NREL is a national laboratory of the U.S. Department of Energy, 

Office of Energy Efficiency & Renewable Energy, operated by the 

Alliance for Sustainable Energy, LLC.

Contract No. DE-AC36-08GO28308

Feasibility Study of Anaerobic 

Digestion of Food Waste in 

St. Bernard, Louisiana

A Study Prepared in Partnership with 

the Environmental Protection Agency 

for the RE-Powering America’s Land 

Initiative: Siting Renewable Energy on 

Potentially Contaminated Land and 

Mine Sites

Kristi Moriarty

Produced under direction of the U.S. Environmental Protection 

Agency (EPA) by the National Renewable Energy Laboratory (NREL) 

under Interagency Agreement IAG-08-0719 and Task No WFD3.1001.

Technical Report

NREL/TP-7A30-57082

January 2013
NREL is a national laboratory of the U.S. Department of Energy, Office of Energy 

Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

Contract No. DE-AC36-08GO28308

National Renewable Energy Laboratory

15013 Denver West Parkway

Golden, CO 80401

303-275-3000 • www.nrel.gov

Feasibility Study of Anaerobic 

Digestion of Food Waste in 

St. Bernard, Louisiana

A Study Prepared in Partnership with 

the Environmental Protection Agency 

for the RE-Powering America’s Land 

Initiative: Siting Renewable Energy on 

Potentially Contaminated Land and 

Mine Sites

Kristi Moriarty

Prepared under Task No. WFD3.1001

Technical Report

NREL/TP-7A30-57082

January 2013
NOTICE

This manuscript has been authored by employees of the Alliance for Sustainable Energy, LLC (“Alliance”) under 

Contract No. DE-AC36-08GO28308 with the U.S. Department of Energy (“DOE”).

This report was prepared as an account of work sponsored by an agency of the United States government. 

Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, 

express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of 

any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately 

owned rights. Reference herein to any specific commercial product, process, or service by trade name, 

trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, 

or favoring by the United States government or any agency thereof. The views and opinions of authors expressed 

herein do not necessarily state or reflect those of the United States government or any agency thereof.

Cover Photos: (left to right) PIX 16416, PIX 17423, PIX 16560, PIX 17613, PIX 17436, PIX 17721

Printed on paper containing at least 50% wastepaper, including 10% post consumer waste.
iii

Acknowledgments

The National Renewable Energy Laboratory (NREL) thanks the U.S. Environmental Protection 

Agency (EPA) for its interest in securing NREL’s technical expertise. 

Special thanks go to Katie Brown,Shea Jones, Lura Matthews, and Jessica Trice from EPA for 

providing assistance on the report and Karen Peycke and Golam Mustafa of Region 6 for providing 

food waste resource information. The authors would also like to thank Rebecca Otte from the 

Regional Planning Commission for coordinating the site information and providing information for 

the report; Rick Sisk and Mike Daigle of TRC; Traci Green and Evita Lagard of Louisiana 

Department of Environmental Quality; and Brian Duff of the U.S. Department of Energy’s Office of 

Biomass Program for their involvement in the project. 
iv

List of Acronyms

AD anaerobic digestion

CHP combined heat and power

CoEAT Co-Digestion Economic Analysis Tool

DOE U.S. Department of Energy

EBMUD East Bay Municipal Utility District

EPA U.S. Environmental Protection Agency

LDEQ Louisiana Department of Environmental Quality

MCRT mean cell residence times

NAICS North American Industry Classification System

NPV net present value

NREL National Renewable Energy Laboratory

OLR organic loading rate

O&M operation and maintenance

RDI Richard’s Disposal Inc.

RFP request for proposals

SPL spent potliner

WWTP wastewater treatment plant
v

Executive Summary

The U.S. Environmental Protection Agency (EPA) Office of Solid Waste and Emergency Response 

Center for Program Analysis developed the RE-Powering America’s Land initiative to reuse 

contaminated sites for renewable energy generation when aligned with the community’s vision for 

the site. The former Kaiser Aluminum Landfill in St. Bernard Parish, Louisiana, was selected for a 

feasibility study under the program. Preliminary work focused on selecting a biomass feedstock. 

Discussions with area experts, universities, and the project team identified food wastes as the 

feedstock and anaerobic digestion (AD) as the technology.

The brownfield site is located in Chalmette, Louisiana, adjacent to the St. Bernard Port on the 

Mississippi River. The brownfield site is 39 acres; however, the center and southern area of the site 

is a mound with hazardous spent potliner (SPL) wastes. This leaves approximately 19 acres available 

for development evenly split on either side of the mound. Infrastructure, including rail, water, 

electricity, and natural gas pipes, are at or adjacent to the site.

Organic food wastes are a significant portion of municipal solids wastes. Only 2.5% are diverted 

from landfills annually. Wastes were estimated for food manufacturers, supermarkets, restaurants, 

hospitals, nursing homes, and universities within the area evaluated, including St. Bernard, Orleans, 

Plaquemines, and Jefferson Parishes. Calculations were based on methodologies developed in past 

state studies for Connecticut and Massachusetts. There is significant food waste in the area and 

interest from large producers in alternative waste disposal options. Total food waste generation in 

the study area is estimated at 70,000 tons per year; however, not all wastes would be available to a 

project. Assumptions of participation by categories of food waste generators led to a low scenario of 

7,000 tons per year and a medium scenario of 15,000 tons per year.

Table ES-1. Estimated Area Food Wastes

Food Waste Producer St. Bernard Plaquemines Orleans Jefferson Total

Tons per Year

Food Manufacturers 0 150 2,745 995 3,890

Supermarkets 396 164 2,952 6,815 10,326

Restaurants 618 485 23,009 23,253 47,364

Hospitals 0 0 861 399 1,260

Nursing Homes 105 70 1,968 2,531 4,674

Universities 0 0 2,284 0 2,284

Total 1,119 868 33,819 33,992 69,798

Source: Calculated based on U.S. Census Bureau 2010 County Business Patterns and Massachusetts Food 

Waste Study1

Ideally, wastes would be collected and delivered by private waste haulers. They already have the 

existing customer relationships, billing systems, and collection equipment. The tipping fee at a 

bioenergy facility must be lower than the landfill fee ($30/ton) to incentivize food wastes generators 

to separate organic and inorganic wastes and to motivate garbage haulers to collect and deliver to the 

 1 “Identification, Characterization, and Mapping of Food Waste and Food Waste Generators in Massachusetts.” 

Draper/Lennon, Inc. Massachusetts Department of Environmental Protection, September 2002.
vi

facility. This study uses a bioenergy plant tipping fee of $20/ton based on conversations with waste 

haulers. 

Food wastes are an excellent candidate for AD due to high moisture and organic content. AD is the 

natural, biological degradation of organic matter in absence of oxygen yielding biogas. Biogas is 

comprised of 60%–70% methane and 30%–40% carbon dioxide and other trace gasses. Biogas is 

capable of operating in nearly all devices intended for natural gas. AD is commonly used in 

wastewater and manure treatment facilities. There are few examples of U.S. food waste digesters. A 

literature review resulted in an expectation of high installation and operating costs for a food waste 

digester. Average installed and operating costs are estimated at $561/ton capacity and $48/ton 

processed, respectively.

Financial analysis was conducted using EPA’s Region 9 Co-Digestion Economic Analysis Tool 

(CoEAT). The net present value (NPV), a measure of the profitability of a project, is estimated at 

-$6.7 million. The lack of profitability is due to very low energy and landfill prices in Louisiana and 

high up-front costs for anaerobic digester technology and costs for ongoing operations. Revenues 

from the plant for both scenarios are not anticipated to be sufficient to overcome costs. 
vii

Table of Contents

1 Study and Site Background................................................................................................................. 1

1.1 Purpose of Study.............................................................................................................................. 1

1.2 Scope of Work ................................................................................................................................. 1

1.3 Study Area and Site Description...................................................................................................... 1

1.4 Site Considerations.......................................................................................................................... 4

1.5 Federal and State Regulations Impacting Anaerobic Digesters....................................................... 4

2 Development of Biomass Energy on Brownfield Sites .................................................................... 6

3 Anaerobic Digestion............................................................................................................................. 7

3.1 Overview.......................................................................................................................................... 7

3.2 Technical Information...................................................................................................................... 8

3.2.1 Digester Types.................................................................................................................... 9

3.2.2 Digester Parameters.......................................................................................................... 11

3.2.3 East Bay Municipal Utility District Food Digestion Experiment Results ........................ 12

3.3 Existing AD Systems..................................................................................................................... 13

3.4 AD Co-Products............................................................................................................................. 15

4 Feedstock Evaluation......................................................................................................................... 17

4.1 Methodology and Study Area Organic Waste Generation............................................................. 18

4.2 St. Bernard Area Food Wastes....................................................................................................... 20

4.2.1 Food Manufacturers.......................................................................................................... 22

4.2.2 Grocery Stores .................................................................................................................. 22

4.2.3 Restaurants........................................................................................................................ 22

4.2.4 Hospitals........................................................................................................................... 23

4.2.5 Nursing Homes................................................................................................................. 23

4.2.6 Universities....................................................................................................................... 23

4.2.7 Other Area Food Wastes................................................................................................... 23

4.3 Potential Business Scenarios.......................................................................................................... 23

4.3.1 Example: Los Angeles Restaurant Organic Food Waste Recycling Program .................. 24

4.4 Feedstock Summary and Conclusions........................................................................................... 25

5 Heat and Power Markets .................................................................................................................... 26

5.1 Power Markets............................................................................................................................... 27

5.2 Thermal Markets............................................................................................................................ 29

5.3 Market Summary ........................................................................................................................... 30

6 Financial Analysis .............................................................................................................................. 31

6.1 Financial Forecast Assumptions.................................................................................................... 32

6.1.1 Capital Costs..................................................................................................................... 32

6.1.2 Operation and Maintenance Costs.................................................................................... 32

6.1.3 Food Waste Quantity ........................................................................................................ 32

6.1.4 Biogas Yield ..................................................................................................................... 32

6.1.5 Tipping Fees ..................................................................................................................... 33

6.1.6 Electricity Sales ................................................................................................................ 33

6.1.7 Heat Sales ......................................................................................................................... 33

6.1.8 Digestate ........................................................................................................................... 33

6.1.9 Financing .......................................................................................................................... 33

6.2 CoEAT Modeling Results.............................................................................................................. 34

6.3 Project Financing ........................................................................................................................... 35

7 Conclusion .......................................................................................................................................... 36

Appendix A: Site Topography.................................................................................................................. 37

Appendix B: Food Waste Generator Details .......................................................................................... 38

Appendix C: Anaerobic Digestion Technology Providers.................................................................... 39
viii

List of Figures

Figure 1. The site in Chalmette, Louisiana............................................................................................... 2

Figure 2. Former Kaiser Aluminum Landfill site...................................................................................... 3

Figure 3. Photo of the south side of the site............................................................................................ 3

Figure 4. EPA AgSTAR anaerobic digestion uses diagram.................................................................... 8

Figure 5. Anaerobic digestion process..................................................................................................... 9

Figure 6. Complete mix digester schematic........................................................................................... 10

Figure 7. High solids digester schematic............................................................................................... 11

Figure 8. EPA food recovery hierarchy................................................................................................... 17

Figure 9. Food waste evaluation area..................................................................................................... 20

Figure 10. St. Bernard Parish population, housing, and estimated demand...................................... 26

Figure 11. Electricity prices ..................................................................................................................... 28

Figure 12. Electricity consumption ......................................................................................................... 28

Figure 13. Natural gas prices................................................................................................................... 29

Figure 14. Natural gas consumption....................................................................................................... 30

Figure A-1. Site topography..................................................................................................................... 37

List of Tables

Table ES-1. Estimated Area Food Wastes................................................................................................ v

Table 1. Anaerobic Digestion Operating Parameters............................................................................ 12

Table 2. East Bay Food Waste Anaerobic Digestion Parameters ........................................................ 13

Table 3. Existing U.S. Food Waste AD Projects..................................................................................... 15

Table 4. Digestate Characteristics .......................................................................................................... 16

Table 5. Food Waste Characteristics ...................................................................................................... 18

Table 6. NAICS Employment Size Class................................................................................................. 19

Table 7. Food Waste Producers in Study Area ...................................................................................... 21

Table 8. Estimated Food Wastes in the Study Area .............................................................................. 21

Table 9. Potential Food Wastes Collection Scenarios .......................................................................... 22

Table 10. Louisiana Electricity Generation by Source .......................................................................... 27

Table 11. Current Electricity Rates Comparison ................................................................................... 27

Table 12. Food Waste Anaerobic Digestion Costs and Capacity......................................................... 31

Table 13. Financial Model Inputs............................................................................................................. 33

Table 14. Technical Financial Model Inputs ........................................................................................... 34

Table 15. Income Statement..................................................................................................................... 34

Table B-1. Food Waste Generator Details .............................................................................................. 38
1

1 Study and Site Background

1.1 Purpose of Study

The U.S. Environmental Protection Agency (EPA) Office of Solid Waste and Emergency 

Response Center for Program Analysis developed the RE-Powering America’s Land intiative to 

reuse contaminated sites for renewable energy generation. EPA engaged Department of Energy’s 

(DOE) National Renewable Energy Laboratory (NREL) to conduct feasibility studies to assess 

the viability of developing renewable energy generating facilities on contaminated sites. The 

former Kaiser Aluminum Landfill site in St. Bernard Parish, Louisiana, was selected for a 

feasibility study under this initiative. 

Biomass was selected as the renewable energy resource, and preliminary work focused on 

selecting a feedstock. It is generally agreed upon in the biomass industry that sufficient feedstock 

must be available within 50 miles of a site for economic performance. The site is not located near 

concentrated woody biomass or agricultural residues. Therefore, area experts, universities, and 

the project team identified food wastes as the feedstock. They selected anaerobic digestion (AD)

as the technology because it can accommodate wet wastes, and food wastes have approximately 

70% moisture content. This study will review the site, feedstock, heat and power market, AD

technology, and economics of the proposed project. 

1.2 Scope of Work

The proposed facility will be an AD system utilizing food waste as feedstock. This feasibility 

study makes an evaluation of the following areas: 

• Site assessment 

• Overview of AD technology

• Feedstock assessment

• Markets for heat and power

• Financial analysis.

1.3 Study Area and Site Description

The site is located in Chalmette, Louisiana, adjacent to the St. Bernard Port. The site is in the 

vicinity of New Orleans, as shown in Figure 1. The circle represents an ideal collection radius of 

approximately 25 miles for food wastes. Food wastes are 70% moisture, and it is economical to 

collect waste from nearby producers. 
2

Figure 1. The site in Chalmette, Louisiana. Illustration done in Google Maps

The brownfield site was formerly used as a landfill for spent potliner (SPL) wastes from the 

Kaiser aluminum facility. The plant was closed in the 1980s, and the landfill was capped. SPL 

wastes were later classified as hazardous due to cyanide and fluoride content. The site is 

39 acres; however, a 25-foot mound containing wastes is located in the center and southern area

of the property, covering approximately 19 acres of the site (the yellow area in Figure 2

represents all 39 acres). There is also a fly ash pond and a small unoccupied building in the

northeast corner of the mound. The property is bounded by St. Bernard Port, Harbor, and 

Terminal District in the northeast and southeast; Chalmette National Battlefield and Cemetery in 

the northwest; and the Mississippi River in the southwest. A detailed drawing of the site is 

available in Appendix A. 

The Louisiana Department of Environmental Quality (LDEQ) and TRC (the land owner) would 

need to approve any development plans that may impact the cap. The costs to fill the surrounding 

land to align with the mound would be prohibitive. One option is to use the land on the south 

side of the mound adjacent to the port as it has easy road access and will not hinder activity at the 

adjacent National Park Service land.
3

Figure 2. Former Kaiser Aluminum Landfill site. Illustration done in Google Maps

TRC acquired the landfill in a bankruptcy settlement in 2004. They retain environmental liability 

and are responsible for checking the landfill cap and maintaining the site. There are no future 

plans to further clean up the site. TRC will donate the property for development while retaining 

environmental liability if it alleviates their maintenance costs and property taxes. 

The terrain of the site surrounding the mound is slightly rolling but should not require greater 

than normal site preparation and earthmoving. 

Figure 3. Photo of the south side of the site. Photo by Kristi Moriarty, NREL
4

1.4 Site Considerations

The criteria for a successful bioenergy facility include feedstock proximity, road and rail access, 

state and federal codes, and proximity to required utilities. Another consideration is a market for 

selling energy from the plant. 

The site is located in St. Bernard Parish, approximately 6 miles east of downtown New Orleans 

and 5.5 miles from Interstate 10. Significant infrastructure exists in the immediate vicinity due to 

the port, oil refineries, sugar plant, and other industries nearby. The site is accessed by Louisiana 

Highway 46/St. Claude Avenue, a multi-lane road. Northfolk Southern Railway is located 

0.2 miles northeast of the site. The site is adjacent to St. Bernard Port on the Mississippi River 

with a 45-foot draft. Entergy Louisiana provides natural gas and electrical service, and a tie-in is 

located 0.2 miles east in the Port. St. Bernard Parish water and sewer services are also available 

near the port. Resulting biopower will ideally be delivered to end-users via Entergy Louisiana’s 

infrastructure. 

Proximity to communities is also an important factor because of increased traffic volume to 

deliver feedstock and odor. The site is located in an industrial area with no residential 

communities nearby. The area is accustomed to truck traffic due to petroleum and other 

industries in the immediate vicinity. 

1.5 Federal and State Regulations Impacting Anaerobic Digesters

The size and design of the plant, the method of steam and power generation, and local permitting 

requirements ultimately affect the actual permits required for an AD project. State agencies 

generally handle permitting. Some states consider anaerobic digesters a waste processing facility. 

The federal regulations and permits required for an AD project include:

• National Emission Standards for Hazardous Air Pollutants covers boilers2

• EPA's National Ambient Air Quality Standards says combustion devices must emit below 

stated levels3

• 2011 EPA Clean Air Act pollution standards requires biomass boilers over 10 million 

Btu/hr for 876 or more hours per year to meet numeric emission standards4

• 40 CFR Part 89 limits emissions on non-road internal combustion engines5

• 40 CFR Part 60 limits emissions on steam generating units over 10 million Btu/hour5

• 40 CFR Part 63 requires reciprocating internal combustion engines or generators over 

300 hp to meet specific carbon monoxide standards5

 2 http://www.epa.gov/ttn/atw/eparules.html. 3 http://www.epa.gov/air/criteria.html. 4 “Final Air Toxics Standards For Industrial, Commercial, and Institutional Boilers at Area Source Facilities.” EPA,

2011. Accessed January 9, 2013: http://www.epa.gov/airtoxics/boiler/area_final_fs.pdf. 5 “Code of Federal Regulations. Title 40. Chapeter 1 – Environmental Protection Agency. Subchapter C – Air 

Programs. Parts 50-99.”U.S. Government Printing Office. Accessed January 9, 2013: 

http://www.gpo.gov/fdsys/browse/collectionCfr.action?collectionCode=CFR.
5

• Resource Conservation and Recovery Act Subtitle D covers solid wastes and says the 

facility may be considered a waste processing facility6

• 40 CFR Part 257 sets disposal standards for owners of non-municipal non-hazardous 

wastes which would include a facility accepting food wastes6

• National Pollutant Discharge Elimination System covers what happens to waste water 

from the facility7

• Prevention of Significant Deterioration and construction permits requires any new major 

source of pollutants to conduct analysis and use best control technologies 8

• Risk management plan requires new facilities to development a plan if certain chemicals 

are stored.

9

The required state permits generally include construction, air, water, and solid waste permits.

Some examples include:

• LDEQ

o Air quality permits

o Water quality permits; water appropriation permits

o Solid waste division approval of plans

• State Department of Transportation

o Highway access permits

o Possible easement rights

• State Department of Health

• State Department of Public Service.

 6 “Code of Federal Regulations. Title 40. Chapeter 1 – Environmental Protection Agency. Subchapter I – Solid 

Wastes. Parts 239-282.”U.S. Government Printing Office. 

http://www.gpo.gov/fdsys/browse/collectionCfr.action?collectionCode=CFR. 7 http://www.epa.gov/compliance/monitoring/programs/cwa/npdes.html. 8 http://www.epa.gov/NSR/psd.html. 9 http://www.epa.gov/oem/content/rmp/.
6

2 Development of Biomass Energy on Brownfield 

Sites

One very promising and innovative use of contaminated sites is to install biomass power 

systems. Biopower systems work well on brownfield sites where there is an adequate biomass 

fuel supply and favorable power sales rates.

The cleanup and reuse of potentially contaminated properties provides many benefits, including:

• Preserving greenfields

• Reducing blight and improving the appearance of a community

• Raising property values and creating jobs

• Allowing for access to existing infrastructure, including electric transmission lines and 

roads

• Enabling a potentially contaminated property to return to a productive and sustainable 

use.

By taking advantage of these potential benefits, biopower can provide a viable, beneficial 

reuse—in many cases generating revenue on a site that would otherwise go unused.

The former Kaiser Aluminum Landfill is owned by TRC, which is interested in donating the site 

to a potential renewable energy project. For many brownfield sites, the local community has 

significant interest in the redevelopment of the site and community engagement is critical to 

match future reuse options to the community’s vision for the site. 

The subject site has potential to be used for other functions beyond the biopower project 

proposed in this report. Any potential use should align with the community vision for the site and 

should work to enhance the overall utility of the property.

Most states rely heavily on fossil fuels to operate their power plants. There are many compelling 

reasons to consider moving toward renewable energy sources for power generation instead of 

fossil fuels, including: 

• Using fossil fuels to produce power may not be sustainable

• Burning fossil fuels can have negative effects on human health and the environment

• Extracting and transporting fossil fuels can lead to accidental spills, which can be 

damaging to the environment and communities

• Depending on foreign sources of fossil fuels can be a threat to national security

• Fluctuating electric costs are associated with fossil-fuel-based power plants 

• Burning fossil fuels emits greenhouse gases, possibly contributing to climate change.
7

3 Anaerobic Digestion

3.1 Overview

AD is the natural, biological degradation of organic matter in the absence of oxygen yielding 

biogas. Biogas is comprised of 60%–70% methane and 30%–40% carbon dioxide and other trace 

gasses. Biogas is capable of operating in nearly all devices intended for natural gas with minimal 

adjustments to account for lower Btu content. In the United States, AD is commonly used in 

wastewater treatment plants (WWTP) and as a method for manure treatment. The technology is 

commercial and has been deployed in the United States for over 30 years. 

EPA hosted a summit for a case study on biodigesters and biogas in 2012.10 The benefits of AD

include renewable energy generation, greenhouse gas emission reductions, reduced water 

pollution, and a potential revenue stream created from waste. The primary barriers are high 

capital costs and low biogas prices. 

There are several potential utilization options for biogas. Common applications include heat, 

power, or combined heat and power (CHP). A portion of generated biogas is required to maintain 

temperature and provide energy for other functions of the digestion process. Remaining energy is 

available for electricity generation or direct combustion for heating purposes. Biogas is typically 

used to power a microturbine or reciprocating engine. Combustion and steam turbines are only 

used in very large systems. 

Other potential scenarios for use of resulting heat or power from anaerobic digester include 

providing space heating for port area buildings or upgrading and compressing biogas for use in 

fleet vehicles (Figure 4). 

 10 “Case Study Primer for Participant Discussion: Biodigesters and Biogas.” EPA Technology Market Summit, May 

2012. Accessed January 3, 2013: http://www.epa.gov/agstar/documents/biogas_primer.pdf.
8

Figure 4. EPA AgSTAR anaerobic digestion uses diagram. Illustration from EPA AgSTAR Program

3.2 Technical Information

This project would need to obtain wastes from multiple sources, increasing the risk of 

contamination. Delivered feedstock may contain silverware, other metals, rocks, and other 

various non-desirable feedstock components. Preprocessing will be necessary to remove these 

contaminants from the food waste feedstock. This is done through various methods of sorting,

including mechanical systems. The digestion process takes place in a closed environment such as 

a tank. Digestion results in biogas primarily composed of methane and carbon dioxide. The goal 

is to produce a biogas with high methane content for energy production. The co-product is 

digestate and consists of solids and liquids remaining after digestion.

The degradation and conversion process occurs in four steps with different classes of bacteria 

responsible for each phase. Figure 5 illustrates the microbial process where the first two steps are 

facultative and the latter two are strictly anaerobic. Operating within defined parameters ensures 

optimal biogas production. 
9

Figure 5. Anaerobic digestion process. Illustration by Kristi Moriarty, NREL

AD technologies are typically optimized for either low solids or high solids content. 

Alternatively, these technologies are referred to as wet or dry even though the feedstock 

generally has moisture content above 70%. Low solids refers to wastes with solid content of 3%–

10%, and high solids refers to solid content of 15% or more. Wet systems (low solids)

mesophilic digesters are the most common and often deployed at WWTPs. Wet digesters slowly 

mix feedstock with microbes to increase the speed of degradation. Water will need to be added to 

food wastes in a wet digester to reduce solids content.

There are few examples of food waste digestion in the United States. Existing or planned 

standalone systems are increasingly evaluating high solids/dry digester technologies. Dry 

digestion is common for food wastes in Europe. Dry systems can be built to scale-up 

(batch/modular) as more wastes become available. This may be desirable, as it will take some 

time to develop the supplier base for food wastes in the study area. The site is not large and 

several reports suggest dry digestion requires less space. Financing novel technologies is 

generally more challenging. Any project evaluating AD should engage both wet and dry digester 

technology vendors. 

3.2.1 Digester Types

There are two methods for introducing feedstock into the digester: batch or continuous. In batch 

systems, the food waste is added to the vessel and sealed for the duration of the AD process. 

Some technologies integrate composting of remaining digestate co-product in the vessel after 

biogas production is completed. The more common method is continuous feeding where 

feedstock is frequently added to the digester. Wastewater and manure AD systems use the 

continuous method. Dry digesters are either batch or continuous. There is also a variation, 

temperature-phased anaerobic digester, a two-reactor digester designed to separate microbial 

processes in order to optimize parameters for different phases. Research has demonstrated that a 

two-stage reactor leads to higher biogas and methane yields, although dual reactors increase 

construction and materials costs. Single-stage systems are more common due to lower capital 

costs. 

Complete mix digesters consist of a large above- or below-ground steel or concrete reactor. They 

are a very common type of continuous digester often used in WWTPs (Figure 6). Waste is 

 HYDROLYSIS ACIDOGENESIS ACETOGENESIS METHANOGENESIS 

Carbohydrates

Fats

Proteins Amino Acids

Sugars

Fatty Acids

Carbon Acids

Alcohols

Hydrogen

Carbon Dioxide

Ammonia

Acetic Acid

Carbon Dioxide

Hydrogen

BIOGAS 

(methane,

carbon dioxide)
10

mechanically mixed keeping microbes and volatile solids in suspension providing good contact 

and efficient biogas production. The mixing also provides a homogenous digestate co-product. In 

the case of food wastes, water will need to be added to reach solids content of 10%–15%. Dry 

digesters (high solids) are similar in functionality and employ either batch or continuous 

feedstock entry. Figure 6 and Figure 7 illustrate various AD technology types. A list of 

technology providers is provided in Appendix B. 

Considerations for all digester types include:

• Insulation and heat exchangers maintain temperature from biogas or waste heat recovered 

from engine exhaust and cooling systems

• Approximately 10% of biogas will be used to provide energy to operate the plant

• It takes time to achieve a steady state for economic methane recovery

• Sewage sludge from a WWTP is often placed in the digester to establish microbial 

populations prior to loading feedstock.

Figure 6. Complete mix digester schematic. Illustration from EPA AgSTAR11

 11 EPA. AgSTAR Technical Series: Complete Mix Digesters – A Methane Recovery Option for All Climates. EPA 

430-F-97-004. EPA, February 1997.
11

Figure 7. High solids digester schematic. Illustration from Kompogas

3.2.2 Digester Parameters

AD systems are typically designed to operate in one of two temperature ranges: mesophilic and 

thermophilic. Mesophilic digesters operate between 95°F and 105°F and thermophilic between

125°F and 140°F. Mesophilic digesters are more common due to lower capital costs and ease of 

operation. Thermophilic digesters produce more energy but are generally more difficult to 

operate. In the United States, nearly all digesters are mesophilic in use at WWTPs and farms. In 

Europe, dedicated food waste digesters tend to use high solids (dry) technology and operate in 

the thermophilic range.

Residence time refers to the length of time for complete degradation of food wastes in a digester. 

It is a function of feedstock properties, temperature, process system, and similar parameters. 

Residence time for a wet mesophilic system ranges from 15–30 days. The residence time in 

thermophilic systems is shorter at about 14 days (wet system) due to higher temperatures. 

Residence times vary widely with more time generally leading to stable biogas production. 

However, longer residence time requires a larger digester, increasing capital costs. Engineering 

design will determine the optimal residence time and size for a project. 

Organic loading rate (OLR) refers to the rate at which volatile solids are added to a digester. It is 

calculated by dividing pounds of volatile solids added to the digester daily by the digester 

volume. OLR is a function of digester volume and residence time. It is essential to standardize 
12

the OLR of volatile solids (about 88% of total solids) into a digester to optimize methane 

production and minimize risk of a system shutdown. Overloading a digester with organic 

materials will send a digester into shock leading to reduced or discontinued methane production.

Retention time refers to the average time microbes are in the digester. Methanogenic bacteria 

grow slower than other bacteria in an anaerobic system. They respond slowly to changes, and 

AD system parameters should change slowly to maintain methanogen populations in the 

digester. Overloading solids may result in high levels of ammonia, which are toxic to 

methanogens. 

Optimizing parameters ensures appropriate methanogenic bacteria population to maximize 

biogas production (Table 1).

Table 1. Anaerobic Digestion Operating Parameters

Source: Loughborough University Biomass Course12 and EPA Region 2 NorthEast Biogas Presentation13

3.2.3 East Bay Municipal Utility District Food Digestion Experiment Results

East Bay Municipal Utility District (EBMUD) co-digests food wastes with wastewater in an 

existing anaerobic digester. They conducted a study to determine parameters of food wastes in an 

anaerobic digester at both mesophilic and thermophilic at mean cell residence times (MCRT) of 

5, 10, and 15 days (Table 2). The 5-day MCRT did not provide stable biogas production. 

Methane content is higher for thermophilic operation at both 10- and 15-day MCRTs. The 15-

day MCRT resulted in greater methane and electricity production rates. A longer MCRT requires 

a larger digester. 

 12 Biomass Course Book, Loughborough University, 2003. 13 “Overview of of Anaerobic Digestion and Digesters.” EPA Region 2. NorthEast Biogas Webinar, March 24, 

2010.

Parameter Range Information

Temperature 95-105°F Mesophilic

125-140°F Thermophilic 

The higher end of the mesophilic range is ideal for 

maximum biogas production

pH 6.5-7.5 Ideal pH is netural at 7.0. Self regulating by anaerobic 

microbes; methanogens unlikely to grow with pH < 6.5

Alkalinity 0.133 ounce/gallon Self regulating by hydrogen in waste converting to 

biocarbonate

Acidity to Alkalinity Ratio 0.3 to 0.5 Easier to measure than VFA or alkalinity

Volatile Fatty Acids (VFA) <0.013 ounce/gallon Higher concentrations will inhibit acetate and biogas 

production

Carbon to Nitrogen Ratio 20 to 30 Higher C:N ratios result in methogens consuming 

nitrogen; lowering biogas production.

Organic Loading Rate

3-5 kg of Volatile Solids per 

cubic meter of digester 

volume per day

Microbes are generally inhibited if loading rate exceeds 

6.4 kg/m3 day

Residence Time 9-95 days Varies widely based on feedstock, temperature, and 

system design
13

Table 2. East Bay Food Waste Anaerobic Digestion Parameters

Parameter

Mesophilic Thermophilic

MCRT units

10 days 15 days 10 days 15 days

Volatile Solids (% of Total Solids) 89.9 86.3 90.6 87 %

Volatile Solids Loading Rate 0.53 0.28 0.54 0.29 lb/ft3-day

Chemical Oxygen Demand Loading Rate 1.09 0.55 1.11 0.57 lb/ft3-day

Volatile Solids Destruction Rate 76.4 73.8 82.4 80.8 %

Methane Content 59 64 60 67 %

Methane Production Rate

9,500 13,300 9,500 13,300 ft3/lb total solids applied

2,600 2,300 2,600 2,300

ft3 per day/

1,000 ft3 digester volume

Biosolids

(% of food waste entering digester) 31 36 26 30 %

Electricity Production Rate 180 280 180 280 kWh per wet ton

Based on wet digester technology fed at a rate of 100 tons per day of food waste

MCRT = mean cell residence time

Source: East Bay Municipal Utility District Study

The resulting biogas must be treated before it is used to generate heat and electricity. The most 

significant contaminant in biogas is hydrogen sulfide, which will corrode equipment if it is not 

treated. An AgSTAR presentation provided costs of $25,000 for hydrogen sulfide treatment 

equipment (based on 200-kW complete mix wet digester).14 Biogas must be upgraded prior to 

entering natural gas pipelines—this requires high capital costs for equipment and significant 

electrical demand for operating it. Biogas from this project is not expected to enter natural gas 

pipelines due to Louisiana prices and natural gas supply. Further processing to remove carbon 

dioxide, hydrogen sulfide, and water allows biogas to be used as a compressed alternative fuel.

However, this is a limited but growing market.

Digester heating requirements are influenced by design and insulation used in digester 

construction. The St. Bernard site is in a warm climate so heating requirements will be low 

compared with other locations. The waste heat captured in the CHP system will be sufficient to 

heat the incoming food waste slurry and the digester system. Some of the heat and electricity 

generated will be used in the plant and administration office. 

3.3 Existing AD Systems

There is a long history of AD of wastewater in the United States. According to EPA’s 2008 

Clean Watershed Needs Survey database, there are 1,455 WWTPs using AD technology. Of 

these, 104 use CHP technology to heat and power the water treatment process. The WWTPs 

using CHP technology tend to use reciprocating engine or microturbine technology. Several 

municipalities co-digest food wastes with wastewater (Table 3). 

Nearly all AD projects are owned and operated by municipalities. Many partner with private 

waste haulers to deliver food waste feedstock. EBMUD used excess AD capacity to produce 

 14 “Estimating Anaerobic Digestion Capital Costs for Dairy Farms.” 2009 AgSTAR National Conference, February 

24–25, 2009, Baltimore, MD.
14

biogas from food wastes. Their system handles between 7,500 and 15,000 tons per year. Excess 

power generation is sufficient to provide electricity for 13,000 area homes.15 EBMUD conducted 

testing to determine the impact on biogas/electricity production as a result of adding food wastes. 

They found it significantly increased energy production compared with wastewater. The 

University of Wisconsin plans to achieve carbon neutrality and deployed a demonstration-scale 

anaerobic digester using novel technology. The university installed a dry/high solids system with 

capacity of 6,000 tons per year and power generation capacity of 2,320 MWh per year, 

representing approximately 8% of university demand.16 

The towns of Gloversville and Johnston, New York, in partnership with Fage, a yogurt 

manufacturer, co-digest wastewater and yogurt wastes. Fage selected the location in New York 

based on available excess capacity in the towns’ shared anaerobic digester system. The systems

include two 350-kW generation sets.17 The resulting energy provides 91% of the WWTP’s 

energy needs. Cottonwood Dairy in California installed an anaerobic digester to process manure 

and wastes from a cheese plant. Electricity and heat are used on-site and excess electricity from 

the 700-kW unit is sold to Pacific Gas and Electric.

18

Since 2002, Toronto has used AD to reduce food wastes in landfills and generate energy. As of 

2011, capacity is 40,000 tons per year with average biogas production of 3,434 cubic feet/ton.19

The resulting biogas is upgraded and delivered to a nearby natural gas line. Toronto is expanding 

and building more AD capacity at other sites with plans to increase annual capacity to 180,000 

tons per year.20

Several communities are planning food waste digesters. Humboldt County, California is 

considering a dry system with capacity of 10,000 tons per year. Cedar Grove Composting in 

Everett, Washington, is seeking permitting for an enormous digester at their existing compost 

facility with capacity of 280,000 tons per year. Zero Waste Energy Development Company in 

San Jose, California, is constructing a dry AD system to handle 90,000 tons per year, eventually 

expanding to 150,000 tons, using a dry/high solids modular design. Harvest Power near 

Vancouver, Canada, already handles large volumes of food wastes at their composting facility. 

They intend to build 30,000 tons per year dry/high solids AD system. w2e Organic Power plans 

to construct an anaerobic digester with capacity of 48,000 tons in Columbia, South Carolina. The 

 15 Gray, D. “Anaerobic Digestion of Food Wastes.” East Bay Municipal Utility District. EPA Region 9, March 2008. 16 “Dry Anaerobic Digestion for University of Wisconsin.” Waste Management World, July 2011. Accessed October 

2, 2012: http://www.waste-management-world.com/index/display/article-display.articles.waste-managementworld.biologicaltreatment.2011.07.Dry_Anaerobic_Digestion_for_University_of_Wisconsin_.QP129867.dcmp=rss.page=1.html. 17 “U.S. Treatment Plant Converts High-Strength Waste to Energy.” Cogeneration & On-Site Power Production, 

January 5, 2011. Accessed January 8, 2013: http://www.cospp.com/articles/print/volume-12/issue-3/projectprofiles/us-treatment-plant-converts-high-strength-waste-to-energy.html. 18 “Joseph Gallo Farms Dairy 700 kW Reciprocating CHP System.” Pacific Region CHP Application Center, 2006. 

Accessed January 8, 2013: http://der.lbl.gov/sites/der.lbl.gov/files/dercam_casestudy_josephgallofarms_v1_2.pdf. 19 “Digesting Urban Residuals Forum Highlights.” CalRecycle, May 2012. Accessed January 8, 2013:

http://www.calrecycle.ca.gov/Organics/Conversion/Events/Digesting12/CaseStudies.pdf. 20 “Update on Anaerobic Digester Projects Using Food Wastes in North America.” Institute for Local Self Reliance. 

City of Atlanta, October 2010. 
15

State of South Carolina will buy power generated by the digester. The company is in planning 

phases to build a food waste digester in Baton Rouge, Louisiana.

21

Table 3. Existing U.S. Food Waste AD Projects

Source: CalRecycle22 and ISLR Study23

Europe has more experience with food-waste-based digesters. As of 2006, there were 127 

operational food waste anaerobic digesters, with capacity of 4.6 million tons.24 This is due to a 

European Union Directive requiring diversion of 65% of 1995 levels of organics from landfills. 

The three most common technologies deployed in Europe are manufactured by Valgora, Ros 

Roca, and Kompogas. 

3.4 AD Co-Products

The AD process produces a co-product commonly referred to as digestate. Digestate consists of 

biosolids (~30%) and liquids (70%).25 It is common to separate solids and liquids. Liquids are 

typically applied directly to agricultural lands as a low-grade fertilizer. Solids are either 

composted (EPA’s preferred method) or used as animal bedding. Co-products can be separated 

using centrifuge, heat/drying, or a screw press. Economic values for digestate products are 

unknown. Many digesters are farm based, and digestate liquids and solids are used on-site. The 

properties of digestate are shown in Table 4. 

 21 “DHEC Approves Permit for Waste-to-Energy Plant.” Colombia Regional Business Report, January 17, 2011. 

Accessed January 7, 2013: http://www.columbiabusinessreport.com/news/37706-dhec-approves-permit-for-wasteto-energy-plant. 22 “Digesting Urban Residuals Forum Highlights.” CalRecycle, May 2012. Accessed January 8, 2013:

http://www.calrecycle.ca.gov/Organics/Conversion/Events/Digesting12/CaseStudies.pdf. 23 “Update on Anaerobic Digester Projects Using Food Wastes in North America.” Institute for Local Self Reliance. 

City of Atlanta, October 2010. 24 Arsova, L. “Anaerobic Digestion of Food Waste: Current Status, Problems and an Alternative Product.” 

University of Colombia, May 2010. 25 Alexander, R. “Digestate Utilization in the U.S.” BioCycle, January 2012. Accessed January 7, 2013: 

http://www.biocycle.net/2012/01/digestate-utilization-in-the-u-s/.

Anaerobic Digester Owner City State Feedstock AD Type

Gills Onions AD Project Oxnard CA Pre-consumer food wastes Wet

San Jose Zero Waste (construction) San Jose CA Food wastes, green wastes Dry (Kompoferm)

Orange County Food Waste Pilot Plant Orange CA Post-consumer food wastes Wet

Monterey Zero Waste AD Pilot Plant Monterey CA Post-consumer food wastes, green wastes Dry (Kompoferm)

Inland Empire-Environ AD project Chino CA Pre-consumer food wastes Wet

University of Wisconsin OshKosh WI Food wastes, green wastes Dry (Bioferm)

City of Toronto Toronto Food wastes Wet

Gloversville and Johnston Johnston NY Waste water, yogurt factory wastes Wet

Cottonwood Dairy CA Manure, cheese wastes Wet

East Bay Municipality Oakland CA Waste water, food wastes Wet

Sacramento County Co. Regional WWTP Sacramento CA Waste water, food wastes Wet

Central Marin Station Marin CA Waste water, food wastes Wet

Humboldt County Waste Authority CA Waste water, food wastes Wet

City of Riverside Riverside CA Waste water, food wastes Wet

Food-Waste-Based Digesters

Co-Digesters-Waste Water and Food Wastes
16

Table 4. Digestate Characteristics

Parameter Digestate Content

Total Solids 6%

Volatile Solids 69%

pH 7.6–8.8

Carbon to Nitrogen Ratio 1.5:1

Nitrogen 15%

Potassium 4.70%

Phosphorus 0.70%

Calcium 0.34%

Sulfur 0.30%

Magnesium 0.19%

Source: WRAP26

 26 “New Markets for Digestate from Anaerobic Digestion.” WRAP. ISS001-001, August 2011. Accessed on January 

8, 2013:

http://www.wrap.org.uk/sites/files/wrap/New_Markets_for_AD_WRAP_format_Final_v2.c6779ccd.11341.pdf.
17

4 Feedstock Evaluation

The St. Bernard site is not close to concentrated production of woody biomass or agricultural 

crop residues. While both are available in Louisiana, minimal quantities are within a 50-mile 

radius of Chalmette—the desired distance for economical delivery of biomass. The greatest 

volume of biomass in the immediate area is organic food waste. Waste Management, the leading 

U.S. private waste hauler, stated that 80 million tons of organic wastes are produced annually. 

According to EPA, food wastes are the top material sent to landfills, and only 2.5% are collected 

and diverted annually. A University of Texas study estimates U.S. food wastes could be diverted 

from landfills to produce 4,900 trillion BTU of energy.27

Food wastes are rich in organic matter and are troubling in landfills as they release methane, a 

potent greenhouse gas. Energy generation, including AD, is an industrial use of food recovery 

(Figure 8). Several municipalities across the United States offer either household or commercial 

collection of food wastes. In addition, there are many private organic recycling companies across 

the United States collecting and receiving organic wastes.

Figure 8. EPA food recovery hierarchy. Illustration from EPA28

Many different facilities produce significant food waste volumes, including restaurants, food 

manufacturers, hospitals, universities, and supermarkets. Healthcare facilities, universities, and 

conference properties produce similar wastes streams comprised of typically 50% 

fruit/vegetables and 50% protein (meat, fish, and poultry) and baked goods. Restaurant food 

waste exhibits more variability in composition. Fast food restaurants often use prepared portions 

of food and tend to generate less waste during preparation. Restaurants preparing food as it is 

ordered are likely to generate largely fruit and vegetable wastes with minimal amounts of bakery, 

sugar, starch, and dairy products. Supermarket waste is mostly produce (90%) with small 

amounts of bakery, seafood, and deli wastes. Supermarket meat wastes are generally collected by 

rendering facilities. 

 

27 Cullar, A.; Webber, M. “Wasted Food, Wasted Energy: The Embedded Energy in Food Waste in the United 

States.” University of Texas, July 2010. Accessed January 7, 2013: http://pubs.acs.org/doi/pdf/10.1021/es100310d. 28 EPA. OSW Food Waste. Accessed January 8, 2013: http://www.epa.gov/waste/conserve/foodwaste/.
18

The Massachusetts Department of Environment Protection funded a study to identify and 

characterize food waste generators.29 The study established a database of food waste generators 

and estimated volumes. Massachusetts evaluated 5,800 generators in 10 different categories 

producing 880,000 tons of food waste annually. The study found that 20% of waste producers 

generate 80% of the total. Food manufacturers, restaurants, and supermarkets produced the 

highest volumes. The study determined that there is no method to accurately predict food wastes 

from a single facility. Food waste generation varies widely even among similar facilities. Large 

food manufacturers tended to already have food waste diversion programs in place—either 

selling as livestock feed (commercial bakery wastes) or composting to combat the high cost of 

trash removal. Connecticut conducted an earlier study that found somewhat similar rates of food 

waste generation; however, fewer categories were analyzed and restaurants were not included.30 

Food wastes have high moisture content and are often the wettest component of household 

garbage (Table 5). The energy content is a function of the type of food waste but ranges between 

1,500 and 3,000 BTU per pound of waste. The energy content determines how much bioenergy 

can be produced from a feedstock. 

Table 5. Food Waste Characteristics 

Source: Waste Age31 

4.1 Methodology and Study Area Organic Waste Generation

Organic food waste residues were calculated based on U.S. Census Bureau data and calculations 

available from the previous Connecticut and Massachusetts studies.29,30 Seafood processors, 

universities, and hospitals were contacted. All expressed interest in separating organic wastes, 

but few could provide estimates of food waste generation. 

Formulas for determining food wastes were identified in the Massachusetts study. The 

referenced study conducted a survey to determine food manufacturer wastes. This study uses the 

same calculation for food manufacturers, grocery stores, and restaurants assuming 3,000 pounds 

of waste each year per employee (based on Massachusetts study). A few large sources were able 

to estimate their wastes and those are summarized later in this section. 

Formula for organic food wastes from food manufacturers, grocery stores, and 

restaurants: 

Organic food wastes (lbs/year) = number of employees * 3,000 (lbs/employee/year) 

 

29 “Identification, Characterization, and Mapping of Food Waste and Food Waste Generators in Massachusetts.” 

Draper/Lennon, Inc. Massachusetts Department of Environmental Protection, September 2002. 30 “Identifying, Quantifying, and Mapping of Food Residuals from Connecticut Businesses and Institutions.” 

Draper/Lennon, Inc. Connecticut Department of Environmental Protection, September 2001. 31 Waste Age. “Profiles in Garbage: Food Waste.” September 2000. Accessed January 7, 2013: 

http://waste360.com/mag/waste_profiles_garbage_food.

Moisture Content 70%

Energy Content 1,500-3,000 Btu/lb

Density 2,000 pounds per cubic yard

Food Waste Characteristics
19

Food wastes from hospitals and nursing home/rehabilitation/mental health facilities were 

estimated using exact and average number of beds. Each hospital reports number of beds. Exact 

number of beds for nursing homes and similar facilities are not available. The Center for Disease 

Control reports that the average number of beds in a nursing home is 106.32 Food wastes from 

universities with dining halls were based on the number of students and meals per year. The 

number of meals and food waste per meal were based on Massachusetts’s data.

Formula for organic food wastes from hospitals and nursing homes:

Hospital food waste (lbs/year) = # of beds * 5.7 (meals/bed/day) * 0.6 lbs (food 

waste/meal) * 365 (days/year)

Nursing home food waste (lbs/year) = # of beds * 3 (meals/bed/day) * 0.6 lbs (food 

waste/meal) * 365 (days/year)

Formula for organic food wastes from universities:

University food waste (lbs/year) = # of students * 0.35 lbs (food waste/meal) * 405 

(meals/student/year)

The Census Bureau identifies types of businesses using numerical codes known as the North 

American Industry Classification System (NAICS).33 This study evaluated business categories,

including food manufacturing, grocery stores, restaurants, and health care facilities, and 

reviewed 2010 company data in Jefferson, Orleans, Plaquemines, and St. Bernard Parishes. Only 

facilities with 10 employees or more were included in the evaluation. Smaller facilities were 

eliminated due to the expectation of low volumes and insufficient staff to separate wastes. 

NAICS reports the number of facilities for a particular type of establishment for several 

categories of employment size (Table 6). Because exact number of employees per establishment 

is unknown, the average number of employees per employment class size was used. As an 

example, there are seven grocery stores in Orleans with between 10 and 19 employees (see 

Appendix A). The average employment in this category is 14.5 jobs leading to estimated 

employment at these seven stores of 101.5 total employees. 

Table 6. NAICS Employment Size Class

Employment Class Size

Employment Categories 1–4 5–9 10–19 20–49 50–99 100–249 250–499

Average # of Employees 2.5 7 14.5 34.5 74.5 174.5 374.5

Source: Census Bureau34

 32 “FastStats Nursing Homes.” Center for Disease Control. Accessed September 27, 2012: 

http://www.cdc.gov/nchs/fastats/nursingh.htm. 33 U.S. Census Bureau County Business Patters. 2010 Data. Accessed September 2012:

http://www.census.gov/econ/cbp/index.html. 34 U.S. Census Bureau County Business Patters. 2010 Data. Accessed September 2012:

http://www.census.gov/econ/cbp/index.html.
20

4.2 St. Bernard Area Food Wastes

The following parishes were evaluated for food waste generation: Jefferson, Orleans, 

Plaquemines, and St. Bernard (Figure 9). Table 7 identifies the numbers of businesses producing 

food waste by category for each parish. Table 8 shows estimated food wastes. Additional details 

are available in Appendix A.

Figure 9. Food waste evaluation area. Illustration done in Google Maps

Food wastes are estimated and do not provide an exact volume of wastes generated in the 

immediate area. Average food waste per facility is not a good indicator of feedstock availability 

as it is typical for a few large generators to provide a large portion of the total. If this project 

advances, the developer should conduct a food waste survey with area producers to determine an 

accurate assessment. 

Any food waste collection project will only capture a portion of available wastes. For example, 

collecting feedstock from some businesses will not be viable due to insufficient staff for 

separating wastes or space constraints limiting the ability to accommodate an additional bin.The 

best case is to work with large waste generators targeting food manufacturers and universities 

first. These food waste generators showed interest in the project, produce predictable volumes of 

waste, and are likely to have less contamination than restaurants.
21

Table 7. Food Waste Producers in Study Area

Facility Type Number of Establishments With More Than 10 Employees

Organic Waste Producer St. Bernard Plaquemines Orleans Jefferson

Food Manufacturers 0 1 20 14

Grocery 7 2 24 43

Restaurants 16 14 382 436

Hospitals 0 0 6 4

Nursing Homes 3 2 56 72

Universities 0 0 4 0

Source: U.S. Census Bureau 2010 County Business Patterns; businesses with more than 10 employees.

Table 8. Estimated Food Wastes in the Study Area

Food Waste Producer St. Bernard Plaquemines Orleans Jefferson Total

Food Manufacturers 0 150 2,745 995 3,890

Super Markets 396 164 2,952 6,815 10,326

Restaurants 618 485 23,009 23,253 47,364

Hospitals 0 0 861 399 1,260

Nursing Homes 105 70 1,968 2,531 4,674

Universities 0 0 2,284 0 2,284

Total 1,119 868 33,819 33,992 69,798

Tons per Year

Source: Calculated based on U.S. Census Bureau 2010 County Business Patterns35 and Massachusetts 

Food Waste Study36

Determining how many facilities would participate was not within the scope of this study. 

However, several universities, hospitals, and food manufacturers expressed interest when 

initially contacted. Table 9 shows potential volumes based on obtaining portions of the estimated 

food wastes in each category. Food waste collection scenarios are based on some individual 

contacts with food manufacturers, hospitals, and universities. Restaurants, supermarkets, and 

nursing homes were not contacted and their interest level is unknown. A project developer will 

need to work with waste haulers and facilities in each category to obtain waste. Actual collection

of food wastes may vary greatly from levels suggested in Table 9. These numbers were 

generated to provide a basis for financial modeling of an AD system.

Initial participation will likely be low, and separating wastes is not a common practice in the 

area. As an example, recycling was reintroduced in 2012 as it was suspended after Hurricane 

Katrina in 2005. Presumably, participation would grow over time as more facilities are aware 

and if there are incentives for separating wastes. It is possible to design an anaerobic digester 

system to be modular and add more capacity as needed. Biomass energy project economics 

generally improve with greater volumes of feedstock. 

 35 http://www.census.gov/econ/cbp/index.html. 36 “Identification, Characterization, and Mapping of Food Waste and Food Waste Generators in Massachusetts.” 

Draper/Lennon, Inc. Massachusetts Department of Environmental Protection, September 2002.
22

Table 9. Potential Food Wastes Collection Scenarios 

Food Waste Producer Low Scenario Medium Scenario

% Obtained Estimate (tons/yr)

% 

Obtained

Estimate 

(tons/yr)

Food Manufacturers 20% 778 30% 1,166.85

Supermarkets 10% 1,033 25% 2,581.5

Restaurants 10% 4,736 20% 9,472.8

Hospitals 20% 252 50% 630

Nursing Homes 5% 234 10% 467.4

Universities 25% 571 50% 1,142

Total (tons per year) 7,604 15,461

4.2.1 Food Manufacturers

There are several large food manufacturing facilities in the area. Folgers Coffee plant in New 

Orleans produces Folgers, Dunkin Donuts, and Millstone brands. Current coffee wastes are 40–

50 tons per month (data provided by a private consultant). Folgers closed other plants in the 

United States to consolidate production in New Orleans and another site in Louisiana. Production 

is set to expand, which will lead to additional wastes. The Census Bureau reports an additional 

four coffee and tea production facilities in the study area. 

According to a private unpublished area study, there are five large seafood processors averaging 

wastes of 20 tons per month. Orleans Parish has several commercial bakeries, including Bunny 

Bread, which produces between 8 and 16 tons of waste per month, which is sometimes used as 

livestock feed. The Census Bureau reports a large dairy manufacturer with more than 250 

employees in Orleans. There are also animal slaughtering operations and meat processors. 

Targeting the largest food manufacturers in the area is important as the waste will be predictable 

with no or low contamination. 

4.2.2 Grocery Stores

Southern Louisiana is characterized by independently owned grocery markets. Chains are rare,

although Rouses and Breaux Marts have several locations. Wal-Mart and Sam’s Club also have a 

presence in the area with estimated wastes per store of 13 tons per month according to Waste 

Management.37 Waste Management’s study also found southeastern chains Publix and Winn 

Dixie to produce 9 tons per week. Costco expects to open a store in New Orleans sometime in 

2013 and could be a potential source for food wastes. Jefferson has the largest estimated grocery 

store wastes followed by Orleans. 

4.2.3 Restaurants

The restaurant business is growing with 1,313 restaurants in New Orleans and the surrounding 

suburbs, up considerably from the 809 the day prior to Katrina.38 The majority of food wastes 

come from food preparation, but post-consumer wastes are also available. Many restaurants in 

the French Quarter are space-constrained and would require use of a smaller bin with regular 

pickup service. Restaurants represent the largest volume of wastes compared to other categories 

 37 Waste Management Organics Overview, January 27, 2011. 38 The New Orleans Menu. http://www.nomenu.com/joomla1/. Personal communication with Tom Fitzsimmons 

August 14, 2012. 
23

but also the greatest number of establishments. It will be crucial to properly train restaurant 

staff—particularly as dish washing has high turnover. Staff will need to understand which items 

are appropriate for a food recycling bin. There is competition for this resource as NOLA Green 

Roots, LLC collects food wastes from residents and businesses on 1-, 3-, and 5-day per week 

pick-up schedules.39 They currently have 11 businesses composting waste—mostly restaurants 

but also Loyola University. NOLA Green Roots composts wastes and sells 25-pound bags of 

compost for $12.99. There are plenty of wastes to accommodate more than one food waste 

facility. 

4.2.4 Hospitals

There are 10 hospitals in the study area—all are located in Orleans and Jefferson Parishes. 

Several hospitals were contacted and are interested in potential food waste recycling. None were 

aware of their current waste volumes. Ochsner Hospital has the most beds and therefore the most 

food wastes followed by Touro, East Jefferson, and Children’s Hospitals. 

4.2.5 Nursing Homes

Nursing homes, including homes for elderly, mental health, and other rehabilitation patients,

were evaluated. These types of homes are concentrated in Orleans and Jefferson Parishes with 56 

and 72, respectively. During a detailed feedstock analysis, it would be valuable to determine 

facilities with the most beds and highest capacity. 

4.2.6 Universities

All area universities are located in New Orleans. Each university was contacted to gauge their 

interest in food waste recycling and estimated volumes. All universities are interested in 

participating. All of the campuses have cafeteria facilities. Tulane and University of New 

Orleans have the largest student population. Loyola University is separating food wastes for a 

privately owned compost facility. Only Tulane provided estimates of food wastes. Bruff 

Commons Hall generates 16–22.5 tons per week for 9 months each year. The Student Union 

generates mixed wastes (without recyclables) of 7.9 tons per week during the academic months 

and 4.25 tons in summer months. Area community colleges are unlikely to have dining facilities. 

4.2.7 Other Area Food Wastes

The convention center and sporting arenas are other potential sources of waste. Some 

conferences, particularly those related to environmental activities, are starting to request that 

conference venues provide recycling and composting bins. Food wastes from the convention 

center and sports arenas will be variable based on when events occur, number of attendees, and 

types of meals served. There are several food wholesalers in the area. Wholesalers tend to deliver 

pre-packaged items and generate few wastes. Area food banks may have spoiled produce 

available for collection. 

4.3 Potential Business Scenarios

While a waste-to-energy facility can purchase trucks, hire drivers, and establish contracts with 

restaurants, food manufacturers, and others, it may make more sense to establish agreements 

 39 NOLA Green Roots and Composting Network. Accessed September 25, 2012: 

http://compostingnetwork.com/site/. 
24

with existing waste haulers to collect and deliver food wastes. They have existing contracts with 

food waste generators, and this will ease the task of billing food waste generators. This is how 

Los Angeles handles their restaurant food waste collection program. Biomass plants have 

feedstock delivered by haulers. 

There are three waste haulers servicing the greater New Orleans area. SDT Waste and Debris 

Services (now Progressive Waste Solutions) collects waste from all of St. Bernard Parish, the 

French Quarter, and the central business district. They are actively growing their recycling 

program (e.g., aluminum and plastics) and are interested in collecting organic wastes. SDT 

collects wastes from all New Orleans universities and hospitals. They stated that a typical frontloading truck has capacity for 30 tons, but they are not aware of any composting or other recycler 

sites able to handle large volumes. This company is proactive and has staff dedicated to growing 

alternative waste streams and diverting from landfills. Richard’s Disposal Inc. (RDI) picks up 

wastes in Algiers, Esplande Ridge, Garden District, Mid-City, Treme, and Uptown. RDI did not 

respond to multiple inquires. Metro Disposal collects wastes in East New Orleans, Gentilly, 

Lakeview, and the 9th Wards. Metarie and Kenner are handled by IESI and Allied Waste 

Services. Collection rates vary among haulers. Restaurants with 3-cubic-yard bins picked up 

6 days a week pay between $225–$275 per month.

Area landfills include Environmental Operators in Venice; River Birch and Highway 90 in 

Avondale; and Gentilly in New Orleans. All offer similar tipping fees of approximately $30/ton. 

According to Waste & Recycling News, Louisiana has the eighth lowest average tipping rate 

among U.S. states in 2012. A food waste project will need to charge less than $30/ton. The lower 

fee is necessary to incentivize waste haulers to collect and deliver food wastes to a separate 

facility. Food waste generators also need a financial incentive to motivate them to separate 

wastes. Based on conversations with waste haulers and close proximity of landfills to New 

Orleans, a tipping fee of $20/ton is likely to motivate separation and delivery of food wastes.

4.3.1 Example: Los Angeles Restaurant Organic Food Waste Recycling Program

As an example of a similar program to that being considered for the Kaiser site, this section 

provides details of a food waste recycling program implemented in Los Angles, California. 

As of June 2012, California is diverting 65% of wastes from landfills with a goal of 75% by 

2020. The City of Los Angeles Restaurant Food Waste Recycling Program was established to 

divert food wastes from landfills. It began as a pilot program in 2005 with 300 restaurants 

participating. As of late 2012, 1,400 restaurants are participating, representing over 16% of food 

establishments in Los Angeles. 

4.3.1.1 Program Information

The manager of the City of Los Angeles Restaurant Food Waste Recycling Program provided the 

following program information:

• 1,400 restaurants participate

• Los Angeles tracks wastes with an average of 2.5 tons per month per restaurant

• Annual collection of restaurant food wastes is estimated at 60,000 tons/year
25

• Pre- and post-consumer restaurant food wastes are collected 

• Private waste haulers enter into a contract with Los Angeles (currently five haulers)

• Private waste haulers negotiate a contract with restaurants to collect food wastes

• Waste haulers provide bins (many are under lock and key); typical size is 3-yard bins but 

90 gallon bins on wheels are available for smaller restaurants

• Waste haulers provide regular training for restaurants on separating wastes

• Collection schedule is determined between waste hauler and restaurant; it is available 7

days a week

• Los Angeles pays haulers a rebate of $45/ton, which is the same as the landfill tipping fee

• Restaurants pay a fee for organic wastes, which is less than the regular garbage rate (the 

rate is negotiated between the hauler and restaurant)

• Waste haulers deliver food wastes to a private compost company with a tipping fee of 

$50/ton of organic waste; resulting compost is sold to agriculture users.

The main driver for restaurant participation is generally reduced costs for waste disposal. The 

waste hauler receives $45/ton from Los Angeles and is charged $50/ton to drop off organic 

wastes at a composting facility. The profit to the waste hauler comes from restaurants paying for 

the service. Waste haulers are able to charge less for organic wastes than regular garbage due to 

the $45/ton rebate. Restaurants are also motivated to join when a large facility nearby joins the 

program. For example, when the Marriot Hotel joined, surrounding restaurants also signed up. 

The Los Angeles program stated there are challenges within strip malls that typically contain 8–

10 businesses, two of which are usually restaurants. The strip mall landlord generally handles 

trash service and will not allow collection of organic wastes. Also, there has been trouble 

enlisting some franchise restaurants due to corporate offices handling waste contracts from out of 

state locations 

4.4 Feedstock Summary and Conclusions

Ample feedstock is available in the surrounding region. It makes sense to begin with St. Bernard 

and Orleans Parishes due to proximity to the site. It is advisable to establish relationships early 

on in the project with primary producers, including hospitals, universities, and the largest food 

manufacturers. The uniformity and predictability of wastes from a few large producers will assist 

in forecasting feedstock volumes and content. Collection of food wastes will benefit the 

environment by diverting wastes known to produce methane emissions and extend the life of 

area landfills. While there is no cost for the feedstock, the project must establish fees that make 

separating organic wastes attractive for food waste generators. This may be achieved by offering 

a tipping rate lower than the landfill providing an incentive for waste haulers to deliver food 

wastes to the Chalmette site. In turn, the waste haulers can provide a more competitive rate for 

food wastes than regular garbage. 
26

5 Heat and Power Markets

St. Bernard Parish is an area of heavy industry dominated by energy and shipping industries. 

Mississippi River ports are crucial to the delivery of petroleum products and natural gas. 

Residential housing units and population were significantly impacted by Hurricane Katrina in 

August 2005. Residential electricity demand, which commands the highest price, has not 

returned to pre-Katrina levels (Figure 10). Louisiana experiences energy prices significantly 

lower than the national average. This is due to the natural gas pricing point at Henry Hub, heavy 

area energy production, and local policies. Henry Hub is a natural gas distribution point in 

Louisiana used as the pricing point for natural gas future contracts on all major exchanges.

The recent boom in natural gas production has led to decreased prices for both heat and 

electricity. 

0

50,000

100,000

150,000

200,000

250,000

300,000

350,000

400,000

450,000

500,000

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

2003 2004 2005 2006 2007 2008 2009 2010 2011

MWh per year

Population and Housing Units

St Bernard Parish Population, Housing Units, Electricity Demand

Housing Units

population

Est. Electricity Demand

Figure 10. St. Bernard Parish population, housing, and estimated demand40

Renewable energy technologies tend to be more expensive than traditional energy sources. 

Louisiana does not have any renewable energy use mandates. However, the Louisiana Public 

Service Commission established a renewable energy pilot program to determine the feasibility of

enacting a statewide renewable portfolio standard (requiring renewable electricity generation).41

The program has a research component where utilities collect data on renewable energy and each 

investor-owned utility must develop at least three projects. These projects may be owned by the 

utility or the utility may establish a tariff to purchase renewable energy from independent 

producers. The tariff amount is set at $30/MWh plus avoided-cost payments. Additionally, both 

 40 Data from the U.S. Census Bureau historical data & DOE EIA Household Fuel Consumption, South Region 2009. 41 LA PSC Docket No. R-28271 Subdocket B. Renewable Energy Pilot Program. Louisiana Public Service 

Commission, November 2010. Accessed January 7, 2013: 

http://lpscstar.louisiana.gov/star/ViewFile.aspx?Id=870fff5f-5836-406f-a888-264776b26095. 
27

cooperative and investor-owned utilities must issue request for proposals (RFPs) for new 

renewable energy sources coming online between 2011 and 2014. The maximum is 350 MW of 

renewable power with each utility’s percentage based on 2009 sales. Entergy, the local utility, 

states on its website that it is opposed to mandated use of renewable energy due to price and 

base-load power concerns. 

5.1 Power Markets

Louisiana electricity generation is dominated by natural gas as an energy source followed by coal 

and nuclear (Table 10). Louisiana tends to have electricity rates significantly lower than the U.S. 

average in all sectors (Table 11). 2011 Entergy Louisiana prices are similar for residential, higher 

for commercial, and lower for industrial rates when compared with average statewide rates 

(Figure 11). While Louisiana offers some financial incentives for solar and wind, there are no 

state incentives for bioheat or biopower. Entergy Louisiana consumption is dominated by the 

industrial sector (Figure 12). There is significant electricity production within 5 miles of the site. 

Three plants produced a combined 1.98 million MWh in 2011. These plants include Entergy’s 

Michoud natural gas plant, Domino Sugar’s natural gas plant (power used on-site), and CII 

Carbon’s coke plant.42 Additionally, Entergy plans to build a 550-MW natural gas unit in 

Westwego, Louisiana in 2013. 

Table 10. Louisiana Electricity Generation by Source43

Energy Source Generation (MWh) % Total

Natural Gas 54,209,144 51.5%

Coal 24,608,886 23.4%

Nuclear 16,614,975 15.8%

Petroleum 4,716,393 4.5%

Wood 2,359,194 2.2%

Other Gases 1,323,511 1.3%

Hydroelectric 1,044,019 1.0%

Other 306,844 0.3%

Other Biomass 80,258 0.1%

Table 11. Current Electricity Rates Comparison44

Sector LA Rank LA U.S. Average

Cents per kWh

Residential Lowest in nation 8.12 12.12

Commercial 2nd lowest in nation 7.28 10.44

Industrial 3rd lowest in nation 4.17 6.95

 42 eGRID. EPA 2010 data. Accessed January 7, 2013: http://www.epa.gov/cleanenergy/energyresources/egrid/index.html. 43 DOE Energy Information Agency. Accessed January 8, 2013: http://www.eia.gov/electricity/data/state/. 44 DOE EIA Average Retail Price of Electricity to Ultimate Consumers, Table 5.6.A, July 2012.
28

4.00

5.00

6.00

7.00

8.00

9.00

10.00

11.00

12.00

2004 2005 2006 2007 2008 2009 2010 2011

cents/kWh

Louisiana Electricity Prices

LA residential

LA commercial

LA industrial

Entergy LA Residential

Entergy LA Commercial

Entergy LA Industrial

Figure 11. Electricity prices45

Figure 12. Electricity consumption46

 45 Data from DOE EIA Average Retail Price of Electricity to Ultimate Customers, By End-Use By state, Table 4 and 

Table 10. Accessed January 8, 2013: http://www.eia.gov/electricity/sales_revenue_price/index.cfm. 46 Data from DOE EIA Retail Sales of Electricity to Ultimate Consumers All Sectors by State and Utility, Table 10. 

Accessed January 8, 2013: http://www.eia.gov/electricity/sales_revenue_price/index.cfm.

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

2004 2005 2006 2007 2008 2009 2010 2011

MWh/year

Entergy Louisiana Electricity Consumption

Entergy LA Industrial

Entergy LA Residental

Entergy LA Commercial
29

There will be challenges in marketing new biopower sources in the area due to low demand, high 

prices, and some industrial customers generating their own power. It needs to be determined if 

there are any potential energy users willing to pay a higher rate for renewable power. 

5.2 Thermal Markets

Louisiana is a dominant producer of natural gas and is the national pricing point for the 

commodity. As shown in Figure 13, natural gas rates have diminished in the past year and 

Louisiana industrial rates are the lowest nationwide at $2.62 per 1,000 cubic feet (mcf). The only 

other state with a similar rate is Texas. Renewable heat from biomass cannot compete with this 

low price. However, natural gas prices, like all commodity prices, fluctuate over time. Louisiana 

natural gas demand is significant in industrial and electricity generation sectors and low in 

commercial and residential sectors (Figure 14). 

Figure 13. Natural gas prices47

 47 Data from DOE EIA Natural Gas Prices by Sector. Accessed January 8, 2013:

http://www.eia.gov/dnav/ng/ng_pri_sum_dcu_nus_m.htm.

0

3

6

9

12

15

18

21

24

27

$ per 1000 cubic feet

Louisiana Natural Gas Prices by Sector

LA Residential

LA Commercial

LA Industrial
30

Figure 14. Natural gas consumption48

5.3 Market Summary 

The market for renewable energy from biomass in the area surrounding the site is limited. This is 

due to energy prices in Louisiana far below national averages. Additionally, for a biogas project 

to be viable in this region, there must be customers willing to pay more for renewable power. 

Neither Louisiana nor Entergy, the local utility, offer incentives for renewable power.

 48 Data from DOE EIA Natural Gas Consumption by Sector. Accessed January 8, 2013: 

http://www.eia.gov/dnav/ng/ng_cons_sum_dcu_nus_m.htm. 

0

100,000

200,000

300,000

400,000

500,000

600,000

700,000

800,000

900,000

1,000,000

2003 2004 2005 2006 2007 2008 2009 2010 2011

million cubic feet

Louisiana Natural Gas Consumption by Sector

Industrial

Commercial

Residential

Electricity Generation
31

6 Financial Analysis

Nearly all food-waste-based digesters in the United States are publicly owned. In many cases, the 

purpose of these digesters is to divert food wastes from landfills. Financial benefits of biopower 

may be a secondary goal. Most existing anaerobic digesters are used to treat wastewater or 

manure with biopower as a by-product. The upfront costs to build an AD plant are considerable 

as are the operation and maintenance (O&M) costs. Many projects attempt to recuperate 

operational costs through collection of tipping fees for wastes. As discussed in the Section 4, it is 

necessary to provide a tipping rate lower than the landfill to incentivize waste haulers to deliver 

feedstock and food waste generators to separate. Unfortunately, area landfill tipping rates are 

among the lowest nationally at $30/ton. Additionally, there are no state mandates or efforts to 

divert organic wastes from landfills. Even with a negative cost for feedstock, economics for AD

facilities are challenging. 

Table 12 shows cost data for several existing and planned food waste digesters. The data was 

obtained from CalRecycle, a California government program, and a City of Atlanta funded 

study.49 The average cost for a new average size digester is $561/ton of installed capacity. This 

average does not include East Bay (used an existing digester) or Cedar Groove—a large facility 

that already owns preprocessing equipment. Less information is available for operational costs or 

tipping fees. The best available O&M cost data is from the East Bay project as it is operational 

and it is in the United States. A University of Columbia study found European capital costs were 

similar, although they trended downwards considerably for large plants; operational costs were 

high at $77–$140 per metric ton.24 The Atlanta study estimates 2–4 jobs per 10,000 tons 

capacity.

Table 12. Food Waste Anaerobic Digestion Costs and Capacity

 49 “Digesting Urban Residuals Forum Highlights.” CalRecycle, May 2012. Accessed January 8, 2013: 

http://www.calrecycle.ca.gov/Organics/Conversion/Events/Digesting12/CaseStudies.pdf. 

“Update on Anaerobic Digester Projects Using Food Wastes in North America.” Institute for Local Self Reliance. 

City of Atlanta, October 2010.

Anaerobic Digester Owner Capacity Capital 

Costs Per Ton Operational Costs

Tipping 

Fee

Energy 

Output

tons/year Million $ $/ton $ per ton $ per ton

East Bay Municipal Utility Districta1 7,500-15,000 $2-5 $266-333 $40-55 $40 220 kWh/ton

City of Toronto1

 Existing 40,000 $18 $450 $90 107m3/tonne biogas

 Planned 27,500 $23 $836 unknown

 Planned 55,000 $34 $618 unknown

University of Wisconsin (pilot)2 6,000 $2.3 $383 400 kW

Cedar Grove Composting, WAb1 280,000 $87 $309 8 MW

Humboldt County, CA1 10,000 $6 $600 $34 $60 2,400 MWh/yr

w2E3 48,000 $23 $479 $35 3.2MW

2-Munger, A. "UW-O to get biow aste energy unit". A-T Online. February 24, 2010. http://w w w .advancetitan.com/new s/uw -o-to-get-biow aste-energyunit-1.1174178#.UH79Y0JpLA4

3-Soberg, M. "W2E to build $23 WtE facility in SC". Biomass Magazine. September 6, 2011. http://biomassmagazine.com/articles/5774/w 2e-to-build-23-

million-w te-facility-in-sc

a-used capacity in an existing digester; expenditures w ere for pre-processing and energy generation equipment

b-facility already has pre-processing equipment for composting operation

1-“Update on Anaerobic Digester Projects Using Food Wastes in North America.” Institute for Local Self Reliance. City of Atlanta. October 2010. 
32

6.1 Financial Forecast Assumptions

The Co-Digestion Economic Analysis Tool (CoEAT) was used to evaluate this project.50 CoEAT 

was developed by EPA Region 9 for the purposes of analyzing the economics of biogas 

production when co-digesting food wastes at wastewater treatment plants in existing wet 

digesters. The tool is flexible and allows a user to evaluate financial performance of a standalone 

food-based digester. This involved only using inputs for food wastes and entering in all capital 

and O&M costs associated with the project. CoEAT is not designed as a rigorous financial 

model. It provides outputs on the feasibility of a potential AD project based on user-defined 

inputs. 

The major variables for the financial analysis are capital costs, O&M costs, tipping fees, and 

sales of electricity and heat. 

6.1.1 Capital Costs

Up-front costs for AD are high due to equipment necessary to produce bioenergy from a food 

wastes, which includes: equipment to weigh and receive feedstock, feedstock preprocessing 

equipment, storage of feedstock prior to digestion, digester, energy generation equipment, and 

hydrogen sulfide clean-up equipment. Several studies were reviewed to determine approximate 

installed costs for food-waste-based digesters. A price of $561/ton of installed capacity was used 

based on Table 12.

6.1.2 Operation and Maintenance Costs

O&M costs covers the costs for all O&M activities, including processing feedstock, 

employment, and chemicals. There is little O&M data currently available. This study uses

average O&M costs as reported by EBMUD’s costs to digest food wastes. They reported $40–

$55/ton; the average used in the financial analysis is $48/ton. 

6.1.3 Food Waste Quantity

Without further study and surveying, it is not possible to determine actual wastes delivered to a 

facility. For the purposes of this study, total food waste (Table 8) and potential collection rates 

(Table 9) were estimated based on a series of assumptions (see Section 4). It is assumed that a 

low scenario would generate 7,600 tons per year and a medium scenario would generate 15,500 

tons per year. These amounts were rounded down to 7,000 and 15,000 tons expecting that some 

waste will be rejected in the pre-processing phase. The financial model only uses the 7,000 ton 

per year scenario. The financials would not be appreciably different as both are considered small 

plants. It is assumed a plant would receive food wastes 5 days per week.

6.1.4 Biogas Yield

The CoEAT model calculates biogas production. It assumes 15 cubic feet of biogas is produced 

for each pound of volatile solids destroyed. Food wastes are estimated to be 30% solid 

(600 lbs/ton). EBMUD established that average volatile solids content of total solids in food 

waste is 88.45% (531 lbs/ton). It is assumed that methane content in biogas is 60% and 10% of 

biogas is used as captive energy to operate the plant and associated buildings. 

 50 CoEAT. Accessed January 7, 2013: http://www.epa.gov/region9/organics/coeat/index.html. 
33

6.1.5 Tipping Fees

A food waste tipping fee of $20/ton was used. Local landfills charge $30/ton. Tipping fees for 

food waste must be lower (or subsidized) to incentivize separation of wastes and collection and 

delivery by private waste haulers. Based on conversations with local haulers, $20/ton would 

likely incentivize separation of food wastes and delivery of wastes to a separate facility.

6.1.6 Electricity Sales

The electricity sales price is set at $0.078/kWh. This is the average 2011 rate for Entergy 

Louisiana for all sectors (residential, commercial, and industrial). 

6.1.7 Heat Sales

The heating rate is set at $2.67/mcf. This is the average Louisiana industrial rate for 2012. 

Industrial rates were used as it is assumed that heat produced from the digester will not enter area 

pipelines. Instead it will be delivered directly to nearby port area users. 

6.1.8 Digestate

The model used does not account for digestate sales—only costs for disposal. The literature 

suggests that some plants compost digestate and sell it at minimal prices as soil amendment or 

animal bedding. Other plants pay to landfill it. It is assumed that digestate from this project 

generates no revenue or costs. The model assumes digestate is given away for agricultural 

purposes. 

6.1.9 Financing

Discount and interest rates of 10% and 7% were used. These rates vary with type of ownership 

and other factors. 

Table 13. Financial Model Inputs

Financial Model Inputs

Capital Costs $561/ton

O&M Costs $48/ton

Food Waste Volume 7,000 tons

Tipping Fee $20/ton

Electricity Rate $0.078/kWh

Heat Rate $2.67/mcf

Discount Rate 10%

Interest Rate 7%

Debt Payment 15 years
34

Table 14. Technical Financial Model Inputs

6.2 CoEAT Modeling Results

The high capital costs and O&M costs greatly exceed annual revenues from tipping fees and 

energy sales. The net present value (NPV) measures the difference between cash inflows and 

outflows and is a key indicator of a project’s profitability potential. A 7,000 ton per year digester 

yielded an NPV of –$6,762,992. The project loses money each year of operation (Table 15). 

Table 15. Income Statement

Income Statement

Revenue $/year

Tipping Fees $ 140,400 

Electricity Sales $ 135,710 

Heat Sales $ 72,050 

Total Revenue $ 348,160 

Expenses

O&M $ 336,000 

EBITDA $ 12,160 

Less

Debt Payments $ 431,163 

Annual Pre-Tax Income $ (419,003)

The project is most sensitive to capital costs, O&M costs, and tipping fees. With all other 

variables remaining the same, a tipping fee of $80/ton is required for the plant to break even. 

Electricity and heat sales are less sensitive. The electricity break-even price, with all other 

variables unchanged, is $0.32/kWh. Heat sales are not significant and have a minor impact on 

overall economics of the plant. 

Parameters Low Scenario Medium Scenario Units

Digester Volume 92,353 197,328 ft3

Inputs

Food Waste Mass 8.1 17.2 short tons/day

Food Waste Biogas Yield 6.65 6.65 ft3 CH4/lb TS

Food Waste Total Solids (TS) 0.3 0.3 solids

Food Waste Volatile Solids (VS) 88.45% 88.45% of total solids

Food Waste % of Total Waste 100% 100% total substrate

Total Feedstock Loading (TS) 16,200 34,614 lbs/day

Feedstock Loading (VS) 14,329 30,616 lbs/day

Outputs

Biogas Production Rate 15 15 ft3 biogas/lb VS destroyed

Daily Biogas Production 190,109 406,199 ft3 biogas/day

Annual Biogas Production 49,428,257 105,611,709 ft3/yr

Annual Excess Biogas Available* 44,485,431 95,050,538 ft3/yr

Methane to Biogas Ratio 0.6 0.6

High Heat Value of Methane 1011 1,011 Btu/ft3

Heat Value Estimate 26,985 57,658 MMBtu/yr

KWh Value Estimate 1,739,866 3,717,514 KWh/yr

*10% of biogas is retained to heat and operate biodigester plant

Value
35

The lowest capital and O&M costs in Table 12 are $309/ton installed and $34/ton O&M. These 

values were evaluated in CoEAT and the NPV remained negative at –$2.4 million. With these 

lower estimates, the project would require a tipping fee of $39/ton to break even. Several studies 

suggested tipping fees of $60 are necessary to cover costs to build and operate a food-based 

AD plant. 

6.3 Project Financing

Project financing for an AD project with favorable economic performance will be difficult. There 

will be a perceived risk as there are few examples of food waste digesters in the United States. 

They are generally co-located at WWTPs. The only standalone plant in the United States is an 

experimental pilot plant at a university. A digester is not believed to have reuse value. This is 

challenging as the digester is one of the most expensive pieces of equipment, but it will not be 

used as collateral due to the lack of perceived reuse. It appears that high solids/dry digester 

technology is preferred for food wastes. However, this is a novel technology not yet proven in 

North America, which will be perceived as a risk to investors. Lenders generally seek proven 

technologies and contractors with experience building a particular type of technology. 

Additionally, digesters in the United States are almost universally owned by municipalities or 

other public entities. This type of project would likely require a loan guarantee to attract 

investors.
36

7 Conclusion

This study finds that there is adequate food waste and the site is capable of supporting a biomass 

facility. However, the project is projected to lose money. This is due to a combination of factors. 

The primary factors predicting poor financial performance include low area tipping fees and 

energy prices as well as high capital costs for the technology. Additionally, there is no state 

policy requiring renewable energy generation. Other possibilities for food wastes may include an 

industrial composting facility or co-digestion of food wastes at a nearby WWTP with excess 

capacity in their anaerobic digester. 
37

Appendix A: Site Topography

Figure A-1. Site topography. Image from TRC
38

Appendix B: Food Waste Generator Details

Table B-1. Food Waste Generator Details

Establishment Type Total # of 

Establishments

10-19 20-49 50-99 100-249 250-499 Total

St. Bernard 

Restaurants 7 9 0 0 0 16

Grocery Stores 5 0 1 1 0 7

Food Manufacturers 0 0 0 0 0 0

Plaquemines

Restaurants 8 6 0 0 0 14

Grocery Stores 0 1 1 0 0 2

Food Manufacturers

 Seafood Processing 0 0 0 1 0 1

Food Wholesalers

 Grain 0 0 0 1 0 1

 Seafood 0 1 0 0 0 1

Orleans

Restaurants 142 170 48 22 0 382

Grocery Stores 7 5 4 8 0 24

Food Manufacturers

 Animal Slaughtering 1 0 0 0 0 1

 Bakery-Commercial 1 2 1 0 1 5

 Bakery-Retail 3 0 0 0 0 3

 Chocolate 0 1 0 0 0 1

 Coffee/Tea 0 0 0 1 1 2

 Cookie, Cracker, Pasta 1 0 0 0 0 1

 Confectionary Sugar 1 0 0 0 0 1

 Dairy 0 0 0 0 1 1

 Dough 1 0 0 0 0 1

 Meat Processor 1 0 0 1 0 2

 Poultry Processor 1 0 0 0 0 1

 Seafood Processor 0 1 0 0 0 1

Food Wholesales

 General Grocery 0 0 1 0 0 1

 Frozen Food 0 1 1 0 0 2

 Other 2 2 0 1 0 5

 Seafood 0 2 0 0 0 2

 Vegetables 1 0 0 0 0 1

Jefferson

Restaurants 175 197 50 14 0 436

Grocery Stores 6 5 15 16 1 43

Food Manufacturers

 Animal Slaughtering 1 0 0 0 0 1

 Bakery-Retail 1 2 0 0 0 3

 Coffee 0 1 0 0 0 1

 Confectionary Sugar 0 1 0 0 0 1

 Fruit/Vegetable Processing 0 1 1 1 0 3

 Seafood Processing 0 1 0 0 0 1

 Seasoning 1 2 1 0 0 4

Food Wholesaler 

 Confectionary 0 0 1 0 0 1

 Dairy 2 0 0 0 0 2

 Frozen Food 1 1 0 1 0 3

 Fruit/Vegetable 1 1 1 0 0 3

 General Grocery 2 2 1 1 0 6

 Meat 1 0 1 0 0 2

 Other 5 4 0 1 1 11

 Seafood 2 1 0 0 0 3

# of Establishments by Employment Size
39

Appendix C: Anaerobic Digestion Technology Providers

There are many AD technologies. Many AD companies are based in Europe and have a U.S.-based 

distributer. This is not an exhaustive list, but it does include many of the companies offering AD 

technology for food wastes. 

ArrowBio

Yoqneam 20692,

ISRAEL

+972-484-11100

972-484-22200 (f)

arrowbio@arrowecology.com

www.arrowecology.com

Bekon

Feringastraße 9 D-85774 

Unterföhring

+49 089- 90 77 959-0

+49 089-90 77 959-29 (f)

contact@bekon.eu

http://www.bekon.eu

BioFERM

617 N. Segoe Road, Ste. 202

Madison, WI 53705

608-467-5523

608-233-7085 (f)

http://www.biofermenergy.com

Biogas Energy, Inc.

815 301 3432

info@biogas-energy.com

http://www.biogasenergy.com/site/index.html

Canada Composting/CCI 

Bioenergy

390 Davis Drive Suite 301 

Newmarket, ON Canada L3Y 

7T8 

905-830-1160

905-830-0416 (f)

kmatthews@canadacomposting.

com

http://www2.ccibioenergy.com

Clean World Partners

2330 Gold Meadow Way

Gold River, CA 95670

800-325-3472

http://www.cleanworldpartners.

com

DRANCO/OWS Inc.

7155 Five Mile Road

Cincinnati, OH 45230

USA

513-535-6760

513-233-3395 (f)

norma.mcdonald@ows.be

http://www.ows.be/pages/index.

php?menu=69&choose_lang=E

N

Ecocorp

626-405-1463

jgingersoll@ecocorp.com

www.ecocorp.com

Entec Biogas USA

Schilfweg 1

6972 Fussach Austria

Austria

+43-5578-7946

+43-5578-7946-800 (f)

office@entec-biogas.at

http://www.entecbiogas.com/en/

Harvest Power

221 Crescent St. Suite 402

Waltham, MA 02453

781-314-9500

http://www.harvestpower.com

New Bio

7679 Washington Ave S.

Edina, MN 55439

952-476-6194

952-476-8622 (f)

http://www.newbio.com

Orgaworld

5123 Hawthorne Road

Gloucester, ON K1G 3N4

Canada

613-822-2056

613-822-2058 (f)

http://www.orgaworld.nl

Quasar Energy Group

2705 Selby Road

Wooster, OH 44691

(216) 986-9999

projectdevelopment@quasarenergygroup.

com

http://www.quasarenergygroup.com

Ros Roca Envirotec

PCiTAL Gardeny

Edifici H2 Planta 2a

25003 Lleida

Spain

+34-973-100-801

http://www.rosrocaenvirotec.co

m/RosRocaWeb.html

Valorga

SAS au capital de 600 000 € -

RCS 444 540 496

1140 avenue Albert Einstein -

BP 51

F 34935 Montpellier Cedex 09

France

+33-0-4-67-99-41-00

+33-0-4-67-99-41-01 (f)

contact@valorgainternational.fr

http://www.valorgainternational

.fr/en/

Zero Waste Energy, LLC 

(Kompoferm)

3470 Mt. Diablo Blvd. Suite 

A215

Lafayette, CA 94549

925-297-0600

http://zerowasteenergy.com