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Michigan Biosolids PFAS-related information and links

Interim Strategy – Land Application of Biosolids Containing PFAS (2024)

The Department of Environment, Great Lakes, and Energy (EGLE) is implementing the following interim strategy/requirements to guide Wastewater Treatment Plants (WWTPs) and landowners/farmers who make decisions on land applying biosolids with detectable concentrations of Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS).  Requirements under the 2024 updated interim strategy are detailed below and apply to all facilities with approved Residuals Management Programs (RMPs) under Michigan’s Part 24 Biosolids Rules.  These requirements are in effect as of January 1, 2024.

2024 Updated Interim Strategy Requirements

Regulated Analytes - Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS)

Two PFAS analytes, PFOA and PFOS, are regulated under the interim biosolids strategy and depending on the concentrations identified of either analyte, may trigger additional actions as identified below.

Industrially Impacted Threshold – PFOS or PFOA at or above 100 micrograms per kilogram (µg/kg)

Biosolids with a PFOS or PFOA concentration of 100 µg/kg or higher are deemed industrially impacted and cannot be land applied.  Additional requirements are as follows:

  • Notify Water Resources Department (WRD) Biosolids Program Staff of PFAS results by submittal via MiEnviro Portal.
  • Arrange for alternative treatment and/or disposal of solids.
  • Sample the biosolids source effluent (within 30 days).
  • Implement a source reduction plan including an investigation of potential sources of PFOS and/or PFOA to the sanitary wastewater and resulting biosolids.

PFOS or PFOA at or above 20 µg/kg

Biosolids with a PFOS or PFOA concentration at or above 20 μg/kg, but below 100 μg/kg, are considered elevated under the updated strategy and trigger the following requirements:

  • Reduced land application rate of 1.5 dry tons per acre (dt/acre) or submittal of an alternative risk mitigation strategy for EGLE approval a minimum 14 days prior to land application.
  • Sampling of the biosolids source effluent (within 30 days).
  • Implement a source reduction plan including an investigation of PFOS and/or PFOA to the sanitary wastewater and resulting biosolids.

PFOS and PFOA below 20 µg/kg

Biosolids with PFOS and PFOA concentrations below 20 µg/kg may be land applied with no additional requirements after submittal of results via MiEnviro Portal and communication of results to the landowner/farmer.

Exceptional Quality (EQ) Biosolids – Additional Requirements

Facilities who wish to obtain and/or maintain the EQ designation for biosolids, must have a combined concentration of PFOS and PFOA below 20 µg/kg under the updated interim strategy.  Compliance with this condition must be demonstrated via quarterly monitoring.   These requirements are in addition to, and do not supersede or replace, in any way, other requirements for EQ designation as defined in the state and federal biosolids regulations.

Monitoring Frequency

All facilities that land apply Class A or Class B biosolids are required to collect one representative sample of the finished biosolids product per calendar year prior to land application.

All facilities with biosolids designated as Exceptional Quality (EQ) are required to collect representative samples of the finished biosolids product on a quarterly basis.

All samples must be submitted to the WRD via the MiEnviro Portal at least two weeks prior to land application.

Landowner and Farmer Communication

Facilities with approved RMPs shall provide the PFOS and PFOA analytical results and additional information specific to PFAS and biosolids in Michigan via hard copy or electronic mail to the landowner and farmer (if different) prior to land application of biosolids.

  • 2024 Example Landowner/Farmer Notification Template (link updated template)

Sampling and Analysis Requirements

Currently, there are no United States Environmental Quality Agency (USEPA)-approved methods for PFAS analysis of sludge and biosolids.  DRAFT EPA Method 1633 (an isotope dilution method) is currently undergoing multi-laboratory validation as part of the federal Clean Water Act method approval process.  When a final PFAS analytical method for wastewater and solids is published in Title 40 of the Code of Federal Regulations (40 CFR), Part 136, Guidelines Establishing Test Procedures for the Analysis of Pollutants, this method shall be required for biosolids sampling conducted under the strategy.

Until there is an approved method, all biosolids PFAS sample results shall at minimum include the 28 analytes previously used on the Michigan PFAS Action Response Team PFAS Minimum Laboratory Analyte List.

Winter Land Application

EGLE requires all facilities with approved RMPs to sample once per calendar year prior to the initial land application of the year.  For some winter land applications, it can be difficult to complete sampling prior to land application when conducted within the first month of the year (January).  If a facility with an approved RMP had a seasonal land application that was intended to be completed by the end of the year (December 31), this application could be completed through January 31 of the following year.  If there is a possibility land application may be extended past January 31, facilities with approved RMPs are required to collect a new biosolids sample for PFAS analysis and submit the results prior to land application.  Requests of land application extensions shall be submitted to the WRD via email.  Decisions regarding winter land application extensions will be based on past biosolids PFAS data, biosolids source effluent data, and any other relevant data.

Note: The implementation of these updated measures is part of an interim strategy to mitigate risk to public health and the environment from potential adverse effects of biosolids containing PFAS.  Notification of these requirements in the updated strategy was made via e-mail to facilities with existing approved RMPs.  These additional requirements are considered a modification to the approved RMP and are made in accordance with provisions outlined within Michigan’s Part 24 Administrative Rules, Land Application of Biosolids, promulgated pursuant to Part 31, Water Resources Protection, of the Natural Resources and environmental Protection Act, 1994 PA 451, as amended (NREPA), specifically Rule 2404(1), and language contained within existing discharge permits.

The following documents further provide additional information on Michigan’s implementation of the Interim Strategy and its requirements:

In early 2018, EGLE’s Water Resources Division (WRD) developed the Industrial Pretreatment Program (IPP) PFAS Initiative Study of 95 municipal Wastewater Treatment Plants (WWTPs) to help identify and systematically reduce and eliminate sources of PFAS (PFOS/PFOA) entering wastewater collection systems.  During this study, some WWTPs were found to have elevated PFAS in their effluent and associated residuals (sludge/biosolids).  Through this study, WRD identified 6 WWTPs with industrially impacted biosolids.  WRD temporarily restricted their land application program until elevated sources of the PFOS were eliminated and residual PFOS concentrations were decreased.

Expanding upon the information collected during the IPP PFAS Initiative, in the fall of 2018, WRD launched a study to evaluate the presence of PFAS in Municipal Wastewater and Associated Residuals.  Through this study, 42 municipal WWTPs were sampled to evaluate the presence of PFAS in influent, effluent, and residuals.  As part of this initiative, 29 land application sites (associated with 10 municipal WWTPs) were evaluated to further understand the potential impact land-applied biosolids has on the environment.  AECOM Technical Services, Inc. (a consulting firm) was contracted by WRD to perform all the sampling in this study. All samples were analyzed for 24 PFAS compounds.

For a summary of the study and initial findings of the IPP PFAS Initiative, see the Summary Report: PFAS in Municipal Wastewater and Associated Residuals (Sludge/Biosolids).  For the complete detailed report covering the IPP PFAS Initiative and the Statewide Study of 42 municipal WWTPs, see Evaluation of PFAS in Influent, Effluent, and Residuals of Wastewater Treatment Plants (WWTPs) in Michigan.

For a summary of the land application site screening results, see Statewide Wastewater Treatment Plant and Biosolids PFAS Study: Field Reports Summary.  See the below attachments for detailed field reports covering the screening results for individual land application sites. Persons with disabilities may request this material in an alternative format by contacting EGLE's ADA Accessibility Coordinator. Please visit for a list of state Coordinators.

Field Report Addendums

To request this material in an alternate format, contact or 800-662-9278.

Additional Biosolids and PFAS information can be located at the following links.