The National Biosolids Data Project, led by the North East Biosolids & Residuals Association (NEBRA) has concluded and now the national data and reports are available at www.biosolidsdata.org. Previously only state-level data was available.

The new data provides details about biosolids management in the United States. The NBDP estimates that, in a typical recent year, the U.S. uses or disposes of 5,823,000 dry metric tons of biosolids. More than half (53%) are treated and recycled to soils as biosolids fertilizers and soil amendments. The other 47% are placed in landfills or incinerated.

The new data and supporting information are available online at a new website created for the project: https://www.biosolidsdata.org.

The NBDP data, compiled from one representative year, 2018, is comparable to data from 2004 that was published by NEBRA et al. in 2007.  The new data reveal that the rate of biosolids recycling has increased about 4% from the 2004 rate of 49%.  And today, more of the highly treated “Class A” biosolids are being used. They account for 27% of biosolids used or disposed in 2018, a 5% higher rate than in 2004. In contrast, the rate of Class B biosolids use has declined by 5%.  Class B biosolids have had less treatment and require more specialized management at permitted sites such as farm fields.  The NBDP attempted to collect similar end use information on septage but, as in 2004, there’s still not a lot of information on the amount and destination of septage residuals, some of which undoubtedly ends up in the solids leaving water resource recovery facilities (WRRFs) and accounted for in this study.

Notably, the new data shows not many other big changes from 2004 to 2018. “That’s somewhat of a surprise to us,” notes Janine Burke-Wells, Executive Director of NEBRA. “Over the past 15 years, there have been large advances and investments in how biosolids are treated and managed. Yet the overall numbers don’t show that. You have to look into the details to see all the improvements.”

In addition to NEBRA, the data project team included sister organizations: California Association of Sanitation Agencies, Northwest Biosolids, and the Mid-Atlantic Biosolids Association, as well as Biocycle.  Initial funding for a literature review and development of the survey tools came from the U.S. Environmental Protection Agency (EPA) Region 4.  Subsequent funding came from the National Association of Clean Water Agencies (NACWA), the Water Environment Federation (WEF) and large public utilities, consulting firms, and biosolids management companies around the nation.

The new biosolids data come from more than two years of surveys, interviews, and data compilation and analysis. For each state and larger U. S. territories, the NBDP provides a summary of how much biosolids each state used or disposed of, how it was managed, and where it went. Each state’s story is told in data tables and a narrative summary. The project also presents nationwide totals. 

Some details of the nationwide biosolids story include:

·       About 1/2 of WRRFs report that biosolids are managed by WRRF staff, while the other half have contracted haulers and land appliers. (Biosolids is important business for some specialized companies.)

·       When biosolids are applied to soils, they are used mostly for corn for animal feed and energy, followed by hay/grass/forage.  Other popular crops for biosolids fertilization are wheat and other grains, followed by Class A EQ products widely used on turfgrass (lawns, erosion control, golf courses, landscaping).

·       When identifying the greatest pressures on biosolids management in 2018, WRRFs showed most concern about rising costs and future outlets for biosolids. State biosolids regulators and WRRFs said that public involvement, contaminants, and the hassles of recycling – including declining nearby farmland – were significant pressures.

·       Most state regulatory agencies have significantly fewer resources dedicated to biosolids oversight in 2018 compared to 2004.

The new NBDP data includes the largest-ever data set looking at economic aspects of biosolids management. For example, surveys of WRRF biosolids programs show that the range of the average costs to have a contractor take and manage solids is ~$49 per wet ton for composting, to ~$58.25 for landfill disposal, to ~$62 for land application, to more than $95 for incineration.

NBDP chose 2018 as the data year for this nationwide compilation because 2018 is representative of biosolids management in the late 2010s and early 2020s, after new EPA sewage sludge incinerator (SSI) regulations took full effect in 2016 and before changes to biosolids management which has been caused by concerns about traces of chemicals in biosolids, such as perfluorinated compounds commonly called “PFAS.” 

“This new data provides us with a solid new baseline that biosolids professionals, researchers, and policy-makers can rely on for many years,” noted Burke-Wells “Biosolids have to be managed, and every community has to support its WRRFs. Many are striving for greater sustainability by using biosolids for renewable energy and recycling them to soils.”