Contaminants of Emerging Concern (CEC) Clean Water Legacy - EH: Minnesota Department of Health

Contaminants of Emerging Concern (CEC) Protecting Minnesota’s Water Resources

The CEC Initiative

Through this initiative, MDH collaborates with partners and the public to identify contaminants of interest; investigates the health and exposure potential of contaminants of emerging concern in water; and informs partners and the public of appropriate actions for pollution prevention and reducing exposures to contaminants that might be unhealthy. MDH scientists with experience in exposure assessment, toxicology, water resources, and communication collaborate closely with other state agencies and groups outside of MDH. Partners include the public; various local, state, and federal government agencies; academic organizations; non-profit groups; industry groups; and drinking water and wastewater professional organizations.

The initiative supports the Clean Water Fund mission to protect drinking water sources and the MDH mission to protect, maintain, and improve the health of all Minnesotans. The CEC Initiative has three main areas of work:

The best way to stay up to date with the CEC Initiative's activities is to subscribe to our GovDelivery email. Major announcements will be posted to our website and shared via GovDelivery.

Why we study contaminants of emerging concern

Water quality studies and monitoring in Minnesota find contaminants from products or sources we never suspected in places we never expected, like our lakes, rivers, groundwater and drinking water. These emerging contaminants are found because:

  • improved research methods allow us to look for new chemicals at lower levels than previously possible;
  • industry and individuals are using new chemicals in a variety of products and applications; and
  • old chemicals are being used in new ways. 

The work of this initiative helps MDH understand the potential health effects of these contaminants. 

Differences between the CEC Initiative and other MDH health-based guidance programs

Prior to the Clean Water Fund, MDH was only able to develop human health-based guidance for contaminants that have already been found in groundwater in Minnesota. 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. 

Additionally, this initiative provides information on how people are exposed to these contaminants. These differences separate the work of this initiative from MDH’s other guidance work, and supplements existing work.

CEC Nomination and Selection Process

Annual CEC Work Plan Stakeholder Meeting
July 8, 2021 at 3:00 PM

MDH will be hosting a virtual meeting via WebEx to discuss and set a draft work plan for the upcoming fiscal year (FY2022 - July 1, 2021 to June 30, 2022). During this meeting we will provide an overview of the ranking process, ranking results, and the draft workplan as well as a high-level summary of CEC activities (see Draft Agenda (PDF)). This meeting is open to the public. Anyone who is interested in attending the public meeting must send an RSVP to no later than June 30th to receive the WebEx registration link.

The CEC initiative invites citizens to submit nominations to our chemical selection process. You can nominate contaminants at any time by visiting the Nominate Contaminants page. Risk managers and stakeholders as well as the public are encouraged to nominate contaminants. MDH staff may identify additional candidate chemicals through our research and outreach with stakeholders.

MDH staff conduct a screening level evaluation of toxicity and exposure potential for nominated contaminants. All eligible contaminants that were nominated by April 9, 2021 have been screened for toxicity and exposure potential. MDH will continue to accept nominations on a rolling basis for consideration in future work plans. A full list of nominated contaminants, including those nominated this year, can be found in the updated Nominated Contaminants Status Table (PDF).

The process used to screen and rank nominated chemicals is explained in the following video presentation.

CEC Initiative’s Nomination, Screening and Ranking Process (video)

CEC Initiative’s Nomination, Screening and Ranking Process Video Transcript and Slides (PDF)

In the event of an urgent need for health-based guidance for a specific contaminant, MDH may develop guidance for a contaminant not included on the annual work plan. In that event, stakeholders will be notified via our GovDelivery email list.

Based on the toxicity and exposure screening results, MDH has assigned a preliminary ranking of high, medium, or low to each contaminant. The preliminary ranking is used to inform selection of contaminants for an in-depth toxicological review and guidance development. Preliminary ranking for the FY22 workplan can be found in the Preliminary Ranking Tables (PDF). Based on a contaminant’s preliminary ranking, availability of sufficient toxicological information, and stakeholder input, MDH creates an annual CEC guidance development workplan.

July 8, 2021: Virtual Public meeting. MDH will host a virtual public meeting to provide an overview of the screening and ranking process, the basis of the draft workplan and to solicit feedback from stakeholders (see Draft Agenda (PDF)). Everyone is invited to attend. Anyone who is interested in attending the public meeting must send an RSVP to by June 30th to receive the WebEx registration link. If you are unable to attend the public meeting, comments and feedback can also be submitted to MDH staff via

Mid August, 2021: Materials Posted. MDH will post a copy of the meeting slides, a summary of the comments received and the FY2022 workplan.

The workplan for the current fiscal year can be found at: Water Guidance Workplan 2021 (PDF). The goal of the CEC initiative is to identify at least ten nominated chemicals each year for the guidance development workplan. Unfortunately, due to all HRA staff being reassigned to the COVID-19 response , we were able to initiate a full review for only one chemical on the FY2021 workplan. The status of each nomination is kept, updated, and summarized in the following table:

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 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.

CEC Special Projects

CEC Special Projects allow MDH staff and qualified partners to consider important questions or issues surrounding CECs. These special projects can be focused on a particular CEC or group of CECs, or they may be designed to increase outreach or provide refined methods in order to evaluate the toxicity of CECs in the future. More information is provided on the Special Projects page.

Updated Monday, 21-Jun-2021 13:54:24 CDT