The U.S. Environmental Protection Agency has signaled its willingness to give the Allegheny County Sanitary Authority much more time to implement a “green first” flow reduction strategy and significantly reduce the billions of gallons a year of illegal wet weather sewage discharges that foul the region’s rivers and streams.

According to a letter sent Wednesday by the EPA to the city and county, the agency’s proposed modifications of Alcosan’s wet weather control plan would extend the authority’s compliance deadline, now 2026, by more than a decade.

The EPA said the extended time line could also “lower service rates to Alcosan customers” by spreading out construction costs.