Sewage Sludge Laws and Regulations
On this page:
- How Sludge Sludge is Regulated
- Standards for the Use or Disposal of Sewage Sludge (40 CFR Part 503)
- Process for Regulating Pollutants in Sewage Sludge
- Compliance
- Other Applicable Programs and Regulations
- Additional Information
How Sewage Sludge is Regulated
The Clean Water Act (CWA) of 1972 and its amendments govern water pollution in the United States and are central to U.S. Environmental Protection Agency’s mission to protect public health and the environment. In 1987, the U.S. Congress passed the Water Quality Act, which amended the CWA to require the EPA to establish a comprehensive program to reduce potential environmental risks associated with sewage sludge management and maximize the beneficial reuse of sewage sludge.
As amended, CWA Section 405(d), 33 U.S.C. 1345(d), requires the EPA to:
- Establish numerical limits and management practices that protect public health and the environment from the reasonably anticipated adverse effects of toxic pollutants in sewage sludge.
- Periodically review existing regulations for the purpose of identifying additional toxic pollutants that may be present in sewage sludge and assesses whether those pollutants may adversely affect public health or the environment based on their toxicity, persistence, concentration, mobility, and potential for exposure.
Standards for the Use or Disposal of Sewage Sludge (40 CFR Part 503)
Per the first requirement of CWA section 405(d) which requires the EPA to establish requirements and management practices for the use and disposal of sewage sludge, the EPA issued the regulations found in 40 CFR Part 503 (or "Part 503").
40 CFR Part 503, Standards for the Use or Disposal of Sewage Sludge, regulates sewage sludge that is applied to land, fired in a sewage sludge incinerator or placed on a surface disposal site. The regulation includes pollutant limits, requirements for pathogen and vector attraction reduction, management practices, monitoring, recordkeeping, and reporting among other requirements. 40 CFR Part 503 applies to any person or treatment works that prepares sewage sludge, applies sewage sludge to the land, fires sewage sludge in an incinerator, and the owners and operators of surface disposal sites.
40 CFR Part 503 has been amended several times since the regulation was finalized in 1993. The original regulation, including the preamble to the regulation, is available in the Federal Register. This version does not include the amendments. The current regulation, including the amendments is available in the Code of Federal Regulations.
- Federal Register: Standards for the Use or Disposal of Sewage Sludge; Final Rules (pdf)
- Code of Federal Regulations: 40 CFR Part 503, Standards for the Use or Disposal of Sewage Sludge
The EPA’s A Plain English Guide to the EPA Part 503 Biosolids Rule summarizes 40 CFR Part 503. While the guide is not a substitute for the actual rule, it is consistent with the content of the original Part 503 rule promulgated in 1993 and can be a helpful tool. The guide has not been updated to include amendments to 40 CFR Part 503 after 1994 which include amended pollutant limits, methods, and best practices for pathogen and vector attraction reduction.
Process for Regulating Pollutants in Sewage Sludge
Section 405(d) of the CWA requires the EPA to review sewage sludge regulations at least every two years for the purpose of identifying additional pollutants that may be present in sewage sludge and, if appropriate, to propose practices and standards for those pollutants consistent with the requirements set forth in the CWA.
The presence of a pollutant in sewage sludge alone does not necessarily mean that there is risk to human health or the environment from its use or disposal. The EPA assesses risk to human health and the environment by modeling the fate and transport of a pollutant through the environment to estimate potential exposures and risks, taking into account different environmental conditions and exposure scenarios.
If a final risk assessment indicates that there are risks above acceptable thresholds when using or disposing of sewage sludge, the EPA will engage in the risk management process to consider regulations. During the risk management deliberation process, the results of the final risk assessment may be integrated with other considerations, such as economic costs and treatment feasibility, to reach decisions regarding the need for and practicability of implementing various risk reduction activities.
Compliance
40 CFR Part 503 is a self-implementing rule. This means that the requirements of Part 503 must be met even if a permit has not been issued. An enforcement action can be taken against a person or wastewater treatment plant (WWTP) who does not meet the requirements of Part 503 even when that person or WWTP does not have a permit for the use or disposal of sewage sludge.
Annual Biosolids Reporting
Certain treatment works specified by Part 503 are required to submit an annual report on biosolids treatment and management practices to their permitting authority by February 19 of each year. Additional information is available including annual reporting requirements, frequently asked questions, and training webinars.
- Submit a Biosolids Annual Program Report on the EPA's Central Data Exchange
- Compliance and Annual Biosolids Reporting
Suspected Noncompliance
Please contact the EPA Biosolids Center of Excellence and/or your regional and state biosolids coordinator if you suspect noncompliance at a wastewater treatment plant, sewage sludge incinerator, land application site or surface disposal site.
- Contact EPA Biosolids Center of Excellence ([email protected])
- EPA Regional and State Contacts for Biosolids
Other Applicable Regulations and Programs
The following regulations and programs often overlap with sewage sludge management. This list is not exhaustive and compliance with these few programs does not guarantee compliance with all applicable requirements.
National Pollutant Discharge Elimination System (NPDES)
The NPDES program oversees and regulates the discharge of pollutants into waters of the United States. A NPDES permit translates general requirements of the Clean Water Act into specific provisions for a person or WWTP discharging pollutants into water to protect human health and the environment. Components of the NPDES program include the biosolids program, state NPDES permits, regulation of federal facilities, the pretreatment program, and the general permits program.
States may receive authorization to run one or more of the NPDES program components. To date, the EPA has authorized nine states (Arizona, Idaho, Michigan, Ohio, Oklahoma, South Dakota, Texas, Utah, and Wisconsin) to implement the biosolids program as part of their NPDES program.
- NPDES State Program Authorization Information
- NPDES State Program Authority - Status of State Approval
Pretreatment
The goal of the EPA's National Pretreatment Program is to prevent the introduction of pollutants into publicly owned treatment works (POTWs) which will pass through or interfere with the operation of a POTW, including use and disposal of sewage sludge.
Resource Conservation & Recovery Act (RCRA)
Disposal of sewage sludge in a municipal waste landfill (MSW) is regulated under the Resource Conservation and Recovery Act.
Clean Air Act (CAA)
Part 503 contains requirements for sewage sludge incinerators (SSIs) including stacking monitoring, sewage sludge pollutant concentrations. SSIs must also comply with CAA requirements. The EPA’s requirements regarding emissions from SSIs were updated in 2016.