A	United States	officeofwater
JB.CPA Environmental Protection	epaszz-f-is-ooi
Agency	March2015
2011 Biosolids Biennial Review
Summary
EPA has published online its 2011 biennial review of
information to evaluate potential harm to human
health or the environment from use or disposal of
sewage sludge, also called biosolids. In 1993, EPA
established comprehensive, health-based numeric
standards for 10 metals and operational standards
for microbial organisms to address different uses
and disposal of sewage sludge. EPA reviews sewage
sludge regulations every two years to identify
additional toxic pollutants and sets regulations for
those pollutants if sufficient scientific evidence
shows they may harm human health or the
environment. At this time, EPA has not identified
additional toxic pollutants in biosolids for regulation
under Clean Water Act section 405(d)(2)(C).
Background
The purpose of the biennial reviews EPA conducts is
to identify, where possible, additional toxic
pollutants and promulgate regulations for those
pollutants consistent with the requirements set forth
in the Clean Water Act. In fulfilling this commitment
for Biennial Review Cycles 2005, 2007, 2009, and
2011, EPA conducted a review of publicly available
information. The Agency searched known databases
and the published literature to capture available
information on occurrence, fate and transport and
human health or ecological effects, as well as other
relevant information, for pollutants that may occur
in U.S. sewage sludge. The available exposure or
toxicity data are not sufficient at this time for many
of the pollutants for EPA to run current biosolids
models and conduct risk assessments. We will
continue these investigations subject to availability
of resources and overall program priorities.
Standards for the Use of Disposal of Sewage Sludge
Under Clean Water Act section 405(d), EPA
establishes numeric limits and management
practices that protect public health and the
environment from the reasonably anticipated
adverse effects of chemical and microbial pollutants
in sewage sludge. In 1993, EPA promulgated
Standards for the Use or Disposal of Sewage Sludge
(found in Code of Federal Regulations (CFR) Title 40
Part 503), resulting in numeric standards for 10
metals and operational standards for microbial
organisms. The 1993 rule established requirements
for the final use or disposal of sewage sludge when it
is: (1) applied to land as a fertilizer or soil
amendment; (2) placed in a surface disposal site,
including sewage sludge-only landfills; or (3)
incinerated.
These requirements apply to publicly and privately
owned treatment works that generate or treat
domestic sewage sludge and to anyone who uses or
disposes of sewage sludge.
EPA Reviews of the "Part 503" Standards
Since promulgation of 40 CFR 503, there have been
three subsequent rounds of review: (1) the Agency's
decision in 2001 that regulation of dioxin and dioxin-
like compounds disposed via incineration or land-
filling was not needed for adequate protection of
public health and the environment; (2) the Agency's
decision in 2003 that regulation of dioxin and dioxin-
like compounds in land-applied sewage sludge was
not needed for adequate protection of public health
and the environment (Federal Register Volume 68,
Issue 206, Page 61084); and (3) a review that
resulted in the ongoing analysis of nine pollutants
and molybdenum. By late 2015, EPA expects to
complete evaluation of these 10 pollutants using

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available data and the Targeted National Sewage
Sludge Survey (TNSSS) results prior to taking action
or determining whether to propose regulating any of
these pollutants under Clean Water Act section
405(d). See EPA's TNSSS Technical Report on our
biosolids website at:
http://water.epa.gov/scitech/wastetech/biosolids/in
dex.cfm#tnsss
2011 Biennial Review
In conducting the biennial review for 2011, EPA
collected publicly available information on
pollutants. The purpose of reviewing information on
pollutants, or potential pollutants, is to assess the
availability and sufficiency of the data to conduct
exposure and hazard assessments. Exposure and
hazard assessments, where sufficient data exist,
allow the Agency to determine the potential for
harm to public health or the environment following
use or disposal of biosolids. Some of the information
generally needed to conduct exposure and hazard
assessment includes the ability to detect and
quantify a given pollutant in sewage sludge,
concentration data in sewage sludge, fate and
transport data for pollutants that may be present in
sewage sludge, chemical and physical properties,
and toxicity to human and ecological receptors. The
Agency assessed whether data for pollutants were
sufficient to conduct human health and ecological
exposure and hazard assessments.
Results of the Literature Search
The Agency's search of the literature for Biennial
Review 2011 identified information for 23 pollutants
relevant to human health or ecological assessments.
Some pollutants have been reported in previous
biennial reviews. EPA revisits previously evaluated
pollutants when literature searches of bibliographic
databases reveal newer data. Two main criteria were
established for selecting a pollutant for an exposure
and hazard evaluation if relevant exposure data are
available: 1) the pollutant has human health or
ecological toxicity values (e.g., studies that are
adequate for evaluating hazards following acute or
chronic exposure) and (2) the data on pollutant
concentrations in U.S. sewage sludge are adequate
(i.e., data are considered adequate when sufficient
details are provided regarding sampling, handling,
and analysis) based on a suitable analytical
methodology for detecting and quantifying pollutant
concentrations.
As its first priority, EPA is in the process of evaluating
10 of the chemicals that were previously found in
EPA's TNSSS and thus have source concentration
data ((i.e., barium, beryllium, manganese,
molybdenum, silver, 4-chloroaniline, fluoranthene,
pyrene, nitrate, and nitrite). On a longer term basis,
EPA will continue evaluating the other 135 chemicals
found in the TNSSS, investigating alternative tools
for estimating missing data (e.g., environmental
properties, human health and ecotoxicity values, and
acceptable concentration data in sewage sludge),
and performing screening-level deterministic
assessments to estimate human health and
ecological risk for biosolids land application
scenarios.
The Agency will continue to assess the availability of
sufficient information for these and other pollutants
identified during the biennial review activities
pursuant to Clean Water Act section 405(d)(2)(C).
Where can I find more information?
To get more information about EPA's Biosolids
Program, please contact Rick Stevens at (202) 566-
1135 or email him at stevens.rick@epa.gov. You may
also visit EPA's Biosolids website at:
http://water.epa.gov/scitech/wastetech/biosolids/
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