Draft Conceptual Drinking Water Supply Plan Outline

04/20/2020, Draft

Minnesota 3M PFC Settlement Conceptual Drinking Water Supply Plan – Outline (Version 5, Draft) April 20, 2020

[Note: This is a working draft and will be updated on a rolling basis as needed.]

Background

The State of Minnesota’s 2018 Agreement and Order (Agreement) with the 3M Company (3M) establishes the 3M Grant for Water Quality and Sustainability Fund (Grant). Under Priority 1 of this Agreement, the Minnesota Pollution Control Agency (MPCA) and the Minnesota Department of Natural Resources (DNR) will use the Grant for long‐term projects to enhance the quality, quantity, and sustainability of drinking water contaminated by per- and polyfluoroalkyl substances (PFAS) for residents and businesses in the East Metropolitan Area. The MPCA and the DNR aim to develop a conceptual plan for addressing drinking water supply with input from the Government and 3M Working Group, the Citizen-Business Group, the Drinking Water Supply Technical Subgroup (Subgroup 1), and members of the general public. The outline below provides information on the scope and anticipated content of the Conceptual Drinking Water Supply Plan (Conceptual Plan). The general approach is also provided.

Outline

1. Introduction a. Overview of the 2018 Agreement i. Background ii. Settlement iii. Priorities iv. Roles and responsibilities v. Communication and public involvement b. Goals i. Long-term program goals ii. Operational goals c. Overview of the Conceptual Plan i. Purpose of the Conceptual Plan ii. Strategic planning effort and planning process d. Next steps: Project design and implementation e. Document contents f. Preparers 2. Approach a. Description of approach [see Figure 1] i. Compile regional background information and community profiles

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04/20/2020, Draft ii. Identify and evaluate water supply improvement options iii. Identify conceptual projects iv. Develop and evaluate scenarios v. Identify recommended scenarios b. Modeling Overview i. Drinking water distribution modeling ii. Groundwater modeling 3. Background a. Regional overview i. Groundwater ii. Surface water iii. PFAS contamination 1. Current extent of contamination 2. State and federal guidance for PFAS iv. Groundwater use 1. Management of groundwater resources 2. Groundwater use constraints and issues v. Surface water use 1. Management of surface water resources 2. Surface water use constraints and issues b. Community water supply profiles i. Overview ii. Community water supply summaries 4. Water supply improvement option identification and evaluation a. Approach to identify and evaluate water supply improvement options i. Identification of water supply improvement options 1. Provide point of use or point of entry treatment of drinking water 2. Create new small community water system(s) (with treatment) 3. Move private well hookups to existing municipal water system(s) (where available) 4. Provide drinking water treatment of existing municipal water system(s) 5. Drill new wells in optimized locations 6. Create new regional water supply system(s) (with treatment) 7. Connect subsets of communities to St. Paul Regional Water Services 8. Create a new surface water treatment plant for use of Mississippi or St. Croix River waters 9. Non-potable and potable reuse of treated 3M containment water 10. Minimize water well usage by reducing current potable demand, through: a. Beneficial use of other non-treated or less treated waters (e.g., grey water, storm water)

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04/20/2020, Draft b. Water conservation ii. Water supply improvement options screening criteria b. Evaluation of water supply improvement options 5. Conceptual project identification a. Approach for identifying conceptual projects i. Preliminary identification of projects ii. Work group and Subgroup 1 input iii. Public input iv. Final list refinement b. Conceptual project list 6. Scenario development and evaluation a. Approach to develop and evaluate scenarios i. Scenario development ii. Scenario modeling and costing iii. Scenario evaluation criteria and evaluation approach b. Overview of scenarios i. Community-specific scenarios ii. Regional scenarios iii. Treatment scenarios iv. Integrated scenarios c. Scenario results summary d. Scenario evaluation summary 7. Recommendation 8. References 9. Appendices a. Community profiles b. Conceptual site model for the East Metropolitan Area c. Numerical model description and construction d. Conceptual project list e. Scenario results f. Scenario supporting documentation g. Scenario evaluation

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04/20/2020, Draft General Approach

Figure 1. General approach for the development of the Conceptual Plan.

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