Lake Coeur d’Alene has been looking a little peaked lately.

That green tinge to its normally blue waters does indicate a slightly sickly lake.

So don’t drink lake water unless it’s treated.

The February floods in North Idaho washed large amounts of sediment into the lake, causing problems for divers and people who draw water from the lake to drink.

“We have very poor visibility right now,” said Eric Rouse, a diver with Tom’s Diving Adventures. “Usually, this time of year it’s a lot better.”

The turbid water was beginning to clear recently when the spring runoff exacerbated the problem.

Much of the sediment is microscopic, slowing the settling process, said Geoff Harvey, senior surface water analyst with Idaho’s Department of Environmental Quality.

“What you’re seeing is the diffraction of light. It gives you that off-green color,” Harvey said.

Some of the clay particles are carrying lead, too.

Tests of water entering drinking water systems along the lake in March showed elevated levels of lead, Harvey said.

“It’s the first time we’ve seen those numbers go to lead levels that exceed the (federal drinking water) criteria,” he said. After filtering and treatment, however, the water is suitable for drinking.

Drinking untreated water won’t necessarily make a person sick, but the lead does pose a long-term health risk - especially for children.

Just in case people don’t already treat their water, the DEQ and Panhandle Health District are issuing a public health notice to remind them to do so in light of the lead problem.

Some people with individual water systems are finding that the fine sediment is clogging their water filters.

“They’re using bottled water,” Harvey said.

Even with the larger amounts of lead floating around the lake, Harvey said he doesn’t expect much of it to wind up on the beaches.

Most of it will drift to the lake bottom, or wash down the river. Lake Coeur d’Alene has a high turnover of water. Twice a year the water is replaced by new water.

“So it’s exporting this stuff and replacing it with cleaner water as we speak,” Harvey said.

, DataTimes