One of the least-visible environmental initiatives in Minneapolis is paying off: The city says it won't discharge any raw sewage into the Mississippi River this year for the first time on record.
That's the payoff from a decades-long sewer separation program, aided by some dry spells that allowed soil to absorb more rain.
"This is really an important milestone," said Council Member Sandra Colvin Roy, who chairs the council's infrastructure committee.
The investment that minimizes the amount of sewage diverted into storm sewers and into the river has been expensive and mostly underground.
But it's paying dividends for those who love the river, said Whitney Clark, executive director of Friends of the Mississippi River.
Minneapolis is one of three metro cities that have been working on eliminating sewage discharges to the river. St. Paul and South St. Paul both completed their work in the mid-1990s.
Colvin Roy said she wasn't even aware of the sewage issue until her 1997 election. She made restarting the stalled separation program a priority in her second term, and it has lasted into her third.
Rain to still carry off water
Minneapolis hasn't seen the last of its sewage enter the river. There are still connections between storm and waste sewers. When it rains, water enters waste sewers until they reach capacity and divert waste through connections into storm sewers routed to the river.
The remaining connections are the costliest and most difficult to correct, according to the city, although work continues. For example, last summer a temporary connection installed during construction of Interstate Hwy. 94 in north Minneapolis was discovered and corrected.
As recently as 2000, 60 million gallons of sewage were bypassed but that has been cut to no more than 3 million gallons annually starting in 2004.
"We make investments every year and it's paying off," said City Council President Barbara Johnson.
The city's sewage discharge into the Mississippi goes back to the first sewers laid in 1870, which carried both waste and storm water. Construction of separate pipes began in the 1920s in the lakes area, but older sewers remained combined.
Separation of existing pipes started in the 1960s and accelerated with state and federal help in the mid-1980s. Less than 5 percent of the city's area still requires separation.
The city employed 11 people who inspected more than 21,000 properties to enforce a city requirement that roof drainpipes be disconnected from waste sewers. The city also built detention ponds that hold back storm water.
More work to do
Minneapolis Mayor R.T. Rybak and Clark agreed that more must be done to reduce storm runoff. Clark said that runoff is degrading the area's lakes and streams, scouring stream banks and carrying sediment. Keeping more rainwater from running off allows the area's groundwater to be recharged.
The city offered credits on its storm water fee to property owners who install "rain gardens" to absorb downspout flow or reduce the hard surface of their lots.
"This is great news, this is great progress, but we want to keep effort going," Rybak said.
Steve Brandt • 612-673-4438