By Kirsti Marohn, Minnesota Public Radio News

Minnesota communities will need almost $5 billion fix aging sewer systems in the next 20 years, according to a new survey.

Every two years, the state Pollution Control Agency surveys Minnesota communities to find out how much money they need to repair or replace wastewater infrastructure like sewer pipes and treatment plants.

The 2017 results, reported to the Legislature Jan. 15, put the projected need for the next 20 years at $4.99 billion. That’s up about 15 percent from the last survey two years ago, when the projected need was $4.2 billion.

Only about 5 percent of the need is related to meeting stricter water quality regulations, said Cara Omana, an environmental specialist with the MPCA. She said most of the cost is to fix aging or inadequate pipes and pumping systems.

“Much of Minnesota’s wastewater infrastructure was built in the ‘70s and ‘80s, so at this point a lot of it is getting older and needs to be replaced,” Omana said.

About 20 percent of wastewater treatment plants in outstate Minnesota are more than 40 years old, which is the expected useful life.

The needed improvements are evenly split between Twin Cities and outstate Minnesota communities, Omana said.

Many small cities struggle to find funding for costly wastewater repairs. In the survey, about 20 percent of cities with fewer than 1,500 residents reported unaffordable wastewater costs.

Gov. Dayton has asked for $167 million in his bonding proposal for water infrastructure, including helping communities pay for improvements.