Advancing Safe and Sustainable Water Reuse in Minnesota 2018 REPORT OF THE INTERAGENCY WORKGROUP ON WATER REUSE ADVANCING SAFE AND SUSTAINABLE WATER REUSE IN MINNESOTA Advancing Safe and Sustainable Water Reuse in Minnesota Minnesota Department of Health Environmental Health Division PO Box 64975 St. Paul, MN 55164-0975 651-201-4700 [email protected] www.health.state.mn.us/waterreuse As requested by Minnesota Statute 3.197: This report cost approximately $50,000 to prepare, including staff time, printing and mailing expenses. Upon request, this material will be made available in an alternative format such as large print, Braille or audio recording. Printed on recycled paper. 1 ADVANCING SAFE AND SUSTAINABLE WATER REUSE IN MINNESOTA Contents Advancing Safe and Sustainable Water Reuse in Minnesota ......................................................... 0 Figures ......................................................................................................................................... 4 Tables .......................................................................................................................................... 5 Acronyms .................................................................................................................................... 6 Report Contributors .................................................................................................................... 7 Executive Summary ..................................................................................................................... 8 Introduction ................................................................................................................................ 9 Why Consider Water Reuse in Minnesota? ............................................................................ 9 Increasing Interest in Reuse .................................................................................................. 10 Benefits, Costs and Risks of Water Reuse............................................................................. 12 Workgroup Establishment/Goal, Objectives, and Activities................................................. 14 Definition of Successful Water Reuse ................................................................................... 16 State Agencies’ Current Roles in Water Reuse ..................................................................... 16 I. Recommendations ............................................................................................................. 21 Recommendation a. Create an expanded workgroup with practitioners, advisors and stakeholders .......................................................................................................................... 23 Recommendation b. Prioritize research needs and integrate ongoing research ................. 23 Recommendation c. Define roles and responsibilities ......................................................... 24 Recommendation d. Establish an information and collaboration hub on the web ............. 25 Recommendation e. Develop a risk-based management system ........................................ 26 Recommendation f. Develop water quality criteria for a variety of reuse systems based on the log reduction target approach for pathogens ................................................................ 29 Recommendation g. Resolve unique issues related to graywater reuse ............................. 30 Recommendation h. Provide education and training ........................................................... 31 II. Water Reuse in Minnesota................................................................................................. 32 Wastewater Reuse ................................................................................................................ 33 Stormwater and Rainwater – Outdoor Reuse ...................................................................... 39 Stormwater and Rainwater – Indoor Reuse ......................................................................... 43 Graywater Reuse ................................................................................................................... 45 Additional Reuse Categories ................................................................................................. 47 Variances for Indoor Stormwater, Wastewater and Graywater Reuse................................ 50 Funding Sources for Reuse.................................................................................................... 51 2 ADVANCING SAFE AND SUSTAINABLE WATER REUSE IN MINNESOTA III. Water Reuse in other Jurisdictions ................................................................................ 53 States..................................................................................................................................... 53 Counties and Municipalities.................................................................................................. 56 International ......................................................................................................................... 57 IV. Managing the Human Health Risks of Nonpotable Water Reuse .................................. 59 Reasons to Consider Human Health ..................................................................................... 59 An Approach for Addressing Human Health Risk ................................................................. 60 Applications of the Log Reduction Approach ....................................................................... 60 What the Log Reduction Approach Looks Like to End Users ................................................ 62 Protecting Health through Proper Storage and Distribution................................................ 64 References................................................................................................................................. 65 Resources .................................................................................................................................. 67 US Resources ......................................................................................................................... 68 International Resources ........................................................................................................ 70 Other Jurisdictions in the US (States, Counties, and Municipalities) ................................... 70 Appendix A. Surveys.................................................................................................................. 73 Minnesota Technical Assistance Program Survey ................................................................ 73 Municipal Separate Storm Sewer System (MS4) Survey ...................................................... 73 Water Reuse Interagency Workgroup Survey ...................................................................... 73 Appendix B. Stakeholder Participation ..................................................................................... 88 Stakeholder List..................................................................................................................... 88 Stakeholder Meeting Summaries.......................................................................................... 89 Appendix C. Liability Risks ......................................................................................................... 96 Insurance Companies ............................................................................................................ 96 Attorney Perspective ............................................................................................................ 96 States and Local Governments ............................................................................................. 96 3 ADVANCING SAFE AND SUSTAINABLE WATER REUSE IN MINNESOTA Figures Figure 1. Some Factors to Consider in Exploring Reuse................................................................ 12 Figure 2. Potential Exposure Pathways......................................................................................... 14 Figure 3. Common types of water reuse projects in Minnesota by source and end use (estimations) ................................................................................................................................. 33 Figure 4. Treated wastewater used for golf course irrigation, Shakopee Mdewakanton Sioux Community .................................................................................................................................... 34 Figure 5. Nonpotable Wastewater Reuse: Current Regulatory Path............................................ 36 Figure 6. Stormwater irrigation system for residential landscape irrigation in city of Carver, Carver County. Homeowners’ association will manage system. .................................................. 40 Figure 7. Large stormwater pond in Waconia will serve new commercial lots along Highway 5 as part of a regional reuse system the city will manage. Water will also be used for street sweeping. ...................................................................................................................................... 42 Figure 8. Schematic of rainwater/stormwater harvesting system from Minnesota Stormwater Manual .........................................................................................................................................