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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: April 2014 

SUBJECT: Summary of Landfill Dataset Used in the Cost and Emission Impacts Analysis of Landfill 

Regulations 

Introduction 

The EPA is reviewing the new source performance standards (NSPS) for municipal solid waste 

(MSW) landfills and issuing an Advanced Notice of Proposed Rulemaking (ANPRM) for a review of the 

emission guidelines. (40 CFR part 60, subpart WWW and 40 CFR part 60, subpart Cc, respectively). 

Currently, the NSPS regulation requires any landfills of at least 2.5 million megagrams (Mg) and 2.5 

million cubic meters in size with estimated nonmethane organic compounds (NMOC) emissions of at 

least 50 Mg per year to collect and control or treat landfill gas (LFG).1

 

As a first step in developing these estimated cost and emission impacts of various changes to the 

current regulatory requirements resulting from the ongoing review of the NSPS/EG, a dataset of existing 

(current) and future (projected) landfills was created (NSPS/EG dataset). For each landfill, the NSPS/EG 

dataset contains landfill-specific information including: 

 Landfill identification (ID) number 

 Waste-in-place year 

 Annual waste acceptance year 

 Landfill closure year 

 Year landfill opened 

 Landfill design capacity (in tons) 

 Landfill design area (in acres) 

 Landfill depth (in feet). 

 The purpose of this memorandum is to summarize the source data and assumptions used to create 

the NSPS/EG landfill dataset. Using the NSPS/EG dataset as an input, a Microsoft® Access database was 

developed to calculate the emission reductions and costs. The assumptions and calculations housed in the 

database are detailed in the April 2014 memorandum, Methodology for Estimating Cost and Emission 

Impacts of MSW Landfill Regulations. 

1. Landfill Data Sources 

                                                           

1 The requirements for existing sources under the state and federal plans implementing the EG are similar to those

for new sources under the current NSPS.
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 Landfill data were obtained from three sources: a landfill and LFG energy project database 

maintained by EPA’s Landfill Methane Outreach Program (LMOP), a voluntary survey of landfills, and 

the Greenhouse Gas Reporting Program (GHGRP). These data sources are described below. 

1.1 LMOP Database 

The LMOP database does not represent the entire universe of landfills in the United States; the 

database includes landfill information provided to LMOP and from publically available sources. A 

snapshot of the database based on data as of July, 2012. At that time, the LMOP database contained 

information for 2,434 landfills, all of which were added to the NSPS/EG dataset. In some cases, the 

amount of information about a particular landfill was very limited. For example, if the only publically 

available information for a landfill was the location and the opening year, only the location and opening 

year were included in the LMOP database. If the combined dataset (from all three sources) showed 

duplicate landfills, 2012 LMOP data were used over voluntary survey data because the LMOP data were 

more recent than the voluntary data. Information in the LMOP database is compiled from a variety of 

sources by voluntary submittal, is updated periodically, and can change. Updates are not subject to a 

prescribed schedule as they would be under a regulatory program. 

The LMOP database also contains a flag field denoting whether or not a gas collection and control 

system (GCCS) is installed and if so, whether energy recovery projects exist at the landfill. A separate 

snapshot of the LMOP database based on data from December 2013 was used to approximate the total 

number of landfills with GCCS installed in order to identify which additional systems might be installed 

voluntarily, in addition to the estimated number of systems based on the methodology discussed in the 

April 2014 memorandum, Methodology for Estimating Cost and Emission Impacts of MSW Landfill

Regulations. 

1.2 Voluntary Data 

EPA conducted a voluntary landfill survey in 2010 and received information from 167 landfills. 

All but five of the landfills that reported information to the survey were already included in the LMOP 

database. These five landfills were added to the NSPS/EG dataset. 

1.3 GHGRP Data 

Subpart HH of the GHGRP collects information from landfills that meet the reporting thresholds 

of the program. Landfill data were added from GHGRP reporting year 2010. All but seven of the GHGRP 

landfills and the majority of the data were already included in the LMOP database because LMOP 

previously compared and combined LMOP and GHGRP data from reporting year 2010. These seven 

landfills were added to the NSPS/EG dataset. Data from GHGRP were reporting year 2010 (which were 

made available in late 2011). Data are updated annually to the GHGRP and data from reporting year 2012 

were recently released in late October 2013. Reporting year 2012 data include new inputs to GHG 

equations that were previously deferred as confidential information and these data will be incorporated 

into the dataset between proposal and promulgation of the Landfill NSPS. 

Data from the various sources were evaluated and combined appropriately. The combination of 

the LMOP database, the voluntary survey dataset, and the 2010 GHGRP data resulted in a dataset of 

2,353 landfills after the following data quality tiers were applied to make corrections and resolve 

inconsistencies between the three datasets: 
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 Landfills closing before November 8, 1987 are not applicable to the state and federal plans 

implementing the EG. To accommodate this rule applicability criterion for the purposes of the 

dataset, any landfill closing before 1988 was removed from the dataset. 

 For landfill open and closure years and design capacity, it was assumed that data reported in the 

GHGRP were the most up-to-date and were used preferentially before data reported in the survey 

or included in LMOP database. 

 For LMOP database fields that had not been recently updated, data reported in the survey was 

used. If the LMOP database data were updated after the 2010 survey, the updated LMOP data in 

this dataset were used. 

 Sometimes landfills in the LMOP database were recorded as separate landfills (e.g., old and new 

landfill), but they were reported as a single landfill in the survey or GHGRP. In these cases the 

landfills were treated as a single entity in this NSPS/EG dataset. In addition, if the landfills had 

the same address in the LMOP database and were not designated as reporting separately to the 

NSPS, they were combined for this dataset. A total of 18 LMOP landfills were combined into 

nine landfills for the NSPS analysis. These combined landfills are designated in the dataset with a 

combined landfill ID, which includes the separate LMOP landfill IDs separated by a period 

(example: landfill ID 1009.1008). 

2. Filling Data Gaps 

The combined NSPS/EG dataset of 2,353 landfills was missing landfill data for recent years 

(2010-2014) and included incomplete data for many landfills. Thus, model landfills were created to 

represent the recent landfill data that were not included in the dataset. Methods were also developed to 

estimate, if possible, the missing parameters for individual landfills, using existing data from LMOP, the 

voluntary survey, and the GHGRP. These data gap filling steps are described below in more detail. 

A dataset of model landfills was developed for inclusion in the NSPS/EG analysis. It was 

assumed that the sizes and locations of landfills opening in the most recent complete 8 years of data 

(2003-2010) would be similar to landfills opening in the next 8 years (2011-2018). Based on existing 

landfills, 37 model landfills were created to represent landfills opening in years 2012 to 2018. Of these 

landfills, 21 were included in the “future” landfill dataset, which includes landfills opening in 2014 to 

2018, because 2014 is the year the NSPS will be proposed and represents the cutoff year for the proposed 

NSPS and EG. The future landfills are designated in the dataset with an “F” as the first digit in the landfill 

ID on (example: landfill ID F1). The other model landfills are designated in the database with an “N” as 

the first digit in the landfill ID, (example: landfill ID N1). The model landfills were created before the 18 

LMOP landfills were combined to better represent new landfill capacity added each year; if the model 

landfills had been developed after the landfills were combined, there would be fewer future landfills. 

Because the dataset did not contain complete data for many landfills, methods were developed to 

estimate the following parameters: 

 Waste-in-place year 

 Annual waste acceptance year 

 Landfill closure year 

 Year landfill opened 

 Landfill design capacity 

 Landfill design area 
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 Landfill depth. 

When there are multiple estimation methods for one of the parameters, the methods were 

followed sequentially as described below. Therefore, parameters were estimated using later methods only 

if the parameters were not estimated using an earlier method.

2.1 Waste-in-place Year 

If waste-in-place year was missing and the landfill is closed, it was assumed that the reported 

waste-in-place year represented the year that the landfill closed. Therefore, the waste-in-place year was 

set as equal to the landfill closure year. 

2.2 Annual Waste Acceptance Year 

If annual waste acceptance year was missing and the landfill is closed, it was assumed that the 

reported annual waste acceptance rate was reported in the year that the landfill closed. Therefore, the 

annual waste acceptance year was set as equal to the landfill closure year. 

2.3 Landfill Closure Year 

For the first estimation method, the landfill closure year was calculated based on waste-in-place, 

waste-in-place year, landfill design capacity, and annual waste acceptance rate. The number of years 

required to fill the landfill to capacity was calculated first by subtracting waste-in-place from the design 

capacity and then dividing by the annual waste acceptance rate. This value was added to the reported 

waste-in-place year to determine the landfill closure year. 

For landfills that we could not calculate the closure year by following the first estimation method, 

a second estimation method was followed. The closure year was calculated based on the year the landfill 

opened, landfill design capacity, and annual waste acceptance rate. The number of years required to fill 

the landfill to capacity was calculated first by dividing landfill design capacity by the annual waste 

acceptance rate. This number of years value was added to the year the landfill opened to estimate the 

landfill closure year. Following this methodology for landfills that were reported as closed, the calculated 

closure year should be prior to 2020, because the landfill was reported to be closed; thus, any calculated 

closure years after 2019 were not included in the NSPS/EG dataset. For landfills that were reported to be 

open, the calculated closure year should be after 2000, because the landfill was reported to be open; thus, 

any calculated closure years prior to 2001 were not included in the NSPS/EG dataset. 

 For the third estimation method, landfill closure was calculated based on waste-in-place, wastein-place year, landfill design capacity, and a calculated waste acceptance rate. The annual waste 

acceptance rate was calculated by dividing the amount of waste-in-place by the number of years the 

landfill had accepted this amount of waste (calculated by subtracting the year the landfill opened from the 

waste-in-place year). The amount of waste to be added was calculated by subtracting the waste-in-place 

from the landfill design capacity. This value was divided by the calculated annual waste acceptance rate 

to estimate the number of years to reach capacity. The number of years to reach capacity was then added 

to the waste-in-place year to estimate the landfill closure year. 

 If the landfill closure year was still missing and the waste-in-place year was not available, it was 

assumed that the waste-in-place year was 1998 because the majority of waste-in-place years in the LMOP 

database were 1998. ERG calculated the annual waste acceptance rate by dividing the amount of wastein-place by the number of years the landfill had accepted this amount of waste (subtraction of the year the 

landfill opened from 1998). The amount of waste to be added was calculated by subtracting the waste-in-
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place from the landfill design capacity. This value was divided by the calculated waste acceptance rate to 

estimate the number of years to reach capacity. The number of years to reach capacity was added to 1998 

to estimate the landfill closure year. 

2.4 Year Landfill Opened 

 If waste-in-place, waste-in-place year, and annual waste acceptance rate were available, these 

parameters were used to estimate the year the landfill opened. The number of years the landfill had been 

active was calculated by dividing the waste-in-place by the annual waste acceptance rate. This value was 

subtracted from the waste-in-place year to estimate the year the landfill opened. 

 For the second estimation method, if annual waste acceptance rate, annual waste acceptance year, 

and waste-in-place were available, these parameters were used to estimate the year the landfill opened. 

The number of years the landfill had been active was calculated by dividing the waste-in-place by the 

annual waste acceptance year. As long as this value did not exceed 100 years, it was subtracted from the 

annual waste acceptance year to estimate the year the landfill opened. 

 Finally, the year the landfill opened was calculated based on the closure year, landfill design 

capacity, and annual waste acceptance rate. The number of years required to fill the landfill to capacity 

were calculated by dividing landfill design capacity by the annual waste acceptance rate. This value was 

subtracted from the landfill closure year and used to estimate the year the landfill opened as long as it did 

not exceed 100 years. 

2.5 Landfill Design Capacity (tons) 

 First, if the waste-in-place year was greater than the landfill closure year, it was assumed that the 

landfill had reached capacity and the landfill design capacity was set equal to the amount of waste-inplace. 

 If the landfill design capacity was available in cubic yards, it was converted to tons using an 

assumed waste density of 0.6 tons per cubic yard. 

 Next, if the landfill had values for waste-in-place, waste-in-place year, year the landfill opened, 

and landfill closure year, then the landfill design capacity was calculated. First, the annual waste 

acceptance rate was calculated by dividing the waste-in-place by the number of years the landfill had 

accepted this amount of waste (which was determined by subtracting year the landfill opened from wastein-place year). The calculated waste acceptance rate was multiplied by the number of years until the 

landfill closes (which was calculated by subtracting the waste-in-place year from landfill closure year) to 

estimate how much waste would be added to the landfill to reach capacity. This amount was added to the 

waste-in-place to estimate the landfill design capacity. 

 If the landfill had values for annual waste acceptance rate, year the landfill opened, and landfill 

closure year, then the landfill design capacity was calculated by multiplying the landfill lifetime by the 

annual waste acceptance rate. The landfill lifetime was calculated by subtracting the year the landfill 

opened from the landfill closure year. This calculation method was not used to estimate landfill design 

capacity if waste-in-place exceeded the calculated design capacity. 

 If the year the landfill opened was not available, the landfill design capacity was calculated based 

on waste-in-place, the years remaining before landfill closure, and annual waste acceptance rate. The 

years remaining before landfill closure were calculated by subtracting the waste-in-place year from the 

landfill closure year. This result was then multiplied by the annual waste acceptance rate to estimate the 
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amount of waste to be added to the landfill to reach capacity. The added waste and the waste-in-place 

were summed to determine the design capacity. 

 Next, the landfill design capacity was calculated based on the landfill lifetime and the annual 

waste acceptance rate. The landfill lifetime was estimated by subtracting the year the landfill opened from 

the landfill closure year. The annual waste acceptance rate was multiplied by the landfill lifetime to 

estimate the design capacity. 

 If the waste-in-place year was not available, it was assumed to be 1998 because the majority of 

reported waste-in-place years in the LMOP database were 1998. Using this assumption, the annual waste 

acceptance rate was calculated by dividing the waste-in-place by the subtraction of the year the landfill 

opened from 1998. The annual waste acceptance rate was then multiplied by the landfill lifetime 

(subtraction of the year the landfill opened from the landfill closure year) to estimate the design capacity. 

 If the landfill design capacity was still missing, it was calculated by multiplying the landfill 

design area (square feet) with the waste depth (feet), and then dividing by an assumed waste density of 45 

cubic feet per ton. 

2.6 Landfill Design Area (acres) 

 If the landfill design area was not recorded in the LMOP database, designed landfill area from the 

voluntary survey for the landfill was used. If the designed landfill area was not reported, but the current 

landfill area (acres) was reported and waste-in-place divided by the landfill design capacity was equal to 

or less than one, then the landfill design area was calculated using current landfill area, waste-in-place, 

and landfill design capacity. This calculation assumes that the ratio of the waste-in-place to the design 

capacity is equal to the ratio of the current landfill area to the design landfill area. The landfill design area 

was estimated by dividing the current landfill area by the fraction of waste deposited (waste-in-place 

divided by design capacity). Similarly, if current landfill area was not reported, landfill design area was 

estimated by dividing the landfill footprint (acres) by the fraction of waste deposited (waste-in-place 

divided by design capacity). 

 If the design area of the landfill had not been estimated any other way, the acreage was calculated 

based on landfill design capacity, landfill design depth, and an assumed waste density of 45 cubic feet per 

ton. 

 Finally, if there were no reported depth or area values for the landfill, and no area was estimated 

by the methods described above, the landfill design was estimated based on a best fit equation created 

from a linear regression analysis of a graph of the reported design areas and design capacities. Two 

different equations–one for landfills with design capacities greater than 5 million tons and one for 

landfills with design capacities less than or equal to 5 million tons were developed. 

 Calculation for landfills with design capacities greater than 5 million tons:

Landfill Design Area (acres) = 0.0000044 * [Landfill design capacity (tons)] + 98.26 

 Calculation for landfills with design capacities less than or equal to 5 million tons:

Landfill Design Area (acres) = 0.000023 * [Landfill design capacity (tons)] + 11.73 

2.7 Landfill Design Depth (feet)

 If the landfill design depth was not recorded in the LMOP database, the designed landfill depth 

from the voluntary survey for the landfill was used. If the designed landfill depth was not reported, but the 
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current landfill depth (feet) was reported, the current landfill depth was used. If neither was reported, but 

the waste depth was reported, the waste depth was used. 

 If there were no reported depth values for the landfill, the depth was calculated based on landfill 

design capacity, landfill design area, and an assumed waste density of 45 cubic feet per ton. The volume 

of waste was calculated by multiplying the landfill design capacity (tons) by the assumed density of 

waste. The landfill design depth was estimated by dividing the waste volume by the landfill design area. 

 Finally, if there were no reported depth or area values for the landfill, and no depth was estimated 

by the methods described above, the landfill design depth was estimated based on a best fit equation 

created from linear regression analysis of a graph of the reported design depths and design capacities. 

Two different equations—one for landfills with design capacities greater than 5 million tons and one for 

landfills with design capacities less than or equal to 5 million tons were developed. 

 Calculation for landfills with design capacities greater than 5 million tons:

Landfill design depth (feet) = 0.00000086 * [Landfill design capacity (tons)] + 108 

 Calculation for landfills with design capacities less than or equal to 5 million tons:

Landfill design depth (feet) = 0.000012 * [Landfill design capacity (tons)] + 56 

3. Final Dataset 

After filling the data gaps (for waste-in-place year, annual waste acceptance year, landfill closure 

year, year landfill opened, landfill design capacity, landfill design area, and landfill depth), there were still 

a number of landfills that did not have sufficient data to include in the NSPS/EG cost and emission 

impact modeling analysis. Of the original 2,434 landfill dataset created by the combination of the LMOP 

database, voluntary survey, GHGRP, and model landfills, 1,853 landfills (76 percent of the total) had 

sufficient data to include in the NSPS/EG analysis–1,832 current landfills (constructed prior to 2014 but 

accepted waste after 1987) and 21 future landfills (constructed in 2014-2018). 

Appendix A provides a detailed listing of the background data sources, data tables, field names, 

and field descriptions (including units of measure) for the EG database. Appendix B provides a similar 

listing for the data tables in the NSPS database. The contents of each dataset are available in a database 

format.2,3 The results of the voluntary survey are not stored in the database, but are provided in another 

docketed spreadsheet.3 

                                                           

2

 ERG. 2014. Modeling Database Containing Inputs and Results of Proposed Revisions to MSW Landfill NSPS. 

3

 ERG. 2014. Modeling Database Containing Inputs and Preliminary Impacts for Review of the MSW Landfill 

Emission Guidelines. 

3

 Summary of Responses to 2010 Voluntary MSW Landfill Survey.