Empire Case Study: Achieving One Water at a Small Wastewater Treatment Plant

Expansion of the Empire Wastewater Treatment Plant (WWTP) from 12 mgd to 24 mgd capacity in 2007 started a process to implement integrated water management (also known as “One Water”), which continues to present day. Metropolitan Council Environmental Services (MCES) leadership and staff leveraged the WWTP’s location adjacent to the Vermillion River, a designated coldwater trout stream, to collaborate with state agencies and a non-profit to construct green infrastructure practices, divert WWTP effluent providing enhanced opportunity for reuse, and restore habitat. The One Water practices provide environmental protections that exceed local and state requirements and take advantage of the direct connection of surface water, wastewater effluent and local shallow groundwater to eliminate all surface runoff from the WWTP process area and to protect and improve the trout stream. Ancillary benefits of the practices include enhanced pollinator, bird, amphibian, fish, and wildlife habitat. Identification of effluent reuse opportunities in the future will serve to lessen withdrawal from regional drinking water aquifers.