Minnesota Biosolids & PFAS Updates: Challenges and Solutions


Amid finalized federal drinking water standards for six PFAS (per- and polyfluoroalkyl substances) chemicals, as well as the classification of PFOS and PFOA as hazardous substances under CERCLA (also known as Superfund), state health departments are still considering PFAS regulations for their state’s distinctive PFAS contaminations.

Minnesota, the land of 10,000 lakes, enjoys vast freshwater resources that support its communities and industries. Unfortunately, due to legacy contamination by 3M, Minnesota’s water-rich communities have been exposed to PFAS via their drinking water, fish tissue, and soil for generations. To prevent the spread of this contamination, state regulators are considering laws that minimize PFAS concentrations in wastewater effluent and biosolids.

Understanding PFAS Contamination in Minnesota

The Twin Cities first detected PFAS, a group of synthetic chemicals that have been used in consumer products worldwide since the 1950s, in the early 2000s in its eastern suburbs, or East Metro. The 3M company disposed of PFAS-containing waste in a manner that contaminated 150 square miles of drinking water, surface water, and soil. This discovery led to more than 170,000 people in 14 communities requiring emergency treatment or alternative safe drinking water sources. Additionally, this contamination led to significant levels of PFAS building up in fish tissue in the region, and the Minnesota Department of Health continues to recommend that people not consume fish from several waterbodies.

To fully comprehend the extent of the contamination and its damage to Minnesota’s natural resources and public health, the state created the Minnesota PFAS Blueprint. The comprehensive Blueprint aims to prevent continued PFAS by requiring companies to report PFAS use in their products, managing pollution that exists, and remediating contaminated sites.

Of the many sources of PFAS, wastewater effluent and biosolids have been identified as critical PFAS contamination vectors, sparking interest from governments and advocacy groups to curb land application of biosolids and treat effluent to close the contamination loop. The initial efforts from the Blueprint have funded studies that monitored the PFOS concentration of 31 Minnesota wastewater streams, revealing wastewater effluent concentrations ranging from no detection to 1.51 parts per billion (ppb), and concentrations in sludge ranging from four to 861 ppb.

Sources of PFAS contamination in Minnesota’s wastewater treatment plants

Whether direct or indirect, PFAS finds its way into water, dissolves, and stays indefinitely. The following are likely PFAS pathways to Minnesota’s wastewater plants:

  • Industrial Discharges: Wastewater treatment plants and Minnesota’s water bodies receive effluent from various industrial sources that may contain PFAS, including manufacturing facilities, chemical plants, and textile manufacturers.
  • Consumer Products: PFAS-containing products used in households, such as non-stick cookware, stain-resistant fabrics, and personal care products, contribute to PFAS contamination in domestic wastewater and landfill leachate. Identifying these products as a major source of contamination, Amara’s Law seeks to remove PFAS from each of these products to stop contamination at the source.
  • Legacy Contamination: Historical use of PFAS-containing firefighting foams and industrial processes has led to accumulated soil and groundwater contamination, with stormwater runoff entering sewer lines and contaminating wastewater treatment plants. 3M’s long-term use of PFAS has also created legacy contamination in Minnesota.
  • Biosolids & Sludge: Coming full circle, PFAS can end up in biosolids during the wastewater treatment process and potentially cause environmental contamination after its disposal and land application. Runoff from these lands can contribute PFAS to local water bodies, creating a contamination cycle.

New laws are being considered and passed by Minnesota regulators to address each of these sources. The implications for wastewater treatment plants could be significant.

Minnesota’s Wastewater Regulations

Historically, the Minnesota Pollution Control Agency (MPCA) encouraged the application of biosolids from wastewater treatment to return nutrient-rich organic matter to the soil. This practice reduced landfill loading and agriculture’s dependance on fertilizers. However, it has since been found that there is PFAS present in sludge, creating an unforeseen problem with this application.

Due to this practice and others, the potential cost of remediating PFAS from soil and groundwater is significant. A 2023 MPCA report found that costs to remove and destroy PFAS from municipal wastewater will range between $2.7 million and $18 million per pound, with an estimated cost to remove PFAS from wastewater streams statewide at $14 billion to $28 billion over the next two decades.

There is a desire to develop screening levels and tools to determine where land-applying biosolids is a safe and responsible practice. However, testing on three streams in the St. Cloud area, where the use of biosolids on farm fields is widespread, found considerably higher PFAS levels than rivers in areas where biosolids were not applied, leading advocacy groups to recommend ceasing biosolids land application and including PFAS as a pollutant in Minnesota biosolid regulations such as the Sewage Sludge Management Rule.

Because of the financial implications on the state and its treatment plants, Minnesota has passed legislation in the past few years to fund PFAS testing, deter the use of PFAS in consumer products, and ultimately ban its use.

Amara Strande, an advocate for stricter regulations on forever chemicals, died of cancer at the age of 20 due to suspected PFAS exposure. Her efforts led the state legislature to pass Amara’s Law, which prohibits manufacturers from intentionally adding PFAS to a wide range of products, including cleaning products, children’s products, cosmetics, cookware, textile furnishings, and several others starting in 2025. In addition, Minnesota now requires that any use of class B firefighting foam containing PFAS be reported to the state. The use of PFAS-containing foam for testing and training is generally prohibited.

Innovative Approaches by the Minnesota Pollution Control Agency (MPCA)

On February 20, 2018, the state of Minnesota settled its lawsuit against 3M in return for an $850 million settlement. About $720 million of this settlement will be invested in drinking water and natural resource projects in the Twin Cities’ East Metro. With the funds gained from the settlement, Minnesota is leading the nation in piloting water treatment solutions, evaluating treatment technologies, and funding PFAS testing to determine the size of its contamination.

In 2022, MPCA purchased a mobile PFAS removal and destruction technology pilot. The pilot uses foam fractionation and a PFAS destruction technology called DEFLUORO to collect and destroy PFAS in heavily affected communities. Minnesota is the first state government in the country to purchase and implement a program like this. The 3M settlement monies will also be used to fund granular activated carbon treatment trains at water treatment plants in East Metro per the Conceptual Drinking Water Plan to prevent further PFAS exposure in the area.

With the help of national consulting firms, MCPA is also conducting thorough evaluations of technology effectiveness and costs for PFAS removal and destruction from wastewater, biosolids, and landfill leachate. Extensive feasibility studies like these are creating resources that can be used nationally for PFAS removal decision-making from effluent and biosolids.

The most sweeping bill that MCPA has introduced is the Minnesota PFAS Blueprint. The Blueprint sets rules and puts funding in place to accomplish:

  • Requiring Companies Disclose Information on PFAS Use
  • Pilot Projects to Fill Knowledge Gaps
  • Establishes Two-year Funding to Understanding PFAS in Wastewater
  • Landfill Leachate and Biosolids PFAS Impact Studies
  • Set Fish Tissue PFOS Values of 0.37 parts per trillion for Lake Elmo, MN

Each of these initiatives depends on testing and treatment to meet the health goals MCPA and the federal government set.

Strategies for PFAS Testing and Treatment

With the 3M settlement funds, Minnesota wastewater systems can use EPA Methods 1633 and 8327 to test for PFAS in wastewater effluent and biosolids to grasp their PFAS contamination level. Identifying PFAS sources, prioritizing sampling sites, and communicating with residents and businesses in the community can help a utility manage PFAS contamination and make a case against big-name polluters.

In addition to considering mitigation and treatment options on-site, multi-utility teams can communicate PFAS’ presence in local drinking water supplies and what’s being done together, presenting a united front against this pervasive emerging contaminant. Mitigation plans can include dual funding strategies to ease treatment cost burdens and meet current and future wastewater and drinking water compliance standards.

While most wastewater systems are not designed to remove PFAS, there are PFAS solutions available that can be placed within existing treatment trains. Technologies proven to remove or destroy PFAS include:

  • Granular Activated Carbon (GAC)
  • Ion Exchange (IX)
  • Reverse Osmosis (RO)

There are also many upcoming technologies being developed to destroy, absorb, and decay PFAS in water.

Looking Ahead at Minnesota’s Regulatory Landscape

Minnesota PFAS regulations may affect wastewater treatment plant permits sooner than expected. As MPCA collects data on PFAS in effluent and biosolids while EPA’s drinking water maximum contaminant limits (MCLs) and CERCLA designation of PFOA and PFOS as hazardous substances take effect, point source dischargers may be held responsible for removing PFAS from the environment, even if they do not produce these chemicals.  

The energy-intensive technologies that remove PFAS from water and biosolids typically require significant capital and operational expenses. Potential state and federal biosolids regulations could also contribute to the cost of operating a wastewater plant and/or biosolids disposal, which may result in higher utility rates and public distrust.

Fortunately, in preparation for the EPA’s drinking water MCLs, water providers across the country have led the way in recovering costs related to PFAS treatment. Many have followed in the footsteps of the state of Minnesota and successfully taken PFAS manufacturers like 3M to court to hold them accountable for the contamination they are responsible for and secured funding to cover PFAS treatment costs. Using the funds obtained through litigation, Minnesota wastewater treatment plants can begin to test for and identify PFAS sources to take big-name PFAS manufacturers to court with the hope of meeting future regulatory compliance without burdening their ratepayers.

Wastewater Cost Recovery Options in Minnesota

While Minnesota is dealing with significant PFAS challenges, the steps taken by the state and individual utilities are helping to manage and reduce contamination. Many different tools and strategies will be required to handle PFAS comprehensively, and they will all come at a cost. New regulations at the state and federal levels may require utilities to spend millions per year on the design and building of new treatment facilities, operational costs, and ongoing monitoring to maintain compliance.

By taking a proactive approach, your utility can sufficiently prepare for CERCLA and the potential liability to follow. Water contamination litigation enables you to seek to hold manufacturers accountable for pollution while protecting your utility's standing as merely a passive recipient. If you have questions about your system's PFAS situation and the cost recovery options available, read our Wastewater Cost Recovery Guide. We are here to help every step of the way.