A lawsuit filed against the Oregon Department of Environmental Quality on Wednesday asks a judge to impose stricter regulations on stormwater pollution from industrial sites across the state.

The lawsuit, filed in Multnomah Couty Circuit Court by environmental groups Columbia Riverkeeper and the Northwest Environmental Defense Center, says the state's permit violates the Clean Water Act by allowing levels of stormwater pollution that could harm salmon, humans and other aquatic life.

The act requires permits limiting pollution for industrial facilities that discharge stormwater to state waters or drains that lead to state waters.

The permit, known as a 1200-Z permit, regulates stormwater pollution from 900 industrial sites across the state. Stormwater runoff from the industrial sites include copper, lead, zinc and other "toxics," the lawsuit says. Stormwater runoff is one of the leading causes for nationwide water pollution.

The environmental groups asked the Department of Environmental Quality to revise its permit in August, but the agency did not, the Columbia Riverkeeper said in a statement on its website.

The groups also expressed concern that Oregon industrial sites are only required to report pollution levels once a year. The state of Washington requires sites report pollution monitoring reports four times a year, the Columbia Riverkeeper said.

The Department of Environmental Quality is evaluating the complaints in the lawsuit, spokeswoman Jennifer Flynt said in a statement Saturday. She did not comment further, citing the pending lawsuit, but said that the department agrees the permit is important for controlling potential sources of stormwater pollution.

In March, the department was sued by environmental groups for its backlog of expired water pollution permits, which is the second-worst in the nation, the lawsuit said.

— Samantha Matsumoto