot intend to develop or is not awarded the rights to an LFG utilization project, the ownershould preserve its rights to develop a utilization project in the future, along with the anyenvironmental attributes associated with the utilization project (e.g., CERs).

8 . 0 C O N C L U S I O N SThe Dhapa Disposal Site is a large disposal site with fairly significant projected LFG generationrates, but relatively modest quantities of recoverable LFG due to the limitations that siteconditions impose on achievable collection efficiencies. Because peak LFG generation ratesoccur shortly after disposal stops, the need to close and remediate disposal areas prior to projectdevelopment causes delays in LFG capture that lower overall collection efficiency. Maximumcollection efficiency will not occur until the LFG system build-out is completed, which is not

projected to occur until after all areas have been remediated (2015) and LFG generation hasdeclined 40 percent from peak levels. Delays in LFG project implementation due to disposalcontinuing past projected area closure dates will lower collection efficiencies further and willlower LFG recovery rates (at least through 2015), despite potentially higher LFG generation.

Based on a preliminary evaluation of potential LFG recovery rates, there appears to be sufficientLFG to support a 1 MW LFGE project over a 9-year period (2013-2021) and a 0.5 MW projectover an 17-year period (2012-2028). Electricity generated from LFG potentially could be used atthe composting facility on-site or sold to the grid. LFG also may be able to be used directly atthe composting facility as a source of thermal energy.

Other potential LFG utilization project options appear to be limited due to the lack of nearbyindustrial facilities. Due to its lower capital costs, a flaring only project may be the mosteconomically feasible alternative. A more detailed study would be required to evaluate thespecific project options identified, including a detailed analysis of revenues, capital and

operating costs, financing, end user location and demand, and technology considerations, and todetermine which if any project options are the most economically viable.


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AT TAC H M E N T AD H A PA WA S T E D I S P O S A L S I T E


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AT TAC H M E N T BL F G M O D E L R E S U LT S


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Disposal Refuse Collection Maximum Baseline**Rate In-Place System Power Plant LFG Flow

Year (Mg/yr) (Mg) (m3/hr) (scfm) (mmBtu/hr)

Efficiency(%) (m 3/hr) (scfm) (mmBtu/hr)

Capacity*(MW) (m 3/hr)

(tonnesCH4/yr)

(tonnesCO2eq/yr)

1981 18,000 18,000 0 0 0.0 0% 0 0 0.0 0 0 0 01982 20,700 38,700 30 17 0.5 0% 0 0 0.0 0 0 0 01983 23,800 62,500 57 34 1.0 0% 0 0 0.0 0 0 0 01984 27,400 89,900 82 48 1.5 0% 0 0 0.0 0 0 0 01985 31,500 121,400 107 63 1.9 0% 0 0 0.0 0 0 0 0

1986 36,200 157,600 133 78 2.4 0% 0 0 0.0 0 0 0 01987 41,600 199,200 160 94 2.9 0% 0 0 0.0 0 0 0 01988 47,800 247,000 190 112 3.4 0% 0 0 0.0 0 0 0 01989 55,000 302,000 223 131 4.0 0% 0 0 0.0 0 0 0 01990 63,300 365,300 261 153 4.7 0% 0 0 0.0 0 0 0 01991 72,800 438,100 303 178 5.4 0% 0 0 0.0 0 0 0 01992 83,700 521,800 351 207 6.3 0% 0 0 0.0 0 0 0 01993 96,300 618,100 406 239 7.3 0% 0 0 0.0 0 0 0 01994 110,700 728,800 470 276 8.4 0% 0 0 0.0 0 0 0 01995 127,300 856,100 542 319 9.7 0% 0 0 0.0 0 0 0 0

1996 146,400 1,002,500 625 368 11.2 0% 0 0 0.0 0 0 0 01997 168,400 1,170,900 720 424 12.9 0% 0 0 0.0 0 0 0 01998 193,700 1,364,600 829 488 14.8 0% 0 0 0.0 0 0 0 01999 222,800 1,587,400 955 562 17.1 0% 0 0 0.0 0 0 0 02000 256,200 1,843,600 1,100 647 19.7 0% 0 0 0.0 0 0 0 02001 294,600 2,138,200 1,266 745 22.6 0% 0 0 0.0 0 0 0 02002 338,800 2,477,000 1,457 858 26.0 0% 0 0 0.0 0 0 0 02003 389,600 2,866,600 1,677 987 30.0 0% 0 0 0.0 0 0 0 02004 448,000 3,314,600 1,929 1,135 34.5 0% 0 0 0.0 0 0 0 02005 515,200 3,829,800 2,219 1,306 39.7 0% 0 0 0.0 0 0 0 0

2006 592,500 4,422,300 2,553 1,503 45.6 0% 0 0 0.0 0 0 0 02007 681,400 5,103,700 2,936 1,728 52.5 0% 0 0 0.0 0 0 0 02008 912,000 6,015,700 3,378 1,988 60.4 0% 0 0 0.0 0 0 0 02009 1,277,500 7,293,200 4,095 2,411 73.2 0% 0 0 0.0 0 0 0 02010 1,303,100 8,596,300 5,249 3,090 93.8 0% 0 0 0.0 0 0 0 02011 1,329,200 9,925,500 6,178 3,636 110.4 0% 0 0 0.0 0 0 0 02012 1,042,100 10,967,600 6,920 4,073 123.7 6% 405 238 7.2 0.7 0 1,270 26,6722013 0 10,967,600 7,017 4,130 125.4 15% 1,068 629 19.1 1.8 0 3,354 70,4362014 0 10,967,600 5,382 3,168 96.2 36% 1,927 1,134 34.4 3.2 0 6,050 127,0542015 0 10,967,600 4,131 2,431 73.8 50% 2,066 1,216 36.9 3.4 0 6,485 136,181

2016 0 10,967,600 3,233 1,903 57.8 50% 1,617 951 28.9 2.7 0 5,075 106,578

TABLE B-1PROJECTION OF LANDFILL GAS GENERATION AND RECOVERY UNDER MID-RANGE SCENARIO

DHAPA DISPOSAL SITE, KOLKATTA, INDIA

MID-RANGE RECOVERY SCENARIOLFG Predicted LFG Methane Emissions

Generation Recovery Reduction Estimates**

Dhapa Kolkatta model final 4-13-10.xls 4/20/2010


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Collection Maximum Baseline** Collection Maximum Baseline**

System Power Plant LFG Flow System Power Plant LFG Flow

YearEfficiency

(%) (m 3/hr) (scfm) (mmBtu/hr)Capacity*

(MW) (m3/hr)(tonnesCH4/yr)

(tonnesCO2eq/yr)

Efficiency(%) (m 3/hr) (scfm) (mmBtu/hr)

Capacity*(MW) (m 3/hr)

(tonnesCH4/yr)

(tonnesCO 2eq/yr)

1981 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01982 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01983 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01984 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01985 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01986 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01987 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01988 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01989 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 0

1990 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01991 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01992 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01993 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01994 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01995 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01996 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01997 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01998 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 01999 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 02000 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 02001 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 0

2002 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 02003 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 02004 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 02005 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 02006 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 02007 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 02008 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 02009 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 02010 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 02011 0% 0 0 0.0 0 0 0 0 0% 0 0 0.0 0 0 0 02012 8% 566 333 10.1 0.9 0 1,778 37,341 2% 162 95 2.9 0.3 0 508 10,6692013 20% 1,372 807 24.5 2.3 0 4,307 90,438 9% 613 361 11.0 1.0 0 1,925 40,4332014 46% 2,465 1,451 44.1 4.1 0 7,740 162,538 21% 1,120 659 20.0 1.9 0 3,516 73,8292015 60% 2,479 1,459 44.3 4.1 0 7,782 163,417 35% 1,446 851 25.8 2.4 0 4,539 95,3272016 60% 1,940 1,142 34.7 3.2 0 6,090 127,894 35% 1,132 666 20.2 1.9 0 3,553 74,6052017 60% 1,550 912 27.7 2.6 0 4,866 102,179 35% 904 532 16.2 1.5 0 2,838 59,6042018 60% 1,265 744 22.6 2.1 0 3,970 83,371 35% 738 434 13.2 1.2 0 2,316 48,6332019 60% 1,053 620 18.8 1.7 0 3,307 69,442 35% 614 362 11.0 1.0 0 1,929 40,5082020 60% 894 526 16.0 1.5 0 2,808 58,972 35% 522 307 9.3 0.9 0 1,638 34,4002021 60% 773 455 13.8 1.3 0 2,427 50,967 35% 451 265 8.1 0.7 0 1,416 29,7312022 60% 678 399 12.1 1.1 0 2,130 44,730 35% 396 233 7.1 0.7 0 1,242 26,0922023 60% 603 355 10.8 1.0 0 1,894 39,771 35% 352 207 6.3 0.6 0 1,105 23,2002024 60% 542 319 9.7 0.9 0 1,702 35,746 35% 316 186 5.7 0.5 0 993 20,8522025 60% 492 289 8.8 0.8 0 1,543 32,410 35% 287 169 5.1 0.5 0 900 18,9062026 60% 449 264 8.0 0.7 0 1,409 29,592 35% 262 154 4.7 0.4 0 822 17,2622027 60% 412 243 7.4 0.7 0 1,294 27,169 35% 240 141 4.3 0.4 0 755 15,849

TABLE B-2PROJECTION OF LANDFILL GAS RECOVERY UNDER HIGH AND LOW RECOVERY SCENARIOS

DHAPA DISPOSAL SITE, KOLKATTA, INDIA

HIGH RECOVERY SCENARIO LOW RECOVERY SCENARIOPredicted LFG Methane Emissions Predicted LFG Methane Emissions

Recovery Reduction Estimates** Recovery Reduction Estimates**

Dhapa Kolkatta model final 4-13-10.xls 4/20/2010


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4/20/2010

Figure B-1. LFG Generation and Recovery Projection

Dhapa Dump Site, Kolkatta, India

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

2000 2005 2010 2015 2020 2025 2030 2035

L F G F l o w a t

5 0 %

M e t

h a n e

( m 3 / h r )

0

100,000

200,000

300,000

400,000

500,000

C E R s ( t o n n e s

C O 2 e )

LFG Generation Predicted recovery - Mid RangePredicted recovery - High range Predicted recovery - Low range

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