Regional Wastewater Facts

Down the drain, into a sewer pipe

Whenever we take a shower, flush a toilet or run the washing machine or dishwasher, we create wastewater. That wastewater is carried through a pipe from the property into a municipal sanitary sewer pipe. That pipe is, in turn, connected to a regional interceptor sewer. 

The regional wastewater collection system includes:

  • 8 wastewater treatment plants 

  • Approximately 610 miles of interceptors, up to 14 feet in diameter 

  • 62 lift stations that pump flows to treatment plants 

  • 206 metering stations that help determine communities’ share of regional costs 

  • 21 rain gauge stations 

The regional wastewater collection and treatment system is operated by Metropolitan Council Environmental Services (MCES). Wastewater services are designed to protect public health and the environment. 

photo close up of person checking water pipes

From pipes to treatment plants 

photo of two men standing in a wastewater treatment facilityCollection interceptors carry wastewater to the 8 treatment plants, which have a combined capacity to treat 358 million gallons per day (mgd). In an average day, the plants treat 250 million gallons of wastewater from 109 of the region’s communities. The plants operate 24 hours a day, 365 days a year, and serve 2.6 million residents in the seven-county Twin Cities region. 

Wastewater treatment results in clean water (effluent), discharged into one of three rivers (Mississippi, St. Croix and Minnesota). In the case of the East Bethel Water Reclamation Facility, effluent is discharged into the ground for groundwater recharge.

Wastewater treatment also results in solid byproducts. MCES incinerates most of its solid byproducts and, in the process, produces energy. The remainder are recycled and processed for a variety of uses. 

MCES strives to keep wastewater service fees competitive and affordable. A 2014 survey by the National Association of Clean Water Agencies (NACWA) confirms that wastewater rates to retail customers in the Twin Cities metro region are about 40% lower than the national average among similar-sized systems. 

Plants have excellent environmental record 

MCES wastewater treatment plants continue to perform at a high level, achieving near-perfect compliance with federal and state clean water discharge limits. The Hastings and St. Croix Valley plants are two of the top 10 plants in the country for consecutive years (25 and 24 years, respectively) of full compliance with clean water discharge permits. 

MCES is working hard to reduce energy consumption at its facilities. Working with Xcel Energy, MCES completed more than three dozen energy-saving projects between 2006 and 2016, with estimated current savings of over $4 million per year. 

MCES reduced purchased energy use 23% by the end of 2015 (from a 2006 baseline) and plans to reduce it another 10% by 2020. 

Metro Plant in Saint Paul is one of nation's largest

photo of a man looking at a screenOpened in 1938, the Metro Plant in Saint Paul was the first wastewater treatment plant located in a major city on the Mississippi River. Today’s upgraded plant is among the largest in the U.S. 

The Metro Plant processes approximately 70% of the total wastewater collected and treated by the MCES system. The 67 communities and more than 550 permitted industries served by the Metro Plant produce average wastewater flows of 175 mgd. 

The Metro Plant has made significant environmental strides, reducing phosphorus discharges to the river by 90% between 2000 and 2011. The plant also cut airborne emissions, like particulates and mercury, by 90%. 

Seven smaller wastewater treatment plants

Located on the Minnesota River in Eagan, the Seneca Plant is the region’s second-largest wastewater treatment facility. The 34 mgd plant serves six communities with a combined population of 245,000 people and treats an average of 22.4 mgd. 

The 32 mgd Blue Lake Plant in Shakopee also is located on the Minnesota River. The plant treats an average of 29.1 mgd and serves a population of 285,000 in 27 southwest metro-area communities. 

The Empire Plant, located in Empire Township, serves some 150,000 people in six growing Dakota County communities. Plant capacity is 24 mgd; it currently treats approximately 10 mgd. The plant’s effluent is piped 12 miles to the Mississippi River. 

The Eagles Point Plant in Cottage Grove serves southern Washington County. The plant treats approximately 4.4 mgd; its 10 mgd treatment capacity serves 72,000 people. 

Located on the scenic St. Croix River, a nationally protected waterway, the 4.5 mgd St. Croix Valley Plant has been recognized as one of the nation’s best advanced treatment plants by the U.S. Environmental Protection Agency. It currently serves three communities with average flows of 3.2 mgd. 

The 2.34 mgd Hastings Plant serves its namesake community and has room for growth through approximately 2019. The plant treats an average of 1.5 mgd and discharges clean water to the Mississippi River. A new 5 mgd plant is also planned. It will be constructed east of downtown Hastings. 

The East Bethel Water Reclamation Facility in northern Anoka County is the Council’s first water reuse facility. It opened in July 2014 and has the capacity to treat 0.41 mgd to very high standards, including phosphorus and nitrogen removal followed by membrane filtration and ultraviolet disinfection. The treated effluent is currently being used to recharge surficial groundwater.

In 2016, MCES Technical Services managed more than $125 million on capital projects that support infrastructure reliability, protect public health, and support regional growth. The MCES Authorized Capital Program provides multi-year authorizations to spend on projects where funding has been secured and the Council has given final approval to proceed. The 2017-2022 Capital Program is $1.4 billion. The Council approved a 2017 Capital Budget of $183 million. Capital expenses are for the eight treatment plants as well as numerous interceptor, lift station, and meter station construction and rehabilitation projects.