May 2025 - Sally Brown Research Library & Commentary

Important Update for MABA Members:
Results from the 2nd National Survey of Biosolids Regulation, Quality, End Use and Disposal in the U.S.

The National Biosolids Data Project (NBDP) has been recently unveiled. You are invited to its comprehensive, user-friendly, data-rich website: http://biosolidsdata.org.  This website provides both a national overview of biosolids generation and utilization/disposal in the target year 2018, but, importantly and most usefully for practitioners in the mid-Atlantic region, the NBDP also includes state summary reports.  Your MABA staff and volunteers are assembling a webpage which will allow quick access to the state reports in our region. 

This NBDP data site was prepared over a two-year period. It was accomplished on a shoe-string budget of about $60,000, with a small EPA grant and some financial contributions from WEF, NACWA and public agencies, and with many hours of volunteer time. The focus  is comprehensive, with details on technologies, particularly the distinction of Class A and Class B levels of pathogen treatment, with categories of utilization outlets and products (compost versus pellets), with capture of landfill and incineration disposal, and with an overview of each state’s regulations. 

A key feature of the project was the survey of water resource recovery facilities (WRRFs), generators of biosolids.  The survey had 452 valid and representative responses from WRRFs in 43 states and DC. This is a set that comprises a flow of about 12,000 MGD, or 34% of total municipal effluent flows in the United States. When generously supplied by public agencies, surveys provided in addition to mass of biosolids and uses, information on pollutant concentrations, program costs and points of view on hurdles and barriers. In a few cases, the surveys of state officials were able to elicit information on septage management.  The EPA biosolids records for 2018 in ECHO (Enforcement and Compliance History Online) was also brought into the analysis. 

Every effort was made to provide comparable data across all states, but this goal was elusive. In the end, the data reports of 32 states were judged of high confidence, 12 were of moderate confidence and 4 of low confidence.  Every state office responsible for biosolids management was afforded an opportunity to review and correct its state’s data and description.  

While this richly compiled database might clearly have commercial value, the results are freely available and are intended to aid in the transparency of biosolids programs to the public. 

Ned Beecher, for 20 years executive director of NEBRA and then special projects coordinator for the early PFAS response,  is the principal investigator for this “second” survey. He was the principal designer of the two surveys (one for state officials and the other for public agencies) and of the database, though with much feedback along the way, Ned had been also the leader of the first survey, which was released fifteen years ago, July 2007, based on biosolids generation and use in 2004, which explains in part the ambitious goals of the current survey. 

Many biosolids practitioners over the years had come to rely on this first survey. It was clear to all who used it recently that the first survey had become dated. Ned took on this herculean project, and now with its completion, we can give hearty kudos to Ned for his vision and persistence. Today you will note from Ned’s email communications that he is now the “former” special project manager for NEBRA and available for hire.  But updates to the second survey, whether to correct or amplify it, or to change it to reflect new developments, will need to be shouldered by others, and we await these folks to emerge and step forward. 

The survey year of 2018 may have the feel of “historical” today. But, at the opening of the project in mid-2020, this was the year most likely to be complete in its data set from federal, state, and municipal sources. The project was intended to be completed by Spring 2021, but whether a victim of pandemic staffing challenges or from competing issues for biosolids practitioners, data collection for this new survey was a slog.  In the mid-Atlantic region, the year 2018 had an atypical influence of large rainfall volumes, and in the Northeast region the discovery of perfluoroalkyl substances disrupted programs. 

Here is the big reveal!  Total biosolids used or disposed of in the U. S. in 2018 was 5,823,000 dry metric tons (dmt). This compares to 6,132,000 dmt reported in the 2004 survey.  This decline in total biosolids was a surprise to the NBDP team. The decline may reflect less double counting than in 2004 of solids hauled from small to larger plants for treatment, or in some locations it may reflect a shift from alkaline stabilization to digestion, the latter technology reducing total dry solids. The 2018 database involved fewer estimations, particularly of biosolids production at small WRRFs. With the estimation in this second survey of the sewered population served, the total national average per capita production of biosolids annually is 37 pounds. That agencies and states show a wide range around this average suggests other aspects at play, perhaps the proportion of combined sewer systems and the acceptance of septage from unsewered areas. 

Here is the second big reveal.  Fifty-three percent of biosolids produced in the United States in 2018 were beneficially used. Within this number are some important findings.  More Class A EQ biosolids are being produced in 2018 than in 2004. Despite policies for organics diversion from municipal waste landfills in some states and regions, the same percentage of biosolids are commingled with municipal waste in 2018 as in 2004.  The percentage of biosolids fed to incinerators has declined, with a fewer number of sewage sludge incinerators in operation.  The survey showed, too, decreased full time equivalent (FTE) employees regulating biosolids at state and federal agencies.  As our industry has asserted in the past, the proportion of our nation's croplands receiving biosolids as a nutrient source is very small, less than 1%.

The Mid Atlantic Biosolids Association participated in the NBDP project. It reviewed electronic record reports to the EPA and state environmental agencies, and also surveyed state officials and larger public agencies.  In the work covering the 7 states and one district in this region, the NBPD documented that the over 1,800 significant POTWs serve 50 million “sewered” customers, producing 1.3 million dry tons of biosolids annually. Sixteen WRRFs in the region produce over 10,000 dmt. NYCDEP is largest agency (~100,000 dmt), and in descending order are Philadelphia Water Department, DC Water, Passaic Valley Water Commission, Middlesex County Utility Authority, Baltimore Department of Public Works, ALCOSAN (Allegheny County, PA), Hampton Roads Sanitation District (VA), City of Rochester (NY), DELCORA, Bergen County Utility Authority (NJ), Suffolk County (NY), Arlington County (VA), Nassau County (NY), and Fairfax County (VA). The average per capita annual biosolids production in the MABA region is 54 dry pounds.

The NBDP state reports include narratives describing notable facilities and programs that serve to treat and use biosolids. In the MABA region report are these distinctive points. Composting is a major treatment technology in the region (e.g., Burlington Co, Rockland Co, Baltimore, A&M Composting, Natural Soils, Spotsylvania (VA) and many small facilities). Two new, large compost facilities under development in reach of Philadelphia.  DELCORA and ALCOSAN are large utilities with sludge Incinerators; others in NY (Rochester), NJ (ACUA) and VA have upgraded to meet new MACT standards.  The US’s principal service companies, Synagro and Denali, have main offices in the MABA region and serve hundreds of agency clients NYC is the sole large facility in the US without a pathway to Class A EQ products. PVSC is the exclusive example of a long-tested Zimpro wet oxidation solids treatment, and this agency accepts solids from dozens of agencies.  Co-digestion with high strength organic waste has great reference facilities in the MABA region (Rahway Valley SA, Lehigh County Authority, and Hermitage, PA). Landis Sewerage Authority in Vineland NJ is arguably the “greenest” WRRF, with zero effluent discharge and wholly onsite biosolids use.

The narrative also sets the stage for understanding how Pennsylvania, producer of significant biosolids, is also a destination for biosolids from other states. The nature of Pennsylvania’s “accommodative” regulation of biosolids, and similarly restrictive rules in New Jersey, Delaware, and Maryland, ensures that the transport of biosolids regionally and in the direction of Pennsylvania is a significant part of the story of biosolids management regionally. This role is only indirectly revealed in the NBDP. That is because the survey was structured to discuss for each state the mass of biosolids production and the utilization outlets for those state-generated biosolids.  

Though the NBDP is the latest information source available to us biosolids practitioners, in a way it is already outdated. Since the 2018 target year for data collection, pressures on two major categories, landfill disposal and land application, have increased.  Important issue areas of PFAS contamination worries, risks of new regulations of soil phosphorus, and the experience of inadequate seasonal storage have underscored the challenges of maintaining farmland for biosolids applications.  But landfill owners have tightened access by biosolids generators to municipal landfills. This is not only a challenge to Pennsylvania agencies, but more widely to agencies in adjoining states in the mid-Atlantic, which have been reliant on Pennsylvania destinations.  

The other side of this “challenges” coin with biosolids in the MABA region is the opportunities for development of merchant facilities and innovative technologies. These include existing innovative facilities, such as  regional composting (A&M Composting, Burlington Co-Composting and Rockland County Composting), thermal hydrolysis combined with mesophilic digestion (DC Water and HRSD), co-digestion plants (e.g., Hermitage Food Waste to Energy Facility) and drying processes (Synagro in Philadelphia and Baltimore).  Indeed, the MABA region is a landing place for emerging thermal biosolids solutions, such as pyrolysis (BioForceTech), hydrothermal carbonization (SOMAX Bioenergy ), PA and gasification (EarthCare, EcoRemedy and Aries Clean Energy) --  solutions that seem to be particularly urgent in this time of PFAS.

The National Biosolids Data Project demonstrates that the mid-Atlantic region, responsible for nearly a quarter of the nation’s biosolids generation. It is your foundation for understanding future opportunities for biosolids management. Go use it: http://biosolidsdata.org. And, we who helped to assemble the database also will welcome corrections and updates as you find them worthwhile for keeping the information current and accurate, and you can do so by contacting Mary Firestone at  [email protected].