Metals Pollute Spokane River Study Finds Elevated Levels Of Lead, Zinc

Elevated levels of lead, zinc and other heavy metals washed downstream from Idaho’s Silver Valley have been detected in the upper Spokane River from the state line through the Spokane Valley.

Some of the sediment collected last October from the riverbed and shorelines contains heavy metals in concentrations far above normal background levels.

The discovery comes from a scientific expedition to measure metals pollution in the Spokane River to Lake Roosevelt - the most comprehensive look at the river so far.

The toxic metals are coming from Lake Coeur d’Alene, which feeds the headwaters of the Spokane River.

“We do have elevated levels of zinc, cadmium and lead above background in the upper Spokane River,” said Mary Jane Nearman of the U.S. Environmental Protection Agency’s regional Superfund office in Seattle.

State agencies are scrambling to assess the environmental and health consequences of the new study by next week, when the EPA plans to release it to the public.

The upper Spokane River has public beaches and is popular with kayakers and anglers.

EPA and U.S. Geological Survey officials will present the river data at a 1 p.m. briefing April 22 at the Spokane Area Chamber of Commerce, said Bill Dunbar, EPA’s congressional liaison in Seattle.

The EPA has been checking the accuracy of the Spokane River findings for several months. The heavy metals measurements were released in late March to the Spokane Indian Tribe for analysis.

The EPA scheduled the Spokane briefing after a public records request from The Spokesman-Review for the river data.

The EPA hired the USGS for the study. In October, USGS scientists collected samples of river sediment from the Idaho state line to Lake Roosevelt. They returned in February to gather more samples east of Spokane city limits.

The USGS can’t comment on its findings until the EPA releases the data, said USGS scientist Paul Woods in Boise.

It’s already known that dissolved zinc, cadmium and lead levels in the Spokane River are 10 to 100 times higher than any other major river in Washington, according to Ecology studies.

The new EPA study is the first to look comprehensively at river sediment, including shorelines near homes in the Spokane Valley.

A decade ago, the USGS detected elevated lead levels downstream of the Silver Valley in Idaho - including major deposits of heavy metalsladen sediment at the bottom of Lake Coeur d’Alene. The sediment covers much of the lake bottom, up to 15 inches deep in some places.

The USGS dated the lake sediments with Cesium 137, a radioactive tracer, to determine their age. They discovered the earliest deposits of heavy metals dated back to the turn of the century - the beginning of Silver Valley mining.

In the past two years, the Spokane River study has been caught in a regional tug-of-war over downstream mining pollution from Idaho.

During high spring flows in May 1997, Ecology collected samples showing high levels of dissolved metals in the river.

In July 1997, the USGS also reported results of a new study showing heavy metals in the Spokane River were both dissolved in the water and attached to sediment. The metals “substantially exceed” federal water quality criteria for the protection of aquatic life, the agency said.

Washington state officials, including Gov.

Gary Locke and Attorney General Christine Gregoire, asked EPA for an expanded study of mine pollution coming into the Spokane River from Lake Coeur d’Alene.

In 1998, the Northwest Mining Association criticized Gregoire for encouraging an EPA study that focuses only on mine pollution, not other sources of Spokane River pollution.

It’s unlikely the new study will lead to any beach closures, said Holly Houston, executive director of the Coeur d’Alene Basin Mining Information Office in Idaho.

“The EPA has said the beaches in Idaho are safe. It’s likely the same conclusions will be reached in Washington,” Houston said.

The EPA is expected to decide by next year how much more heavy metals cleanup should be done in the region’s waterways, including the Spokane River.

The Washington Attorney General’s Office has estimated it will cost at least $1 million to clean up metals in the Spokane River from the Idaho state line to Lake Roosevelt.

This sidebar appeared with the story: MEETING EPA and U.S. Geological Survey officials will present the river data at a 1 p.m. briefing April 22 at the Spokane Area Chamber of Commerce.