1 

MEMORANDUM

TO: Hillary Ward, U.S. Environmental Protection Agency, OAQPS/Sector Policies and 

Programs Division, Fuel and Incineration Group 

FROM: Eastern Research Group, Inc. (ERG) 

DATE: June 2015 

SUBJECT: Updated Methodology for Estimating Cost and Emission Impacts of MSW Landfill 

Regulations 

Introduction 

The EPA is reviewing the new source performance standards (NSPS) and emission guidelines 

(EG) for municipal solid waste (MSW) landfills. Currently, the regulations require landfills of at least 2.5 

million megagrams (Mg) and 2.5 million cubic meters in design capacity with estimated nonmethane 

organic compounds (NMOC) emissions of at least 50 megagrams (Mg) per year to collect and control 

landfill gas (LFG). As part of the proposed revisions, a Microsoft® Access database was developed to 

calculate the cost and emission impacts associated with varying certain control parameters and applying 

these parameters to a dataset of existing and model future landfills. The development of the dataset is 

discussed in other memoranda.1 The purpose of this memorandum is to summarize the methodology for 

the evaluations.

1. General Assumptions 

The emission reductions and costs associated with the requirements of the current rule are 

considered the baseline and each alternative was compared to this baseline. All existing landfills that 

accepted waste after November 19872 as well as future landfills that are predicted to open or modify in 

the 5-year period of January 2014 through December 2018 are included in the analysis. Annual estimates 

of emission reductions and costs were estimated for each landfill and alternative control scenario in year 

2025. Costs were estimated using both a 7 percent and 3 percent interest rate. 

The alternatives differ from the baseline by variations in the emission rate thresholds and the 

design capacity thresholds. Shorter lag times were only evaluated for wet landfills as discussed in another 

memorandum.3 A description of each variable is presented below: 

• The emission rate threshold in the current rule is 50 Mg per year NMOC. The alternatives 

include lower NMOC thresholds. 

 

1

 ERG. 2014. Summary of Landfill Dataset Used in the Cost and Emission Analysis of Landfill Regulations; ERG. 

2015. Summary of Updated Landfill Dataset Used in the Cost and Emission Reduction Analysis of Landfills 

Regulations. 2015. 

2

 The designated facility under the EG is each existing MSW landfill that has accepted waste since November 8, 

1987 and for which construction, reconstruction, or modification was commenced on or before July 17, 2014. 

3

 ERG. 2015. Revised Cost and Emission Impacts Resulting from the Landfill EG Review.
2 

• The design capacity threshold in the current rule is 2.5 million Mg and 2.5 million cubic meters. 

Other landfill design capacity thresholds were evaluated as alternatives. 

• The initial lag time is the time period between when the landfill exceeds the emission threshold 

and when GCCS are required to be installed. The current rule allows a 30-month initial lag time, 

which was modeled as a 3-year lag time since the first-order decay equation used to model 

emissions is on an annual, instead of monthly, basis. Further, because the current rule requires 

annual NMOC emission reports to be submitted by 6 months into the following calendar year, the 

landfill would get 30 months after the submittal of its first NMOC emission report showing an 

exceedance to install the GCCS, which is approximately 36 months after the excess emissions 

occurred. Shorter initial lag times were examined among the alternatives. 

• The expansion lag time is the amount of time allotted for the landfill to expand the GCCS into 

waste being placed in new areas of the landfill. The current rule allows 2 years after initial waste 

placement in closed areas and 5 years after initial waste placement in active areas of the landfill; 

so the actual lag time varies by landfill depending how quickly expansion areas are filled and 

closed. Based on input received during public outreach, most modern large landfills do not reach 

final grade within 2 years and a majority of landfills are complying with the 5 year provision. 

Therefore, a 4-year expansion lag time was assumed to represent the baseline. A shorter lag time 

was examined as an alternative. 

2. Estimating Emission Impacts 

2.1 Waste Estimates 

First, the quantity of waste maintained in each landfill was estimated for each year of the analysis, 

based on one of two methods: 

1. For landfills reporting to GHGRP: 

a. Historical annual waste acceptance rate (AWAR) data beginning with the year the landfill 

opened through 2013 were generally available in GHGRP data tables 

‘HH_ANN_WASTE_DISPOSAL_QTY’ and ‘HH_HIST_YR_WASTE_QTY’. These data 

were used to compute cumulative waste-in-place (WIP) amounts for each year of the model. 

b. If data were missing for 2012 or 2013 reporting years at open landfills, the last known year’s 

AWAR was used to fill data gaps. 

c. To estimate future year AWAR for landfills open past 2013, one of four methods was used: 

i. For landfills with calculated 2013 WIP less than reported landfill capacity: 

AWAR = (Design Capacity - 2013 WIP)/(Estimated landfill closure year - 2013) 

ii. For landfills with calculated 2013 WIP greater than or equal to reported landfill 

capacity: 

AWAR = 2013 AWAR 

iii. For landfills with calculated future AWAR greater than 10% of the 2013 AWAR: 

AWAR = 2013 AWAR 

iv. For landfills with 2013 AWAR = 0, future annual AWAR = 0.

2. For other landfills that were not GHGRP reporters, the landfill waste data were calculated one of 

two ways: 

a. When a landfill’s AWAR and WIP values were available in the landfill dataset and 

associated with a particular year, those values were extrapolated to estimate the landfill’s 

AWAR and WIP for each year. This estimation method was designated Option A in the 

database table of Calculated Inputs_Annual Waste. 
3 

• When a Landfill_WIP and Landfill_WIP_Year are reported, the AWAR up until the 

Landfill_WIP_Year is estimated based on the following relationship: 

AWAR = Landfill_WIP / (Landfill_WIP_Year - Landfill _Year_Open+1). 

• The AWAR after the Landfill_WIP_Year is based on the following relationship: 

AWAR = (Landfill_Design_Cap_tons - Landfill_WIP) / (Landfill_Closure_Year - 

Landfill _WIP_Year+1). 

2. When WIP and AWAR values were not available in the landfill dataset, the AWAR was 

estimated using the landfill open and closure years and the landfill capacity and assuming a 

constant AWAR over the lifetime of the landfill. This estimation method was designated 

Option D in the database table of Calculated Inputs_Annual Waste.

• AWAR = Landfill_Design_Cap_tons / (Landfill_Closure_Year - Landfill _Year_Open+1)

Next, the annual WIP was calculated by summing the AWAR over time. 

2.2 Emission Equations 

After the annual quantity of waste was estimated for each landfill, a first order decay equation 

(Equation 1) was used estimate annual methane emissions from each landfill for each year. The dataset 

includes annual emission estimates for 2014-2039. 

Eq. 1:

kt

4t 0 CH k L M e

−

= × × ×

Where: 

 CH4t = Methane, ft3 in year t 

 k = Methane generation rate, year-1

 L0 = Potential methane generation capacity, ft3 methane per ton 

 M = Mass of waste accepted in year t, tons 

 t = Analysis year (year 1 through 50), year 

The volume of LFG produced by a landfill was estimated using Equation 2. 

Eq. 2: LFGt = CH4t × 2 

Where: 

 LFGt = Landfill gas, ft3 in year t 

CH4t = Methane, ft3 in year t 

2 = Multiplier to convert methane to LFG (assuming that LFG is 50 percent 

methane), unitless 

The mass of NMOC emissions produced by each landfill was estimated based on the amount of 

LFG produced at the landfill, as shown in Equation 3. 

Eq. 3: NMOCt = LFGt ÷ 35.32 × 595 × 3.6E-9

Where: 

NMOCt = NMOC in year t, Mg in year t 

LFGt = Landfill gas, ft3 in year t 

35.32 = Conversion, ft3 per m3
4 

595 = Concentration of NMOC in LFG, ppm NMOC by volume as hexane 

3.6E-9 = Conversion factor, Mg NMOC per m3 LFG 

The mass of methane emissions produced by each landfill was estimated based on the volume of 

methane produced at the landfill, as shown in Equation 4a. 

Eq. 4a: Mg CH4 = CH4t × 0.0423 ÷ 2000 ÷ 0.90718 

Where: 

 Mg CH4 = Methane in year t, Mg in year t 

 CH4t = Methane, ft3 in year t (From Equation 1) 

 0.0423 = Density of methane, lb per ft3

 2000 = Conversion, lb per short ton 

 0.90718 = Conversion, short ton per Mg 

The mass of methane emissions, in terms of carbon dioxide equivalents, produced by each landfill 

was estimated using the Equation 4b. 

Eq. 4b: Mt CO2eq = Mg CH4 × GWPCH4

Where: 

 Mt CO2eqt = Methane emissions as carbon dioxide equivalents, Mt in year t4

 Mg CH4t = Methane, Mg in year t (From Equation 4a) 

 GWPCH4 = 25, Global Warming Potential of Methane 

2.3 NSPS/EG and AP-42 Default Values for Calculating Emissions5

The current NSPS requires the use of Tier 1 default value for the potential methane generation 

capacity (L0) and methane generation rate (k) to determine when the landfill exceeds the 50 Mg NMOC 

per year emission rate threshold. The NSPS L0 is equal to 5,458 ft3 methane per ton of waste and the 

NSPS k values are 0.05 per year for areas receiving 25 inches or more of rainfall per year and 0.02 per 

year for areas receiving less than 25 inches of rainfall. While the NSPS offers a conservatively high Tier 1 

default NMOC concentration, the regulations allow the use of Tier 2 tests to determine NMOC 

concentration. (Many landfills have conducted Tier 2 tests and gotten values that are consistent with the 

AP-42 average NMOC concentration of 595 ppmv.) Therefore, the combination of the Tier 1 defaults for 

k and L0 and the NMOC concentration of 595 ppmv were used to represent how landfills currently 

calculate NMOC emissions to determine if they have to install controls under the NSPS. Because the use 

of these values result in estimates of LFG and NMOC that are in accordance with the current NSPS; in 

this evaluation these estimates were called LFGNSPS/EG and NMOCNSPS/EG. NSPS defaults tend to 

overestimate actual emissions at most landfills (due to the conservatively high L0 and k values). 

EPA has collected and compiled available emission factor data for landfills in the report 

Compilation of Air Pollutant Emission Factors (AP-42).6 The AP-42 L0 is equal to 3210 ft3 methane per 

ton of waste. The AP-42 k values are 0.04 per year for areas receiving 25 inches or more of rainfall per 

year and 0.02 per year for areas receiving less than 25 inches of rainfall. The use of these values, in 

 

4

 A megagram is equal to a metric ton. 

5

 The modeling requirements for existing sources under the state and federal plans implementing the EG are similar 

to those for new and modified sources under the current NSPS. 

6

 USEPA AP-42, Fifth Edition, Volume I Chapter 2: Solid Waste Disposal. 

http://www.epa.gov/ttn/chief/ap42/ch02/index.html 
5 

combination with the NMOC concentration of 595 ppmv, result in estimates of LFG and NMOC that are 

in accordance with the AP-42; in this evaluation these estimates were called LFGAP-42 and NMOCAP-42. 

As previously mentioned, for this evaluation, LFGNSPS/EG and NMOCNSPS/EG were used to 

determine when landfills would install controls. To determine when landfills may remove controls, the 

current rules allow landfills to measure the actual collected gas flow rate as well as the concentration 

(instead of relying on Tier 1 default L0 and k defaults). Because the AP-42 values for L0 and k produce 

results that more closely match actual gas flow rates and emissions, LFGAP-42 and NMOCAP-42 were used 

in this analysis to determine when landfills would remove controls. 

Landfill-Specific k Factors 

As noted above, the k values depend on the amount of precipitation at the landfill. For this 

evaluation, long-term precipitation data by county are available for most landfill locations.7 Some 

landfills in remote areas or U.S. Territories did not have data available and data from nearby weather 

stations from the National Oceanic and Atmospheric Administration (NOAA) were obtained and 

averaged over the available data period for each location.8 The k factors were assigned to each landfill 

based on the resulting amount of precipitation at each landfill. 

2.4 Emission Reductions

To estimate emission reductions, the amount of LFG, methane, and NMOC emitted at each landfill 

was estimated using the equations in Section 2.1. After the emissions at each landfill exceed the NMOC 

emission rate threshold of each control scenario, the model assumed that the collection equipment was 

installed and operational at the landfill after the initial lag time of the control scenario. For example, if the 

landfill exceeded the NMOC emission threshold in year 1, and the initial lag time was 3 years, the landfill 

would begin collecting gas in year 4. As the landfill was filled over time, the model assumed the landfill 

would expand the GCCS into new areas of waste placement in accordance with the expansion lag time of 

the control scenario. If the landfill was not expanding the gas collection system (i.e., by installing wells in 

new areas of waste placement) every year, the landfill may have produced more emissions than could be 

collected until the gas collection system was expanded. 

Once the landfill reached the maximum gas production and the gas production started to decrease, 

the analysis assumed that the GCCS would collect all of the emitted gas. To determine the amount of LFG, 

methane and NMOC collected, the analysis used the LFGAP-42 and NMOCAP-42, estimates with the 

appropriate lag times. This was the best estimate of actual gas collected. See Table 1 for an example of the 

collected gas estimate at a landfill where the initial lag time was 3 years and the expansion lag time was 4 

years. 

Table 1. Example of Collected NMOC Estimate at a Landfill with an Initial Lag Time of 3 Years and 

an Expansion Lag Time of 4 Years 

Year NMOCNSPS/EG NMOCAP-42 Collected NMOC

1 50.2 27.7 0.0

2 50.4 27.9 0.0

3 50.6 28.0 0.0

4 50.8 28.2 28.2

5 51.0 28.3 28.2

 

7

Prism Climate Group. 30-year Normals (1981-2010). http://www.prism.oregonstate.edu/normals/, Accessed 

September 2015.

8

 NOAA climate division data are available online at: http://www.ncdc.noaa.gov/cdo-web/ 
6 

6 51.1 28.5 28.2

7 51.3 28.6 28.2

8 51.5 28.7 28.7

9 51.6 28.9 28.7

10 51.7 29.0 28.7

11 51.9 29.1 28.7

12 52.0 29.2 29.2

13 52.1 29.3 29.2

14 52.2 29.4 29.2

15 52.3 29.5 29.2

The emission reductions are equal to the amount of collected NMOC and methane that is 

combusted. The amount of collected NMOC and methane destroyed by combustion controls was estimated 

by multiplying the amount of collected gas by a destruction efficiency of 98 percent. The 98 percent 

destruction efficiency accounts for the fact that combustion is not 100 percent efficient. 

3. Cost Equations 

The cost equations used in this regulatory evaluation were derived from EPA’s Landfill Gas 

Energy Cost Model (LFGcost-Web), version 3.0, which was developed by EPA’s Landfill Methane 

Outreach Program (LMOP). LFGcost-Web estimates costs for gas collection, flare and energy recovery 

systems and was developed based on cost data obtained from equipment vendors and consulting firms 

that have installed and operated numerous gas collection and control systems. LFGcost-Web encompasses 

the types of costs included in the EPA Office of Air Quality Planning and Standards (OAQPS) Control 

Cost Manual including capital costs, annual costs, and recovery credits. Total capital costs include 

purchased equipment costs, installation costs, engineering and design costs, costs for site preparation and 

buildings, costs of permits and fees, and working capital. Total annual costs include direct costs, indirect 

costs, and recovery credits. Direct annual costs are those that are proportional to a facility-specific metrics 

such as the facility’s productive output or size. Indirect annual costs are independent of facility-specific 

metrics and may include categories such as administrative charges, taxes, or insurance. Recovery credits 

are for materials or energy recovered by the control system.

For this evaluation, all costs are presented in 2012$. The costs included in LFGcost-Web are in 

2013$ and were adjusted to 2012$ using a factor of 2 percent for capital costs and 2.5 percent for O&M 

costs. 

The analysis presents the annualized capital cost of flares, wells, wellheads (including piping to 

collect gas) and engines over the lifetime of the equipment. It was assumed that the equipment would be 

replaced when its lifetime was over, so the annualized capital costs were incurred as long as the landfill 

still had controls in place. In order to calculate the annualization factors, it was assumed that flares, wells, 

well heads, and engines had a 15-year lifetime. In addition, there was a mobilization/installation charge to 

bring well drilling equipment on site each time the gas collection system was expanded. Because the 

landfill would be drilling wells to expand the control system during the expansion lag year, it was 

assumed that this capital installation cost had a lifetime equal to the expansion lag time. 

A number of the capital costs equations depend on the number of wells at each landfill. In order 

to estimate the number of wells at each landfill, the number of acres that have been filled with waste for 

each landfill for each year were estimated. For landfills not reporting a GCCS area to GHGRP, it was 

assumed that the percent of design area filled (acres) would track the ratio of waste in place/design 

capacity (e.g., if a landfill had a waste-in-place amount equivalent to 40 percent of design capacity, then 

40 percent of the planned acreage would be filled). For GHGRP landfills who reported a GCCS area (as 
7 

discussed in section 2.3 of another memorandum)9 this value was compared to the calculated area based 

on ratio of waste in place/design capacity discussed above. The maximum of the reported value or this 

calculated area was used as the starting point for an estimated GCCS area in year 2014, and that area grew 

overtime, tracking the ratio of waste in place/design capacity. In addition, it was assumed that each 

landfill would install one well per acre, consistent with the guidelines provided in the LFGcost-Web 

model, and that the number of wells would increase periodically based on expansion lag time. See Table 2 

for an example of the number of wells estimated annually at a landfill where the initial lag time is 3 years 

and the expansion lag time is 4 years. 

Table 2. Example of Number of Wells at a Landfill with an Initial Lag Time of 3 Years and an 

Expansion Lag Time Equal to 4 Years (and the landfill reaches the emission rate threshold in year 1) 

Year Acreage Number of Wells

1 98.2 0

2 102.9 0

3 107.5 0

4 112.1 112

5 116.8 112

6 121.4 112

7 126.1 112

8 130.7 131

9 135.4 131

10 140 131

11 140 131

12 140 140

13 140 140

14 140 140

15 140 140

3.1 Capital Costs 

The equations used in this evaluation to calculate capital costs for flares, wells, wellheads 

(including gas collection piping), mobilization/installation, and engines are presented below. All costs 

equations are shown on an individual landfill and year basis. 

Flare Capital Costs 

 

Flares are the primary control device used at landfills. All landfills required to comply with the 

control scenario were assumed to install flares. Landfills using engines were assumed to have flares as the 

back-up control device for periods when the engines are not operating. The capital flare costs were 

estimated using the equation below, which was based on the installed cost of the knockout, blower, and 

flare system as determined in LFGcost-Web. The flares were sized based on the maximum LFG flow rate 

over the 15-year flare lifetime, which could be as late as 2039 for projects that were expected to begin 

operation in 2025. 

Eq. 5: 

1

61.0

15yr max

capital 15,y

,4 600 02.1( )

525,600

LFG

Flare z

−

× ×

















= ×

 

9

 Summary of Updated Landfill Dataset Used in the Cost and Emission Reduction Analysis of Landfills Regulations. 

2015. 
8 

Where: 

Flare capital = Installed annualized cost of knockout, blower, and flare system, 2012$ 

z 15,y = Annualization factor where x=15 yrs and y=interest rate (0.07 or 0.03), 

unitless 

LFG15yrmax = Maximum LFG collected for 15 year project period, ft3 per year 

525,600 = Conversion factor, minutes per year 

$4,600 = Installed capital cost of knockout, blower, and flare system, 2013$ per 

ft3/min LFG 

(1.02)-1 = Adjustment from 2013$ to 2012$, unitless10

Vertical Gas Extraction Well Capital Costs 

The vertical gas extraction well capital costs were based on a dollar per linear foot of well depth 

installed estimate from LFGcost-Web. As shown in the equation below, wells were assumed to have a 

depth of 10 feet less than the landfill depth. The method used to estimate the number of wells at the 

landfill each year is described above. 

Eq. 6: Well capital = z 15,y × (Depth – 10) × 85 × Wells annual × (1.02)-1

Where: 

Well capital = Installed annualized cost of vertical wells, 2012$ 

z 15,y = Annualization factor where x=15 yrs and y=interest rate (0.07 or 0.03), 

unitless 

Depth = Landfill waste depth, feet 

10 = feet 

$85 = Installed capital cost of one vertical well, 2013$ per foot of well depth 

Wells annual = Number of vertical wells operated each year 

(1.02)-1 = Adjustment from 2013$ to 2012$, unitless 

Wellhead Capital Costs 

The capital wellhead cost covered the equipment associated with each well, including the 

wellhead and pipe gathering system (and any additional fittings/installations connecting the wells, and 

was dependent on the number of wells. In addition, this capital cost encompasses engineering, permitting, 

and surveying fees associated with the wellfield installation that are also dependent on the number of 

wells. The capital wellhead costs at each landfill were estimated using a dollar per well installed cost from 

LFGcost-Web for wellheads, pipe gathering system, engineering, permitting, and surveying and the 

number of wells at each landfill. 

Eq. 7: Wellhead capital = z 15,y × 17,700 × Wells annual × (1.02)-1

Where: 

Wellhead capital = Installed annualized cost of wellheads, 2012$ 

z 15,y = Annualization factor where x=15 yrs and y=interest rate (0.07 or 0.03), 

unitless 

$17,700 = Installed capital cost of one wellhead, 2013$ per well 

Wells annual = Number of wells operated each year 

 

10 Equation uses a formula of (1+inflation rate/100)t

, where capital cost escalation is assumed to be 2 percent 

and t is equal to -1 year 
9 

(1.02)-1 = Adjustment from 2013$ to 2012$, unitless 

Mobilization/ Installation Costs for Wellfield Expansion 

The cost occurs upon installation of a new gas collection system (i.e., wellfield) and each time the 

wellfield was expanded into new areas of the landfill, so the frequency was dependent on the expansion 

lag time. This cost was independent of the number of wells being added. It included costs such as 

planning, set-up, and mobilization costs to get the well drilling rig and pipe crew on site. This cost was 

estimated using the following equation from LFGcost-Web: 

Eq. 8: Installation capital = z x,y × 20,000 × (1.02)-1

Where: 

Installation capital= Mobilization/installation annualized cost, 2012$ 

z x,y = Annualization factor where x=expansion lag time in yrs and y=interest 

rate (0.07 or 0.03), unitless 

$20,000 = Mobilization/Installation costs, per occurrence, 2013$ 

(1.02)-1 = Adjustment from 2013$ to 2012$, unitless 

Engine Capital Costs 

Engines were assumed to be installed only at landfills that produced enough LFG to power the 

engine and only when the electricity buyback rates allowed the operation of the engine to be profitable. 

Standard engines used at landfills have approximately 1 MW capacity, which equates to 195 million ft3

per year of collected LFG (at 50 percent methane). Therefore, engines were assumed to be installed at 

landfills that had at least 195 million ft3 per year of collected LFG for at least 15 years, which could be as 

late as 2039 for engines there were installed in 2025. 

The engine capital and operation and maintenance (O&M) equations were calculated and 

summed to determine at what electricity buyback rate an engine would be profitable. The profitable 

electricity buyback rate was greater than $0.0594 per kWh at a 7 percent interest rate and greater than 

$0.0430 per kWh at a 3 percent interest rate; it was assumed engines were only installed in States with 

buyback rates exceeding those values. 

Multiple engines may be present at a landfill when there is sufficient gas flow to support 

additional engines. As noted above, one engine required 195 million ft3 per year of collected LFG. To 

have two engines on site, the landfill must have had double that amount of LFG (390 million ft3 per year) 

for at least 15 years after the project start date, which could be as late as 2039 for projects starting in 

2025. 

The capital costs for engines were based on the capital costs for standard reciprocating enginegenerator sets in LFGcost-Web. These costs included gas compression and treatment to remove 

particulates and moisture (e.g., a chiller), reciprocating engine and generator, electrical interconnect 

equipment, and site work including housings, utilities, and total facility engineering, design, and 

permitting. 
10 

Eq. 9: Engine capital = z 15,y, y × 2,650,000 × (1.02)-1 × Engine multiplier

Where: 

Engine capital = Installed annualized cost of engines, 2012$ 

z 15,y = Annualization factor where x=15 yrs and y=interest rate (0.07 or 0.03), 

unitless 

$2,650,000 = Installed capital cost of one reciprocating engine-generator set, 2013$ per 

engine 

(1.02)-1 = Adjustment from 2013$ to 2012$, unitless 

Engine multiplier = Number of engines needed 

3.2 Operation and Maintenance (O&M) Costs 

The equations used in this evaluation to calculate O&M costs for flares, wells, electricity, and 

engines are presented below. All cost equations are shown on an individual landfill and year basis. These 

costs for all landfills were summed by year and the resulting annual sums were used to estimate NPV 

costs. 

To accurately estimate annual electricity costs and engine revenue from the generation and sale of 

electricity, two electricity prices were needed. Landfills must purchase electricity to operate the blowers 

used to collect LFG. EPA used 2012 commercial average retail electricity prices by State from the U.S. 

Energy Information Administration (EIA) to estimate electricity purchase prices at the landfill11. 

Landfills utilizing engines generate revenue from the sale of the LFG-produced electricity. The 

amount of revenue generated depends primarily on the buyback rate negotiated between the landfill (or 

third party developer) and the electric company purchasing the LFG-generated power. Average (mean) 

wholesale prices for each State were calculated using 2012 resale generation and revenue data from EIA 

to estimate electricity buyback rates12. These wholesale prices generally fit in the range of typical 

buyback prices for LFG of $0.025 - $0.11/kWh, as discussed in LMOP’s Project Development 

Handbook.13 Additionally, LFGcost-Web uses a default buyback rate of $0.06/kWh and the U.S. average 

of the wholesale prices used is $0.0655/kWh. 

EIA wholesale data were not available for three States (HI, RI, & WV). For these States, 

electricity purchase price data from EIA were used to estimate buyback rates14. The buyback rates were 

estimated by first determining the ratio of each State’s purchase price to the overall average U.S. purchase 

price. This ratio was then multiplied by the calculated average U.S. wholesale price to estimate a buyback 

rate. Electricity price data for the U.S. territories of Guam, Puerto Rico, and the Virgin Islands were not 

found. Therefore, EIA profile analyses for these three territories were used to escalate U.S. average prices 

to estimate electricity prices for each island15.

Flare O&M Costs 

 

11 U.S. DOE/EIA. Electricity: Detailed State Data, Annual Data for 2012. Average Price by State by Provider (EIA861), 1990-2012. Released November 12, 2013. http://www.eia.gov/electricity/data/state

12 U.S. DOE/EIA. Electric power sales, revenue, and energy efficiency Form EIA-861 detailed data files. 2012 

Operational Data (Formerly File 1). Released October 29, 2013. http://www.eia.gov/electricity/data/eia861

13 U.S. EPA LMOP Chapter 4 of Project Development Handbook. 

http://epa.gov/lmop/documents/pdfs/pdh_chapter4.pdf 

14 U.S. DOE/EIA. Electricity: Detailed State Data, Annual Data for 2012. Average Price by State by Provider (EIA861), 1990-2012. Released November 12, 2013. http://www.eia.gov/electricity/data/state

15 U.S. DOE/EIA. Territory Profile and Energy Estimates (for Guam, Puerto Rico, and the U.S. Virgin Islands). 

Profile Analysis, Electricity. December 18, 2013. http://www.eia.gov/state
11 

An estimate of the flare O&M costs from LFGcost-Web was used to estimate the flare annual 

costs, as shown in the equation below: 

Eq. 10: Flare O&M = 5,100 × (1.025)-1

Where: 

Flare O&M = Flare annual O&M costs, 2012$ 

$5,100 = Annual O&M flare cost, 2013$ 

(1.025)-1 = Adjustment from 2013$ to 2012$, unitless16

Well O&M Costs 

An estimate of the O&M costs for vertical gas extraction wells from LFGcost-Web was used to 

estimate the well annual costs, as shown in the equation below: 

Eq. 11: Well O&M = 2,600 × Wells annual × (1.025)-1

Where: 

Well O&M = Well annual O&M costs, 2012$ 

$2,600 = Annual O&M well costs, 2013$ per well 

Wells annual = Number of wells operating each year 

(1.025)-1 = Adjustment from 2013$ to 2012$, unitless 

Electricity O&M Costs 

The electricity cost of operating the blowers was calculated using the electricity usage of blowers 

from LFGcost-Web and the electricity purchase price. 

Eq. 12: Electricity O&M = 0.002 × Electricitypurchase × LFG collected 

Where: 

Electricity O&M = Electricity annual O&M costs, 2012$ 

0.002 = Electricity usage by blowers, kWh per ft3 LFG 

Electricity purchase = Electricity purchase price, 2012$ per kWh 

LFG collected = Amount of LFG collected, ft3 per year 

Engine O&M Costs 

For landfills with engines installed, the O&M costs of the engine were estimated using the annual 

costs for standard reciprocating engine-generator sets from LFGcost-Web, and taking into account the 

amount of time that the engine was operating each year (assumed gross capacity factor in LFGcost-Web 

for engines) and the number of engines on site. 

Eq. 13: Engine O&M = 0.025 × 1,000 × 8,760 × 0.93 × (1.025)-1 × Engine multiplier

Where: 

Engine O&M = Engine annual O&M costs, 2012$ 

0.025 = Annual O&M engine cost, 2013$ per kWh 

 

16 Equation uses a formula of (1+inflation rate/100)t

, where O&M cost escalation is assumed to be 2.5 percent and t 

is equal to -1 year. 
12 

1,000 = Amount of electricity as kW produced by a 1 MW engine, kW per engine 

8,760 = Conversion factor, hours per year 

0.93 = Fraction of time that the engine is online, unitless 

(1.025)-1 = Adjustment from 2013$ to 2012$, unitless 

Engine multiplier = Number of engines 

Engine Revenue Costs 

For landfills with engines installed, the revenue of the electricity produced by the engines was 

calculated using the equation below. This equation assumed that all electricity generated was sold to the 

grid (instead of some of the electricity generated being used to power the GCCS). 

Eq. 14: Engine revenue = 1,000 × 8,760 × 0.93 × Electricity buyback × Engine multiplier

Where: 

Engine revenue = Engine annual revenue, 2012$ 

1,000 = Amount of electricity as kW produced by a 1 MW engine, kW per engine 

8,760 = Conversion factor, hours per year 

0.93 = Fraction of time that the engine is online, unitless 

Electricity buyback = Electricity buyback rate, 2012$ per KWh 

Engine multiplier = Number of engines 

4. Summary 

This memorandum summarizes the emission reduction and cost equations used to evaluate the 

cost and emission impacts of various control scenarios considered under the review of the NSPS and EG. 

The EPA determined which landfills met the design capacity and emission rate thresholds for each 

regulatory option, then calculated the emission reductions and costs for each landfill in 2025 under each 

control scenario using the equations described in this memorandum. The results of applying this 

methodology to the landfills dataset are discussed in other memoranda and are detailed in the database.17, 

18, 19, 20 

 

17 ERG. 2015. Updated Cost and Emissions Impacts Resulting from the Landfills NSPS Review. 

18 ERG. 2015. Modeling Database Containing Inputs and Results of Supplemental Proposal for MSW Landfill 

NSPS. 

19 ERG. 2015. Revised Cost and Emission Impacts Resulting from the Landfill EG Review. 

20 ERG. 2015. Modeling Database Containing Inputs and Results for Proposed Review of the MSW Landfill 

Emission Guidelines.