Clean Water Act: Images from the past

The MPCA is honoring 40 years of the Clean Water Act. As these photos depict, the law has made a profound difference in Minnesota, where clean water is essential to our quality of life and economy.

    1927 sewage outlet mpls 

This sewer in downtown Minneapolis was one of several such outfalls in 1927. More than 1.5 million gallons of sewage, runoff and other waste discharged to the Mississippi River.

    Green slime on a soda can next to a river 

In 2007, citizen complaints prompted an MPCA investigation of toxic blue-green algae in Little Rock Lake in Benton County. Excess nutrients that fuel algal blooms in lakes and rivers continue to be a challenge in making our lakes and streams fishable and swimmable.

    slime growth on water surface from industry discharge 

In 2010, chronic industrial runoff created a layer of slime in a Rochester creek, leading to an MPCA investigation and corrective action. The Clean water Act included provisions for state enforcement programs.

    oil being stirred up from sediment sediments in river 

In 2007, oil surfaces in a stormwater runoff pond in Freeborn County. The oil came from a large petroleum spill that was not cleaned up. Under MPCA enforcement, the business emptied the pond, removed the contaminated soil, and then restored the pond to its intended use to catch runoff before flowing to a creek.

    boiling water industrial discharge into water body 

In 2005, a citizen complaint of discoloration of a stream resulted in the MPCA finding boiling water discharged from an industry to a creek in Owatonna. Discharge permits include temperature standards to protect fish and wildlife. The Clean Water Act states that all discharges into the nation's waters are unlawful unless authorized by a permit and sets controls for municipalities and industries.

oil floating on river, person in boat   Old photo of people looking at dead fish   1960s honeymead spill - aerial photo of site

(Three photos above) A soybean oil spill on the Blue Earth River near Mankato had devastating effects on fish and wildlife downstream in 1963. At the time, no law required the reporting or cleanup of such spills. The public outcry led to the formation of the Minnesota Pollution Control Agency in 1967.

    sewers being built in twin cities  

In the 1920 and 1930s, the Twin Cities metro area built sewage treatment systems, including giant tunnels like above,  to convey wastewater south of St. Paul instead of directly dumping the wastewater into the Mississippi. The Pigs Eye plant was completed in 1938.

    boys canoeing on the river near sewer outlet 

Canoeists look at huge culvert discharging acrid-smelling liquid into the Mississippi River in 1973 in Minneapolis. (Photo by Donald Emmerich in the National Archives )

    person swinging on a rope and swimming under a bridge near downtown minneapolis 

A teenager swings into the Mississippi from a rope attached to a railroad trestle downtown near 16th Avenue northeast in Minneapolis in 1973. The goal of the Clean Water Act is to make all waters swimmable and fishable where possible. (Photo by Donald Emmerich in the National Archives )

    trash dumped at rivers edge, algae growth on water surface 

Until the Clean Water Act went into full force, garbage was routinely dumped in the back waters of the Mississippi Rover along Versailles Avenue in St. Paul. This photo was taken in 1973. (Photo by Donald Emmerich in the National Archives )


Sewage in the Mississippi River in 1933 made the river unhealthy in the Twin Cities metro area. The Mississippi in the metro area was once a dead zone with sewage choking the life out of fish. Thanks to significant investments in wastewater treatment – with much of the funding from the Clean Water Act – rivers across Minnesota are much healthier. (Photo courtesy of the Metropolitan Council)