Wastewater reuse is the practice of highly treating and reusing wastewater treatment plant effluent for beneficial use. This highly treated wastewater, called reclaimed water, must meet water quality guidelines established by the Minnesota Pollution Control Agency (MPCA) before it can be used. Resuse can be a cost-effective solution for industrial or growing areas, or when there may be barriers to accessing groundwater for nonpotable uses.
Thrive MSP 2040, the Metropolitan Council’s guiding framework, sets a Met Council goal of pursuing wastewater reuse where economically feasible to promote sustainable water resources. The 2040 Water Resources Policy Plan provides further information about the Council's approach to wastewater reuse.
In 2017, the Met Council board authorized a Wastewater Reuse Policy Task Force to develop recommendations for its consideration. The task force presented the recommendations at a public hearing in April 2018. In May 2018, the Met Council approved amendments to the 2040 Water Resources Policy Plan (Business Item 2018-109).
Features of the plan amendment include:
- Establishing a wastewater reuse pilot program
- Emphasizing the need for cooperation with local communities and water suppliers
- Implementing an actual cost-of-service basis, not a single rate, for reclaimed water service
- Encouraging pursuit of non-Met Council funding for reuse projects
- Requiring long-term reclaimed water service agreements with users
- Reporting about the reuse pilot program at MCES's annual budget meetings
- Establishing criteria for a regional cost share for wastewater resuse projects based on regional wastewater system benefit, including a cap on the allowable cumulative amount of regional cost shares granted (approximately $1.65 million/year)
Treated effluent use at wastewater treatment plants
At most MCES wastewater treatment plants, we use treated effluent (which meets the plants' permits but does not meet MPCA's guidance for reclaimed water) for various plant activities. For example, we use treated effluent for cooling water in the solids incineration process at the Metro and Seneca treatment plants. Many plants use treated effluent for activities such as tank cleaning and to keep pumps from overheating.
Transitioning from treated effluent use and groundwater use to reclaimed water use at the Metro Plant
At the Metro Plant, we are designing facilities to further treat effluent to meet the MPCA’s reclaimed water guidance level. This reclaimed water will then take the place of the treated effluent and groundwater used now for many plant activities. Using reclaimed water will provide a higher level of worker health protection than the plant effluent and will reduce groundwater use by over one million gallons a day.
East Bethel Water Reclamation Facility
The East Bethel Water Reclamation Facility treats 57,000 gallons of wastewater per day to MPCA’s highest level for wastewater reuse. This reclaimed water is pumped to one of two rapid infiltration basins, where it filters through a surficial sand aquifer and ultimately flows to Crooked Brook. (See graphic, below)
Other potential project
A potential wastewater reuse project is the Southeast Metro Water Reclamation Facilities project, to treat Empire Plant effluent to be reused by the city of Rosemount. More information about this potential project can be found in the facility plan for the proposed Southeast Metro Water Reclamation Facility (PDF).