The Washington state Department of Ecology says it has submitted a water quality plan for the Spokane River and Lake Spokane to the U.S. Environmental Protection Agency for final approval.

The plan has been 12 years in the making, and the forwarding of it to EPA brings the bodies of water "a major step closer to being cleaner, healthier, and a better place for fish to thrive and people to enjoy," Ecology says. EPA will have 30 days to review the plan and notify Ecology of its decision, although the federal agency also could request an extension.

The Spokane River/Lake Spokane Dissolved Oxygen Water Quality Improvement Plan, often referred to as the total maximum daily load (TMDL) report, will guide work toward bringing the Spokane River into compliance with water quality standards for dissolved oxygen. Lake Spokane refers to the 25-mile-long section of river and reservoir that stretches between Nine Mile Dam and Long Lake Dam northwest of Spokane.

The river and lake contain too much phosphorus and other substances that act like fertilizers, causing algae and other aquatic plants to grow and thrive, Ecology says. When the plants decompose, they use up dissolved oxygen that fish need to breathe.

In addition, unsightly algae blooms can become toxic and cause nuisance smells or human skin irritations, Ecology says. In so doing, they can make Lake Spokane unhealthy for swimming, and compromise its ecological balance, it says.

Under the federal Clean Water Act, when a body of water fails to meet water quality standards for certain pollutants, Ecology must study the problem and produce a plan to improve water quality.

"This document will lead to noticeable improvements in the aesthetics and productivity of the Spokane River and Lake Spokane while contributing to investments in Spokane's economy," says Kelly Susewind, DOE water quality program manager. "We are eager to move from planning into doing and start measuring success in the watershed."

The water quality improvement plan is expected to lead to a more than 90 percent reduction in phosphorus pollution from industrial and municipal pipes. Due to the sensitivity of the Spokane River system, the phosphorus limits for industrial and municipal discharges are among the most stringent in the country, Ecology says.

Along with installing pollutant-reduction equipment, "point-source" dischargers, meaning those that discharge from a pipe, will have a number of options for reducing phosphorus, such as eliminating septic systems, treating their storm water, and using non-phosphorus fertilizers, Ecology says. In addition, it says, the plan gives Avista Corp., which operates Long Lake Dam, a portion of the responsibility to improve dissolved oxygen levels in Lake Spokane.

The improvement program includes a long-term monitoring program for the river and lake so that improvements can be measured. It also includes strong incentives for investing in water-conservation efforts, which help protect water quality.