United States
Environmental Protection
\r ^1	Agency
Office of Water
EPA-822F21003
February 2021
Biosolids Biennial Report N-8 (Reporting Period
2018-2019)
Summary
The Clean Water Act (CWA) requires EPA to review
federal biosolids (sewage sludge) standards every
two years to identify additional toxic pollutants that
occur in biosolids and then set regulations for those
pollutants if sufficient scientific evidence shows they
may harm human health or the environment. The
biennial review process is intended to fulfil the CWA
requirement to identify additional pollutants that
occur in biosolids. EPA has now published a report
on the 2018-2019 review period.
Background
EPA collected and reviewed publicly available
information for (1) pollutants in biosolids that were
newly identified during the literature search
timeframe (2018-2019) for Biennial Report N-8; and
(2) pollutants in biosolids that were previously
identified in EPA national sewage sludge surveys
conducted in 1988, 2001, and 2009 and/or in
previous biennial reviews. Information was collected
on the occurrence, fate and transport of these
pollutants in the environment and their effects on
human health and ecological receptors. The types of
information collected are needed to conduct risk
assessments.
Results of the 2018-2019 Biennial Review
As a result of the literature search, EPA found 18
new articles that provide relevant data on chemical
pollutants that may occur in U.S. biosolids. The
articles identified 116 new chemicals in biosolids: 50
polychlorinated biphenyls (PCBs) (39 congeners, 10
homologs and total PCBs); four pesticides; 19 flame
retardants; eight perfluoroalkyl substances (PFAS);
three antibiotics; one metal; two inorganics; and 29
other organics. The articles also identified new data
for 48 chemicals that were previously identified in
biosolids. Concentration data for biosolids were
found for 61 of the 116 new chemicals and for 34
chemicals identified in previous biennial reviews.
EPA searched additional data sources for data
needed for risk assessment. Human health toxicity
values were found in multiple sources for four of
the new chemicals and 112 previously identified
chemicals. Ecological toxicity data were found for 63
newly identified chemicals and 71 previously
identified chemicals in the ECOTOX database.
Additional ecological toxicity data were found for 99
of the newly identified chemicals in the Estimation
Programs Interface (EPI) Suite™ (U.S. EPA 2017).
Physical-chemical properties were identified for 102
new chemicals and five previously identified
chemicals. Bioconcentration or bioaccumulation
factors were identified for one new chemical in the
literature; for 99 new chemicals in EPI Suite; and for
40 new chemicals in peer-reviewed databases
maintained by Arnot and Gobas (2006), Environment
and Climate Change Canada (2006), and Oak Ridge
National Laboratory (2020).
Two articles identified five new microbial pollutants
in biosolids and data for five previously identified
microbial pollutants found in biosolids.
Where can I find more information?
To view Biennial Report N28 for the reporting period
2018-2019 and get more information about EPA's
Biosolids Program, visit EPA's Biosolids website:
https://www.epa.gov/biosolids.

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