The Metro Wastewater Treatment Facility, located in St. Paul of Ramsey County, is the largest wastewater treatment facility in Minnesota and one of the largest in the country. It has been in operation since 1938 and currently has the capacity to treat 251 million gallons per day. The treated effluent from the facility discharges into the Mississippi River. To inquire about data from the facility, please contact Ricky Arora, Manager Process Information at (651) 602-8191 or Ricky.Arora@metc.state.mn.us.