FINAL REPORT 

July 20, 2007

North East Biosolids and Residuals Association (NEBRA)

P. O. Box 422, Tamworth, NH 03886

phone 603-323-7654, email info@nebiosolids.org

www.nebiosolids.org

A National Biosolids

Regulation, Quality, End

Use & Disposal Survey
A National Biosolids Regulation, Quality, End Use, and Disposal Survey – Final Report, July 20, 2007 - ii

PROJECT TEAM

Ned Beecher - North East Biosolids and Residuals Association (NEBRA)

Kristy Crawford - NEBRA

Nora Goldstein - BioCycle: Advancing Composting, Organics Recycling & Renewable Energy

Greg Kester - Wisconsin Department of Natural Resources

Maile Lono-Batura - Northwest Biosolids Management Association (NBMA)

Elizabeth Dziezyk – NEBRA Intern, University of Maine, Orono 

with statistical analysis of online survey data by

John Peckenham, PhD, Senator George J. Mitchell Center for Environmental & Watershed 

Research, University of Maine, Orono

Tai Cheng, PhD, Department of Resource Economics & Policy, University of Maine, Orono

ACKNOWLEDGMENTS

The authors are grateful for the guidance and input to this project from the following: Robert K. 

Bastian, USEPA Washington; David Taylor, Robert Dominak, and Chris Hornback, National

Association of Clean Water Agencies (NACWA); Kawana Cohen, USEPA Washington; Lauren 

Fondahl, USEPA Region 9; and Robert Brobst, USEPA Region 8. Thanks also to Herschel Elliott, 

Penn State University; Lynne Moss, CDM; and staff at the USEPA offices of Regions 4, 5, 6, and 

10 for help with data collection. Thanks to the following reviewers: Robert K. Bastian, Robert

Brobst, Lauren Fondahl, Mike Heitz, David Taylor, Robert Dominak, Robert Rubin, Sam Hadeed, 

and Rick Stevens. We acknowledge, however, that the contents and any bias that follow are our sole

responsibility. Thanks to the wastewater operators and biosolids program managers who took the

time and effort to complete the online survey of individual treatment works. And thanks especially 

to the state biosolids and septage program coordinators around the nation who took the time and 

effort to complete the state survey and review our data compilations. 

This National Biosolids Information Initiative was funded by a U.S. Environmental Protection 

Agency (USEPA) Water Quality Cooperative Agreement Grant (Section 104b) to the North East

Biosolids and Residuals Association (NEBRA); Robert K Bastian served as USEPA Project Officer.

PLEASE SUBMIT COMMENTS & CORRECTIONS TO info@nebiosolids.org.

_______________________________________________________________________________

COPYRIGHT © NORTH EAST BIOSOLIDS AND RESIDUALS ASSOCIATION. 

Dissemination of electronic and paper copies for individual, non-commercial use is hereby

permitted. All other rights reserved. NEBRA, P.O. Box 422, Tamworth, NH USA.
A National Biosolids Regulation, Quality, End Use, and Disposal Survey – Final Report, July 20, 2007 - iii

ANATIONALBIOSOLIDSREGULATION,QUALITY,ENDUSE,ANDDISPOSALSURVEY

FINAL REPORT - JULY 20, 2007

CONTENTS

TERMINOLOGY USED IN THIS REPORT...............................................................................................................................................................iv

EXECUTIVE SUMMARY.......................................................................................................................................... 1

1. INTRODUCTION................................................................................................................................................... 2

2. METHODS............................................................................................................................................................... 4

THE NATIONAL SURVEY..........................................................................................................................................................................................5

ONLINE SURVEY OF TWTDS ...................................................................................................................................................................................7

DATA QUALITY ..........................................................................................................................................................................................................7

3. RESULTS................................................................................................................................................................ 8

INFRASTRUCTURE.....................................................................................................................................................................................................8

Enumerating Treatment Works Treating Domestic Sewage ....................................................................................................... 8

Industrial Pretreatment................................................................................................................................................................10

BIOSOLIDS END USE AND DISPOSAL..................................................................................................................................................................11

BIOSOLIDS QUALITY ..............................................................................................................................................................................................15

National Data Regarding Class A, Class B................................................................................................................................15

Metals and Organic Chemicals...................................................................................................................................................16

TREATMENT PRACTICES .......................................................................................................................................................................................17

STATE REGULATIONS, PERMITTING, AND OTHER REQUIREMENTS .........................................................................................................18

Responsible Agencies and Divisions..........................................................................................................................................18

Delegation for 40 CFR Part 503 .................................................................................................................................................19

Agency biosolids program FTEs................................................................................................................................................20

Updated regulations ....................................................................................................................................................................23

State regulations more restrictive than Part 503.........................................................................................................................23

More stringent pollutant limits ...................................................................................................................................................24

Other indicators of state regulatory activity...............................................................................................................................24

TRENDS ......................................................................................................................................................................................................................25

Is the beneficial use of biosolids increasing? .............................................................................................................................25

Pressures on biosolids recycling.................................................................................................................................................26

Legislative or regulatory activity happening or imminent pertaining to biosolids...................................................................27

SEPTAGE MANAGEMENT.......................................................................................................................................................................................28

RECOMMENDATIONS FOR FUTURE STUDIES................................................................................................ 28

CONCLUSIONS ........................................................................................................................................................ 29

REFERENCES .......................................................................................................................................................... 29

APPENDICES (in separate document)

A. The Data Collection Tools / Questionnaires

B. Additional Data on State Legal and Regulatory Structures

C. Additional Data: Incinerators, Septage

D. U. S. and State-by-State Biosolids Regulation, Quality, Treatment, End Use, and Disposal Data

Caution regarding use of data: 

The data presented throughout this

report are compiled from responses

to surveys and other

communications with diverse

individuals. While every effort has

been made in good faith to ensure

data quality and present data

objectively, the report authors and

NEBRA assume no responsibility or

liability for outcomes that may result

from their use.

ABBREVIATIONS USED

BDMS – Biosolids Data Management System

CWNS – Clean Watersheds Needs Survey

FTE – Full-Time Equivalency

MGD – Million Gallons per Day

NACWA – National Association of Clean Water Agencies

NBMA – Northwest Biosolids Management Association

NEBRA – North East Biosolids and Residuals Association

NPDES – National Pollution Discharge Elimination System

POTWs – Publicly-Owned Treatment Works

TWTDS – Treatment Works Treating Domestic Sewage

USEPA – United State Environmental Protection Agency

WEF – Water Environment Federation
A National Biosolids Regulation, Quality, End Use, and Disposal Survey – Final Report, July 20, 2007 - iv

TERMINOLOGY USED IN THIS REPORT

biosolids

The term “biosolids” is in widespread use amongst water quality professionals in North America. Its

generally accepted definitions refer to agricultural uses or land application. For example, the National

Research Council (2002) used the definition “sewage sludge that has been treated to meet the regulatory

requirements for land application set out in the Code of Federal Regulations, Title 40 (Part 503).” MerriamWebster’s Collegiate Dictionary, Tenth Edition (1998) defines biosolids as follows: “biosolid n.: solid

organic matter recovered from a sewage treatment process and used esp. as fertilizer -- usu. used in pl.” The

New Oxford Dictionary of English, 1998 edition defines it as “biosolids: plural noun: organic matter

recycled from sewage especially for use in agriculture.”

It is worth noting, however, that these dictionary definitions do not preclude using the term “biosolids” to

refer to treated municipal wastewater solids that are incinerated or placed in a landfill or a surface disposal

unit. U. S. EPA (1994) defined “biosolids” as “a primarily organic solid product produced by wastewater

treatment processes that can be beneficially recycled. The fact that biosolids can be recycled does not

preclude their being disposed.” NACWA (2006) defines “biosolids” as “primary and waste activated organic

matter (solids) removed from the wastewater that has been further processed (e.g. digested; chemically

conditioned with lime, polymers, and other products; thermally conditioned).”

beneficial use

The term “beneficial use” is used in this report to refer to biosolids that are applied to soils to take advantage

of the nutrients and organic matter they contain. This meaning of the term “beneficial use” has been in

widespread use since at least 1984 (see EPA beneficial use policy in June 12, 1984 Federal Register) and

was clearly defined in 1991 (see the July 18, 1991 Federal Register), when EPA joined with other federal

agencies, including USDA, FDA, and Department of Interior, to issue the Interagency Policy on Beneficial

Use of Municipal Sewage Sludge on Federal Land with the following definition: “Beneficial Use means any

application of sludge on land specifically designed to take advantage of the nutrient and other characteristics

of this material to improve soil fertility or structure and thereby further some natural resource management

objective.” Synonymous expressions used in this report are “end use,” “biosolids recycling,” and “biosolids

recycling to soils.”

disposal is used in this report to refer to disposition of solids in ways that do not take advantage of these

soil-enhancing qualities – this includes incineration, landfilling, and surface disposal.

It is important to note, however, that, today, the term “beneficial use” is appropriately applied to uses of

biosolids in other ways than application to soils, such as for energy production. Such beneficial uses are

increasing. Indeed, as energy becomes an ever-more-important aspect of sustainable development (including

biosolids management), “beneficial use” could be defined as “putting a particular biosolids product to its best

and highest use by maximizing the utilization of nutrients, organic matter, moisture, and/or other qualities -

including extracting the maximum amount of energy possible.”

Nonetheless, this report continues to use the older, narrower definition of “beneficial use,” partly because of

precedent and common understanding of the term and partly because the surveys conducted for this report

were based on past surveys that used this narrower definition. In addition, at this time, state agency staff and

other biosolids management professionals have not established systems to differentiate between incineration

or landfilling programs that involve energy recovery and those which do not. Thus there is scant data

available regarding what portion of the biosolids incinerated and landfilled could be considered to fall under

the newer, developing definition of “beneficial use.”
National Biosolids Regulation, Quality, End Use, and Disposal - 1

EXECUTIVE SUMMARY

In the United States, the infrastructure that leads to the production of sewage sludge (also called 

“wastewater solids,” and – when treated and tested – “biosolids”) includes 16,583 wastewater 

treatment facilities, according to the Environmental Protection Agency (USEPA). Of these, the

largest ~3,300 generate more than 92% of the total quantity of wastewater solids produced in the U. 

S. The data reported below are derived from reporting and compilation systems that account for 

these larger facilities and, to varying degrees, for minor and other smaller facilities as well.

The treated solids – biosolids – removed from wastewater at these wastewater treatment facilities –

can be legally used or disposed of in three ways: by application to soils (“land application”), by 

landfilling (or surface disposal), and by incineration. The Clean Water Act provides the legal basis

for management of biosolids nationwide, and regulations at 40 CFR Part 503 (Part 503) establish 

minimum national standards that are protective of public health and the environment. Each local

wastewater treatment facility makes its own decision regarding how their solids are managed. 

Data compiled from state regulatory agencies, U. S. Environmental Protection Agency (USEPA) 

offices, individual wastewater treatment facilities, and other sources indicate that 7,180,000 dry 

U. S. tons of biosolids were beneficially used or disposed in the fifty states in 2004.

Of that total, approximately 55% were applied to soils for agronomic, silvicultural, and/or land 

restoration purposes, or were likely stored for such uses. The remaining 45% were disposed of in 

municipal solid waste (MSW) landfills, surface disposal units, and/or incineration facilities.

Of the total applied to soils, 74% was used on farmlands for agricultural purposes. Another 22% 

were treated and tested to meet the USEPA’s highest quality classification (“Class A EQ”), and 

were publicly distributed for a variety of uses, including landscaping, horticulture, and agriculture. 

Small percentages were used for land restoration and in silviculture.

Of the total not applied to soils, most (63%) were disposed of in MSW landfills. Thirty-three

percent were processed in incinerators, while the remaining 4% were placed in biosolids-only 

surface disposal units.

Of the total 7,180,000 dry U. S. tons of biosolids in 2004, approximately 23% were treated to Class

A standards – and almost all of that met Class A EQ standards. Another 34% were treated to Class

B standards. For the remainder (43%), there is no data (or no data was obtained) regarding whether 

or not it met Class A or Class B standards. This lack of data is mostly due to the fact that

wastewater solids that are landfilled or incinerated are not generally subjected to the same

stabilization, testing, and reporting requirements.

Most states have additional regulatory programs that go above and beyond Part 503. Thirty-seven 

states require management practices for land application that are more stringent than those in Part

503, and sixteen have adopted pollutant limits that are more stringent than those in Part 503. Seven 

states have received formal delegation for administration of Part 503, and most state regulatory 

programs work with relatively up-to-date regulations and are addressing current issues. However, 

the number of full-time equivalent employees (FTEs) working on biosolids at state agencies

nationwide appears to have declined over the past six years by at least eight. 

Overall, current data suggest little change nationwide, since the late 1990s, in the rate of biosolids

recycling to soils (USEPA, 1999), and half of state biosolids coordinators report that the amounts of 

biosolids applied to soils are not increasing in their states.
National Biosolids Regulation, Quality, End Use, and Disposal - 2

1. INTRODUCTION

How much wastewater solids (sewage sludge) is produced in the United States, and what happens to 

it? What is its quality? How much is Class A and how much is Class B? What solids treatment

technologies are being used and how are these changing? How do the various states regulate

biosolids? How comprehensive are these programs? What are the trends in biosolids management?

For the past ten years, agencies regulating wastewater solids and biosolids, scientists researching 

them, engineers designing for them, concerned citizens, policy makers, and other interested 

stakeholders have relied on limited and aging sources of information to answer these questions:

• a 1999 U. S. Environmental Protection Agency (USEPA) report (USEPA Office of Solid 

Waste, 1999) that estimated total solids production based on reported national wastewater 

flow, and 

• surveys of state biosolids coordinators conducted by BioCycle – the most recent being from

December 2000 (Goldstein, 2000). 

As public interest in biosolids management has grown in recent years, so has reliance on the data

presented by these two critical sources and partial data from a few other sources (e.g. see National

Research Council, 2002). Public policy decisions are affected by such data, as are those in research 

and engineering. There is widespread agreement on the need for updated, accurate information on 

biosolids/wastewater solids regulation, quality, and end use and disposal.

Consistent data on biosolids management is difficult to obtain and compile. A great deal of data on 

biosolids is generated at individual treatment works treating domestic sewage (TWTDS), in 

accordance with regulatory requirements. Each year, TWTDS provide data to USEPA (and, in 

many cases, to states) in paper reports. While these are reviewed for enforcement purposes, only in 

some states are they compiled electronically. Encouraging electronic filing of biosolids data is

being considered by USEPA and some states, but the diversity and abundance of data makes it

difficult to attain such a goal. At this time, only about 30% of states have developed electronic

record-keeping. Similarly, at USEPA, only a few of the regional offices have effective electronic

record-keeping. Data collection and compilation are often of low priority in comparison to 

permitting and enforcement and other demands. Therefore, compiling national data efficiently 

remains a challenge.

With no centralized data collection and storage system yet in place, disparate pieces of data from

various states and USEPA regions must be painstakingly collected and interpreted to produce a

useful national picture. In conducting the surveys and other information-gathering for this report, 

those involved have come to appreciate the hard work represented by the BioCycle surveys of the

late 1990s. 

This current effort was made possible by a grant from USEPA’s Office of Water. We hope this

report takes the level of understanding of biosolids management in the U. S. one step further. What

is remarkable is that the results of this project corroborate the effectiveness of past efforts. 

This project’s goals were to:

1. compile the most comprehensive “national picture” to date on regulation, quality, end use, 

and disposal of U. S. biosolids and septage, providing critical information for agencies, 

vendors, states, USEPA, and stakeholders to make informed decisions, and 
National Biosolids Regulation, Quality, End Use, and Disposal - 3

2. document a replicable protocol for future repetitions to improve consistency for analysis of 

trends. 

What is new in our approach?

• USEPA’s 1999 approach of estimating biosolids production based on wastewater flow was

effective in creating rough national totals (this current project has proven them to be fairly 

accurate). However, this current effort relied on such estimates only as a way to fill data

gaps and to corroborate the accuracy of data compiled from reports of actual biosolids used 

and disposed.

• Building on BioCycle’s lead, we saw state biosolids coordinators (and USEPA regional staff 

and others) as the best potential sources of information, especially with regard to the

regulations and management of biosolids. Most of the effort of this project was spent

extracting information from these diverse sources, using a 10-page survey as a starting point

(a copy of the survey appears as Appendix A).

• While it still has room for improvement, there is a growing volume of electronic biosolids

data that we were able to obtain, including records kept in the USEPA-developed “Biosolids

Data Management System” (BDMS), which a few states and USEPA regions have been 

using. In addition, new user-friendly online survey tools made it possible to conduct a pilot

online survey of individual wastewater treatment facilities.

• Compiled and easily-accessible septage management information is even more lacking. One

page of the survey of state biosolids (and septage) coordinators gathered information on 

septage management, in an attempt to begin to build a coherent national picture of this

important activity.

A preliminary report was provided to USEPA and the general public in April, 2007; it provided the

most important data collected. This final report was released in July, 2007, and includes all of the

preliminary report, as well as additional information on state regulations, trends, and

recommendations for similar future surveys and data collection efforts. This report can be

downloaded at no cost for individual, non-commercial use from these websites:

www.nebiosolids.org or www.nwbiosolids.org. 
National Biosolids Regulation, Quality, End Use, and Disposal - 4

2. METHODS

This project involved:

1. a literature review to learn from past data collection efforts;

2. a Data Needs & Availability Survey to learn from state agencies, USEPA regions, and others

what information would be nice to have and what information is readily available;

3. a comprehensive survey of biosolids regulation, quality, end use, and disposal in each state, 

completed by the state coordinator and others (this survey was defined with the information 

from the Data Needs and Availability Survey);

4. additional data collection from USEPA regions and individual TWTDS;

5. an on-line survey of individual treatment works, which filled gaps where states had no data

and served as a test of this method of gathering data;

6. comparisons to data from other sources (National Association of Clean Water Agencies, 

prior surveys, estimates applying USEPA’s 1999 method); and

7. refinement of a working protocol for future data collection efforts.

From reviewing the literature and discussing data collection strategies with others who have

collected such data in the recent past (e.g. Elliott, 2005), challenges were identified. The following 

is a listing of the most significant, with discussion of how they have been addressed in this survey 

effort:

• What kinds of facilities should data be collected for? just Publicly-Owned Treatment Works

(POTWs)? or private & federal treatment works as well, e.g. all Treatment Works Treating 

Domestic Sewage (TWTDS)? In reality, as shown by USEPA (1999), the difference in 

numbers between the larger group of TWTDS and the subset of POTWs is relatively small, 

making the distinction less critical. This project requested data on all TWTDS.

• The diversity of 50 state programs (Puerto Rico and other territories were not included in 

this survey effort) yields data of diverse quality and comprehensiveness. To address this, 

state data was interpreted and fit into one survey structure, with the assistance of state

biosolids coordinators. In addition, a rough numerical state data quality rating was applied 

(4 rating options: 0 for lowest quality to 3 for highest quality). The data from states with 

low data quality ratings were further analyzed for comprehensiveness and quality, using 

comparisons with other reported data (e.g. from the survey of members of the National

Association of Clean Water Agencies – NACWA) and CWNS data. These measures made

diverse data sets more comparable and compatible.

• TWTDS and states collect data using a diversity of units of measure; for example Maryland 

uses wet U.S. tons. Most states track data in dry U. S. tons and USEPA tends to use dry 

metric tons. The choice for standard measure for this report was dry U. S. tons, but, in order 

to maximize participation, the surveys allowed data to be provided in a variety of formats

and the project team conducted conversions. Note that, while national totals are presented 

below in dry U. S. tons, the data presented in each of the state-by-state summaries in

Appendix D are in the units used by that state’s biosolids coordinator or the related EPA

regional office (depending on the source of the data).

• Many small facilities send their wastewater solids to larger facilities; how to avoid double

counting? This conundrum is further exacerbated by the fact that some facilities measure

their final biosolids output after they are composted or otherwise amended (e.g. with

alkaline products), whereas many facilities measure before such treatments. Avoiding errors
National Biosolids Regulation, Quality, End Use, and Disposal - 5

associated with this issue is difficult; this remains an unsolved issue and may affect the data

reported here.

• Many small facilities (and a few larger ones) use lagoon or other storage systems that only 

use or dispose of solids every 5 to 20 years. Such events are assumed to be randomly and 

evenly distributed over the years, so that data from one year to the next will capture similar 

numbers of events and volumes of solids.

• When categorizing biosolids as “beneficially used,” different people use differing 

definitions; for example, in their study in Pennsylvania, Elliott et al. (2005) considered 

biosolids used as alternate daily cover at landfills to be in the “disposal” category, because it

is often difficult, in practice, to ensure the distinction at the final disposal site, and 

agronomic benefits are not realized. In this current project, biosolids used for alternate daily 

cover were classified as disposal. Although this report’s definition of “beneficial use” is

restricted to those biosolids applied to soils in one way or another (see p. iv), other nonagricultural beneficial uses are becoming more common, especially energy-related uses

(biogas, incineration with recovery of heat, bioreactor landfill technology, etc.).

In summary, the strategy was to collect data from those sources most likely to have the highest

amount and quality: the state agency biosolids coordinators. Then, as data gaps became apparent –

and many did – the project team filled them with information from USEPA regional biosolids

coordinators, online research of state biosolids regulatory programs, and through direct contact with 

the largest TWTDS in the state to acquire wastewater solids generation, quality, and end use and 

disposal data, facility-by-facility, until a reasonably high percentage of the state’s wastewater flow

(and population) were accounted for (a strategy utilized by Elliot et al., 2005). In a few cases (e.g. 

Connecticut, Missouri), no state data was collected, and solids production, end use, and disposal

totals were estimated for use in national totals. 

As the state data were collected, they were compiled in a Filemaker Pro 8 database, using the same

format as the biosolids quality and end use survey of state coordinators (the survey is included in 

Appendix A). Subsets of data were exported into Excel spreadsheets for analysis, charting, and 

mapping. Data quality checks were conducted whenever data were entered or transferred. 

In the end, this approach resulted in a significant refinement of overall data quality that has not been

achieved by any prior nationwide effort. However, the quality of the data still requires reporting of 

our best estimates in thousands of dry U.S. tons in the case of most states. Data from relatively few

states are of sufficient quality to be reported in hundreds or tens of dry U. S. tons.

THE NATIONAL SURVEY

The “Biosolids Quality and End Use Survey” was the major focus of this project. It was developed 

using concepts and questions from previous surveys (Goldstein, 2000; Elliott et al., 2005) and 

results from our cursory Data Needs and Availability Survey of ~20 state biosolids coordinators and 

other stakeholders in biosolids management.

The 10-page Biosolids Quality and End Use Survey asked for data and opinions regarding...

• state biosolids agency and coordinator contact information,

• wastewater treatment and biosolids infrastructure,
National Biosolids Regulation, Quality, End Use, and Disposal - 6

• regulation and permitting,

• biosolids quality (2004 data requested),

• biosolids end use and disposal (2004 data requested),

• trends in biosolids management,

• biosolids testing and reporting requirements, 

• biosolids treatment practices, and

• septage management.

After review by NACWA biosolids committee members and others, this survey was sent to all 50 

state agency biosolids coordinators, as well as some USEPA regional biosolids coordinators, in 

April, 2006 (Appendix A). During the next ten months, the project team collected and compiled the

data and opinions provided by the state coordinators. 

Upon completion of initial data entry, it was clear that more extensive data collection would be

required. State coordinators had filled in the survey to varying degrees of completeness, and in 

order to proceed with further collection, each state’s data had to be interpreted, compiled, and key 

data gaps identified. The information provided by state coordinators was converted into one

narrative summary and one Excel spreadsheet summary of consistent format for each state. In order 

to check the quality of the data and its interpretation by the project team - as well as to fill data gaps

– these two-document draft summaries were provided to state biosolids coordinators for review and 

follow-up phone discussion (a few state coordinators did not receive a summary and did not conduct

this review). This was a process that had been utilized by BioCycle in some of their survey work. 

This “reflecting” of data back to state coordinators utilized the same units of measure (e.g. dry 

metric tons, dry U. S. tons) that the state coordinators had used. Some of the two-document

summaries were also reviewed by the appropriate USEPA regional biosolids coordinator. The final, 

revised data summaries resulting from this process are included as state-by-state reports in 

Appendix D.

The final step in data analysis was to compile the information from all 50 states (including best

estimates for a few states) into a national picture. All states’ numerical data were maintained and 

kept consistent, by electronic transfers, in three formats:

1. in the individual state spreadsheets mentioned above, 

2. in the original Filemaker database, and 

3. in a single spreadsheet used to calculate national totals. 

In the national totals spreadsheet, appropriate conversions were applied to biosolids quantity data

from those states that provided their data in anything but dry U. S. tons. This national totals

spreadsheet also included columns with data on state population and the state’s total wastewater 

flow (from USEPA’s CWNS data set for 2004). This allowed for easy direct comparison between 

each state’s reported total biosolids quantity and the estimated total derived by using the USEPA

Biosolids Generation Factor (U. S. EPA Office of Solid Waste and Emergency Response, 1999), 

thus helping ensure the accuracy of the reported data. The national totals data is discussed in the

“results” below and is presented in a spreadsheet of “U. S. Totals” at the beginning of Appendix D. 
National Biosolids Regulation, Quality, End Use, and Disposal - 7

ONLINE SURVEY OF TWTDS

One final step was taken: collection of data from individual Treatment Works Treating Domestic

Sewage (TWTDS) using an online survey system, Survey Monkey. The online survey was intended 

to provide semi-independent data that could be used to corroborate data provided by the survey of 

state coordinators. Its design was derived using questions from the survey of state biosolids

coordinators, with its target audience (individual TWTDS) in mind. Northwest Biosolids

Management Association created the online survey structure and layout. It was intended to take 15 

to 20 minutes for a knowledgeable person at a treatment facility to complete. 2004 data was

requested. To generate responses, NEBRA sent (with the help of the National Biosolids

Partnership) a formal email announcement to biosolids contacts around the country; the email

included instructions and a link to the survey website. The email included a request that the email

be forwarded to any U. S. wastewater treatment facility and be included in any pertinent

newsletters. A deadline was also included, which allowed about three weeks for people to respond 

by completing the online survey. NEBRA’s contact information was provided, and some questions

and comments were received and addressed. This outreach was relatively minimal and simple;

future efforts could likely gain far larger numbers of responses.

Once the online survey deadline was passed, the online survey data was downloaded into an Excel

spreadsheet and thoroughly reviewed for quality and accuracy. Any questionable data were

corrected by direct contact with the agency reporting (the survey provided the option of including 

contact information, but did not require it) or were deleted. Statistical analysis of the data was

completed by Professors Tai Cheng and John Peckenham at the University of Maine, Orono.

The response rate to the online survey was 250 (1.5%) of the 16,000+ TWTDS in the country. This

small response precluded much useful extrapolation from the survey data. However, the survey 

data proved useful in filling data gaps in several states. It also proved to be an excellent test of 

utilizing an online survey software service to collect key biosolids quality, end use, and disposal

data. The online system proved efficient and easy to use. We recommend use of this kind of survey 

for collection of basic data on a regular basis in the future.

Information collected via the online survey is integrated in the results, below, and the online survey 

questionnaire appears in Appendix A.

DATA QUALITY

With the large volumes and variety of data being compiled in this project, the chance for data

quality to be compromised was of concern. This was addressed by establishing protocols for data

checking and tracking in those parts of the project where an error would have the most significant

impacts. These included the following data quality control measures:

• After data was transferred from the Biosolids Quality and End Use Surveys completed by 

state coordinators into the Filemaker Pro 8 database, data entry was subsequently 

independently checked.

• Use of the standardized summaries for each state’s data ensured consistency of compilation 

and reporting, which made errors stand out.
National Biosolids Regulation, Quality, End Use, and Disposal - 8

• As the regulation, quality, end use, and disposal data for each state was compiled in the

summary Excel spreadsheet template, one standard calculator spreadsheet was utilized for 

all states, with consistent and comparable rows of data fed into the calculator from the

Filemaker database. In addition, on the state summary spreadsheet, various estimates of 

total wastewater solids generation for the state (such as by using the USEPA 1999 method) 

appeared next to the total reported by the state coordinator, supplying a constant

corroboration of overall data accuracy.

• One team member did a final review of each state’s summary and state coordinators (and/or 

the USEPA regional coordinators) were asked to review the summary (this step was not

completed for some states, due to lack of time or lack of response).

• In spreadsheets, all data was cleaned and checked logically and erroneous or suspicious data

were investigated further.

• Data in final reports were spot checked again for accuracy, however, given the volumes of 

data involved, their accuracy is not 100% guaranteed.

3. RESULTS

The Biosolids Use and Disposal Survey, completed by state biosolids coordinators, provided the

majority of the data reported below. Gaps in the state-reported data were filled with information 

from USEPA regional offices, individual TWTDS, and other sources. The results of the online

survey of individual TWTDS are integrated into the discussions below, as appropriate. 

Caution regarding use of data: The data presented throughout this report are compiled from

responses to surveys and other communications with diverse individuals. While every effort has

been made in good faith to ensure data quality and present data objectively, the report authors and 

NEBRA assume no responsibility or liability for outcomes that may result from their use.

INFRASTRUCTURE

Enumerating Treatment Works Treating Domestic Sewage

In the U.S., the infrastructure that leads to production of sewage sludge (also called “wastewater 

solids,” and, when treated, “biosolids”) includes an estimated 16,583 Treatment Works Treating

Domestic Sewage (TWTDS).1 The vast majority of these treatment facilities are small: 13,261 

treat wastewater flows equal to or less than 1 million gallons per day (MGD) – see Table 1. That

leaves 3,322 that treat flows greater than 1 MGD, of which only 551 treat flows greater than 10 

MGD.

USEPA uses a rough estimate that a population of 10,000 people accounts for 1 MGD of flow. 

Analysis of this project’s online survey data of 250 TWTDS indicated that an increase of 10,000 

people served by a TWTDS increases the daily wastewater flow by 1.54 MGD, which means that a

 1 USEPA’s draft Clean Watershed Needs Survey (CWNS) database for 2004 included 33,852 NPDESpermitted dischargers – systems that discharge to waters of the U.S. in accordance with the Clean Water Act,

about half of which do not perform treatment (are not TWTDS).
National Biosolids Regulation, Quality, End Use, and Disposal - 9

population of 6,500 people accounts for 1 MGD of flow. A cursory review of CWNS data for 2004 

corroborates the fact that 1 MGD TWTDS serve this range of population: 6,500 to 10,0002.

Thus, the 13,261 smallest TWTDS – considered “minors” by USEPA – are in relatively small

communities. And as Elliott et al. (2005) discovered in their detailed survey work in Pennsylvania, 

these small TWTDS manage their wastewater solids in ways that are not necessarily represented by 

how larger TWTDS manage them. For example, minor (</= 1 MGD) facilities will often:

• store solids in wastewater or sludge lagoons that are only cleaned out every 5 – 20 years;

• utilize the lowest-cost and least-hassle method for managing solids, such as landfilling (as

Elliott et al. found in PA); and/or

• transport untreated solids to larger TWTDS for treatment.

These, and other factors – including the sheer number of minor facilities –significantly impede

accurate characterization of the management of wastewater solids from these small TWTDS. Prior 

national surveys, and, to a large extent this current research, have ignored the smallest TWTDS. 

This is justified, in part, because these facilities treat only 8% of total flow (MGD) and use or 

dispose of the same small – or even lesser – percentage of solids. These solids are insignificant on 

national, regional, and state scales. Many likely become part of larger TWTDS’ solids production, 

but most cannot be easily counted on a state or national scale and these may not be included in the

data presented in this report.

 2 The range in the number of MGD produced by a population of 10,000 is explained, in part, by:

• the amount of industrial flow discharged to the sewer and treated by the TWTDS, in addition to the

population, in their service area (industrial flows can be low or as much as 90+% in some cases (e.g.,

Dalton, GA - home of indoor/outdoor carpet manufacturing).

• the amount of use of water conservation devices (low flush toilets, low flow showerheads, etc.)

• climate differences (desert vs high rainfall areas)

• TWTDS with combined sewers (and CSOs) vs those with separate sanitary and storm sewer systems

Table 1 (courtesy of Robert K. Bastion, USEPA)
National Biosolids Regulation, Quality, End Use, and Disposal - 10

It is the ~3,300 TWTDS with flows greater than 1 MGD – and especially the ~550 over 10 MGD –

that are most significant for understanding each state’s biosolids management situation and the

national picture. Facilities treating more than 1 MGD treat 93% of existing flow and, given the

significant correlation between flow and solids production, an equivalently high percentage of 

wastewater solids production, end use, and disposal.

Industrial Pretreatment

There is considerable professional and public interest with regards to the ~3,300 largest TWTDS, 

because they include facilities in urban areas, where industrial inputs to wastewater flows (and, 

therefore, biosolids) are more likely. Under 40 CFR Part 403, USEPA requires local wastewater 

treatment facilities to implement and enforce industrial pretreatment programs aimed at reducing 

inputs to sewage systems of anything that could negatively impact the functions of the facility and 

the quality of the effluent and solids. 

One measure of this program was assessed by asking of state biosolids coordinators the number of 

TWTDS that “currently have active industrial pretreatment programs.” The aggregated total

response was approximately 1,440, 43% of all major TWTDS. This is a minimum number, as the

survey failed to obtain 100% response on this question. TWTDS that do not have active

pretreatment programs – including many in the 1 to 10 MGD range (serving populations less than 

65 to 100 thousand – are mostly not required to do so because of lack of Significant Industrial Users

(SIU) of the sewage system, i.e. the threat of discharge to the sewers of potentially harmful

substances is minimal. As has been reported elsewhere, the Part 403 pretreatment program –

coupled with Part 503 and state regulations – has significantly improved the quality of biosolids

(National Academy of Sciences, 2002).

Further data on pretreatment was compiled from the project’s online survey. Respondents to that

survey were biased significantly toward larger facilities.

3

 Of the 219 responses to the pretreatment

question, 77% said their facility has an active industrial pretreatment program (Figure 1).

Figure 1 – Prevalence of industrial

pre-treatment in larger TWTDS

completing online survey

 3 Of the 250 responses, 199 were from major facilities (> 1 MGD); that’s 80% of the sample. CWNS data

indicate that, nationwide, only 8% of TWTDS are majors.
National Biosolids Regulation, Quality, End Use, and Disposal - 11

BIOSOLIDS END USE AND DISPOSAL

The data compilation efforts of this project build on prior estimates (USEPA Office of Solid Waste, 

1999) and reports compiled from states (Goldstein, 2000). However, for the first time, at least some

actual measured biosolids quantities were compiled for every state (the exception is Missouri, for 

which a rough estimate for total biosolids used or disposed was necessary to complete national

totals.) 

Ten states (Illinois, Massachusetts, Minnesota, New Hampshire, New Jersey, New York, Rhode

Island, Vermont, Washington, Wisconsin) and the District of Columbia were able to efficiently 

provide comprehensive data on wastewater solids end use and disposal. Other states (e.g. 

Delaware, Georgia, Maryland) efficiently provided somewhat less comprehensive estimates (the

difficulty with Maryland data is that it is reported in wet U. S. tons, requiring an estimate of the

appropriate percent solids to apply to convert the data to dry equivalents).

For other states (e.g. California, Colorado, Hawaii, Montana, Nevada, North Dakota, South Dakota, 

Wyoming), it was relatively easy to compile robust data with the added help of EPA regional

offices (Regions 8 & 9) that track biosolids closely using electronic databases. The use and disposal

of biosolids in Pennsylvania had just been studied closely by researchers at Penn State University 

(Elliott et al., 2005), and their data was incorporated here.

Other states (e.g. Indiana, Kansas, Kentucky, Nebraska, New Mexico, North Carolina, South 

Carolina, Texas, Virginia) required painstaking compilation of data from incomplete information 

provided by state coordinators, EPA regional offices, the NACWA Financial Survey, and direct

contact with individual TWTDS. In these cases, this required contacts with from three to fifteen of 

the largest individual TWTDS in the state. In each case, we managed to obtain data on solids end 

use and disposal from the largest TWTDS for at least 60% to 70% of the state’s estimated total

wastewater flow (as reported by the 2004 Clean Watersheds Needs Survey). We roughly estimate

that achieving this level of data compilation likely accounts for 85% or more of the solids produced 

in the state, because many smaller TWTDS transport solids to larger facilities or store solids for 

longer periods, thus using or disposing no solids in a typical year.

The estimated total quantity of wastewater solids beneficially used or disposed in each state in 2004 

is reported in Table 2.
National Biosolids Regulation, Quality, End Use, and Disposal - 12

Table 2 – State-by-State Population, Wastewater, and Total Solids Used / Disposed in 2004

State

Estimated State

Population

(U. S. Census, 2004)

Number of

TWTDS (CWNS

2004)

Total Est.

Wastewater Flow

(MGD)

(CWNS 2004)

Reported Solids Used &

Disposed (dry U. S. tons)

Alabama 4,525,375 278 470 68,000

Alaska 657,755 172 78 17,000

Arizona 5,739,879 166 465 99,500

Arkansas 2,750,000 350 279 58,000

California 35,842,038 633 4,170 788,500

Colorado 4,601,821 315 425 113,500

Connecticut 3,498,966 94 386 99,000

Delaware 830,069 19 103 23,500

Dist. of Columbia 554,239 1 370 105,800

Florida 17,385,430 322 1,429 300,000

Georgia 8,918,129 350 755 200,000

Hawaii 1,262,124 21 136 22,000

Idaho 1,395,140 186 135 23,300

Illinois 12,712,016 721 2,231 348,000

Indiana 6,226,537 411 1,033 197,000

Iowa 2,952,904 730 358 67,000

Kansas 2,733,697 634 273 32,000

Kentucky 4,141,835 245 331 94,500

Louisiana 4,506,685 353 546 63,500

Maine 1,314,985 148 137 32,200

Maryland 5,561,332 161 444 111,500

Massachusetts 6,407,382 128 780 168,800 

Michigan 10,104,206 404 1,409 374,000

Minnesota 5,096,546 516 462 152,000

Mississippi 2,900,768 317 295 61,000

Missouri 5,759,532 732 805 170,000

Montana 926,920 211 82 12,000

Nebraska 1,747,704 469 197 34,000

Nevada 2,332,898 57 136 62,300

New Hampshire 1,299,169 88 101 27,000

New Jersey 8,685,166 156 1,216 261,200

New Mexico 1,903,006 66 102 80,500

New York 19,280,727 588 2,766 353,300

North Carolina 8,540,468 457 645 135,000

North Dakota 636,308 284 56 8,600

Ohio 11,450,143 780 1,853 358,000

Oklahoma 3,523,546 493 355 58,500

Oregon 3,591,363 213 392 61,000

Pennsylvania 12,394,471 856 1,600 304,000

Rhode Island 1,079,916 20 131 30,300

South Carolina 4,197,892 173 462 54,000

South Dakota 770,621 280 61 10,500

Tennessee 5,893,298 245 742 241,000

Texas 22,471,549 1380 2,221 708,000

Utah 2,420,708 106 305 58,400

Vermont 621,233 87 45 9,000

Virginia 7,481,332 225 682 176,400

Washington 6,207,046 246 838 110,600

West Virginia 1,812,548 217 194 29,000

Wisconsin 5,503,533 597 667 179,800

Wyoming 505,887 123 47 27,000

U. S. TOTALS 293,656,842 16,824 34,201 7,180,000 
National Biosolids Regulation, Quality, End Use, and Disposal - 13

In 2004, 49% of U. S. wastewater solids were beneficially used (applied to land for agronomic, 

silvicultural, or land restoration purposes), while 45% were disposed (Table 3, Figures 2 and 3). 

Another 6% were stored, or their final use or disposal was not reported. However, the following key 

factors apply:

• It is likely that most of the 6% “other” was also destined for beneficial uses (application to 

land). This means that the rate of beneficial use of biosolids tracked in 2004 was probably 

close to 55%.

• In this survey, biosolids reported as used for landfill daily cover were included in the

“disposal” side of the equation. Some states (e.g. California, Washington) define landfill

daily cover as a beneficial use, as did Elliott et al. (2005). By these state’s definitions, the

national rate of beneficial use might be a percentage point higher.

• Tracking by states and data compilation for this project rely predominantly on data from

major TWTDS (> 1 MGD). Elliott et al. found that, in Pennsylvania, what larger TWTDS

do with their solids is not a good predictor of what smaller TWTDS do. In addition, because

some TWTDS use more than one method of end use and/or disposal, some TWTDS are

double-counted. Thus, data on number of entities throughout this report are approximate and 

only provide some sense of relative proportions; they not reliable for extrapolations.

• Data on wastewater solids in Puerto Rico and other territories were not collected for this

report and are not included in the totals. They are estimated to total no more than 30,000 

dry U. S. tons.

 Table 3 – Biosolids Use and Disposal Practices, 2004 U. S. Totals

Figure 2

Quantity of 

Biosolids Percentage (by quantity)

Beneficial Use (applied to soils) 3,507,000 49%

Disposal 3,252,000 45%

Other (long-term storage, etc.) 421,000 6%

Total 7,180,000 100.00%
National Biosolids Regulation, Quality, End Use, and Disposal - 14

Agricultural uses of biosolids dominate the beneficial use practices (Figure 4). Most of this is

traditional Class B land application, but a good portion is Class A – at least 613,000 dry U. S. tons. 

The distribution of Class A “Exceptional Quality” (EQ) biosolids makes up one quarter of the U. S. 

total and includes significant

amounts of biosolids compost

and heat-dried pellet fertilizer. 

Reclamation – the use of 

biosolids to improve disturbed or 

marginal soils and lands (e.g. 

mine lands) – requires relatively 

large amounts of biosolids per 

acre of land, but only 3% of 

beneficially used biosolids are

land applied for this purpose. 

Some biosolids that were

specified as having been applied 

to rangeland are included in the

“forestland” category; clearly, silvicultural uses of biosolids are limited. Figure 4

Figure 3
National Biosolids Regulation, Quality, End Use, and Disposal - 15

Most U. S. wastewater solids that are not applied to soils go to municipal solid waste (MSW) 

landfills (Figure 5). The 63% landfilled reported here for 2004 includes some that was used as

alternative daily cover. Disposition of wastewater solids by incineration (thermal oxidation) 

predominates in a few densely populated states (e.g. Connecticut, Rhode Island) and manages large

volumes of solids in several other states (e.g. at Anchorage, Cleveland, and Indianapolis). Data

collected by NACWA’s Biosolids Committee (Dominak, pers. comm., 2007) indicates that, in 

2004, there were 234 operating incinerators in the U. S. (a state-by-state listing of operating 

incinerators appears in Appendix C). Dedicated surface disposal units, also known as monofills, 

handle only a small percentage of the nation’s wastewater solids.

Figure 5

Data for the entire U. S., as well as each individual state and the District of Columbia (in 

alphabetical order) appear in Appendix D.

BIOSOLIDS QUALITY

National Data Regarding Class A, Class B

The survey of state biosolids coordinators included a table requesting information on the numbers

of TWTDS producing biosolids of various qualities (e.g. Class A or Class B), as well as the

amounts of biosolids of each quality. It attempted to attain details to the level of separating Class A

Exceptional Quality (EQ) biosolids of various kinds (“heat dried,” “composted,” and “other”) from

other Class A biosolids, as well as differentiating between Class B biosolids that meet Table 3 (the

“high quality” standard) or only Table 1 (“ceiling limits”) of the federal Part 503 regulations.

As it turned out, data collected only supported reporting of the quantities and percents of Class A, 

Class B, and biosolids for which no data was available (Figure 6). Note that the total amount of 

data compiled regarding biosolids quality was 94% of the total biosolids quantity reported used or 

disposed. Therefore, the following data is intended only to provide a general picture and should be

used with caution.
National Biosolids Regulation, Quality, End Use, and Disposal - 16

For a large percentage of wastewater solids (2,903,000 dry U. S. tons or 43%), there is no data (or 

no data was obtained) regarding whether or not it met Class A or Class B standards. This lack of 

data is mostly due to the fact that wastewater solids that are landfilled or incinerated are not

generally subjected to the same stabilization, testing, and reporting requirements. It should be noted 

that there are some TWTDS that produce Class A biosolids (e.g. heat dried pellets) that are burned 

in incinerators and can provide an energy recovery benefit.

Figure 6

Of the remaining 57% of biosolids for which quality data were available for 2004, 60% (2,273,000 

dry U. S. tons) were Class B and 40% (1,532,000 dry U. S. tons) were Class A. Almost all of the

Class A biosolids met the Exceptional Quality (EQ) criteria. 

Note that Figure 6 shows a total larger percentage of Class A and B biosolids (57%) than the

percentage of beneficially used biosolids in Figure 2 (55%, with the assumption that the 6% other 

were stored for eventual beneficial use). This is mostly because some Class A and Class B 

biosolids were not applied to soils (i.e., they were landfilled or incinerated).

Data on biosolids quality for the entire U. S., as well as each individual state and the District of 

Columbia (in alphabetical order) appear in Appendix D.

Metals and Organic Chemicals

There is considerable robust data on the quality of biosolids with regards to elements regulated by 

Part 503 (“heavy metals”). The volumes of data, and the compilation of such data required to 

conduct significant analysis, makes this difficult on a national scale – and beyond the scope of this
National Biosolids Regulation, Quality, End Use, and Disposal - 17

project. The best sources of information regarding metals data are published papers that focus on 

particular elements or particular states or situations (e.g. Stehouwer, 2000; Chaney et al., 1999). 

Data regarding unregulated elements (e.g. boron, silver) and unregulated organic chemicals are even 

less available, but, where they do exist, can be voluminous. Some states, such as Maine and New

Hampshire, require biosolids to be tested for scores of compounds on at least an occasional basis. 

Such data is sometimes compiled and reported in state agency documents. Many larger public

wastewater treatment facilities conduct testing on their biosolids for many different parameters to 

ensure product quality (e.g. Milorganite® and Boston’s MWRA fertilizer pellets). However, 

compiling such information on a national scale is difficult at this time, in part because of lack of 

standardized data reporting and compilation in electronic formats. As with the regulated elements, 

the best current sources of information are published papers (e.g. Overcash et al., 2005; Kinney et

al., 2006). 

TREATMENT PRACTICES

There is a diversity of technologies used to manage the solids (sewage sludges) removed during the

treatment of wastewater. In order to allow for efficient handling and transport, they are stabilized 

and, in most cases, dewatered. Stabilization processes generally reduce putrescibility and potential

odors, as well as pathogen and vector-attraction levels. Dewatering processes convert solids that

are at least 95% water to a semi-solid material that is from 50% to 85% water. 

The survey of state biosolids coordinators requested estimates of the number of TWTDS utilizing 

each kind of common stabilization and dewatering technology. Responses were received from only 

~50% of states regarding numbers of TWTDS using each technology and ~25% of states regarding 

quantities of biosolids treated by each technology. Nonetheless, the data provided (Table 4) gives a

sense of the relative abundance of different treatment technologies.
National Biosolids Regulation, Quality, End Use, and Disposal - 18

Table 4 – Reported Estimates of Biosolids Treatment Technologies in Use

*CAUTIONS IN USING THIS DATA: These are minimum estimates from incomplete data from states and

other sources. They serve only to provide a rough sense of the relative importance of various technologies.

STATE REGULATIONS, PERMITTING, AND OTHER REQUIREMENTS

In the U.S., the use and disposal of wastewater solids (sewage sludge) and biosolids is governed by 

USEPA regulations, 40 CFR Part 503. The Part 503 rule established risk-based standards for 

pollutants, pathogen and vector attraction reduction, and basic management requirements (e.g. 

agronomic loading rate). Most states have additional, state-level regulations that impose additional

restrictions and require additional management practices, treatment processes, and/or testing 

requirements. The data presented below were derived from responses by state biosolids

coordinators to questions in the 10-page Biosolids Quality and End Use Survey. One objective of 

the national survey was to characterize the comprehensiveness and strictness of state regulatory 

programs, as they build requirements above and beyond the Part 503 program.

Responsible Agencies and Divisions

Over half of states (58%) assign biosolids regulatory oversight to the water/wastewater division of 

their state environmental agency (Table 5). In another 30% of states, the solid waste division of the

state environmental agency is responsible, either entirely or in part. In Arkansas, the environmental

agency’s water/wastewater program and solid waste program, as well as the public health 

department are involved. In Connecticut, where incineration is the prevalent disposal method, the

Reported Estimates of Number 

of TWTDS Using*...

Estimated Quantity of 

Biosolids Produced 

Using*...

Stabilization Technology

Aerobic Digestion 2200 85,000 

Digestion-anaer./other 1000 1,217,000 

Lime/Alkaline 900 285,000 

Long-term (lagoons, reed beds, etc.) 500 97,000

Composting 200 471,000 

Thermal (not incineration) 60 112,000 

Other 20 5,400 

Dewatering Technology

Belt Filter Press 650 415,000 

Drying beds 400 380,000

Centrifuge 150 880,000

Plate & Frame Press 50 65,500 

Vaccuum Filter 20 4,200 

Screw Press 10 3,400 

Other 40 600 
National Biosolids Regulation, Quality, End Use, and Disposal - 19

air quality division of the environmental agency is involved, along with the water/wastewater 

division (air quality involvement in other states with incinerators is also likely). In New Jersey and 

other states, the solid waste division is involved in some biosolids disposal options (in many states, 

landfilling biosolids involves solid waste divisions). In Virginia, three environmental agency 

divisions (water, solid waste, and air) – as well as the public health department – have been 

involved in biosolids management. However, as of 2007, new Virginia legislation has turned over 

most responsibility to the environmental agency.

Table 5 – State agency and division responsible for regulation

water/wastewater program of the

state environmental agency

solid waste program of the state

environmental agency

water/wastewater program & solid

waste program of the state

environmental agency

29 States 8 States 8 States

58% 16% 16%

Alabama, Delaware, Florida, Hawaii,

Illinois, Iowa, Kansas, Louisiana,

Massachusetts, Michigan Minnesota,

Missouri, Nebraska, New Hampshire,

New Mexico, North Carolina, North 

Dakota, Ohio, Oklahoma, Oregon,

Rhode Island, South Carolina, South 

Dakota, Tennessee, Texas, Utah,

West Virginia, Wisconsin, Wyoming

Alaska, Indiana, Kentucky, Maine,

Maryland, Mississippi, New York,

Washington

California, Colorado, Georgia, Idaho,

Montana, Nevada, Pennsylvania,

Vermont

Delegation for 40 CFR Part 503

Since 1993, when the Part 503 rule was adopted, USEPA has offered states the option of becoming 

delegated to administer the rule. Delegation requires that states have robust regulatory and 

enforcement programs that ensure that TWTDS’ compliance with Part 503 (at a minimum) is

demonstrated. Delegation allows states some autonomy, and can streamline the regulatory process

by avoiding involvement of, and reporting to, both state and federal authorities. As of 2006, 

relatively few states have decided to pursue the delegation option; delegated states are Arizona, 

Michigan, Ohio, Oklahoma, South Dakota, Texas, Utah, and Wisconsin (Figure 7).
National Biosolids Regulation, Quality, End Use, and Disposal - 20

NOTES: South Dakota and

Utah adopted all of Part 503 

by reference. Michigan is

delegated for land

application only. Ohio and 

Wisconsin are delegated for

land application, landfilling,

and surface disposal (not

incineration and septage).

Oklahoma and Texas

reported only that they are

delegated.

Agency biosolids program FTEs

Staff time applied to a particular program area can be expressed as full-time equivalents: the total

staff hours per week divided by 40. USEPA has used this statistic in past reports, such as in its

response to the Inspector General’s report (USEPA Inspector General, 2000 & 2002). Table 6 

compares this survey’s data and that past data. 

When all states are combined (except the three for which no data was provided in 2006), there

appears to be a reduction in staffing for biosolids programs of close to 19 FTEs between 2000 and 

2006. A few states seem to account for large amounts of these trends. Even if these large changes

in these few states are ignored (e.g. Florida’s apparent reduction of 7.5 FTEs), the overall change

appears to be a loss nationwide of at least 8 FTEs. These reductions in staffing are likely a result of 

increasing demands on environmental agencies and the resultant shifting of priorities and staff 

assignments. 

It is important to recognize that, in the case of states in USEPA Region 8 (and, to some extent, 

Region 9), considerable regulatory permitting, oversight, and enforcement are conducted by the

Figure 7 – Delegation
National Biosolids Regulation, Quality, End Use, and Disposal - 21

Table 6 – Number of reported FTEs, FTEs per million population and change since 2000

State

Estimated FTEs

per million

population

Estimated number of fulltime equivalents in 

biosolids program 2006

Estimated number of fulltime equivalents in biosolids

program 2000 (NRC, 2002)

CHANGE from 2000

to 2006

Alabama 0.00 0 1.5 -1.5

Alaska 0.30 0.2 0.1 0.1

Arizona ND ND* 0.25 ND

Arkansas 0.18 0.5 0.75 -0.25

California 0.05 1.8 1.75 0.05

Colorado 0.22 1 1 0

Connecticut 0.03 0.1 1 -0.9

Delaware 1.20 1 1 0

Florida 0.55 9.5 2 7.5

Georgia 0.22 2 1 1

Hawaii 0.59 0.75 1 -0.25

Idaho 0.43 0.6 0.25 0.35

Illinois 0.12 1.5 2 -0.5

Indiana 0.48 3 3 0

Iowa 0.17 0.5 0.33 0.17

Kansas 0.09 0.25 0.25 0

Kentucky 0.14 0.6 0.6 0

Louisiana 0.33 1.5 1.75 -0.25

Maine 3.04 4 4 0

Maryland 0.00 ND* 12 ND

Massachusetts 0.20 1.3 2.5 -1.2

Michigan 0.54 5.5 6 -0.5

Minnesota 0.29 1.5 1.5 0

Mississippi 0.24 0.7 0.67 0.03

Missouri 0.00 0.01 0.1 -0.09

Montana 0.05 0.05 0.1 -0.05

Nebraska 0.01 0.01 1 -0.99

Nevada 0.09 0.2 0.25 -0.05

New Hampshire 1.92 2.5 4 -1.5

New Jersey 1.30 11.33 11.33 0

New Mexico 0.00 0 0.1 -0.1

New York 0.23 4.5 4.5 0

North Carolina 0.47 4 7 -3

North Dakota 0.00 0 0.25 -0.25

Ohio 0.17 2 4 -2

Oklahoma 0.28 1 2 -1

Oregon 0.56 2 2.4 -0.4

Pennsylvania 0.65 8 12 -4

Rhode Island 0.46 0.5 1 -0.5

South Carolina 0.24 1 6 -5

South Dakota 0.65 0.5 0.5 0

Tennessee 0.51 3 2.2 0.8

Texas 0.13 ND* 11.5 ND

Utah 0.02 0.05 1 -0.95

Vermont 4.43 2.75 3 -0.25

Virginia 0.53 4 7 -3

Washington 0.81 5 3.9 1.1

West Virginia 0.77 1.4 3 -1.6

Wisconsin 2.18 12 12 0

Wyoming 0.10 0.05 0.25 -0.2

TOTALS 103.7 (*no 2006 data

for 3 states)

146.0 (125.2 if exclude 3 

states with no 2006 data) -18.5
National Biosolids Regulation, Quality, End Use, and Disposal - 22

USEPA regional offices, working in conjunction with state staff. In addition, in many states,

additional oversight and enforcement are provided through state agency district offices and at the

county level – meaning that the numbers of state agency FTEs in Table 6 do not paint the entire

picture for any state.

Also included in Table 6 and depicted in Figure 8 is the calculation of FTEs per million people in 

the state population; this creates a fairer comparison of the relative involvement by different state

regulatory agencies. The results show that, for example, Vermont, with its 2.75 FTEs, really has the

greatest commitment of staff time relative to its small population (4.43).

What is USEPA’s commitment to the biosolids program? This data was not collected in this study. 

However, as of 2002, according to the National Research Council (2002), “each of the 10 EPA

Regions have between 0.2 and 2 full-time employees (FTEs), and a total nationwide of 8.8 FTEs, 

working in all areas of biosolids management. The EPA ORD has 2 FTEs devoted to the program, 

and EPA headquarters has 4.8 FTEs.”

Figure 8 – Number of FTEs per million people (graduated color scheme: darkest shading equals

most FTEs)
National Biosolids Regulation, Quality, End Use, and Disposal - 23

Updated regulations

Three states have regulations that have not been updated since the 1980s: Illinois, Missouri, and 

Vermont. Fifteen states adopted updated regulations in the 1990s – almost all after the

promulgation of the federal Part 503 rules in 1993. All other states have been actively updating 

their biosolids regulations over the past six years, a good indication of state commitment to 

regulatory oversight and enforcement (except no data was provided for AZ, ID, and ND). An 

example is South Dakota, which was delegated in 2001; that involved updating state rules to 

reference Part 503.

Nine states have no formal regulations specifically addressing biosolids management (some of these

may have guidelines or other regulations, such as groundwater protection requirements, that are

applied): Alabama, Arkansas, Connecticut, Kansas, Montana, Nebraska, Nevada, New Mexico, and 

Wyoming. Wastewater treatment facilities and biosolids management programs in these states

adhere to the Part 503 rules, which are enforced by USEPA.

Details regarding the updating of each state’s regulations are provided in Appendix B-1.

State regulations more restrictive than Part 503

When asked “are your state’s biosolids regulations more restrictive than the federal Part 503 rule?,”

37 states answered “yes” with regards to management practices, four answered “yes” with regards

to pathogen and/or vector attraction standards, and sixteen answered “yes” with regards to pollutant

limits. Ten states do 

not have state

regulations more

restrictive than Part

503 (Figure 9). 

Figure 9
National Biosolids Regulation, Quality, End Use, and Disposal - 24

Additional details about more stringent state regulatory structures are provided in Appendix B.

More stringent pollutant limits

Tables 7 and 8 show the numerical pollutant (“heavy metal”) limits that have been adopted by those

states that have pollutant standards different than the federal USEPA Part 503 limits. Table 7 shows

the “ceiling” limits (higher numerical limits – no biosolids exceeding these may be applied to land) 

and Table 8 shows the lower (“high quality”) limits. Additional states may have pollutant limits

different from Part 503; a few state coordinators indicated as much, but did not provide details.

Few states have adopted different numerical limits for Cumulative Pollutant Loading Rates (CPLR), 

as compared to Part 503. Those that have are Indiana, Maine, New Hampshire, New York, Illinois, 

Maryland, and Vermont. Even fewer states diverge from Part 503 numerical standards for Annual

Pollutant Loading Rates (APLR); they are Indiana, Kentucky, Maine, and Vermont.

Table 7 – Pollutant ceiling limits for land application of biosolids for those states with limits

different from 40 CFR Part 503

Other indicators of state regulatory activity

Other questions in the survey of state biosolids coordinators addressed a variety of other state

regulatory details, including current, “cutting edge” biosolids land application issues, such as

management of phosphorus and other nutrients. The responses to these questions provide a further 

glimpse of state regulatory involvement in biosolids management and show to what extent states go 

above and beyond Part 503 requirements. See Appendix B for this additional information, 

including:

• State regulation updates

• State mechanisms used to regulate end use / disposal and permitting of land application sites

• Legal liability

• Different Class B biosolids to one site

• Allowing more restrictive local ordinances

• Who must report biosolids data to state?

• State regulatory requirements for testing and reporting

• Additional indicators of state regulatory activity 

• Top 3 pressures on biosolids recycling.

State As Cd Cr Cu Pb Hg Mo Ni Se Zn

Part 503 Table 1 75 85 4300 840 57 75 420 100 7500

Hawaii 20 15 200 1500 300 10 15 100 25 2000

Indiana 75 85 N/A 4300 840 57 75 420 100 7500

Iowa 3000 75

Kentucky TCLP

Maine 41 39 3000 1500 300 10 75 420 100 2800

Maryland 25 1000 1000 10 200 2500

New Hampshire 32 14 1000 1500 300 10 35 200 28 2500

New York 75 85 1000 4300 840 57 75 420 100 7500

Rhode Island 75 85 3000 4300 840 57 75 420 100 7500

Vermont 25 1000 1000 1000 10 200 2500

Washington 75 85 4300 840 57 75 420 100 7500

West Virginia 75 85 3000 4300 840 57 75 420 100 7500
National Biosolids Regulation, Quality, End Use, and Disposal - 25

Table 8 – High quality pollutant limits for land application of biosolids for those states

different from 40 CFR Part 503

* In some states, such as Vermont, older state regulations have not been updated to be consistent with federal

Part 503 standards; in such cases, the more stringent regulatory standards – that of Part 503 – apply.

TRENDS

Is the beneficial use of biosolids increasing?

In 2000, the BioCycle survey of state biosolids programs noted that “out of the 43 states responding, 

20 states answered yes and 22 answered no” to the question “is beneficial use of biosolids

increasing in your state?” In the current survey, the responses to the same question were 19 and 26, 

respectively, out of a total of 45 responses (Figures 10 and 11).

Figure 10 - Is the beneficial

use of biosolids increasing in

your state? Responses of 

state biosolids coordinators in 

2006 and 2000 (Goldstein, 

2000).

 Current 2006 data

 

2000 data

State As Cd Cr Cu Pb Hg Mo Ni Se Zn

EPA Table 3 41 39 1500 300 17 420 36 2800

Hawaii 20 15 200 1500 300 10 15 100 25 2000

Illinois

Indiana 41 39 1500 300 17 75 420 100 2800

Iowa 1000 75 36

Kentucky 10 450 250 50 900

Maine 10 10 1000 1000 300 6 75 200 100 2000

Maryland 12.5 500 500 5 100 1250

Massachusetts 41 14 1000 1000 300 10 10 200 36 2500

New Hampshire 10 10 160 1000 270 7 18 98 18 1780

New York 41 21 1000 1500 300 10 40 200 100 2500

Rhode Island 41 39 1200 840 300 17 75 420 36 2800

Vermont* 25 1000 1000 1000 10 200 2500

Washington 41 39 1500 300 17 75 420 36 2800

West Virginia 20 39 1000 1500 250 10 18 200 36 2800

Is the beneficial use of biosolids increasing in your state?

your
National Biosolids Regulation, Quality, End Use, and Disposal - 26

While the rate of beneficial use of biosolids, in terms of application to soils (see discussion of 

terminology, p. iv), has apparently not increased significantly in recent years, other beneficial uses

of biosolids are likely increasing – although this was not measured by this current survey work. 

For examples, increasing numbers of TWTDS today are... 

utilizing methane from digestors to produce energy;

recovering heat from incinerators;

using biosolids incinerator ash as clean daily cover at landfills, as a soil conditioner, in cement and 

asphalt, and as clean fill material at a variety of locations; and

• piloting recovery of energy from landfilled biosolids (“bioreactor landfills”).

Pressures on biosolids recycling

The online survey of individual TWTDS asked respondents to identify the three most important

pressures on biosolids recycling. Figure 12 is a compilation of the ~250 responses from around the

nation. The #1 priority responses appear in the darkest color; the #3 priority responses appear in the

lightest color.

Figure 11
National Biosolids Regulation, Quality, End Use, and Disposal - 27

Figure 12

State coordinators were also asked to identify the top three pressures on biosolids recycling. Their 

compiled responses appear as Appendix B-10.

Legislative or regulatory activity happening or imminent pertaining to biosolids

State biosolids coordinators were asked to indicate if any state legislative or regulatory activities

that would affect biosolids management were happening or were imminent. Figure 13 displays their 

responses: half of the states

are not experiencing such 

activities.

Figure 13

TRADITION – long-used technologies and practices are hard to change
National Biosolids Regulation, Quality, End Use, and Disposal - 28

Of those states that are experiencing or expecting changes to regulations or statutes, most (14) 

expect the changes to have no affect on beneficial use of biosolids (Figure 14). However, five state

coordinators expect state regulatory changes to reduce the beneficial use of biosolids (applications

to soils), four state coordinators expect local regulations to reduce the beneficial use of biosolids, 

and two expect changes in state statute to reduce beneficial use. Overall, few of the expected 

changes are expected to increase beneficial use (applications to soils).

SEPTAGE MANAGEMENT

The survey of state coordinators also requested information on septage management. In some

states, the biosolids coordinator is involved in the state regulatory program for septage. In others, a

different person was the source of data on septage management.

Overall, in most states, less septage management data is available than biosolids management data. 

This is partly due to the fact that, in many states, septage management is partly or wholly overseen 

by local county or even municipal structures. 

The state-by-state data collected by this survey regarding septage management in the U. S. is

presented in Appendix C.

RECOMMENDATIONS FOR FUTURE STUDIES

The process of collecting and compiling data on biosolids management in the U.S. for this report

underscored the importance of robust state-based data collection and compilation efforts. Those

states with robust electronic biosolids data programs were able provide detailed reports on demand, 

helping make an efficient national compilation of data possible. There are many states, however, 

that do not yet have this capability, and USEPA, while considering expanding its data reporting 

requirements and electronic data compilation systems, is still many years away from establishing 

such a system. 

Figure 14
National Biosolids Regulation, Quality, End Use, and Disposal - 29

Therefore, in the near future (ten years), it is likely that the process used for this study – compilation 

of data obtained from the fifty state biosolids coordinators, various USEPA offices, and individual

large TWTDS – will be necessary. It is a time-consuming and difficult process that yields adequate, 

but not precise, results.

What this study did determine to have considerable potential as a future tool for compiling national

data was the use of an online survey system. The online survey pilot was deemed a success: it was

relatively simple to set up and yielded useful data in a format that is easily manipulated and 

analyzed. A nationwide online survey of individual TWTDS is currently the most promising and 

cost-efficient way to update the most essential data on biosolids management.

CONCLUSIONS

Data collected from state biosolids coordinators, USEPA regional offices, individual wastewater 

treatment facilities, and others present a comprehensive picture of the management of wastewater 

solids in the U. S. for the year 2004. An estimated 55% of wastewater solids were applied to soils –

mostly as Class B biosolids. The remainder was disposed of in landfills and incinerators. The

treatment of biosolids to the Class A level seems to be increasing, accounting for almost 1⁄4 of total

wastewater solids applied to soils in 2004. Many state biosolids regulatory programs continue to 

advance, addressing current new topics (e.g. nutrient management), even as some have reduced the

number of staff hours devoted to their biosolids programs. Overall, current data suggest little

change nationwide, since the late 1990s, in the rate of biosolids recycling to soils (USEPA, 1999), 

and half of state biosolids coordinators report that the amounts of biosolids applied to soils are not

increasing in their states.

REFERENCES

California Association of Sanitation Agencies’ 1999 Biosolids Management Practices Survey in the

State of California.

Chaney, R. L., J. A. Ryan, et al. (1999). Metals. Environmental Availability in Soils. W. C. 

Anderson, R. C. Loehr and B. P. Smith, American Academy of Environmental Engineers: 

112-146.

Elliott, H.A., R.C. Brandt, and J.S. Shortle. 2005. Biosolids Disposal in Pennsylvania: Cost

Comparisons and Policy Considerations. Final Report. Center for Rural Pennsylvania, 

Harrisburg, PA.

Goldstein, Nora, 2000. The state of biosolids in America: The BioCycle nationwide survey. 

BioCycle: Journal of Composting & Organics Recycling, 41: 12, December.

Kinney, C., E. Furlong, S. Zaugg, M. Burkhardt, S. Werner, J. Cahill, and G. Jorgensen. 2006. 

Survey of organic wastewater contaminants in biosolids destined for land application. 

Environ. Sci. & Technol.
National Biosolids Regulation, Quality, End Use, and Disposal - 30

National Association of Clean Water Agencies (NACWA). 2006. Biosolids Management: Options, 

Opportunities & Challenges. Washington, DC.

National Research Council. 2002. Biosolids Applied to Land: Advancing Standards and Practice. 

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organic compounds in land-applied waste. J. Environ. Qual., 34: 29-41.

Stehouwer, R. C. (2000). Testimony prepared for the joint hearing of the PA House Committees on 

Environmental Resources and Energy and Agriculture and Rural Affairs regarding Land 

Application of Biosolids. May 17.

U.S. EPA Office of Inspector General. 2000. Audit Report, Water, Biosolids Management and 

Enforcement (2000-P-10), March 20.

U.S. EPA Office of Inspector General. 2002. Status Report, Land Application of Biosolids (2002-S000004), March 28.

U.S. EPA Office of Wastewater Management. 2000. Summary of State Biosolids Programs, Draft

Report. EPA 832-D-00-002. December.

U.S. EPA Office of Wastewater Management. 2004. A Plain English Guide to the EPA Part 503 

Biosolids Rules. EPA/832/R-93/003. September.

U. S. EPA Office of Solid Waste and Emergency Response, 1999. Biosolids Generation, Use, and 

Disposal In The United States. EPA530-R-99-009. September.

U. S. EPA Office of Wastewater Management, 2006. Clean watersheds needs survey. Online at

http://www.epa.gov/owm/mtb/cwns/index.htm. Retrieved February 6, 2007.