Heavy metals detected this spring in the Spokane River during high runoff exceeded federal safety limits for aquatic life.
The Washington Department of Ecology made that announcement Monday after notifying Eastern Washington legislators of the “politically sensitive” findings, said department spokeswoman Jani Gilbert.
From April through June, lead, zinc and cadmium all exceeded long-term federal limits set to protect fish and other river life, Ecology investigators said.
The heavy metals don’t exceed federal drinking water standards and are not a threat to human health, said toxicologist David McBride of the Washington Department of Health.
Ecology’s new findings may be ammunition for a Washington state lawsuit against the mining companies in Idaho’s Silver Valley that sent millions of tons of mine sediments into Lake Coeur d’Alene.
Some of those sediments are being flushed into the Spokane River and are gradually making their way downstream.
Ecology’s new study “confirms the need for a comprehensive assessment of the river,” said Assistant Attorney General Owen Clarke, the lawyer in charge of an assessment of potential natural-resource damage to the river from a century of mining.
The attorney general’s office soon will choose a consultant to conduct additional studies, Clarke said.
In April, Gov. Gary Locke approved spending $300,000 on the Spokane River study.
The new Ecology test results aren’t surprising, but more work is needed, said Laura Skaer of the Northwest Mining Association. The association fought funding for the study and has criticized Ecology’s past sampling methods.
“There’s a leap of logic to take a flood event and compare that to chronic long-term exposure,” Skaer said. “Just because EPA criteria are exceeded in flood events doesn’t mean there’s natural-resource damage.”
A Spokane environmental group says the results confirm their fears.
“These water samples offer further evidence that Idaho’s mining pollution is flooding into Washington during high-flow periods,” said Michele Nanni of the Inland Empire Public Lands Council.
Ecology routinely samples the river at the state line once a month.
This spring’s special sampling took place during high flows. That’s when stirred-up river-bottom sediment and additional sediments containing dissolved metals are washed into the river from the entire watershed.
Among Ecology’s findings:
Lead levels were three to six times higher than the EPA’s long-term water quality limits, but don’t exceed short-term limits.
Zinc was above both limits, while cadmium levels were slightly higher than the federal criteria for long-term exposure.
During this year’s sampling program, Ecology water quality specialists were careful to respond to the mining association’s criticism of their past efforts.
The mining group said past sampling may have exaggerated heavy metals concentrations because many of the samples were taken from behind bridges where sediments tend to collect.
“We were careful this time to collect (water samples) above and below the bridges. We can now safely exclude those localized effects,” said Ken Dzinbal of Ecology’s environmental investigations program in Olympia.
“What we are seeing is coming down the river. The results are very consistent with what we’ve been seeing for the last couple of years. Upstream mining activity is still the suspected source - and the logical source,” Dzinbal said.
An Ecology team sampled water from the right third, left third and the center of the river, and at five locations, starting 2.5 miles upstream from the Washington-Idaho state line and proceeding to below Long Lake Dam. Samples were taken once in April, once a week in May, and once in the first week of June.
, DataTimes ILLUSTRATION: Color photo
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