Biennial Reviews of Sewage Sludge Standards

Section 405 of the Clean Water Act (CWA) requires the EPA to:

• (1) identify those toxic pollutants which, on the basis of available information on their toxicity, persistence, concentration, mobility, or potential for exposure, may be present in sewage sludge in concentrations which may adversely affect public health or the environment, and propose regulations specifying acceptable management practices for sewage sludge containing each such toxic pollutant and establishing numerical limitations for each such pollutant and;
• (2) from time to time, but not less often than every 2 years, review the regulations for the purpose of identifying additional toxic pollutants.

The regulation, “The Standards for the Use or Disposal of Sewage Sludge,” was published on February 19, 1993, in 40 CFR part 503 (often referred to as “Part 503”), fulfilling the first CWA requirement. The biennial review process is intended to help fulfill the second CWA requirement by identifying additional pollutants that occur in biosolids and compiling data that may be used to assess risk. 

A biennial report alone does not result in adding regulated pollutants in sewage sludge under 40 CFR part 503. The biennial review assists in meeting the CWA requirement to identify additional pollutants in biosolids and compiles data that may be used to assess risk. Not all of pollutants that have been found in biosolids will be present in every wastewater treatment facility. Pollutants found in biosolids will vary depending upon inputs to individual wastewater treatment facilities over time. The presence of a pollutant in biosolids alone does not mean that the biosolids pose harm to human health and the environment. Pollutants found in biosolids must be assessed for risk to human health and the environment. For more information refer to EPA’s process for assessing risk from pollutants found in biosolids. 

Biennial Reviews:

• Biennial Report No. 9 (Reporting Period 2020-2021) and Fact Sheet
• Biennial Report No. 8 (Reporting Period 2018-2019) and Fact Sheet
• Biennial Report No. 7 (Reporting Period 2016–2017) and Fact Sheet
• Biennial Report No. 6 (Reporting Period 2014–2015) and Fact Sheet
• Biennial Report No. 5 (Reporting Period 2012–2013) and Fact Sheet
• Biennial Report No. 4 (Reporting Period 2010–2011) and Fact Sheet
• Biennial Report No. 3 (Reporting Period 2008–2009)
• Biennial Report No. 2 (Reporting Period 2006–2007)
• Biennial Report No. 1 (Reporting Period 2004–2005)