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October 09, 2008 3:42 am

E. coli count down in Shoshone

Written by Tribune Staff


Recent tests show signs of improvement

August test results suggest there are fewer Escherichia coli (E. coli) colonies in the Shoshone River and Bitter Creek than there were last year.

“We are showing some improvement,” said Ann Trosper, watershed coordinator for the Powell-Clark's Fork Conservation District.

“...Still not out of the woods, but a definite improvement.”

Where Bitter Creek dumps into the Shoshone River, there were 401 colonies of E. coli per a 100 milliliter vessel in 2007. August 2008 numbers confirmed 380 colonies, Trosper said.

In an area on Bitter Creek where septic systems have been repaired, 2007 numbers were 137 colonies per 100 milliliter vessel. In August 2008, that number dropped significantly to 54. An irrigation waste ditch dumps into the creek at that location, so the site has been referred to as a “hot spot,” Trosper said.

Trosper and the Wyoming Department of Environmental Quality hope to clean up, or at least improve, the waters of the Shoshone River and Bitter Creek.

Trosper dips a bucket in the Shoshone River near Willwood at a public access road off Road 9 (Wyo. 295). Water from the bucket will be transfered to small sample containers.

It is a lovely spot. The river rolls in smooth, greenish current while trees and grass reach verdantly from the river's bank. But nasty bacteria squirm about beneath its placid surface — E. coli and fecal coliform.

Trosper is sampling five sites on the Shoshone River and nine on Bitter Creek. Each site must be sampled five times to obtain one average, and Trosper said she obtains two averages from each spot.

This year, Trosper sampled sites on the Shoshone from the Corbett Dam downstream to the Penrose Dam.

On Bitter Creek, she dips near the University of Wyoming Research Center downstream to the confluence of Bitter Creek and the Shoshone River.

Trosper tests her samples in a kitchen at the district office, a process approved by the DEQ.

Samples are treated with Colilert, an agent that allows the water's properties to become visible under a black light.

Then the samples are poured into trays that separate the water into small, sealed compartments, resembling plastic TV dinner trays with multiple cubicles covered with clear plastic.

Trosper sets the samples in an incubator. After baking, the trays are placed beneath an enclosed black light. It is like looking through an old-fashioned View-master. Some of the little compartments are bright yellow, like amber street lights, and others are white in color like scalded milk. Yellow equals fecal coliform, and white means E. coli.

Trosper's study is being funded by a Wyoming Department of Agriculture grant. She said the funding will end June 2010, signaling the end of her sampling.

E. coli comes from the intestines of all mammals. From there, where E. coli are entering the water is unknown. All the DEQ knows or sure is the Shoshone is impaired with E. coli from Yellowtail Dam upstream. The exact entry location has not been identified at this time.

But the source of the problem is not the point, Trosper said.

The district and the Wyoming Department of Environmental Quality hope to fix the problem, not point fingers at polluters.

If livestock are dumping E. coli in the river, that can be mitigated, Trosper said. Likewise, leaking leach fields from septic systems also can be mended. If wildlife are to blame, that is, for the most part, beyond human control.

The reduction of E. coli may be attributed to the DEQ's cost-share program that allowed people near Bitter Creek to replace their aging septic systems. The 23 property owners who entered the program had half their cost covered by the DEQ. Trosper said the average price to homeowners was between $4,500 and $5,000.

Trosper commended people who dipped into their pockets to fix their septic systems.

“They're all people with bills like everybody else,” Trosper said.

Those grants are over, at least until the DEQ can provide the Environmental Protection Agency with maximum daily load limit data of E. coli in the river.

E. coli counts also may be down because the Shoshone and Bitter Creek had higher water this year, thanks to good runoff. Only time and continued samples will tell, Trosper said.

In the meantime, Trosper will continue to monitor streams and educate the public.

“We have got to keep watching and pressing forward,” Trosper said.

The E. coli abatement is good news, but not great news.

“It's not a show-stopper,” Trosper said, “but it's showing we're going in the right direction.”