Phosphorus not only helps turn lawns green, it’s also responsible for turning portions of Long Lake into a pea-green soup of algae.
A massive cleanup is being launched to restore the health of the reservoir by keeping phosphorus out of the Spokane River.
Phosphorus, a life-giving element critical to survival, is found in many foods and is a byproduct of human and animal waste. Studies have shown a typical, well-fed human excretes between 1 and 3 grams of phosphorus per day, which is a fraction of an ounce. But when you add up the region’s roughly half-million people, that amounts to between 1,100 pounds and 3,400 pounds of phosphorus in sewage each day.
Businesses and cities along the river manage to remove all but about 200 pounds of the phosphorus, according to the Washington Department of Ecology, but this is still enough phosphorus to produce bumper crops of algae in Long Lake, also known as Lake Spokane. When the algae dies and sinks to the bottom of the reservoir, it decomposes and sucks away oxygen required for living organisms such as fish and insects.
The problem is worst in summer, when river flows drop and the phosphorus is more concentrated, according to officials with the Department of Ecology.
The oxygen-depleted water violates state, tribal and federal laws. To restore oxygen – and life – to Long Lake, businesses and cities along the river are being required to reduce dramatically the amount of phosphorus they discharge into the river. Within a decade, the total amount of phosphorus being discharged into the river is expected to be cut from about 200 pounds a day to less than 10, according to the proposed cleanup plan.
The cleanup is expected to cost about $500 million across the region, with the city of Spokane spending at least $300 million in sewage treatment plant upgrades and cities in North Idaho spending an estimated $100 million in upgrades. Spokane County is building a $120 million plant. Businesses along the river also plan to spend millions to meet the new standards. Inland Empire Paper Co., which is owned by the same parent company that owns The Spokesman-Review, will spend at least $5 million to clean up wastewater it discharges into the river, said Doug Krapas, environmental engineer for the company.
The businesses and cities have a decade to reach the targets, said Jani Gilbert, spokeswoman for the Department of Ecology.
As dischargers clean up their wastewater, an effort will also be under way to reduce nonpoint sources of phosphorus, such as runoff from farm fields and lawns. Ecology is developing plans to reduce phosphorus in tributaries, including Hangman Creek and the Little Spokane River.
Stringent as the Spokane River cleanup plan may be, some environmentalists and even agency scientists have criticized it as being too weak. Last month, the Ecology scientist in charge of the cleanup plan, Drea Traeumer, quit, saying the proposed plan would not meet Washington’s water purity laws.
The proposed plan is continuing to move forward, though. Ecology spokeswoman Gilbert said provisions exist in the plan to make changes to ensure cleanup goals are met.