Contaminants of Emerging Concern (CEC) Initiative
Clean Water Fund

MDH’s CEC Initiative prioritizes chemicals that have been found or are likely to be found in Minnesota drinking water and have little or no information available about human health risk. The CEC Initiative allows MDH to take a proactive approach to the protection of drinking water by considering contaminants that:

• have been found in groundwater, surface water, or soil; or
• have not been found in Minnesota but have the potential to enter our waters.

The work of this initiative helps MDH understand the potential health effects of these contaminants. Because pollutants have no boundaries and preventing chemicals from getting into our drinking water can't be done by state agencies alone, the CEC Initiative also shares findings about CECs with individuals and groups inside and outside of state government.

The CEC Initiative is funded by the Clean Water Fund. Prior to the Clean Water Fund support, MDH was only able to develop human health-based guidance for contaminants that were already found in groundwater in Minnesota. The CEC Initiative has three main areas of work:

• CEC Nomination and Selection (See Nominate Contaminants)
• Contaminant Evaluation and Review
• CEC Special Projects

Annual CEC meeting

The Contaminants of Emerging Concern (CEC) Initiative hosts an annual meeting to review CEC activities over the past fiscal year and a look ahead at upcoming projects. The 2024 CEC Annual meeting was held on Thursday, Sept. 19. The presentation is summarized here: Contaminants of Emerging Concern (CEC) Presentation Summary (PDF). The agenda included:

• HRA and CEC Overview
• Where We've Been - The PFAS Story
• Where We Are and Where We Are Going - Toxicity Assessment
• Where We Are and Where We Are Going - Exposure Assessment
• How to Nominate Chemicals

We encourage you to Nominate Contaminants to the CEC Initiative. A table of the Nominated Contaminants Status and Information (PDF) is available from this page. 

Contaminant Evaluation and Review

MDH staff research where and how a contaminant is used in the state, its potential to enter Minnesota waters, and its toxicity to humans. If there is sufficient information on health effects, staff calculate health-based water guidance - a concentration of contaminant in water that poses little or no health risk to people drinking that water. For some contaminants, the information is too limited. In this case, the guidance may describe the hazard posed by the chemical instead of a certain level in water.

Reviews of chemicals consist of:

1. an exposure review, documenting the typical uses of the chemical and where releases are likely to occur (in coordination with the Minnesota Pollution Control Agency (MPCA), the Minnesota Department of Agriculture (MDA), and other parties with access to relevant information); and
2. a toxicological review, providing the most current information on the adverse health effects from exposure to the chemical. Refer to the Health-Based Guidance Development Process web page for more information on guidance development.

2025 Contaminants Under Review:

See Chemicals Under Review for current reviews by the Contaminants of Emerging Concern Initiative.

2025 CEC Initiative Workplan

• Trifluoroacetate (TFA)
• Cobalt
• o-toluidine
• Germanium
• 5,6-Dimethyl-1-H-Benzotriazole
• Four Nonylphenols: (NP2EO, NP1EO, NP2EC, NP3EC)
• Nodularin
• Metformin

Completed in 2025:

• Tributyl Phosphate

Completed in 2024:

• Perfluorooctane Sulfonate (PFOS)
• Perfluorooctanoate (PFOA)

Subscribe to GovDelivery to stay up to date with CEC Initiative activities.