Wrangell Cooperative Association’s environmental office this month began notifying the public of the presence of coliforms in a popular off-grid water source.
The pipe just to the north of the Mile 10 marker on Zimovia Highway has supplied Wrangell residents with fresh water for decades, a fixture well before the logging road had been paved. For those living beyond municipal water sources, options for potable water are fairly limited, and for those without a water catchment or well system set up, the pipe provides relatively easy access to supplies.
WCA’s Indian Environmental General Assistance Program (IGAP) office began testing samples from the pipe in May, since drinking water safety was named as one of the top five environmental priorities by residents surveyed by the Tribe in 2015. Acquiring a laboratory incubator and other testing equipment for the task, the program’s intent was to test for coliforms in local freshwater sources on a monthly basis. After making its detection earlier this month, IGAP began testing the pipe site on a weekly basis.
Coliforms are bacteria, which when found in drinking water can indicate the presence of other pathogens. IGAP technician Kim Wickman explained she tests for general coliforms – which themselves are unlikely to cause illness – and for Escherichia coli (E. coli), strains of which can be harmful and fatal.
“General coliforms are what we have seen,” she said.
To test for the presence of these bacteria, Wickman adds to samples a nutrient-laden product called Coliscan Easygel. “We take a 5 mL sample and we add it to an array medium,” she explained. These samples are then kept at a relatively high, stable heat for a 24-hour period, priming conditions for coliforms present in the water to reproduce and colonize.
Enzymes present in the Easygel react with enzymes released by coliforms as they ferment lactose, which set off distinctive splashes of color visible to the unaided eye. The greater hazard to water safety, the medium is formulated so that E. coli produces a different, bluish hue than other coliforms, which show pink, making it more easily distinguishable. Other bacterial colonies do not show up.
So far the last three 10-Mile samples have shown swatches of pink, meaning only general coliforms have been detected. What caused their recent appearance is still unknown, and could be due to a number of factors such as recent rainfall. Their presence could be seasonal, or it could just come and go.
“We haven’t quite found a rhyme or reason for it,” said Wickman.
IGAP coordinator Chris Hatton explained she believes the pipe draws its water from the ground, rather than from surface sources. Though testing only began this spring she said she has been scrutinizing the pipe since the previous year, testing it for flow rate and clarity. Output can vary, taking a minute and a half or two to fill a five-gallon bucket, but even during extended freezing conditions Hatton noted the pipe still flows.
“I’ve only ever seen it clear,” she added. “I think that’s why people rely on it and trust it.”
Since discovering the microorganisms, IGAP has made efforts to inform residents of their presence. Taking to the radio, posting updates on Facebook and pinning notices on local bulletin boards, the office has been advising users of the 10-Mile pipe to exercise caution. It recommends boiling, filtering or chemically treating water until the system is cleared. The office will continue taking samples from the site on a weekly basis until giving the all-clear, with the most recent sample results expected late Tuesday.
In letting people know about present risks, Wickman explained the office has been wary of causing too much of a stir. The ad hoc water source is unmanaged but on state land, and a similar arrangement in the Anchorage area has led the state to remove such structures. Alaska Dispatch News in April highlighted one pipe at Mile 109 of the Seward Highway which draws visitors and residents alike to drink from it. Despite its popularity, the article reported the pipe has previously been removed by Department of Transportation staff due to concerns it affects traffic. It reappears, but its future existence remains tenuous.
“We don’t want this issue here,” said Wickman.
Other issues IGAP has been focusing on include detecting contaminants in subsistence food sources, such as the presence of saxitoxin in area shellfish; solid waste issues and recycling accessibility; outdoor and indoor air quality; and threats to water quality posed by Canadian mining operations along transboundary river systems.
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