An official website of the United States government.


A Guide to the Biosolids Risk Assessments for the EPA Part 503 Rule

40 CFR Part 503 was developed as a comprehensive risk-based rule to protect the public health and the environment from reasonably anticipated adverse effects of pollutants that may be present in biosolids (sewage sludge). This guide provides an understanding of the multi-pathway risk assessment that was used for evaluating and setting limits to manage pollutants in biosolids. 

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.