Biosolids Laws and Regulations

Rule Summary

The Clean Water Act (CWA) of 1972 (the Law or Statute), as amended, has been the primary Federal Law in the U.S. governing water pollution and has been central to our country’s endeavors to improve the quality of the environment. A PDF of the CWA from the U.S. Senate, as well as a summary, are available.

Section 405 (found starting on page 205 of the referenced PDF of the CWA) sets the framework for sewage sludge (biosolids) regulations and in 1993 brought the management of residuals from the wastewater treatment processes under the National Pollutant Discharge Elimination System permit program and the Part 503 Standards for the Use or Disposal of Sewage Sludge.

40 CFR Part 503 (the Rule or Regulation), Standards for the Use or Disposal of Sewage Sludge, establishes standards, which consist of general requirements, pollutant limits, management practices, and operational standards, for the final use or disposal of sewage sludge generated during the treatment of domestic sewage in a treatment works. Standards are included for sewage sludge applied to the land, placed on a surface disposal site, or fired in a sewage sludge incinerator. Also included are pathogen and alternative vector attraction reduction requirements for sewage sludge applied to the land or placed on a surface disposal site.

In addition, the standards include the frequency of monitoring and recordkeeping requirements when sewage sludge is applied to the land, placed on a surface disposal site, or fired in a sewage sludge incinerator. Also included are reporting requirements for Class I sludge management facilities, publicly owned treatment works (POTWs) with a design flow rate equal to or greater than one million gallons per day, and POTWs that serve 10,000 people or more.

This rule applies to any person who prepares sewage sludge, applies sewage sludge to the land, or fires sewage sludge in a sewage sludge incinerator and to the owner/operator of a surface disposal site, as well as the exit gas from a sewage sludge incinerator stack.

Additional Resources

Policy and Regulatory

You may find additional biosolids policy and regulatory information elsewhere on this website.


EPA's National Pretreatment Program identifies specific requirements that apply to Industrial Users (IUs) or nondomestic sources of wastewater to a Publicly Owned Treatment Works (POTW), additional requirements that apply to all Significant Industrial Users (SIUs), and certain requirements that only apply to Categorical Industrial Users (CIUs). Publicly owned treatment works (POTWs) collect wastewater from homes, commercial buildings, and industrial facilities and transport it via a series of pipes, known as a collection system, to the treatment plant. Here, the POTW removes harmful organisms and other contaminants from the sewage so it can be discharged safely into the receiving stream. Additional information may be found on EPA's pretreatment website.


If you are a publicly owned treatment works that meets the applicability requirements and your sewage sludge is land applied, surface disposed, or you operate a sewage sludge incinerator, you will need to submit an annual report by February 19 of each year covering the previous year. Information is available that includes a sewage sludge annual report review guide, frequently asked questions regarding annual reporting requirements persuant to Part 503, and a guide for preparers on monitoring, record keeping, and reporting requirements of Part 503.