oEPA
Anaerobic Digestion
Facilities Processing
Food Waste in the
United States in 2016
September 2019
EPA/XXX/X-##/###
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Author
Melissa Pennington, Sustainability Coordinator, EPA Region 3, Philadelphia, PA
Acknowledgements
EPA would like to acknowledge all the facility operators who provided data for this report. Not only did
these individuals provide data, but in many instances, they took the time to speak with us and clarify the
data provided. The operators really went above and beyond this year. EPA greatly appreciates this effort
and this report could not be generated without their valuable input. We hope that the information
provided in this report is useful to all facility operators and the industry as a whole.
The behind the scenes work on the development and maintenance of the electronic surveys is substantial.
This project could not happen without the outstanding technical support of David MacFarlane in EPA
Region 3's Information Systems Branch who steadfastly and efficiently revised the electronic surveys and
assisted with data management.
All the tedious and time-consuming work that went into the quality assurance review of the datasets can
be attributed to the tireless efforts of Chris Carusiello in EPA's Office of Land and Emergency Management,
Office of Resource Conservation and Recovery. Chris deserves the highest kudos for his efforts!
Document Review
Technical peer review of this document was provided by:
Anelia Milbrandt, Senior Researcher, National Renewable Energy Laboratory (NREL), Golden, CO
Debra L. Forman, Ph.D., Information Management Team Leader/Toxicologist, EPA Region 3,
Philadelphia, PA
Quality Assurance
EPA conducted a rigorous quality assurance review of the data and calculations used to generate the
information in this report. All critical data points were checked for outliers, an assessment of units was
conducted to ensure accuracy, and specific data points were compared to test for certain conditions (e.g,
reported capacity is greaterthan reported amounts of feedstock processed). Where necessary, anomalies
with verified with the respondent.
Disclaimer
The anaerobic digestion facilities and their locations are provided for informational purposes only.
Companies mentioned in this database are not certified or approved by US EPA. EPA does not guarantee
the accuracy or completeness of the information contained in this report.
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Table of Contents
List of Tables iii
List of Figures iv
Executive Summary v
I. Background 1
II. Survey Data Collection 2
III. Results 3
A. Response Rates and Location Data 3
B. Processing Capacity 9
C. Operational Dates 11
D. Food Waste Processed 12
E. Non-Food Waste Processed 13
F. Feedstock Types 13
G. Feedstock Sources 16
H. Tipping Fees 18
I. Pre-processing 19
J. Operational Specifications 20
K. Biogas Production 21
L. Biogas Uses 22
M. Gas Cleaning Systems 24
N. Solid Digestate Uses 25
O. Liquid Digestate Uses 28
IV. Conclusion 29
Appendix A - Operational Digesters and Co-Digestion Systems A-l
Appendix B - Digesters and Co-Digestion Systems Under Development or Temporarily Shut-Down ..B-l
Appendix C- Digesters and Co-Digestion Systems that have Ceased Operations C-l
Appendix D - Survey Questions D-l
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List of Tables
Table ES-1: Number of Operational Anaerobic Digestion Facilities Surveyed vi
Table ES-2: Total Capacity for Processing Food Waste and vi
Table ES-3 Total Amount of Non-Food Waste Processed by Digester Type (2016) vi
Table ES-4: Summary of Biogas Data Reported by Digester Type (2016) vii
Table 1: Number of Operational and Non-Operational Anaerobic Digestion Facilities Surveyed 3
Table 2: Comparison of Facilities Responding to 2017 Survey and Facilities Responding to the 2018
Survey 3
Table 3: Number of Operational Anaerobic Digestion Facilities Surveyed 4
Table 4: Number of Anaerobic Digestion Facilities in the Planning/Construction Phase Surveyed 4
Table 5: Number of Operating Anaerobic Digestion Facilities in each State by Facility Type 8
Table 6: Total Capacity for Processing Food Waste via Anaerobic Digestion by Digester Type 11
Table 7: Total Amount of Food Waste Processed by Each Digester Type (2016) 12
Table 8: Total Amount of Non-food Waste Processed by each Digester Type (2016) 13
Table 9: Types of Food Waste and Non-Food Waste Feedstocks Processed at Stand-Alone Digesters . 14
Table 10: Types of Food Waste and Non-food Waste Feedstock Processed at On-Farm Co-Digesters.. 15
Table 11: Types of Food Waste and Non-Food Waste Feedstock Processed 15
Table 12: Sources of Food Waste and Non-Food Waste Feedstock Processed by Stand-Alone Digesters 16
Table 13: Sources of Food Waste and Non-Food Waste Feedstock Processed by On-Farm Co-Digesters 17
Table 14: Sources of Food Waste and Non-Food Waste Feedstock Processed 18
Table 15: Pre-processing Activities for Stand-Alone Digester Facilities 19
Table 16: Pre-processing for On-Farm Co-Digestion Facilities 19
Table 17: Pre-processing for Co-Digestion Facilities at WRRFs 20
Table 18: Temperature Range Data for each Digester Type 20
Table 19: Data on Wet vs. Dry Systems for each Digester Type 21
Table 20: Summary of Biogas Data Reported by Digester Type (2016) 21
Table 21: Uses of Biogas Produced at Anaerobic Digesters 23
Table 22: Gas Cleaning Systems at Anaerobic Digesters 25
Table 23: Solid Digestate Uses 27
Table 24: Liquid Digestate Uses 28
Table 25: 2018 Survey Results 30
Table 1A: Stand-Alone Anaerobic Digestion Facilities Digesting Food Waste in the U.S. (2018) A-l
Table 2A: Stand-Alone Anaerobic Digestion Facilities Digesting Food Waste in the U.S. (2017) A-3
Table 3A: On-Farm Digesters Co-Digesting Food Waste in the U.S. (2018) A-4
Table 4A: On-Farm Digesters Co-Digesting Food Waste in the U.S. (2017) A-4
Table 5A: WRRF Digesters Co-Digesting Food Waste in the U.S. (2018) A-5
Table 6A: WRRF Digesters Co-Digesting Food Waste in the U.S. (2017) A-6
Table IB: Stand-Alone Anaerobic Digestion Facilities Under Development in the U.S B-l
Table 2B: WRRF's with Co-Digestion Systems under Development in the U.S B-l
Table 1C: Facilities that Have Ceased Operation in the U.S C-l
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List of Figures
Figure ES-1: Confirmed Operating Food Waste Digesting Facilities by State vii
Figure 1: Operating Stand-Alone Food Waste Digesting Facilities by State 5
Figure 2: Operating On-Farm Food Waste Co-Digestion Systems by State (2016) 6
Figure 3: Operating WRRF Food Waste Co-Digestion Systems by State 7
Figure 4: Operating Food Waste Digesting Facilities by State 8
Figure 5: Distribution of First Year of Digester Operation by Digester Type 12
Figure 6: Top Five Feedstocks Accepted by Digesters Taking Food Waste by Digester Type 16
Figure 7: Top Five Sources of Digester Feedstock by Digester Type 18
Figure 8: Top Five Uses of Biogas by Digester Type 24
Figure 9: Top Five Constituents Removed by Digester Type 25
Figure 10: Top Five Uses of Solid Digestate by Digester Type 27
Figure 11: Uses of Liquid Digestate by Digester Type 28
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Executive Summary
In 2014, the United States (U.S.) Environmental Protection Agency (EPA) began building a dataset of
names and locations of anaerobic digestion (AD) facilities processing food waste to better understand the
practice and the prevalence of food waste digestion in the United States. In December 2016, EPA was
granted the authority to survey digesters annually for 3 years, from 2017 - 2019. This report is the second
in a series of three reports. Each report includes data for three types of AD facilities: (1) stand-alone food
waste digesters; (2) on-farm digesters that co-digest food waste; and (3) digesters at water resource
recovery facilities (WRRFs) that co-digest food waste.
In 2017, EPA surveyed operators of AD facilities that accept food waste to identify the number of facilities
in the U.S. and their locations, and to learn about their operations. In September 2018, this data was
published in the report titled: Anaerobic Digestion Facilities Processing Food Waste in the United States
in 2015.
EPA administered the survey again in 2018. The data collected during the 2018 survey is summarized in
this report. Three data points are specific to the calendar year 2016: amount of food waste1 processed,
amount of non-food waste2 processed, and amount of biogas produced. Processing capacity, feedstock
types, feedstock sources, tipping fees, pre-processing/de-packaging, operational specifications, biogas
uses, gas cleaning systems, solid digestate uses, and liquid digestate uses reflect circumstances in 2018.
The third collection of AD data is targeted to begin later in 2019 at which time EPA will collect data for the
three time-specific data points (amount of food waste processed, amount of non-food waste processed,
and amount of biogas produced) for operating years 2017 and 2018 and remaining data will reflect
circumstances for 2019. Data from the 2019 survey will be summarized in the third report in this series
targeted for publication in 2020. EPA will continue to gather data and seek to verify data received in 2017
and 2018 to clarify the information in these reports over time. The data used in this report was voluntarily
submitted by survey respondents.
For the 2018 survey (data summarized in this report), EPA received responses from 134 operational
facilities. Table ES-1 shows these responses broken down by facility type. EPA offered the survey to 198
operating facilities including all 137 facilities that provided responses in 2017. EPA also made the survey
available on the Agency's website. EPA has continued to build the dataset of AD facilities that are known
to be operational, in the planning and design phase, under construction, and facilities that have ceased
operation or ceased co-digestion activities. This report provides information on the status of AD facilities
in each of these situations.
1 Food-based materials include, but are not limited to: food scraps that have been separated and collected by
municipalities from residential sources; food scraps that have been separated and collected from institutions or
venues (e.g., prisons, hospitals, stadiums); food scraps from food preparation at restaurants, cafeterias, and other
food services; plate scrapings from restaurants, cafeterias, and other food services; fats, oils and grease (FOG);
unused food collected from grocery stores (e.g., bakery items, bruised fruit, items past shelf life); and pre-consumer
by-products of the food and beverage processing industries.
2 Non-food waste feedstocks include, but are not limited to: mixed yard waste, crop residues, manure, wastewater
solids (sludge), septage, de-icing fluid, lab (or pharma) wastes, paper mill wastes, and crude glycerin.
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The 2018 response rates for each type of survey are comparable to the response rates from the 2017
survey. The operational facilities responding to the 2017 survey and the operational facilities responding
to the 2018 survey are not identical. Not all operating facilities that responded to the 2017 survey
responded to the 2018 survey, so results may not be directly comparable from the previous report. Table
ES-1 summarizes response rates for operational facilities by digester type. See Section II for a more
detailed description of respondent participation in the 2017 and 2018 surveys (specifically Table 2).
Table ES-1: Number of Operational Anaerobic Digestion Facilities Surveyed
and Response Rate by Digester Type
Digester type
Number of
Facilities Surveyed
Submitted
Survey
Survey Response
Rate
Stand-alone digesters
62
46
74%
On-farm co-digesters
59
16
27%
Co-digestion systems at WRRFs
77
72
94%
Total
198
134
68%
During the 2018 survey, EPA confirmed that 11 facilities have ceased operations (3 stand-alone facilities,
3 farm co-digestion systems, and 5 co-digestion systems at WRRFs). These facilities will no longer receive
surveys and have been removed from the response rate data in Table ES-1.
Processing Capacity and Amounts Processed
Based on data submitted by 131 survey respondents, the total processing capacity for food waste in all
three digester types combined as of 2018 is about 24 million tons per year. Based on data submitted by
126 survey respondents, the total amount of food waste processed in all three digester types in 2016 was
about 10.7 million tons (Table ES-2).
Table ES-2: Total Capacity for Processing Food Waste and
Total Amount of Food Waste Processed by Digester Type
Digester Type
Reported Capacity
in 2018 (tons per year)
Reported Amount
Processed in 2016 (tons)
Stand-alone digesters
21,126,270
9,222,413
On-farm co-digesters
256,044
154,789
Co-digestion systems at WRRFs
2,610,808
1,314,554
Total
23,993,122
10,691,756
Based on data submitted by 62 survey respondents, the total amount of non-food waste processed in all
three digester types combined was about 492 million gallons and 103,952 tons (Table ES-3).
Table ES-3 Total Amount of Non-Food Waste Processed
by Digester Type (2016)
Digester Type
Liquid Amount
(in gallons)
Solid Amount
(in tons)*
Stand-alone digesters
31,021,709
82,730
On-farm co-digesters
1,734,745
0
Co-digestion systems at WRRFs
459,216,246
21,222
Total
491,972,700
103,952
* Amounts were reported in liquid and solid units. Because there is no common conversion factor for
non-food waste, these values are separated.
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Biogas Production
Based on data submitted by 119 survey respondents, the total amount of biogas produced at digesters in
2016 was 40,304 standard cubic feet per minute (SCFM), equivalent to 126 megawatts (MW) installed
capacity, 939 million kilowatt-hours (kWh) generated per year, or enough energy to power 79,820 homes
for a year.
Table ES-4: Summary of Biogas Data Reported by Digester Type (2016)
Digester type
SCFM*
MW
kWh/yr
(million)
Number of Homes
Powered for One Year
Stand-alone digesters
10,498
33
246
20,911
On-farm co-digesters
4,053
13
97
8,246
Co-digestion systems at WRRFs
25,753
80
596
50,663
Total
40,304
126
939
79,820
* SCFM values are reported by facility operators and added together to get total SCFM for 2016 (40,304).
The MW, kWh/yr, and homes powered numbers are calculated using the LMOP interactive conversion
tool. These values are rounded to the nearest whole number, which accounts for the fact that the
column totals may not sum.
These figures likely underestimate actual processing capacity, food waste and non-food waste processed,
and biogas production because not all operational facilities provided a survey response.
Based on facilities returning surveys in 2018, 31 states have at least one operating digester (Figure ES-1).
States with ten or more confirmed operating digesters included California (30), Wisconsin (14) and Ohio
(11).
Figure ES-1: Confirmed Operating Food Waste Digesting Facilities by State
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Operational Specifications and Pre-Processing Activity
In terms of operational specifications, the majority of the digester types were found to be wet and
mesophilic systems, similar to the previous survey. The top pre-processing/de-packaging activity for both
stand-alone digesters and co-digestion facilities at WRRFs was screening and/or sorting. For on-farm co-
digesters the number one activity was manual or mechanized de-packaging.
Feedstock Sources and Types
When aggregated, the top five feedstock sources for anaerobic digesters in the U.S. in 2018 are:
• Food/beverage processors;
• Restaurants and food service;
• Grocery stores/supermarkets
• Industrial sources; and
• Municipal/residential sources.
When aggregated the top five feedstocks accepted by anaerobic digesters in the U.S. in 2018 are:
• Fats, oils and greases (FOG);
• Food processing industry waste;
• Beverage processing industry waste;
• Fruit/vegetative waste; and
• Food service waste, pre- and post-consumer.
Biogas Uses and Cleaning Systems
The top use of biogas among all three digester types was to produce combined heat and power (CHP).
The next two highest uses by digester type were:
• Stand-Alone Digesters: to produce electricity (sold to the grid), and to fuel boilers and furnaces
to heat other spaces/produce electricity used behind the meter (tied);
• On-Farm Co-Digesters: to produce electricity (sold to the grid), and to produce electricity used
behind the meter; and
• Co-Digestion Facilities at WRRFs: to fuel boilers and furnaces to heat digesters, and to fuel boilers
and furnaces to heat other spaces.
In 2018 approximately 78% of stand-alone digesters, 56% of farm co-digesters and 69% of co-digesters at
WRRFs reported that they utilize gas cleaning systems. The top constituents removed for all digester types
included moisture and sulfur.
Solid and Liquid Digestate Uses
The top three solid digestate uses by specific digester type were:
• Stand-Alone Digesters: composted into a reusable/salable product, other, and de-watered/dried
and land applied;
• On-Farm Co-Digesters: processed into animal bedding, de-watered and land applied, and
composted into a reusable/salable product; and
• Co-Digestion Facilities at WRRFs: de-watered and land applied, landfilled, and land applied "as
is" with no dewatering or drying.
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The top uses of liquid digestate for stand-alone digesters, on-farm co-digesters, and co-digestion facilities
at WRRFs, respectively, were: discharged to a wastewater treatment plant, reused as fertilizer via land
application, and recirculated through the digester.
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I. Background
In the United States (U.S.), food is the greatest fraction of material, by weight, in the municipal solid waste
stream. In 2015, approximately 37.5 million tons of food from the residential, commercial, and
institutional sectors was sent to landfills and combusted for energy,3 imposing significant economic and
environmental costs. To help alleviate these costs, the U.S. Environmental Protection Agency (EPA)
encourages diversion of food waste from landfills, including its use in anaerobic digestion (AD) facilities.
In 2014, EPA began building a dataset of names and locations of AD facilities processing food waste. EPA
built the original dataset using publicly available information (e.g., American Biogas Council project
profiles, BioCycle articles, EPA AgSTAR4 database).
To enhance the quality and quantity of available data, EPA sought and was granted authority to collect
information through a survey for digesters (see Appendix D for a list of survey questions). The approval
allows EPA to collect data annually for 3 years, from 2017 to 2019. This report is the second in a series of
three reports. Each report includes data for three types of AD facilities: (1) stand-alone food waste
digesters; (2) on-farm digesters that co-digest food waste; and (3) digesters at water resource recovery
facilities (WRRFs) that co-digest food waste. This information is gathered to better understand the
practice and prevalence of digestion of food waste in the United States (e.g., the current amount of food
waste being processed by digesters, available capacity, etc.).
Data collected during the 2017 survey was published in the report titled Anaerobic Digestion Facilities
Processing Food Waste in the United States in 2015. Data collected during the 2018 survey is summarized
in this report. This report includes data from operational year 2016 for the following three data points:
the amount of food waste5 processed, the amount of non-food waste6 processed, and the amount of
biogas produced. Processing capacity, feedstock types, feedstock sources, tipping fees, pre-processing/de-
packaging, operational specifications, biogas uses, gas cleaning systems, solid digestate uses, and liquid
digestate uses reflect circumstances in 2018.
Data collected during the 2019 survey will be summarized in the anticipated third report in this series
targeted for publication in 2020.
3 Advancing Sustainable Materials Management 2015 Fact Sheet, Table 1, page 8. Estimate includes residential,
commercial, and institutional sources of food waste, but not industrial or on-farm sources.
4 AgSTAR is an EPA program that promotes the use of biogas recovery systems to reduce methane emissions from
livestock waste.
5 Food-based materials include, but are not limited to: food scraps that have been separated and collected by
municipalities from residential sources; food scraps that have been separated and collected from institutions or
venues (e.g., prisons, hospitals, stadiums); food scraps from food preparation at restaurants, cafeterias, and other
food services; plate scrapings from restaurants, cafeterias, and other food services; fats, oils and grease (FOG);
unused food collected from grocery stores (e.g., bakery items, bruised fruit, items past shelf life); and pre-consumer
by-products of the food and beverage processing industries.
6 Non-food waste feedstocks include, but are not limited to: mixed yard waste, crop residues, manure, wastewater
solids (sludge), septage, de-icing fluid, lab (or pharma) wastes, paper mill wastes, and crude glycerin.
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To identify respondents for the 2018 survey, EPA used the information gathered during the 2017 survey
as a starting point. Ongoing research conducted throughout 2017 and 2018 also contributed to the
development of both the list of operating AD facilities that accept food waste (See Appendix A, Tables 1A,
3A and 5A) and the list of AD facilities under development (See Appendix B).
This report does not address whether the food waste processed at AD facilities could have been
prevented, donated to feed people, or used to feed animals. By the time food that may at one time have
been recoverable is received by an AD facility, it is considered "food waste." Therefore, the term "food
waste" is used throughout this document to describe the food-based feedstock being processed in
digesters.
II. Survey Data Collection
Under ICR (No. 2533.01), EPA developed electronic data collection surveys for each digester type: stand-
alone food waste digesters, on-farm digesters that co-digest food waste, and digesters at WRRFs that co-
digest food waste. EPA emailed the surveys directly to digester owners and operators and made the
surveys available on EPA's Anaerobic Digestion website. This report is based on data collected during the
2018 survey. EPA collected data from June 2018 through February 20197, and then the surveys were
inactivated. For the 2018 survey, the time-specific data points8 reflect operating year 2016. All other data
reflects circumstances in 2018.
This data collection allowed EPA to:
• Identify the number and location of AD facilities that are operational and under development9;
• Document the total processing capacity at AD facilities;
• Document how much food waste and non-food waste was processed (in 2016);
• Document how much biogas was produced (in 2016);
• Document the types of food and non-food wastes, and the sources of these wastes, that are
accepted at these AD facilities;
• Analyze the end-uses of AD products (biogas and digestate); and,
• Understand additional information about AD facilities such as pre-processing/de-packaging
activity, operational specifications, and gas cleaning systems.
Completion of the survey was voluntary, and the data collected was freely reported by survey
respondents. All the AD facilities that responded to the 2017 survey (both operating facilities and facilities
under development) received the 2018 survey10. Additional facilities to survey each year are identified on
an on-going basis as a result of research and collaboration with Agency partners. The number of facilities
surveyed and the number of facilities responding to the survey in 2018, both operating and non-operating,
are identified in Table 1.
7 Data collection is typically confined to the calendar year in question. However, a significant amount of time was
lost due to the 2018-2019 government shutdown.
8 Amount of food waste processed, amount of non-food waste processed and amount of biogas produced
9 This data is current as of December 2018.
10 Data collected during the 2017 survey was published in the 2018 report titled Anaerobic Digestion Facilities
Processing Food Waste in the United States in 2015, September 2018. Data collected during the 2018 survey is
included in this report.
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Table 1: Number of Operational and Non-Operational Anaerobic Digestion Facilities Surveyed
and Responding to the 2018 Survey
Operational Status
Number of Facilities
Surveyed
Number of Surveys
Submitted
Survey Response
Rate
Operational
198
134
68%
Non-operational
34
20
59%
Total
232
154
66%
The operational facilities responding to the 2017 survey and the operational facilities responding to the
2018 survey are not identical. Not all operating facilities that responded to the 2017 survey responded to
the 2018 survey. Also, there were several facilities that responded to the 2018 survey that did not respond
to the 2017 survey. Table 2 provides information on the number of facilities providing surveys for both
years. Please see Tables 1A, 3A, and 5A for lists of those facilities that responded to the 2018 survey and
Tables 2A, 4A, and 6A for lists of those facilities that responded to the 2017 survey, located in Appendix
A. Please note that the names of several facilities have changed slightly (e.g., Niagara BioEnergy is now
known as Generate Niagara Digester due to an ownership change). Facilities responding to the 2017
survey can be cross-checked with facilities responding to the 2018 survey by location.
Table 2: Comparison of Facilities Responding to 2017 Survey and
Facilities Responding to the 2018 Survey
Digester Type
Number of
Surveys
Submitted (2017)
Number of
Surveys
Submitted (2018)
Number of Facilities
Reporting in 2017 that
did not Report in 2018
Number of New
Facilities
Reporting in 2018
Stand-alone
digesters
50
46
11*
7
On-farm co-
digesters
15
16
10
11
Co-digestion
systems at WRRFs
72
72
3
3
Total
137
134
13
21
*Two of these facilities have ceased operation and one facility was incorrectly categorized as a stand-alone facility for the 2017 survey and
returned an on-farm digester survey for 2018.
For both the 2018 report and this report, EPA aggregated the technical data collected for each facility
(e.g., processing capacity) and summarized it such that individual facility information could not be
identified. Personally Identifiable Information will be protected to the extent allowable under the Freedom
of Information Act.
III. Results
A. Response Rates and Location Data
Out of the 232 surveys distributed to AD facilities, 134 were returned by operational facilities. This report
only identifies the status of those facilities providing survey responses. Another 64 facilities are believed
to be operating (for a total of 198), however the status of these facilities cannot be documented at this
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time.11 The number of operational facilities surveyed and the number of operational facilities returning
responses by facility type is provided in Table 3. Lists of facilities confirmed via survey response to be
currently operating can be found in Appendix A (Tables 1A, 3A and 5A).
Table 3: Number of Operational Anaerobic Digestion Facilities Surveyed
and Responding to Survey by Digester Type
Digester Type
Number of Facilities
Surveyed
Number of Surveys
Submitted
Survey Response
Rate
Stand-alone digesters
62
46
74%
On-farm co-digesters
59
16
27%
Co-digestion systems at WRRFs
77
72
94%
Total
198
134
67%
EPA is also tracking facilities that are under development or temporarily shut-down. EPA distributed 47
surveys to a group of stand-alone AD facilities and WRRF co-digestion systems that are in one of the
following phases: planning, design, permitting, under construction, start-up mode or temporarily shut-
down. No on-farm co-digesters under development have been identified as under development or
temporarily shut-down. EPA received survey responses confirming the operational status of 20 facilities
that are in one of these categories. Lists of these facilities and their operational status as reported via
survey response can be found in Appendix B (Tables IB and 2B). This report only identifies the status of
those facilities providing responses. The operational status of the remaining 27 facilities surveyed cannot
be documented at this time. The breakdown of the number of non-operational facilities surveyed and the
number of facilities returning responses by facility type is provided in Table 4.
Table 4: Number of Anaerobic Digestion Facilities in the Planning/Construction Phase Surveyed
and Responding to Survey by Digester Type
Digester Type
Number of Facilities
Surveyed
Number of Surveys
Submitted
Survey Response
Rate
Stand-alone digesters
24
12
50%
On-farm co-digesters
0
0
-
Co-digestion systems at WRRFs
23
8
40%
Total
47
20
43%
EPA's research also identified facilities that have ceased operations or did not advance beyond the pilot
stage for a variety of reasons. The facilities that have ceased operation are identified in Appendix C. It has
been documented that 12 WRRFs considering co-digestion did not advance beyond the pilot stage. A list
of these facilities is not included in this report.
Stand-Alone Digesters
Stand-alone digesters are primarily built to process food waste. While many of these digesters accept
other organic materials (e.g., manure, wastewater solids), they are typically designed for food waste
processing. Stand-alone digesters are divided into two categories, as described below: multi-source food
waste digesters, and industry dedicated digesters.
11 The 64 facilities in this category that did not respond to the survey are believed to be operational based on
current research, available public information and information provided by facility representatives other than
survey responses (e.g., phone and face-to-face conversations).
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Multi-Source Food Waste Digester: A digester that accepts and processes feedstocks from offsite
sources. These feedstocks may be accepted both for their tipping fee revenue and their biogas
yield potential. These digesters are sometimes called "merchant digesters." Feedstocks are
predominantly food waste, although non-food waste feedstocks (e.g., manure and wastewater
solids) may also be processed at these digesters. In most instances, feedstocks are obtained from
many different sources.
Industry-Dedicated Digester: A digester that is developed to manage food waste generated from
a single business (e.g., grocery store chain, food or beverage processing plant). These digesters
may accept organic materials from other sources for tipping fees, but this practice is not typical
for this type of digester.
EPA received 46 survey responses from a field of 62 operational stand-alone facilities for a response rate
of 74%. The remaining 16 operational facilities did not submit data. EPA received 12 survey responses
from a field of 24 non-operational stand-alone facilities for a response rate of 50%. The remaining 12 non-
operational facilities did not submit data. See Tables 3 and 4 above for response rates for operational and
non-operational facilities. See Appendix A (Table 1A) for a list of operational stand-alone facilities and
Appendix B (Table IB) for a list of stand-alone facilities under development.
According to the survey responses received from the 46 operating stand-alone digesters: 23 are multi-
source (50%); 19 are industry dedicated (41%); and four were identified by survey respondents as "other"
(9%).
Operational stand-alone digesters are located within 21 states. See Figure 1 for a map and Table 5 for a
listing of the number of operating stand-alone facilities by state.
Stand-Alone
11
1 1
'
0 1
0
0 1
CT:
1
DE:
0
HI:
0
MD:
0
MA:
3
NJ
2
Rl:
0
Figure 1: Operating Stand-Alone Food Waste Digesting Facilities by State
5
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On-Farm Co-Digesters
According to EPA's AgSTAR program, there are approximately 250 anaerobic digester facilities operating
on livestock farms in the U.S. These digesters are primarily used for manure management. This survey
targeted only those digesters that are co-digesting food waste.
Using the information gathered from on-farm co-digesters during the 2017 survey as a starting point, EPA
identified and surveyed 59 on-farm co-digester facilities that are potentially co-digesting food waste. EPA
received 16 survey responses out of the 59 identified digesters for a response rate of 27%. The remaining
43 farms did not submit data. The exact reason or reasons for this low response rate is not known. EPA
spent a significant amount of time seeking accurate contact information for the identified on-farm co-
digesters as well as a substantial effort contacting the operators of on-farm co-digesters by phone and
email to improve the response rate. Unfortunately, the number of responses for on-farm co-digesters
remained low for the 2018 survey. This report identifies the status of only those on-farm co-digesters
providing responses. The operational status of the remaining 43 farms surveyed cannot be documented
at this time. The actual number of digesters on farms that are co-digesting food waste is believed to be
much higher than 16, but this cannot be confirmed due to the lack of participation in this survey.
Operational on-farm digesters co-digesting food waste were identified in 8 states. See Table 3A in
Appendix A for a list of the 16 farms that provided data and Figure 2 for a map depicting the number of
operating on-farm co-digesters by state.
On-Farm
%
1
0 0
CT:
0
DE:
0
HI:
0
MD:
0
MA:
1
NJ
0
Rl:
0
Figure 2: Operating On-Farm Food Waste Co-Digestion Systems by State (2016)
6
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Digesters at Water Resource Recovery Facilities (WRRFs)
The Water Environment Federation and the American Biogas Council built and maintain a database of
information on WRRFs.12 This database identifies approximately 1,200 WRRFs in the U.S. that have
anaerobic digesters to manage wastewater solids, and roughly 20% of these facilities co-digest materials,
including food waste from offsite sources.
EPA received 72 survey responses from a field of 77 WRRFs with operational food-waste co-digestion
systems for a response rate of 94%. The remaining five facilities did not submit data. Independent from
the 77, EPA received 8 survey responses from a field of 23 non-operational co-digestion systems at WRRFs
for a response rate of 35%. The remaining 15 non-operational facilities did not submit data. This report
identifies the status of only those facilities providing responses. The operational status of the remaining
20 WRRFs surveyed cannot be documented at this time. See Tables 3 and 4 above for response rates for
operational and non-operational WRRF co-digestion systems. See Table 5A in Appendix A for a list of the
72 facilities providing data and Figure 3 for a map depicting the number of operating WRRF food waste
co-digestion systems by state. WRRFs with operating co-digestion systems are located within 25 states.
WRRF
Figure 3: Operating WRRF Food Waste Co-Digestion Systems by State
12 Please see http://www.resourcerecovervdata.org/biogasdata.php for a listing of those WRRFs with operating
anaerobic digesters.
-------
Total Operating Digesters in the U.S.
Figure 4 and Table 5 summarize total operating digesters by type and location. Note that there are other
operating AD facilities processing food waste in the U.S. Table 5 identifies the number of operating
facilities that provided survey responses.
Figure 4: Operating Food Waste Digesting Facilities by State
Table 5: Num
ber of Operating Anaerobic Digestion Facilities in each State by Facility Type
Number of Facilities*
State
Stand-Alone
On-Farm
WRRF
Alabama
0
0
0
Alaska
0
0
0
Arizona
0
0
1
Arkansas
0
0
1
California
11
0
19
Colorado
0
0
1
Connecticut
1
0
0
Delaware
0
0
0
Florida
2
0
2
Georgia
1
0
3
Hawaii
0
0
0
Idaho
0
0
0
Illinois
0
0
3
Indiana
1
2
1
Iowa
1
0
4
Kansas
0
0
1
Kentucky
0
0
0
8
-------
Number of Facilities*
State
Stand-Alone
On-Farm
WRRF
Louisiana
0
0
0
Maine
0
l
1
Maryland
0
0
0
Massachusetts
3
1
1
Michigan
1
0
2
Minnesota
1
0
1
Mississippi
0
0
0
Missouri
1
0
1
Montana
0
0
0
Nebraska
0
0
0
Nevada
0
0
0
New Hampshire
1
0
0
New Jersey
2
0
3
New Mexico
0
0
0
New York
3
2
3
North Carolina
1
0
0
North Dakota
0
0
0
Ohio
9
0
2
Oklahoma
0
0
0
Oregon
1
0
3
Pennsylvania
1
3
4
Rhode Island
0
0
0
South Carolina
0
0
1
South Dakota
0
0
0
Tennessee
1
0
0
Texas
1
0
2
Utah
0
0
0
Vermont
1
2
1
Virginia
0
0
2
Washington
0
2
0
West Virginia
0
0
0
Wisconsin
2
3
9
Wyoming
0
0
0
Total
46
16
72
*The number of digesters per state shown in Table 5 represents the digesters that EPA received surveys from in 2018.
Table 5 is not directly comparable to Table 2 from "Anaerobic Digestion Facilities Processing Food Waste in the United
States in 2015", September 2018. The number of digesters shown in the previous Table 2 included digesters
submitting surveys in 2017 and other confirmed operational digesters.
B. Processing Capacity
Processing capacity refers to the maximum amount of food waste feedstock an anaerobic digester can
accept per unit time. In this survey, that unit of time was one year. EPA collected data on food waste
processing capacity in either gallons or tons per year.13 Capacity reported in gallons per year was
13 Throughout this document "ton" refers to a US ton, which equals 2,000 lb.
9
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converted to tons per year to quantify the total capacity available for processing food waste.14 EPA
recognizes that most anaerobic digesters typically process a liquid slurry. However, for food waste
processing capacity, EPA converted the data from gallons per year to tons per year because tons are the
industry standard for measuring food waste.
Out of the 134 operational facilities that provided survey responses, 131 provided information about food
waste processing capacity. EPA documented that the total capacity for processing food waste in all three
digester types combined is 23,993,122 tons per year (Table 6). Note that the actual processing capacity
for digesters in the United States is higher than the values reported in Table 6 because not all operating
facilities responded to the survey.
Stand-Alone Digesters
For stand-alone digesters, all 46 (100%) of the survey respondents provided data on processing capacity.
Stand-alone digester operators were asked to provide the following:
Provide the total capacity of your facility in tons per year or gallons per year.
The total current processing capacity reported for food waste at stand-alone digesters in the U.S. is about
21 million tons per year.
On-Farm Co-Digesters
EPA asked operators of on-farm co-digesters to consider the following when calculating available food
waste processing capacity:
Taking into account the average volume of manure from your livestock processed in your
anaerobic digestion system, please identify the available capacity to co-digest other feedstocks.
EPA's goal was to determine how much outside food waste could potentially be processed at on-farm co-
digesters in the U.S. All 16 survey respondents provided data on processing capacity, which totals 256,044
tons per year. This number only represents 27% of the on-farm co-digestion systems identified by EPA to
be operating in the U.S. Therefore, the actual capacity is likely to be greater than this amount.
Co-Digestion Facilities at WRRFs
Determining the capacity for WRRFs to co-digest food waste is more challenging because there are more
factors to consider than just the size of the tanks. EPA asked plant operators to consider the following
when calculating available food waste processing capacity:
Please identify your facility's available capacity to accept feedstocks from offsite sources for all
digesters combined. When calculating this available capacity, please take into account the
average volume of wastewater solids processed at your facility and the total capacity of your
digesters. Assume that your facility has all the necessary equipment to receive additional
feedstocks (e.g., a receiving station, storage, mixing equipment, etc.)
14 The gallons to tons conversion for food waste was calculated based on a factor of 3.8 lbs/gallon. This factor
comes from Volume-to- Weight Conversion Factors, USEPA ORCR, April 2016).
10
-------
Again, EPA's goal was to determine how much food waste could potentially be processed at WRRFs in the
U.S. The data in this report directly reflects the information provided by the plant operators that
responded to the survey.15 For operating WRRF co-digestion systems, 96% of respondents (69 out of 72)
provided data on processing capacity. The total current processing capacity reported for food waste at
co-digestion systems at WRRFs in the U.S. was about 2.6 million tons per year.
Total Food Waste Processing Capacity
Table 6 below summarizes the total capacity for each type of digester and provides the mean and median.
The total current processing capacity reported for food waste at all three types of digesters in the U.S.
was about 24 million tons per year.
Table 6: Total Capacity for Processing Food Waste via Anaerobic Digestion by Digester Type
Digester Type
Reported Capacity
(tons per year)
Mean
(tons per year)
Median*
(tons per year)
Respondents
Providing Data
Total Surveys
Received
Stand-alone
21,126,270
459,267
48,725
46
46
digesters
On-farm co-
256,044
16,003
13,110
16
16
digesters
Co-digestion
2,610,808
37,325
9,500
69
72
systems at
WRRFs
Total
23,993,122
131
134
*Amounts were reported by facility response.
C. Operational Dates
The dates that the AD facilities surveyed became operational have not changed since the last publication.
However, the individual facilities that provided data are slightly different than last year (see Table 2). It is
still the general perception that processing food waste via AD is a relatively new practice.
It continues to be true that most of the facilities that provided data for this survey began operations before
2015 (Figure 5). A stand-alone digester that began operations in 1958 was the earliest start date recorded
this year. For co-digestion at WRRFs, the earliest start date reported was 1959 and for co-digestion at
farms the earliest start date reported was 1985.
Twenty-one stand-alone and WRRF digesters began processing food waste in the 1980s and 1990s,
whereas only one farm co-digester started operations in that timeframe. In the early 2000s, AD of food
waste and co-digestion of food waste with other waste streams started to become more prevalent in the
U.S. One farm began co-digestion operations in 1985. Except for this farm, the practice seems to have
taken a little longer to reach the farming sector. According to the survey responses received from farmers,
co-digestion at on-farm digesters did not begin to occur more frequently until the early 2000s.
15 In some cases, the capacity to process food waste reported by plant operators was less than the reported amount
of food waste processed. For the facilities where this discrepancy was significant, EPA reconciled the numbers based
on additional input from the operators.
11
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11
¦ ¦ ¦ 1 ¦ ¦ ¦ 11 ¦ ¦ 1 ¦ 111 ¦ 11 ¦ 11111
llii
oo(T>Lntooo(T>o^-io^-ir\icn<3-Lntor--.oo(T>o^-irMcn^-i-ntor--«oo
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Figure 5: Distribution of First Year of Digester Operation by Digester Type
D. Food Waste Processed
EPA requested data on the amount of food waste processed via AD, reported in either gallons ortons. The
amount of food waste processed reported in gallons was converted to tons.16 As with information about
capacity, the amount of material processed is reported in tons because tons is the industry standard for
measuring food waste. Note that the actual amount of food waste processed in 2016 was likely to be
higher than the value reported in Table 7 because not all facilities known to be operating provided data.
In addition, out of the 134 operational facilities that provided survey responses, 126 provided information
about the amount of food waste processed. Projecting or predicting volumes processed at non-reporting
facilities was not within the scope of this report.
Table 7: Total Amount of Food Waste Processed by Each Digester Type (2016)
Digester Type
Reported Amount
Processed (tons)
Mean
(tons per year)
Median*
(tons per year)
Respondents
Providing Data
Total Surveys
Received
Stand-alone digesters
9,222,413
209,600
21,919
44
46
On-farm co-digesters
154,789
9,674
8,075
16
16
Co-digestion systems
at WRRFs
1,314,554
12,033
4,787
66
72
Total
10,691,756
126
134
* Amounts were reported by facility response
16 The gallons to ton conversion for food waste was calculated using 3.8 lbs/gallon (See Volume-to-Weight
Conversion Factors, USEPA ORCR, April 2016).
12
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E. Non-Food Waste Processed
EPA also collected data on the amount of non-food waste processed via AD, in either gallons or tons. Non-
food waste feedstocks include, but are not limited to: mixed yard waste, crop residues, manure,
wastewater solids (sludge), septage, de-icing fluid, lab (or pharma17) wastes, paper mill wastes, and crude
glycerin. Given that the content of non-food waste feedstocks is highly variable and can be liquid or solid,
there is no suitable conversion factor to combine values reported in different units. Therefore, both liquid
volume and solid weight amounts reported by facility operators are presented in Table 8.
The scope of the survey is limited to anaerobic digesters that digest food waste. Therefore, it does not
include documentation of non-food waste processed at facilities that do not process any food waste. For
example, this project does not include the amount of manure being digested at farm digesters that do not
co-digest food, or the amount of wastewater solids being digested in digesters at WRRFs that do not co-
digest food. As a result, the numbers below represent only a portion of non-food waste being digested in
the U.S. The non-food waste data collected was intended to provide additional information about the
types of wastes being processed via AD.
Processing of non-food waste occurs at stand-alone digesters but the frequency is relatively low. For
example, of the 46 stand-alone digesters providing survey responses, only 20 reported that non-food
waste is processed (43%). Non-food waste is processed at all on-farm co-digesters (manure) and WRRF
digestion systems (wastewater solids).
Table 8: Total Amount of Non-food Waste Processed by each Digester Type (2016)
Digester Type
Liquid Amount
(in gallons)
Solid Amount
(in tons)*
Respondents
Providing Data
Total Surveys
Received
Stand-alone digesters
31,021,709
82,730
20
46
On-farm co-digesters
1,734,745
0 +
8
16
Co-digestion systems at WRRFs
459,216,246
21,222
34
72
Total
491,972,700
103,952
62
134
* Amounts were reported in liquid and solid units. Because there is no common conversion factor for non-food waste,
these values are separated.
+ The amount of non-food waste reported to be processed in 2017 (for the 2015 calendar year) was 2,103 tons. Two of
the three farms reporting non-food waste processed in tons did not provide a survey response in 2018 and one farm no
longer processes any non-food waste from offsite.
As mentioned previously, not all operational digesters provided data for this project. The actual amount
of non-food waste processed at anaerobic digesters in 2016 is likely to be higher than the values reported
above.
F. Feedstock Types
A wide variety of feedstocks are processed in digesters throughout the U.S. Some feedstocks are more
common than others, which varies based on local availability, demand, and type of digester accepting the
feedstock. Tables 9, 10 and 11 and Figure 6 show the types of food waste and non-food waste feedstocks
processed at each of the three types of digesters.
17 In the survey, lab wastes are described as "pharma" wastes which is an abbreviation of pharmaceutical.
13
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Feedstocks are classified as follows:
• Food: beverage processing industry waste; food processing industry waste; FOG; fruit/vegetative
wastes; food service waste pre- & post-consumer; retail food waste; rendering wastes; and
source-separated commercial, institutional or residential organic wastes.
• Non-Food: crude glycerin; manure; wastewater solids (sludge); septage; crop residues; mixed
yard waste; de-icing fluid; lab (or pharma) wastes; and paper mill wastes.
For the 2018 survey, respondents from 45 of the 46 stand-alone facilities (98%), all 16 on-farm co-
digesters (100%), and 71 of the 72 WRRFs (99%) provided data on the type of feedstocks processed. Figure
6 shows the top five feedstocks accepted by digester type. The top five feedstocks processed overall are:
FOG, food processing industry waste, beverage processing industry waste, fruit/vegetable wastes, and
pre-and-post- consumer food services waste. EPA did not collect data on the quantity of individual
feedstocks processed.
There were a few results worth noting in comparison to the feedstock data collected in 2017 survey for
stand-alone digesters. The top five feedstocks processed at stand-alone digesters remained the same:
beverage processing industry waste, food processing industry waste, fats oils and greases (FOG), fruit and
vegetative waste and food service waste, pre- and post- consumer. The number of stand-alone digesters
processing manure decreased by 50% (16 digesters reported in 2017 compared to 8 digesters reported in
2018). Zero facilities reported processing septage, de-icing fluid, and paper mill waste in 2018.
Table 9: Types of Food Waste and Non-Food Waste Feedstocks Processed at Stand-Alone Digesters
Number of Stand-Alone
Percentage of Stand-Alone
Feedstock
Facilities processing
Facilities processing this
this feedstock
feedstock*
Beverage processing industry waste
33
73%
Food processing industry waste
26
58%
Fruit/vegetative wastes
24
53%
FOG
23
51%
Food service waste, pre- & post-consumer
18
40%
Retail food waste
17
38%
Crude Glycerin
17
38%
Source-separated commercial, institutional or
14
31%
residential organic wastes
Manure
8
18%
Wastewater solids (sludge)
8
18%
Rendering wastes
7
16%
Crop residues
7
16%
Other (please specify)*
5
11%
Mixed yard waste
4
9%
Lab (or Pharma) wastes
3
7%
* Percentage calculated based on the 45 facilities providing data on the type of feedstocks processed in 2016.
+ Other reported feedstocks include organic non-food industrial wastes and leachate from compost operation.
14
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Table 10: Types of Food Waste and Non-food Waste Feedstock Processed at On-Farm Co-Digesters
Number of On-Farm
Percentage of On-Farm
Feedstock
Facilities processing this
Facilities processing this
feedstock
feedstock*
Food processing industry waste
14
88%
FOG
12
75%
Beverage processing industry waste
11
69%
Fruit/vegetative wastes
9
56%
Food service waste, pre- & post-consumer
6
38%
Crude glycerin
6
38%
Retail food waste
5
31%
Rendering waste
5
31%
Source-separated commercial, institutional or
25%
residential organic wastes
Wastewater solids (sludge)
4
25%
Manure from other farms
1
6%
De-icing fluid
1
6%
Other
1
6%
* Percentage calculated based on 16 farms providing survey responses.
The top five feedstocks processed at WRRFs remained the same: fats oils and greases (FOG), food
processing industry waste, beverage processing industry waste, septage and wastewater solids (sludge)
from other WRRFs. The number of facilities co-digesting source-separated commercial, institutional or
residential organic wastes doubled, and the number of facilities co-digesting beverage processing industry
waste almost doubled between the 2017 and 2018 surveys.
Table 11: Types of Food Waste and Non-Food Waste Feedstock Processed
at Co-Digestion Systems at WRRFs
Feedstock
Number of WRRFs
Percentage of WRRFs
processing this feedstock
processing this feedstock*
FOG
60
85%
Food processing industry waste
37
52%
Beverage processing industry waste
30
42%
Septage
26
37%
Wastewater solids (sludge)
24
34%
Food service waste, pre- & post-consumer
18
25%
Fruit/vegetative wastes
14
20%
Source-separated commercial, institutional or
residential organic wastes
10
14%
Other (please specify)f
8
11%
Rendering wastes
7
10%
Crude glycerin
6
8%
Retail food waste
6
8%
De-icing fluid
5
7%
Lab (or Pharma) wastes
2
3%
Poultry litter
2
3%
Manure
1
1%
* Percentage calculated based on 71 WRRFs providing feedstock data in survey responses.
+ Other reported feedstocks include landfill leachate, landfill gas condensate, propylene glycol, wastewater from cleaning
biodiesel process equipment and pressed municipal solid waste.
15
-------
1 nn
-------
Source
Number of Facilities
Receiving Feedstock
from Specified Source
Percentage of
Facilities Receiving
Feedstock from
Specified Source*
Schools
5
11%
Farmers markets
4
9%
Airports
4
9%
Healthcare
4
9%
Laboratories/ pharmaceutical companies
4
9%
Prisons
3
7%
Other
1
2%
* Percentage calculated is based on 45 facilities providing data on feedstock sources.
Table 13: Sources of Food Waste and Non-Food Waste Feedstock Processed by On-Farm Co-Digesters
Source
Number of Facilities Receiving
Feedstock from Specified Source
Percentage* of On-farm
Digesters Receiving Feedstock
from Specified Source
Food/beverage processors
16
100%
Biodiesel production
6
38%
Grocery stores/supermarkets
5
31%
Industrial
5
31%
Restaurants and food service
5
31%
Corporate complex
3
19%
Healthcare
3
19%
Municipal/Residential
3
19%
Retail stores
3
19%
Fruit/vegetable farms
2
13%
Hospitality
2
13%
Laboratories/pharmaceutical companies
2
13%
Schools
2
13%
Wastewater treatment plants
2
13%
Other
2
13%
Airports
1
6%
Other livestock farms
1
6%
Prisons
1
6%
Sports and entertainment venues
1
6%
* Percentage calculated based on 16 farms providing data on feedstock sources.
17
-------
Table 14: Sources of Food Waste and Non-Food Waste Feedstock Processed
by Co-Digestion Systems at WRRFs
Source
Number of Facilities Receiving
Feedstock from Specified Source
Percentage of WRRFs
Receiving Feedstock
from Specified Source*
Restaurants and food service
51
72%
Food/beverage processors
51
72%
Municipal/residential
28
39%
Other wastewater treatment plants
24
34%
Grocery stores/supermarkets
22
31%
Industrial
18
25%
Schools
16
23%
Biodiesel production
9
13%
Retail stores
9
13%
Fruit/vegetable farms
9
13%
Hospitality
9
13%
Sports and entertainment venues
9
13%
Healthcare
7
10%
Laboratories/pharmaceutical companies
6
8%
Prisons
6
8%
Airports
5
7%
Corporate complex
4
6%
Farmers markets
3
4%
Other
3
4%
Livestock farms
2
3%
* Percentage based on 71 WRRFs providing data on feedstock sources.
120
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tipping fees; and availability of organics recycling options. EPA included survey questions about tipping
fees to gain a better understanding of how digesters may be using them to offset capital expenditures and
maintenance costs. EPA recognizes that tipping fee data may be considered proprietary and therefore
made these questions optional as part of completing the survey.
Most survey respondents for all three digester types either did not answer the questions about tipping
fees, or indicated "$0.00" or "prefer not to say/' as the answer. As was the case with the 2017 survey, not
enough information was collected to draw meaningful or useful conclusions about tipping fee trends.
I. Pre-processing
EPA asked operators about the types of pre-processing activities performed at their facilities. Respondents
from 21 of the 46 stand-alone facilities (46%), 6 of the 16 on-farm co-digesters (38%), and 41 of the 72
WRRFs (57%) provided data on pre-processing of feedstocks. Multiple types of pre-processing can occur
at any one facility. Tables 15, 16 and 17 show the number of facilities that reported the use of each type
of pre-processing activity to prepare feedstocks for digestion. Third-party processing is typically
conducted at an offsite location and pre-processed feedstocks are then transported to the digester in a
ready to digest form.
Table 15: Pre-processing Activities for Stand-Alone Digester Facilities
Pre-processing Activity
Number of Facilities with
Specified Pre-processing
Activities
Screening and/or sorting
8
Manual or mechanized de-packaging/de-bagging
7
Grinding, particle size reduction or maceration
6
Mixing
4
Third-Party Processing
4
Shredding/crushing
2
Solids concentration using Dissolved Air Flotation Tanks
1
Metals removal
1
pH adjustment
1
Hydrolysis
1
Table 16: Pre-processing for On-Farm Co-Digestion Facilities
Pre-processing/De-packaging Activity
Number of Facilities with
Specified Pre-processing
Activities
Manual or mechanized de-packaging/de-bagging
3
Third-Party Processing
3
Grinding, particle size reduction or maceration
1
Mixing
1
Dewatering and compressing
1
19
-------
Table 17: Pre-processing for Co-Digestion Facilities at WRRFs
Number of Facilities with
Pre-processing/De-packaging Activity
Specified Pre-processing
Activities
Screening and/or sorting
16
Third-Party Processing
14
Grinding, particle size reduction or maceration
13
Mixing
7
Manual or mechanized de-packaging/de-bagging
4
pH Adjustment
2
Heating
1
Centrifugal Separation
1
J. Operational Specifications
EPA asked respondents to share information about the operational specifications of their digesters,
including temperature range and whether operations were wet or dry. The temperature ranges are
typically 86 - 100° F for mesophilic and 122 - 140° F for thermophilic. Wet and dry classifications of
digesters refer to the moisture content of the feedstocks. A wet digester generally processes feedstock
with less than 15% solids content, whereas a dry digester generally processes feedstock with greater than
15% solids content.
Respondents from 43 of 46 stand-alone digesters (93%), 15 of 16 on-farm co-digesters (94%), and 71 of
72 WRRFs (99%) provided data on temperature range. Respondents from 44 of 46 stand-alone digesters
(96%) and all 16 on-farm co-digesters (100%) provided data on whether their digester system was wet or
dry. This question was not posed to WRRFs because all WRRF digester systems are wet. Tables 18 and 19
show the data for temperature range and wet versus dry facilities by facility type.
Table 18: Temperature Range Data for each Digester Type
Temperature Range
Response Rate
Digester
Type
Mesophilic
Thermophilic
Unheated
Number of Respondents
Providing Data for this
Survey Question
Total Surveys
Received
Stand-alone
22
9
12
43
46
digesters
On-farm co-
12
3
0
15
16
digesters
Co-digestion
59
12
0
71
72
systems at
WRRFs
Total
93
24
12
129
134
20
-------
Table 19: Data on Wet vs. Dry Systems for each Digester Type
Wet vs. Dry Systems
Percentage
Response Rate
Digester
Type
Wet
Dry
Wet
Dry
Number of Respondents
Providing Data for this
Survey Question
Total Surveys
Received
Stand-alone
39
5
89%
11%
44
46
digesters
On-farm co-
16
0
100%
0%
16
16
digesters
Co-digestion
-
-
100%
-
-
-
systems at
WRRFs*
Total
55
5
60
62
* This question was not posed to WRRFs because all WRRF digester systems are wet.
K. Biogas Production
Biogas production data was collected in, or converted to, standard cubic feet per minute (SCFM), which is
the industry standard unit of measurement for biogas. The total biogas produced is summarized below as
reported by facility type. SCFM was then used to estimate installed capacity in megawatts (MW), and
generation potential in kilowatt-hours per year (kWh/yr) using methods described in the interactive
conversion tool18 on EPA's Landfill Methane Outreach Program (LMOP) website. The LMOP interactive
conversion tool assumes landfill gas is 50% methane. The calculation for SCFM landfill gas to MW capacity
was revised for the purposes of this report to reflect that biogas tends to be about 60% methane.19 To
provide a frame of reference, EPA presents the kWh/yr values for each type of digester in terms of
powering homes.20 Table 20 shows biogas production data by facility type.
Table 20: Summary of Biogas Data Reported by Digester Type (2016)
Digester Type
Respondents
Providing
Data
Surveys
Received
SCFM*
MW
kWh/yr
(million)
Number of
Homes Powered
for One Year
Stand-alone digesters
40
46
10,498
33
246
20,911
On-farm co-digesters
12
16
4,053
13
97
8,246
Co-digestion systems at
WRRFs
67
72
25,753
80
596
50,663
Total
119
134
40,304
126
939
79,820
* SCFM values are reported by facility operators and added together to get total SCFM for 2016 (40,304). The MW,
kWh/yr, and homes powered numbers are calculated using the LMOP interactive conversion tool. These values are
rounded to the nearest whole number, which accounts for the fact that the column totals may not sum.
18 https://www.epa.gov/sites/production/files/2016-05/interactiveconversiontool.xls
19 Anaerobic Digestion and its Applications, EPA, October 2015, page 9.
20 The average home consumed 11,764 kWh of delivered electricity in 2017, the most recent date for which data is
available (https://www.epa.gov/energy/greenhouse-gases-equivalencies-calculator-calculations-and-references).
21
-------
L. Biogas Uses
Most facilities have more than one use for the biogas, and the survey permitted multiple responses.
Respondents from 43 of 46 stand-alone facilities (93%), all 16 on-farm co-digesters (100%), and 70 of 72
WRRFs (97%) provided data on biogas uses. Table 21 summarizes the ways in which respondents reported
using the biogas produced and Figure 8 shows the top five uses of the biogas produced at AD facilities as
reported by each type of respondent.
Stand-Alone Digesters
The stand-alone digester survey asked respondents if the biogas produced was used onsite, sold, or both.
The data reported show that 74% used the biogas onsite, 5% sold it, and 23% used it both onsite and sold
it. The survey also asked respondents if they were able to utilize all the biogas produced at their facility.
Sixty-nine percent (69%) reported that all the biogas produced was used. This result represents a decrease
from the 2017 survey last year when 82% of stand-alone facilities reported that all biogas produced was
used. For the 2018 survey, 31% reported that they did not use all the biogas produced. Facilities that did
not use all the biogas produced uniformly reported that they flared the unused biogas.
On-Farm Co-Digesters
The survey asked on-farm co-digester respondents if the biogas produced was used onsite, sold, or flared.
The reported data show that 81% used the biogas onsite, 25% sold it, and 31% flared at least some of the
biogas. This result represents a decrease from last year when 60% of on-farm co-digesters reported flaring
at least some of the biogas produced.
Co-Digestion Systems at WRRFs
The WRRF co-digester survey asked respondents if the biogas produced was used onsite, sold, or flared.
The reported data show that 94% used the biogas onsite, 4% sold it, and 64% flared at least some of the
biogas. The survey also asked WRRF respondents if they utilized all the biogas produced at their facility.
Seventy-one out of 72 WRRFs (99%) provided data for this question. Forty-five percent of the facilities
reported that they used all the biogas produced for onsite purposes. The other 55% confirmed that they
flared the unused biogas.
The following other uses were reported by one WRRF operator at four individual facilities:
• Produce heat to run furnace on sludge dryer;
• Provides fuel for heat drying facility;
• Supplement natural gas in a sludge dryer; and
• Used exclusively by sludge pelletizing process.
22
-------
Table 21: Uses of Biogas Produced at Anaerobic Digesters
Stand-Alone Digesters
On-Farm Co-Digesters
Co-Digestion Systems at
WRRFs
Biogas Use
Number of
Facilities
Reporting
Use
Percentage
of Facilities
using Biogas
as Specified*
Number of
Facilities
Reporting
Use
Percentage
of Facilities
using Biogas
as Specified*
Number of
Facilities
Reporting
Use
Percentage
of Facilities
using Biogas
as Specified§
Produce heat and
electricity (CHP)
26
60%
13
81%
53
76%
Fuel boilers and
furnaces to heat
digesters
4
9%
4
25%
42
60%
Fuel boilers and
furnaces to heat other
spaces
13
30%
4
25%
23
33%
Produce electricity
(sold to grid)
17
40%
11
69%
11
16%
Produce electricity
used behind the meter
(including net
metering)
13
30%
8
50%
15
21%
Produce mechanical
power
0
-
1
6%
2
4%
Compressed to vehicle
fuels: used for
company
fleet/personal vehicles
3
7%
0
-
0
-
Compressed to vehicle
fuels: sold to customers
2
5%
0
-
0
-
Renewable natural gas
(inject to pipeline)
0
-
0
-
2
3%
*: Percentage out of the 43 stand-alone facilities providing data on biogas uses.
+: Percentage out of the 16 farms providing survey responses.
§: Percentage out of the 70 WRRFs providing survey responses.
23
-------
100
(D
to
Ctf)
¦
1—
o
Q.
tn
^ 40
¦
CU
<4—
<4—
o
QJ
_Q
E
3
-
Produce heat and Fuel boilers and Fuel boilers and Produce Produce
electricity (CHP) furnaces to heat furnaces to heat electricity (sold to electricity used
digesters other spaces grid) behind the meter
¦ Stand-Alone Digesters ¦ On-Farm Digesters ¦ Co-Digestion Systems at WRRFs
Figure 8: Top Five Uses of Biogas by Digester Type
M. Gas Cleaning Systems
Each facility type was asked whether they had a gas cleaning system (yes or no). Respondents from 45 of
46 stand-alone facilities (98%), all 16 on-farm co-digesters (100%), and 71 out of 72 WRRFs (99%)
answered this question. The data reported show that gas cleaning systems were utilized at 35 out of 45
(78%) of stand-alone food waste digesters, nine out of 16 (56%) on-farm co-digesters, and 49 out of 71
(69%) digesters at WRRFs.
Each facility type was also asked what constituents were removed by their gas cleaning systems. All 35
stand-alone facilities, 9 on-farm co-digesters and 48 out of 49 WRRFs that utilize gas cleaning systems
provided data on the constituents removed by these systems. Table 22 summarizes the type and
frequency of constituents removed by gas cleaning systems for each type of digester and Figure 9 shows
the top five constituents removed by digester type.
24
-------
Table 22: Gas Cleaning Systems at Anaerobic Digesters
Stand-Alone Digesters
On-Farm Co-Digesters
Co-Digestion Systems at
WRRFs
Constituent
Number of
Facilities
Reporting
Removal
Percentage
Reporting
Removal of this
Constituent*
Number of
Facilities
Reporting
Removal
Percentage
Reporting
Removal of this
Constituent
Number of
Facilities
Reporting
Removal
Percentage
Reporting
Removal of this
Constituent
Sulfur
28
80%
6
67%
35
73%
Moisture
23
66%
8
89%
43
90%
Siloxanes
5
14%
1
11%
43
90%
Carbon
Dioxide
4
11%
1
11%
4
8%
Hydrogen
Sulfide
1
3%
1
11%
4
8%
Compressed
gas
1
3%
0
—
3
6%
VOCs
1
3%
0
-
0
-
*: Percentage out of 35 stand-alone digesters providing data on constituents removed.
+: Percentage out of 9 on-farm digesters providing data on constituents removed.
§: Percentage out of 48 WRRFs providing data on constituents removed.
80
Moisture Sulfur Siloxanes Carbon Dioxide Hydrogen Sulfide
¦ Stand-Alone Digesters ¦ On-Farm Digesters ¦ WRRF Digesters
Figure 9: Top Five Constituents Removed by Digester Type
N. Solid Digestate Uses
EPA asked how facilities used the solid digestate they produce, allowing respondents to provide more
than one answer. Respondents from 44 of 46 stand-alone facilities (91%), all 16 farm co-digesters (100%),
and 71 of 72 WRRF digesters (99%) provided data on the uses of solid digestate. According to the survey
responses, there are six WRRFs that landfill all the solid digestate produced. The following
uses/destinations of solid digestate were reported for the three digester types surveyed at the
25
-------
frequencies specified in Table 23 below. Figure 10 shows the top five uses of solid digestate by digester
type.
Stand-alone digester operators also reported the following other uses, summarized from survey
responses:
• Picked up by composter (one respondent - verbatim);
• Digestate remains in liquid form and it is land applied (four respondents);
• No solid digestate produced (three respondents);
• Digestate is sold to other facilities (two respondents); and
• Solid onion remains are sold as cattle feed (one respondent - verbatim).
On-farm co-digester operators also reported the following other uses, summarized from survey
responses:
• No solid digestate (only liquid) which is land-applied (two respondents).
WRRF digester operators also reported the following other uses for biosolids produced, summarized from
survey responses:
• Struvite harvesting process is utilized (one respondent - verbatim);
• Sent to a biosolids recycling facility (one respondent - verbatim);
• Processed into fertilizer by a third-party (two respondents);
• Transported to drying beds and land applied by a third-party (one respondent - verbatim).;
• Used as backfill material in exhausted gypsum mines (one respondent - verbatim).; and
• Dewatered and land disposed on site (one respondent - verbatim).
Out of the responses received from WRRF digester operators, 68 facilities out of 72 (94%) indicated that
they produce a Class A or Class B biosolid.21 Thirty seven percent of the responding facilities produced
Class A biosolids, and 63% produced Class B biosolids.
The federal biosolids rule is contained in 40 CFR Part 503 and defines two types of biosolids with respect
to pathogen reduction, Class A and Class B, depending on the degree of treatment the solids have
received. Class A biosolids contain no detectible levels of pathogens. Class B biosolids are treated but
still contain detectible levels of pathogens. There are buffer requirements, public access, and crop
harvesting restrictions for virtually all forms of Class B biosolids.
21 For additional information on biosolids, please see: https://www.epa.eov/sites/production/filles/2018"
12/documents/plain-english-guide-part503-biosolids-rule.pdf"
26
-------
Table 23: Solid Digestate Uses
Stand-Alone Digesters
On-Farm Co-Digesters
Co-Digestion Systems at
WRRFs
Digestate Use
Number of
Facilities
Reporting
Use
Percentage
using Solid
Digestate
as Specified*
Number of
Facilities
Reporting
Use
Percentage
using Solid
Digestate as
Specifiedf
Number of
Facilities
Reporting
Use
Percentage
using Solid
Digestate as
Specified§
De-watered and
land applied
10
23%
6
38%
41
58%
Composted into
a reusable/
salable product
16
36%
3
19%
8
11%
Landfilled
4
9%
0
-
11
15%
Other
14
32%
3
19%
9
13%
Processed into
animal bedding
0
-
10
63%
0
-
Dried into a
reusable/
salable product
(e.g., fertilizer)
0
-
0
-
9
13%
Land applied as
is with no
dewatering or
drying
3
7%
0
-
10
14%
Incinerated
0
-
0
-
1
1%
* Percentage calculation based on 44 stand-alone facilities providing data on use of solid digestate.
+ Percentage calculation based on 16 farms providing data on use of solid digestate.
§ Percentage calculation based on 71 WRRFs providing data on use of solid digestate.
60
-------
O. Liquid Digestate Uses
EPA asked how facilities manage liquid digestate, allowing respondents to provide more than one answer.
Respondents from 39 of 46 stand-alone facilities (96%), all 16 on-farm co-digesters, and 71 of 72 (99%)
WRRFs provided data on the management of liquid digestate, as summarized in Table 24.
Of the 17 stand-alone digesters that used digestate as fertilizer via land application, only two facilities
further processed it prior to application (12%). All 16 on-farm co-digester operators indicated that liquid
digestate was land applied. Two of these on-farm co-digester operators indicated that the liquid was
further processed prior to application (13%). Seven WRRF digesters indicated that the liquid digestate
they produced was land applied, and three of these facilities further processed it prior to application.
Table 24: Liquid Digestate Uses
Stand-Alone Digesters
On-Farm Co-Digesters
Co-Digestion Systems at
WRRFs
Digestate Use
Number of
Facilities
Reporting
Use
Percentage
using Liquid
Digestate
as Specified*
Number of
Facilities
Reporting
Use
Percentage of
using Liquid
Digestate as
Specified1
Number of
Facilities
Reporting
Use
Percentage of
using Liquid
Digestate as
Specified§
Recirculated
through digester
10
26%
7
44%
60
85%
Reused as
fertilizer via land
application
17
44%
16
100%
7
10%
Discharged to a
wastewater
treatment plant
20
51%
0
-
0
-
Other
3
8%
0
-
11
15%
* Percentage calculation based on 39 stand-alone facilities providing data on use of liquid digestate.
+ Percentage calculation based on 16 farms providing data on use of liquid digestate.
§ Percentage calculation based on 71 WRRFs providing data on use of liquid digestate.
(D
to
Ctf)
c
80
60
o
Q.
(D
.34 40
° 20
(D
_Q
£
3
Recirculated through Reused as fertilizer via Discharged to a
digester land application wastewater treatment
plant
Other
I Stand-Alone Digesters ¦ On-Farm Digesters
I WRRF Digesters
Figure 11: Uses of Liquid Digestate by Digester Type
28
-------
IV. Conclusion
The 2018 survey (results summarized in this report) helped EPA estimate how many AD facilities were
processing food waste in the U.S., where those facilities are located, and their processing amounts and
available capacity. EPA also gathered information on the non-food waste processed at these facilities,
feedstock types and sources, tipping fees, pre-processing/de-packaging techniques, operational
specifications, biogas production and uses, gas cleaning systems, and solid and liquid digestate uses.
Lastly, EPA gathered information on facilities not yet operational, but that were anticipated to become
operational in the future, which will be critical to tracking growth in capacity over time as future reports
are developed.
Based on information received directly from facilities that responded to the survey, the total processing
capacity for food waste at these AD facilities is nearly 24 million tons per year. The total amount food
waste reported to be processed (in 2016) was over 10 million tons and the total amount of non-food
waste reported to be processed (in 2016) was over 490 million gallons and nearly 104,000 tons. The total
amount of biogas produced (in 2016) was over 40,000 SCFM. Additional information on AD facilities is
summarized in Table 25.
The extent to which the results of the 2018 survey can be compared with the 2017 survey should be
caveated by the fact that the individual facilities responding from year to year are not identical. It should
also be noted the facilities voluntarily chose to submit data. For example, although the results of the
survey show an increase in capacity for stand-alone digesters, it may be because a facility with a high
capacity did not respond in the 2017 survey. Furthermore, due to the fact that the 2018 report had
different facilities respond to the survey, the report cannot be used to express how the state of AD is
increasing or decreasing. EPA will continue to gather data and seek to verify data received in 2017 and
2018 to clarify this information in these reports over time. Data collected during the 2019 survey will
be summarized in the anticipated third report in this series targeted for publication in 2020.
29
-------
Table 25: 2018 Survey Results
Area of Data Collection
Result
Total Processing Capacity
23,993,122 tons per year
Total Food Waste Processed (2016)
10,691,756 tons
Total Non-Food Waste Processed at Co-
491,972,700 gallons and 103,952 tons
Digesting Facilities (2016)
Total Biogas Produced (2016)
40,304 SCFM
Top-Three States with the Most Digesters
California; Wisconsin; Ohio
Top-Three Feedstock Types
FOG; Food Processing Industry Waste; Beverage
Processing Industry Waste
Top-Three Feedstock Sources
Food/Beverage Processors; Restaurants & Food
Services; Grocery Stores/Supermarkets
Top-Three Biogas Uses
Produce Heat and Electricity (CHP); Fuel Boilers and
Furnaces to Heat Digesters; Fuel Boilers and Furnaces
to Heat Other Spaces
Top-Three Constituents Removed
Moisture; Sulfur; Siloxanes
Top-Three Uses of Solid Digestate
De-watered/dried and Land Applied; Composted into
a Reusable/Salable Product; Other
Top-Three Uses of Liquid Digestate
Recirculated Through Digester; Reused as Fertilizer
via Land Application; Discharged to a Wastewater
Treatment Plan
30
-------
Appendix A - Operational Digesters and Co-Digestion Systems
This appendix lists the facilities for which survey responses were received in 2018 and 2017 for each
digester type. Tables 1A, 3A and 5A list facilities that provided survey responses in 2018 and were
operational as of December 2018. Tables 2A, 4A and 6A list facilities that provided survey responses in
2017 and were operational as of December 2017. These tables are not identical to the corresponding
tables in Appendix A of the report issued in 2018. The table descriptions are as follows:
Table 1A: Stand-Alone Anaerobic Digestion Facilities Digesting Food Waste in the U.S. (2018)
Table 2A: Stand-Alone Anaerobic Digestion Facilities Digesting Food Waste in the U.S. (2017)
Table 3A: On-Farm Digesters Co-Digesting Food Waste in the U.S. (2018)
Table 4A: On-Farm Digesters Co-Digesting Food Waste in the U.S. (2017)
Table 5A: WRRF Digesters Co-Digesting Food Waste in the U.S. (2018)
Table 6A: WRRF Digesters Co-Digesting Food Waste in the U.S. (2017)
Table 1A: Stand-Alone Anaerobic Digestion Facilities Digesting Food Waste in t
he U.S. (2018)
Multi-Source
Stand-Alone Facility Name
Location
(MS)/lndustry-
Dedicated
(ID)/Other*
l
Ralphs Recovery System
Compton, CA
ID
2
Fairfield Brewery BTS
Fairfield, CA
ID
3
MillerCoors Brewery
Irwindale, CA
ID
4
Zero Waste Energy - Monterey
Marina, CA
MS
North State Rendering Co. Inc./John S. Ottone
Oroville, CA
MS
5
Renewable Energy Project
6
Gills Onions
Oxnard, CA
ID
7
CleanWorld SATS
Sacramento, CA
MS
8
Kompogas SLO LLC
San Luis Obispo, CA
MS
9
Zero Waste Energy Development Company
San Jose, CA
MS
10
Blue Line Biogenic CNG Facility
South San Francisco, CA
MS
11
LA BTS
Van Nuys, CA
ID
12
Quantum Biopower
Southington, CT
MS
13
Harvest Power Orlando
Bay Lake, FL
MS
14
Jacksonville BTS
Jacksonville, FL
ID
15
Cartersville BTS
Cartersville, GA
ID
16
City of Waterloo Anaerobic Lagoon
Waterloo, IA
OTHER
17
Waste No Energy, LLC
Monticello, IN
MS
18
Stop & Shop Freetown Distribution Center
Assonet, MA
ID
19
Garelick Farms
Franklin, MA
ID
20
CRMC Bioenergy Facility
New Bedford, MA
OTHER
21
Generate Fremont Digester, LLC
Fremont, Ml
MS
22
Hometown BioEnergy
Le Sueur, MN
MS
23
St. Louis BTS
St. Louis, MO,
ID
24
Full Circle Recycle
Zebulon, NC
MS
25
Merrimack BTS
Merrimack, NH
ID
26
Newark BTS
Newark, NJ
ID
27
Lassonde Pappas
Seabrook, NJ
ID
A-l
-------
Multi-Source
Stand-Alone Facility Name
Location
(MS)/lndustry-
Dedicated
(ID)/Other*
28
AB-lnbev Baldwinsville
Baldwinsville, NY
ID
29
Buffalo BioEnergy
West Seneca, NY
MS
30
Generate Niagara Digester
Wheatfield, NY
MS
31
Emerald BioEnergy
Cardington, OH
MS
32
Collinwood BioEnergy
Cleveland, OH
OTHER
33
Central Ohio BioEnergy
Columbus, OH
MS
34
Columbus BTS
Columbus, OH
ID
35
Dovetail Energy
Fairborn, OH
MS
36
Campbell Soup Supply Company
Napoleon, OH
ID
37
Three Creek BioEnergy, LLC
Sheffield Village, OH
MS
38
Buckeye Biogas, LLC
Wooster, OH
MS
39
Zanesville Energy, LLC
Zanesville, OH
MS
40
Stahlbush Island Farms
Corvallis, OR
OTHER
41
Yuengling Beer Company
Pottsville, PA
ID
Bush Brothers and Company Process Water
ID
42
Recovery Facility
Dandridge, TN
43
Houston BTS
Houston, TX
ID
44
Magic Hat Resource Recovery Center
South Burlington, VT
MS
45
FCPC Renewable Generation
Milwaukee, Wl
MS
46
Urban Dry Digester - UW Oshkosh
Oshkosh, Wl
MS
* "OTHER" represents two industry dedicated digesters that accept outside feedstocks periodically.
A-2
-------
Table 2A: Stand-Alone Anaerobic Digestion Facilities Digesting Food Waste in the U.S. (2017)
Multi-Source
Stand-Alone Facility Name
Location
(MS)/lndustry-
Dedicated
(ID)/Other*
l
Ralphs Renewable Energy Facility
Compton, CA
ID
2
Fairfield Brewery BTS
Fairfield, CA
ID
3
MillerCoors Brewery
Irwindale, CA
ID
4
Monterey Regional Waste Management District
Marina, CA
MS
5
North State Rendering
Oroville, CA
MS
6
Gills Onions
Oxnard, CA
ID
7
CR&R Material Recovery Facility
Perris, CA
MS
8
Sacramento BioDigester
Sacramento, CA
MS
9
ZWEDC
San Jose, CA
MS
10
Blue Line Biogenic CNG Facility
South San Francisco, CA
MS
11
LA BTS
Van Nuys, CA
ID
12
Quantum Biopower
Southington, CT
MS
13
Jacksonville BTS
Jacksonville, FL
ID
14
Harvest Power Orlando
Lake Buena Vista, FL
MS
15
Cartersville BTS
Cartersville, GA
ID
16
Waste No Energy, LLC
Monticello, IN
MS
17
Stop & Shop Freetown Distribution Center
Assonet, MA
OTHER
18
Garelick Farms
Franklin, MA
ID
19
Garelick Farms
Lynn, MA
ID
20
Ken's Foods Inc
Marlborough, MA
ID
21
CRMC Bioenergy Facility
New Bedford, MA
MS
22
Exeter Agri-Energy
Exeter, ME
MS
23
Michigan State Univ. - South Campus Anaerobic Digester
Lansing, Ml
MS
24
Hometown BioEnergy
Le Sueur, MN
MS
25
St. Louis BTS
St. Louis, MO,
ID
26
Merrimack BTS
Merrimack, NH
ID
27
Newark BTS
Newark, NJ
ID
28
Lassonde Pappas
Seabrook, NJ
ID
29
CH4 Generate Cayuga LLC.
Auburn, NY
MS
30
AB-lnbev Baldwinsville
Baldwinsville, NY
ID
31
Buffalo BioEnergy
West Seneca, NY
MS
32
Niagara BioEnergy
Wheatfield, NY
MS
33
Emerald BioEnergy
Cardington, OH
MS
34
Central Ohio BioEnergy
Columbus, OH
MS
35
Columbus BTS
Columbus, OH
ID
36
Dovetail Energy
Fairborn, OH
MS
37
Haviland Energy
Haviland, OH
MS
38
Quasar
Independence, OH
MS
39
Buckeye Biogas LLC
Wooster, OH
MS
40
Zanesville Energy
Zanesville, OH
MS
41
Stahlbush Island Farms
Corvallis, OR
MS
42
D.G. Yuengling and Son, Inc.
Pottsville, PA
ID
43
Kline's Services
Salunga, PA
MS
44
Houston BTS
Houston, TX
ID
45
Vermont Tech Community AD
Randolph, VT
MS
46
Purpose Energy Digester at Magic Hat Brewery
South Burlington, VT
OTHER
A-3
-------
Stand-Alone Facility Name
Location
Multi-Source
(MS)/lndustry-
Dedicated
(ID)/Other*
47
Bush Brothers & Company
Augusta, Wl
ID
48
Montchevre - Betin
Belmont, Wl
ID
49
Forest County Potawatomi Community Digester
Milwaukee, Wl
MS
50
UW-Oshkosh Urban Dry Digester
Oshkosh, Wl
MS
* "Other" reflects an industry dedicated digester that accepts outside feedstocks periodically, and a facility that processes
feedstocks from several of their own internal retail supermarkets.
Table 3A: On-Farm Digesters Co-Digesting Food Waste in the U.S. (2018)
Farm Name
Location
l
Green Cow Power
Goshen, IN
2
BioTown Ag
Reynolds, IN
3
Rutland AD1
Rutland, MA
4
Exeter Agri-Energy/Stonyvale Farm
Exeter, ME
5
Patterson Farms Inc
Auburn, NY
6
Noblehurst Green Energy
Linwood, NY
7
Oregon Dairy Farm LLC
Lititz, PA
8
Reinford Farms
Mifflintown, PA
9
Oak Hill Farm
Nottingham, PA
10
Chaput Family Farms
North Troy, VT
11
Vermont Technical College Anaerobic Digester
Randolph Center, VT
12
Vander Haak Dairy
Lynden, WA
13
Qualco Energy
Monroe, WA
14
Holsum Elm Dairy
Hilbert, Wl
15
Holsum Irish Dairy
Hilbert, Wl
16
Allen Farms
Oshkosh, Wl
Table 4A: On-Farm Digesters Co-Digesting Food Waste in the U.S. (2017)
Farm Name
Location
l
Link Energy
Riceville, IA
2
Bar-Way Farm
Deerfield, MA
3
Pine Island Farm
Sheffield, MA
4
Kilby's Inc.
Colora, MD
5
Exeter Agri-Energy/Stonyvale Farm
Exeter, ME
6
Patterson Farms Inc
Auburn, NY
7
Noblehurst Green Energy
Linwood, NY
8
CH4/Synergy Biogas
Wyoming, NY
9
Kish-View Farm
Belleville, PA
10
Schrack Farms
Loganton, PA
11
Reinford Farms
Mifflintown, PA
12
Monument Farms Three-Gen
Weybridge, VT
13
Clean Fuel Dane, LLC
Dane, Wl
14
Five Star Dairy, LLC
Elk Bridge, Wl
15
Allen Farms
Oshkosh, Wl
A-4
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Table 5A: WRRF Digesters Co-Digesting Food Waste in the U.S. (2018)
WRRF Name
Location
l
Fourche Creek Water Reclamation Facility
Little Rock, AR
2
Wildcat Hill Wastewater Treatment Plant
Flagstaff, AZ
3
Delta Diablo WWTP
Antioch, CA
4
Bakersfield Wastewater Treatment Plant #2
Bakersfield, CA
5
Bakersfield Wastewater Treatment Plant # 3
Bakersfield, CA
6
Hill Canyon Wastewater Treatment Plant
Camarillo, CA
7
Encina Wastewater Authority (EWPCF)
Carlsbad, CA
8
Joint Water Pollution Control Plant
Carson, CA
9
Sacramento Regional Wastewater Treatment Plant
Elk Grove, CA
10
Fairfield-Suisun Sewer District
Fairfield, CA
11
Fresno-Clovis RWRF
Fresno, CA
12
City of Hayward Water Pollution Control Facility
Hayward, CA
13
Napa Sanitation District
Napa, CA
14
East Bay Municipal Utility District Main Wastewater Treatment Plant
Oakland, CA
15
Silicon Valley Clean Water
Redwood City, CA
16
Oro Loma Sanitary District
San Lorenzo, CA
17
Central Marin Sanitation Agency
San Rafael, CA
18
El Estero WWTP
Santa Barbara, CA
19
Santa Rosa Regional Water Reuse Plant (Laguna Treatment Plant)
Santa Rosa, CA
20
Victor Valley Wastewater Reclamation Authority
Victorville, CA
21
City of Watsonville WWTP
Watsonville, CA
22
Santa Rita Wastewater Reclamation Plant (City of Durango WWTP)
Durango, CO
23
South Cross Bayou Advanced Water Reclamation Facility
St. Petersburg, FL
24
Thomas P Smith Water Reclamation Facility (TPS Treatment Plant)
Tallahassee, FL
25
F. Wayne Hill Water Resources Center
Buford, GA
26
South Columbus Water Treatment Facility
Columbus, GA
27
Lower Poplar Street Water Reclamation Facility
Macon, GA
28
Ames Water Pollution Control Plant
Ames, IA
29
Davenport Water Pollution Control Plant
Davenport, IA
30
Des Moines Metropolitan Wastewater Reclamation Authority
Des Moines, IA
31
Dubuque Water & Resource Recovery Center
Dubuque, IA
32
Downers Grove Sanitary District Wastewater Treatment Center
Downers Grove, IL
33
Rock River Water Reclamation District
Rockford, IL
34
Urbana & Champaign Sanitary District
Urbana, IL
35
West Lafayette Wastewater Treatment Facility
West Lafayette, IN
36
DLS Middle Basin Wastewater Treatment Plant
Overland Park, KS
37
Greater Lawrence Sanitary District
North Andover, MA
38
Lewiston-Auburn Water Pollution Control Authority
Lewiston, ME
39
Delhi Charter Township Wastewater Treatment Plant
Holt, Ml
40
Flint Biogas Plant
Flint, Ml
41
St. Cloud Nutrient, Energy and Water Recovery Facility
St. Could, MN
42
City of Springfield Southwest Wastewater Treatment Plant
Springfield, MO
43
Joint Meeting of Essex & Union Counties
Elizabeth, NJ
44
Rahway Valley Sewerage Authority
Rahway, NJ
45
Landis Sewerage Authority
Vineland, NJ
46
Newtown Creek Wastewater Resource Recovery Facility
Brooklyn, NY
A-5
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WRRF Name
Location
47
LeRoy R. Summerson Wastewater Treatment Facility
Cortland, NY
48
Gloversville Johnstown Joint Wastewater Treatment Facility
Johnstown, NY
49
City of London Wastewater Treatment Plant
London, OH
50
City of Wooster Water Resource Recovery Facility
Wooster, OH
51
Gresham Wastewater Treatment Plant
Gresham, OR
52
City of Pendleton Wastewater Treatment Facility
Pendleton, OR
53
Clean Water Services - Durham Advanced Wastewater Treatment Facility
Tigard, OR
54
Hermitage Municipal Authority
Hermitage, PA
55
Derry Township Municipal Authority
Hershey, PA
56
Milton Regional Sewer Authority
Milton, PA
57
New Castle Sanitation Authority
New Castle, PA
58
Mauldin Road Water Resource Recovery Facility
Greenville, SC
59
Southside Wastewater Treatment Plant
Dallas, TX
60
Waco Metro - Area Regional Sewage System
Waco, TX
61
North River Wastewater Treatment Facility
Mt. Crawford, VA
62
Opequon Water Reclamation Facility
Winchester, VA
63
Village of Essex Junction Water Resource Recovery Facility
Essex Junction, VT
64
Appleton Wastewater Treatment Plant
Appleton, Wl
65
Fond du Lac Regional Wastewater Treatment & Resource Recovery Facility
Fond du Lac, Wl
66
City of Kiel Wastewater Facility
Kiel, Wl
67
MMD South Shore Water Reclamation Facility
Oak Creek, Wl
68
City of Port Washington Wastewater Treatment Plant
Port Washington, Wl
69
City of Rice Lake Wastewater Treatment Plant
Rice Lake, Wl
70
Stevens Point Wastewater Treatment Plant
Stevens Point, Wl
71
City of West Bend Wastewater Treatment Plant
West Bend, Wl
72
Wisconsin Rapids Wastewater Treatment Facility
Wisconsin Rapids, Wl
Table 6A: WRRF Digesters Co-Digesting Food Waste in the U.S. (2017)
WRRF Name
Location
l
Fourche Creek Water Reclamation Facility
Little Rock, AR
2
Wildcat Hill Wastewater Treatment Plant
Flagstaff, AZ
3
Delta Diablo WWTP
Antioch, CA
4
Bakersfield Wastewater Treatment Plant # 2
Bakersfield, CA
5
Bakersfield Wastewater Treatment Plant # 3
Bakersfield, CA
6
Hill Canyon Wastewater Treatment Plant
Camarillo, CA
7
Encina Wastewater Authority (EWPCF)
Carlsbad, CA
8
Joint Water Pollution Control Plant
Carson, CA
9
Sacramento Regional Wastewater Treatment Plant
Elk Grove, CA
10
Fairfield-Suisun Sewer District
Fairfield, CA
11
Fresno-Clovis RWRF
Fresno, CA
12
City of Hayward Water Pollution Control Facility
Hayward, CA
13
Napa Sanitation District
Napa, CA
14
East Bay Municipal Utility District Main Wastewater Treatment Plant
Oakland, CA
15
Silicon Valley Clean Water
Redwood City, CA
16
Oro Loma Sanitary District
San Lorenzo, CA
17
Central Marin Sanitation Agency
San Rafael, CA
18
El Estero WWTP
Santa Barbara, CA
19
Santa Rosa Regional Water Reuse Plant (Laguna Treatment Plant)
Santa Rosa, CA
A-6
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WRRF Name
Location
20
Victor Valley Wastewater Reclamation Authority
Victorville, CA
21
City of Watsonville WWTP
Watsonville, CA
22
Santa Rita Wastewater Reclamation Plant (City of Durango WWTP)
Durango, CO
23
North Regional WWTP
Pompano Beach, FL
24
South Cross Bayou Advanced Water Reclamation Facility
St. Petersburg, FL
25
Thomas P Smith Water Reclamation Facility (TPS Treatment Plant)
Tallahassee, FL
26
F. Wayne Hill Water Resources Center
Buford, GA
27
South Columbus Water Treatment Facility
Columbus, GA
28
Lower Poplar Street Water Reclamation Facility
Macon, GA
29
Ames Water Pollution Control Plant
Ames, IA
30
Davenport Water Pollution Control Plant
Davenport, IA
31
Des Moines Metropolitan Wastewater Reclamation Authority
Des Moines, IA
32
Dubuque Water & Resource Recovery Center
Dubuque, IA
33
Downers Grove Sanitary District Wastewater Treatment Center
Downers Grove, IL
34
Rock River Water Reclamation District
Rockford, IL
35
Urbana & Champaign Sanitary District
Urbana, IL
36
West Lafayette Wastewater Treatment Facility
West Lafayette, IN
37
DLS Middle Basin Wastewater Treatment Plant
Overland Park, KS
38
Greater Lawrence Sanitary District
North Andover, MA
39
Lewiston-Auburn Water Pollution Control Authority
Lewiston, ME
40
Delhi Charter Township Wastewater Treatment Plant
Holt, Ml
41
City of Springfield Southwest Wastewater Treatment Plant
Springfield, MO
42
Theresa Street WRRF
Lincoln, NE
43
Joint Meeting of Essex & Union Counties
Elizabeth, NJ
44
Village of Ridgewood Water Pollution Control Facility
Glen Rock, NJ
45
Landis Sewerage Authority
Vineland, NJ
46
Newtown Creek Wastewater Resource Recovery Facility
Brooklyn, NY
47
LeRoy R. Summerson Wastewater Treatment Facility
Cortland, NY
48
Gloversville Johnstown Joint Wastewater Treatment Facility
Johnstown, NY
49
City of Watertown Pollution Control Plant
Watertown, NY
50
City of London Wastewater Treatment Plant
London, OH
51
Gresham Wastewater Treatment Plant
Gresham, OR
52
City of Pendleton Wastewater Treatment Facility
Pendleton, OR
53
Clean Water Services - Durham Advanced Wastewater Treatment Facility
Tigard, OR
54
Hermitage Municipal Authority
Hermitage, PA
55
Derry Township Municipal Authority
Hershey, PA
56
Milton Regional Sewer Authority
Milton, PA
57
New Castle Sanitation Authority
New Castle, PA
58
Mauldin Road Water Resource Recovery Facility
Greenville, SC
59
Southside Wastewater Treatment Plant
Dallas, TX
60
Waco Metro - Area Regional Sewage System
Waco, TX
61
North River Wastewater Treatment Facility
Mt. Crawford, VA
62
Opequon Water Reclamation Facility
Winchester, VA
63
Village of Essex Junction Water Resource Recovery Facility
Essex Junction, VT
64
Appleton Wastewater Treatment Plant
Appleton, Wl
65
Fond du Lac Regional Wastewater Treatment & Resource Recovery Facility
Fond du Lac, Wl
66
City of Kiel Wastewater Facility
Kiel, Wl
67
MMD South Shore Water Reclamation Facility
Oak Creek, Wl
68
City of Port Washington Wastewater Treatment Plant
Port Washington, Wl
A-7
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WRRF Name
Location
69
City of Rice Lake Wastewater Treatment Plant
Rice Lake, Wl
70
Stevens Point Wastewater Treatment Plant
Stevens Point, Wl
71
City of West Bend Wastewater Treatment Plant
West Bend, Wl
72
Wisconsin Rapids Wastewater Treatment Facility
Wisconsin Rapids, Wl
A-8
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Appendix B - Digesters and Co-Digestion Systems Under
Development or Temporarily Shut-Down
This appendix lists the stand-alone facilities and co-digestion systems at WRRFs that are under
development and temporarily shut-down. No on-farm co-digesters have been identified that are currently
under development. The lists in Table IB and 2B are current as of December 2018. The table descriptions
are as follows:
Table IB: Stand-Alone Anaerobic Digestion Facilities Under Development in the U.S.
Table 2B: WRRF's with Co-Digestion Systems Under Development in the U.S.
Table IB: Stand-Alone Anaerobic Digestion Facilities Under Development in the U.S.
Stand-Alone Facility Name
Facility Status
Location
l
CleanWorld/UC Davis Renewable Energy Anaerobic
Digester (READ)
Temporary Shut-Down
Davis, CA
2
Agromin Organic Recycling Compost Facility
Planning stage; Design
stage; Permitting Process
Oxnard, CA
3
Organic Energy Systems (OES)
Procurement
San Bernardino, CA
4
Tajiguas Resource Recovery Project
Planning stage; Design
stage; Permitting Process
Santa Barbara, CA
5
Turning Earth LLC
Fully permitted, seeking
construction financing
Southington, CT
6
BTS Biogas LLC - Maryland Food Center
Under Construction
Jessup, MD
7
Orbit Energy Charlotte
Start-up Mode
Charlotte, NC
8
Linden Renewable Energy
Planning stage; Design
stage; Permitting Process
Linden, NJ
9
Gloucester City Organic Recycling
Under Construction
Marlton, NJ
10
Point Breeze Renewable Energy
Planning stage; Design
stage; Permitting Process
Philadelphia, PA
11
Orbit Energy Rhode Island
Start-up Mode
Johnston, Rl
12
Freestate Farms Integrated Facility
Planning stage; Design
stage; Permitting Process
Manassas, VA
Table 2B: WRRF's with Co-Digestion Systems under Development in the U.S.
WRRF Name
Facility Status
Location
l
South Slope Wastewater Treatment Plant
Planning stage; Design
stage; Permitting Process
Moline, IL
2
Kinross Township Wastewater Treatment Plant
Under Construction
Kincheloe, Ml
3
Western Lake Superior Sanitary District
Planning stage; Design
stage; Permitting Process
Duluth, MN
4
Empire Wastewater Treatment Plant
Under Construction
Farmington, MN
5
Village of Ridgewood Water Pollution Control Facility
Temporary Shut-down
Glen Rock, NJ
6
Rome Water Pollution Control Facility
Planning stage; Design
stage; Permitting Process
Rome, NY
7
City of Newark Wastewater Treatment Plant
Temporary Shut-down
Newark, OH
8
Green Bay Metropolitan Sewerage District
Under Construction
Green Bay, Wl
B-l
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Appendix C - Digesters and Co-Digestion Systems that have
Ceased Operations
This appendix lists the facilities for each digester type that have ceased operations. This list is current as
of December 2018.
Table 1C: Facilities that Have Ceased Operation in the U.S.
Stand-Alone Digesters
Digester Name
Location
1
Heartland Biogas
LaSalle, CO
2
CR&R
Perris, CA
3
Garelick Farms
Lynn, MA
Farm Co-digestion Systems
Digester Name
Location
4
Zuber Farms
Byron, NY
5
George Deruyter Dairy
Outlook, WA
6
Wild Rose Dairy
LaFarge, Wl
WRRF Co-Digestion Systems
Digester Name
Location
7
Hyperion Treatment Plant
Playa Del Rey, CA
8
Metropolitan Syracuse Wastewater Treatment Plant
Syracuse, NY
9
Struthers Wastewater Treatment Plant
Struthers, OH
10
Janesville Wastewater Treatment Plant
Janesville, Wl
11
Sheboygan Wastewater Treatment Plant
Sheboygan, Wl
C-l
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Appendix D - Survey Questions
This appendix provides the lists of questions asked via a survey for each digester type regarding their use
of food waste and food-based materials as a feedstock. EPA distributed the surveys via email directly to
facility contacts, when known, and made the survey available on EPA's website. When the 2019 survey is
available, it will be posted at the same location.
Survey 1: Stand-Alone Anaerobic Digestion Facility Survey Questions
Survey 2: On-Farm Digester Survey Questions
Survey 3: Co-Digestion Systems at Water Resource Recovery Facilities Survey Questions
D-l
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