Waterloo, Iowa say homeowners have not suffered a single raw sewage spill since adopting a controversial foundation drain disconnection program at the start of this year.

Nearly 1,000 houses in the initial target area have replaced their connection to the sanitary sewer system with sump pumps during the first seven months of the program.

Rainfall and groundwater that once overloaded sanitary sewer mains is now being pumped into backyards and streets.

"We've had no (sanitary sewer overloads) at all this year since this started," said Waste Management Services Superintendent Larry Smith. "It is definitely having an effect."

The city reported 20 sanitary sewer overloads in 2014.

More details here.