1 MEMORANDUM

TO: Hillary Ward, U.S. Environmental Prot ection 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 WW W 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 nonmet hane organic compounds (N MOC) 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 ongoi ng 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 assumpti ons 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.2 Landfill data were obtained from three sources: a landfill and LFG energy project database maintained by EPA’s Landfill Methane Outreach Progr am (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 uni verse 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 par ticular 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 we re 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 de noting whether or not a gas collection and control system (GCCS) is installed and if so, whether energy recovery project s exist at the landfill. A separate snapshot of the LMOP database based on data fro m 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 2 010 and received information from 167 landfills. All but five of the landfills that reported informati on 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 alr eady included in the LM OP 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). Da ta are updated annually to the GHGRP and data from reporting year 2012 were recently released in late October 2013. Repor ting year 2012 data include new inputs to GHG equations that were previously deferred as confiden tial information and these data will be incorporated into the dataset between proposal a nd promulgation of the Landfill NSPS.

Data from the various sources were evaluated a nd combined appropriately. The combination of the LMOP database, the voluntary survey dataset, a nd 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:3  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 19 88 was removed from the dataset.

 For landfill open and closure years and design capac ity, it was assumed that data reported in the GHGRP were the most up-to-date and were used pref erentially before data reported in the survey

or included in LMOP database.

 For LMOP database fields that had not been r ecently 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 landf ill in the survey or GHGRP. In these cases the landfills were treated as a single entity in this N SPS/EG dataset. In addition, if the landfills had

the same address in the LMOP database and we re 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 incl udes 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 include d in the dataset. Methods were also developed to estimate, if possible, the missing parameters for indi vidual landfills, using exis ting data from LMOP, the voluntary survey, and the GHGRP. These data gap filli ng 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 openi ng 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 creat ed to represent landfills opening in years 2012 to 2018. Of these landfills, 21 were included in the “future” landfill dataset, which includ es landfills opening in 2014 to 2018, because 2014 is the year the NSPS will be propo sed and represents the cuto ff year for the proposed NSPS and EG. The future landfills are designated in the da taset with an “F” as the fi rst 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, met hods 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 area4  Landfill depth.

When there are multiple estimation methods fo r 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 la ndfill closed. Therefore, th e 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 clos ure 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 a cceptance 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 clos ure year by following the first estimation method, a second estimation method was followed. The closure y ear 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 di viding landfill design capacity by the annual waste acceptance rate. This number of years value was adde d to the year the landfill opened to estimate the landfill closure year. Following this methodology for la ndfills that were reported as closed, the calculated closure year should be prior to 2020, because the la ndfill was reported to be closed; thus, any calculated closure years after 2019 were not included in the NSPS/E G dataset. For landfills that were reported to be open, the calculated closure year should be after 20 00, 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 closur e was calculated based on waste-in-place, wastein-place year, landfill design capacity, and a calcu lated 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 ad ded was calculated by subtracting the waste-in-place from the landfill design capacity. This value was divided by the calcula ted annual waste acceptance rate to estimate the number of years to reach capacity. Th e 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 w aste-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 a dded was calculated by subtracting the waste-in-5 place from the landfill design capacity. This value was di vided by the calculated waste acceptance rate to estimate the number of years to reach capacity. The num ber 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 annua l waste acceptance rate were available, these parameters were used to estimate the year the la ndfill 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 wast e acceptance rate, annual waste acceptance year, and waste-in-place were available, these parameters we re 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 di d 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 calc ulated 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 acceptan ce 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 th an the landfill closure year, it was assumed that the landfill had reached capacity and the landfill design cap acity was set equal to the amount of waste-inplace.

If the landfill design capacity was available in c ubic 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 wast e-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 wast e acceptance rate was multiplied by the number of years until the landfill closes (which was calculated by subtracting th e waste-in-place year from landfill closure year) to

estimate how much waste would be added to the landf ill 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 accepta nce rate, year the landfill opened, and landfill closure year, then the landfill design capacity was ca lculated by multiplying the landfill lifetime by the annual waste acceptance rate. The landfill lifetime w as calculated by subtracting the year the landfill opened from the landfill closure year. This calculati on 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 land fill closure, and annual waste acceptance rate. The years remaining before landfill closure were calculat ed 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 the6 amount of waste to be added to the landfill to r each capacity. The added waste and the waste-in-place were summed to determine the design capacity.

Next, the landfill design capacity was calcula ted based on the landfill lifetime and the annual waste acceptance rate. The landfill lifetime was estimat ed by subtracting the year the landfill opened from the landfill closure year. The annual waste acceptan ce 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 la ndfill 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 cal culated using current landfill area, waste-in-place, and landfill design capacity. This calculation assumes that the ratio of the wast e-in-place to the design capacity is equal to the ratio of the current landf ill 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 estim ated 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 ar ea values for the landfill, and no area was estimated by the methods described above, the landfill design w as 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 cap acities greater than 5 million tons and one for landfills with design capacities less than or e qual 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 capac ities less than or equal to 5 million tons: Landfill Design Area (acres) = 0.000023 * [L andfill 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 the7 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 la ndfill, 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 la ndfills with design capacities greater than 5 million tons and one for landfills with design capacities less than or e qual 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 capac ities 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, land fill design area, and landfill depth), there were still

a number of landfills that did not have sufficient da ta to include in the NSPS/EG cost and emission impact modeling analysis. Of the original 2,434 landf ill 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 (cons tructed prior to 2014 but accepted waste after 1987) and 21 future la ndfills (constructed in 2014-2018).

Appendix A provides a detailed listing of the backgr ound 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 cont ents of each dataset are available in a database

format. 2,3 The results of the voluntary survey are not stor ed 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 an d Preliminary Impacts for Re view of the MSW Landfill

Emission Guidelines.

3 Summary of Responses to 2010 Voluntary MSW Landfill Survey.