To call another person “pond scum” can be a powerful insult, because pond scum offends the senses. It’s gray, foamy, smelly and always dirty. Pond scum floats on top of waters that should be clean and filled with life.

When photographs of algae blooms in Lake Spokane were shown recently at Environmental Protection Agency hearings in Coeur d’Alene, they looked like the worst case of pond scum ever seen in this region. The algae blobs floated on a lake known for its swimming and water-skiing. It was sickening. Yet few people attended the hearings and even fewer were there representing the interests of Lake Spokane residents.

EPA was in town holding hearings on permits for three North Idaho wastewater treatment plants – in Coeur d’Alene, Post Falls and the Hayden area. All three discharge into the Spokane River, the same Spokane River that crosses the Idaho-Washington border and eventually forms the reservoir behind Long Lake Dam, officially named Lake Spokane but often called Long Lake.

EPA is proposing strict limits on several pollutants in North Idaho wastewater discharge, especially phosphorus. The EPA folks at the meeting showed the “pond scum” photos to make the point that the permit process in North Idaho would help mitigate algae blooms in Lake Spokane.

Getting tough on phosphorus in Idaho is a good thing. Phosphorus is like crack cocaine to the algae in Lake Spokane. Algae inhales it voraciously, blooms out of control and then, while dying, destroys the life around it by sucking up dissolved oxygen, needed by fish and other aquatic life.

In Washington, a get-tough-on phosphorus effort resulted recently in a collaborative group of environmentalists, dischargers and others agreeing to work together for the next 20 years to clean up the phosphorus in the Spokane River on the Washington side. All well and good, too.

Idaho was not officially part of the cleanup plan implementation agreement, though Idaho environmentalists, dischargers and water quality officials attended the collaborative meetings for almost two years. EPA officials say it’s because the dissolved oxygen levels were not impaired in the river in Idaho, as they were in Washington. But other regions of the county have successfully completed cross-state watershed cleanup plans, and they should be the default mode for the Spokane River from here on out.

Soon, people will hear a lot about another river enemy – PCBs. These toxic chemicals can cause cancer. A PCB cleanup plan is not just a Washington river issue. Nor just an Idaho river issue. It’s a watershed issue that needs regional solutions, including an effective way to address the huge contribution to pollution that comes from non-point sources.

The Spokane River cleanup can be a complicated issue to follow and understand. It combines chemistry, history and emotion. And it requires delving into topics difficult to get excited about, such as sewage treatment.

But a watershed approach demands vigilance by all Spokane River stakeholders, from the EPA to the weekend swimmers at Lake Spokane. It’s the only way to guarantee that meetings about the future of the Spokane River get good attendance. And the only way that “pond scum” won’t ultimately choke the life out of a river shared by all along its 111-mile route.