Friday, August 3, 2007

Chemicals did not cause fish kill

Elkhorn Golf Course vindicated after massive die-off


By TREVOR SCHUBERT
Express Staff Writer

Photo by Nils Ribi A brook trout lies belly-up following the Elkhorn fish kill on May 31. Recently released test results found no definitive reason why roughly 150 brook and rainbow trout died.

On May 31, roughly 150 rainbow and brook trout turned up dead in Elkhorn Creek. This week, the Department of Agriculture released results of tests conducted on water and fish tissue samples showing "no conclusive evidence that the chemicals used caused any of the fish kill," said Pamela Juker, communications director for the Department of Agriculture.

The preliminary investigation and toxicology reports indicated the contamination came from a licensed contractor working for Elkhorn Golf Course in Sun Valley, but no scientific evidence supports the initial claim. The contractor was treating four ponds along the golf course with diquat dibromide and Cutrine-Plus.

The Environmental Protection Agency has approved both chemicals, classifying diquat dibromide as a general use herbicide that is slightly toxic to fish. Cutrine-Plus is an algaecide containing elemental copper that is used in drinking water reservoirs, in lakes that farm fish and in golf course water hazards.

Department of Agriculture tests found no diquat present and only trace levels of cutrine.

"The amount of copper was well below any toxic level," Juker said. "It is our determination that it could even be naturally occurring copper."

Juker went on to say "we really don't know what caused the fish kill. It could have been low levels of oxygen in the water. However, anything beyond our scientific analysis would be speculation."

The contractor treating the ponds used a lower concentration of chemicals than allowed by law, Juker said. In addition, the contractor did not treat the entirety of the ponds, but was only "spot treating" algae along the perimeter.

Of the four ponds where chemicals were introduced, the contractor used 38 percent of the allowable concentrations in one pond, and 31 percent, 65 percent and 77 percent of the allowable concentrations in the others. In the four ponds that were directly treated there was only one dead fish found, Juker said. The other dead fish were found in ponds that were not treated and in the creek itself.

"It has been my experience with past fish kills that the toxicity often passes through the system pretty fast," said Doug Howard, regional administrator for the Idaho Department of Environmental Quality. "After that, there usually are not any long-term affects."

The DEQ took four water samples the day after the fish kill and tested for nearly 50 different chemical compounds. Howard said all results came back "non-detect" except for trace amounts of copper in the zone of the fish kill. The amount of copper present was nominal, Howard said.

"Our results are consistent with those of the Department of Agriculture," Howard said.

The Department of Agriculture is sending its results to the EPA for review before officially closing the case.

"We could close the case right now, but we want to be sure we cover all the bases," Juker said.

Potential fines levied by the Department of Agriculture would have been "label violations for the misuse of a product," Juker said.

The maximum monetary penalty is $3,000. In addition, the contractor's license to work with herbicides and algaecides could have been revoked. However, test results appear to show the contractor used the chemicals correctly and no evidence supports fines against the golf course.




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