Tests show algae levels rising in Lake CdA

COEUR d’ALENE – Chlorophyll levels, an indicator of algae growth and deteriorating water quality, have begun to increase again in Lake Coeur d’Alene, a government scientist told a National Academy of Sciences committee reviewing the area’s biggest Superfund project.

“The increase in chlorophyll we’ve seen is troubling to me – it’s in the early stages of getting back to what it was in the 1970s,” said Paul Woods, a scientist with the U.S. Geological Survey in Boise who has studied the lake for years.

When large algae blooms broke out on the lake in the 1970s, Idaho officials moved to clean up some sources of nutrients contributing to the problem, including raw and partially treated sewage from inadequate treatment systems.

But runoff also comes from nonpoint sources such as clearcut forests. An early “lake management plan” had little money and no legal clout.

“Nothing ever happened with the first lake management plan,” Woods said.

In its last public meeting in the region, the 19-member committee reviewing the U.S. Environmental Protection Agency’s plans to scrub mine wastes from the Coeur d’Alene Basin zeroed in on what’s known scientifically about how heavy metals and other contaminants are impacting the lake – and what needs to be done to protect it.

Recent studies are getting a better handle on what’s happening with the tons of lead, zinc, arsenic and other heavy metals from the Silver Valley that still flow into the lake each year from the Coeur d’Alene River. About 92 percent of the lead and 35 percent to 45 percent of the zinc is retained in the lake; the rest flows into the Spokane River, Woods said

“We used to think (heavy metals in incoming water) rarely went into the Spokane River. It’s actually fairly common,” Woods said.

From January to September, water flows across the lake’s surface and into the Spokane River. But from October to December, when river temperatures are colder than the lake water, the heavy metals are carried deep into the lake. Nearly all the metals enter the lake from the Coeur d’Alene River, not the St. Joe River, the USGS studies show.

C. Herb Ward, an academy panel member and an environmental remediation expert from Rice University in Houston, pressed for an answer on what a truly protective lake management plan would contain and cost.

He didn’t get an immediate answer. The issue is one of the biggest controversies surrounding EPA’s 2002 Record of Decision to launch a $359 million, 30-year partial cleanup of mine wastes from Mullan to Spokane. The EPA agreed not to insist on any cleanup of the approximately 77 million tons of metals-tainted mine sediments at the bottom of the lake but to wait for Idaho to develop an effective lake management plan to curtail nutrients and prevent more metals from mobilizing out of the sediments.

Remediation experts for the Spokane and the Coeur d’Alene tribes assailed that decision.

The EPA’s (cleanup) remedy is a “weak, ‘wait and see’ decision,” said Fred Kirschner, a scientist and consultant to the Spokane Tribe.

Philip Cernera, remediation manager for the Coeur d’Alene Tribe, said EPA’s decision to defer cleanup in the lake means the tribe is left to manage one of the nation’s largest toxic waste repositories. A federal court has ruled that the tribe owns the lower third of the lake.

“The lake was never meant to handle this,” Cernera said.

Thomas Pedersen, a University of Victoria professor and consultant to Silver Valley mining companies, said the lake remains a “net sink” for zinc, a hazard to fish and aquatic life, because more zinc stays in the lake than flows out. But he warned that eutrophication driven by future increases in nutrient loads “remains a threat.” Eutrophication results when aquatic plants such as algae, fed by an excess of nutrients in the water, take over a lake and consume most of the water’s oxygen, leaving little or none for the fish.

Pedersen disagrees with some lake studies that say metals could be remobilized out of the sediments in the future when less zinc is carried into the lake from the Silver Valley. He theorized that when the zinc concentration is lowered, plankton will release less zinc.

All the scientists agreed there’s still not enough data to fully understand the lake’s geochemistry. A current USGS study is looking at the lake’s benthic flux – the interaction of bottom sediments with lake water.

At a public comment session Wednesday in Spokane, some citizens criticized an $850,000 NAS study of the EPA’s decision-making in the Silver Valley. It’s unacceptable for the National Academy to spend that money to “study the studies,” while people living within the boundaries of the original 21-square-mile Superfund site remain at risk from lead pollution, said Barbara Miller, director of the Silver Valley Community Resource Center in Kellogg.

“People at the Bunker Hill site only want what other people take for granted – clean homes and health intervention,” Miller said.

State Sen. Lisa Brown, a Gonzaga University professor and a Democrat from Spokane’s 3rd Legislative District, said Washington state residents affected by the mine wastes from Idaho are “generally satisfied” with the EPA’s cleanup plans.

“We understand that opinions differ across the border, and the Idaho delegation brought you here. We trust that your review will not be politicized … your job is to assess the long-term risks,” Brown said.

It’s imperative that the academy’s review is credible, said Dr. John Osborn, a Spokane physician and Sierra Club leader who has criticized some committee members because they are consultants to mining companies. “We need the National Academy of Sciences to do a study that’s unassailable in terms of bias and conflicts of interest,” he said.

Spokane officials worry about the potential health effects of mine contamination in the Spokane River, said Dr. Kim Thorburn, Spokane County’s health officer.

She said the Spokane Regional Health District has translated fish consumption advisories into Russian and other languages because immigrant groups heavily fish the river.