E. coli testing done on Snake

August 2, 2017 GMT

The state of Wyoming is investigating whether there are dangerous levels of E. coli bacteria in Jackson Hole’s most prized recreational waters: Flat and Fish creeks and the Snake River.

Ongoing testing this summer and fall was initiated to build on existing assessments of Flat Creek, ailing from stormwater pollution from the streets of Jackson, and Fish Creek, suspected of being impaired because of too many nutrients in the watershed. The added sampling for E. coli — a human health hazard traced to animal and human feces — could deepen the level of impairment if concentrations of the bacteria surpass recreational standards.

Asked whether the streams and river samples have registered concerning, unsafe levels of bacteria, three DEQ officials declined to answer. Test results, at this point, are not being made public.

“We know that Fish Creek is used heavily by recreational users, and because we were already up there we thought it was important,” said Lindsay Patterson, supervisor of surface water standards for the Wyoming Department of Environmental Quality.


The request to publicize early test results was run up the flag pole to the DEQ’s water quality administrator, Kevin Frederick, who also declined to provide data to the News&Guide.

E. coli tests, state officials said, are gathered bimonthly, and the results are averaged to create a “geometric mean” that’s used to determine if a waterway is safe. The tests must also be run through the DEQ’s “quality assurance, quality control” process to be sure there were no flaws in sampling methods or test processing.

The regulatory E. coli standard for streams and rivers where people float, swim and submerge themselves, such as Flat Creek, is 126 “coliform units” per 100 milliliters. It’s a stringent level set by the U.S. Environmental Protection Agency that’s intended to result in no more than eight gastrointestinal illnesses per 1,000 swimmers.

At this juncture the results for Flat and Fish creeks and the Snake River are considered “raw,” DEQ Watershed Protection Manager David Waterstreet said, and still must be verified via the quality control process before they’re considered complete.

“We find water quality here very important and we find protection of locals and local stakeholders to be important,” Waterstreet said. “We could convey any information that we are concerned with, but at this time the information is unsubstantiated until we go through our QA/QC process.”

Test sites on Flat Creek are located at the High School Road bridge and where the stream flows under South Highway 89 in South Park.

Because of sediment deposited into its water each year from stormwater runoff, Flat Creek has been listed as “threatened” by the DEQ since 2000 between the historic Cache Creek confluence north of the Town Square and where it terminates in the Snake River.


Fish Creek’s test sites are located where the stream crosses a corner of the Bridger-Teton along Fish Creek Road and just downstream of the Wilson bridge. Piggybacking on U.S. Geological Survey research, the DEQ has been sampling and assessing Fish Creek for a suspected nutrient impairment since 2016. The spring-fed West Bank stream is considered a Class 1 water — the most pristine — but is considered to have degraded in quality over the decades. An advocacy group, Friends of Fish Creek, has formed to try to pinpoint and fix its ailments.

DEQ personnel are testing the Snake River for E. coli downstream of its confluence with Flat Creek in South Park.

Teton County officials and local residents vigorously opposed a 2015 DEQ plan to categorically downgrade standards in tens of thousands of miles of low-flow creeks around the state to allow five times more E. coli.

Teton Conservation District officials at the time requested that local waters be removed altogether from the downgrade, an appeal that was denied. But Wyoming did alter its plans as a result of conservationists’ pleas so that creeks and seasonal washes that flow in wilderness areas or are part of Wild and Scenic waterways retained the most stringent E. coli standards.

All three Teton County waters currently being examined for E. coli have flows that vastly exceed a 6-cubic-feet-per second threshold, and so their standards weren’t altered by the statewide E. coli regulatory downgrade.

Teton County waterways have been sampled for E. coli before.

In 2003 Teton Conservation District sampled five sites in the Fish and Flat creek basins for E. coli, and ran genetic tests to determine where it was coming from. Five out of 162 samples at the time returned concentrations of E. coli that exceeded 298 “coliform units” per 100 milliliters — a level that more than doubles the current regulatory standard.

But wildlife — not humans — was the source of the majority of the bacteria, said Carlin Girard, Teton Conservation District’s water resource specialist.

“Avian, rodent and ungulates signatures comprised over 50 percent [of the E. coli] in the Fish Creek and Flat Creek basins,” Girard said. “The management implications of E. coli that originates from wildlife sources are different than human-derived sources.”

E. coli traced to septic systems, or other human sources, he said, is the most dangerous and concerning.

It’s unclear when the results of E. coli tests from Flat and Fish creeks and the Snake River will be made public.

An assessment report in the works for the Fish Creek watershed typically would take between six months and a year to develop, Waterstreet said. DEQ may also release the results once the tests have gone through the quality control process this fall. The state agency, he said, has contacted Wyoming’s attorney general to see if it is required to release the results at that time.