Tag Archives: nutrient loading

Flathead Basin pollution model completed

A long-awaited model for nutrient pollution in the Flathead Basin has been released, with mixed results . . .

A long awaited computer model for nutrient pollution in the Flathead Basin is completed. The U.S. Environmental Protection Agency contracted with TetraTech to support development of the model, and a draft report on the model was released Nov. 3.

Deficiencies in the model are described in the draft report. While the model reportedly did well in simulating point sources, nonpoint source modeling proved difficult, an issue with political ramifications for the Flathead’s cities and towns, where officials are concerned about spending millions of dollars on treatment plants that will provide small incremental benefits to the watershed.

“There is uncertainty associated with the simulated loading results from many of the nonpoint sources,” the report concludes. “Given the lack of source-specific monitoring data, quantifying the uncertainty is not possible.”

Many nonpoint sources are caused by natural changes in the watershed, and the report states that “additional work outside of this modeling framework would be necessary to quantify the split between natural and anthropogenic (manmade) nonpoint sources.”

Read more . . .

‘State of the Lake’ report discusses water quality, modeling and oil spill threat

Here’s a good summary of the ‘State of the Lake” report given at the Flathead Lakers annual meeting . . .

The bad news about Flathead Lake is that primary productivity, or the lake’s ability to grow algae, climbed back above 100 grams of carbon per square meter per year in 2012, exceeding the water quality target of 80.

“The good news is that the decline in dissolved oxygen at the bottom of the lake isn’t getting any worse,” Flathead Lake Biological Station director Jack Stanford reported in his annual State of the Lake report at the Flathead Lakers’ annual meeting.

Nitrogen, a nutrient that contributes to algae growth, is increasing, Stanford said, but the increased nitrogen means that algae growth is now being limited by the amount of phosphorus coming into the lake.

Read more . . .