Idaho cities will be required to cut the amount of phosphorus they discharge into the Spokane River by more than 90 percent over the next decade to protect water quality, according to draft wastewater permits released Thursday.
The new limits will require millions of dollars in improvements to treatment plants, operated by the cities of Coeur d’Alene and Post Falls and the Hayden Area Regional Sewer Board, which pump treated sewage into the river.
The stricter permits are designed to comply with the federal Clean Water Act and protect water quality in both Idaho and Washington stretches of the river, said Michael Lidgard, a permit manager for the Environmental Protection Agency.
Stricter limits will be phased in over 10 years. Over time, river users will see fewer algae-slimed rocks in the river and fewer algae blooms in Long Lake, a Washington reservoir 43 miles downstream from Post Falls, said Brian Nickels, an EPA permit writer.
Washington dischargers into the Spokane River have been operating under similar permits since 2011.
A 45-day comment period on the draft Idaho permits runs through Sept. 3. EPA officials expect to issue the final permits later this year.
Idaho dischargers said they received the 50-page permits Thursday morning and weren’t ready to comment.
“I have to go over it, my engineer has to go over it and my attorney has to go over it,” said Ken Windram, manager of the Hayden Area Regional Sewer Board. “This is not a quick process.”
Setting the new discharge limits has been a long and contentious journey. Idaho dischargers have been operating under extensions for permits that expired in 2004. The EPA issued new permits in 2007, but had to make them stricter to protect downstream water quality in Washington.
In 2010, Post Falls and the Hayden sewer board filed a lawsuit in U.S. District Court in Boise, asking a judge to halt implementation of the pending discharge standards. The city of Coeur d’Alene later joined the suit.
The litigation has been on hold until the new permit limits were issued.
Idaho dischargers hired their own consultant to review the computer modeling used to develop the permits, said Sid Frederickson, Coeur d’Alene’s wastewater superintendent.
But the city is also moving forward with a pilot treatment project designed to remove more nutrients from the wastewater, he said. The city has received bonding authority for up to $36 million in plant upgrades.
Spokane contractor Williams Brother was awarded an $8.6 million contract to start building the first phase of the treatment upgrades in August. The city will run one to two years of tests on the pilot facility before deciding whether the technology is successful enough to expand, Frederickson said.
In addition to removing more nutrients, Coeur d’Alene’s draft permit calls for reducing the amount of cadmium and lead discharged into the Spokane River.
Idaho dischargers will also be required to participate in a regional task force to develop ways to reduce the volume of PCBs flowing into the river.