Scientists at PSI and the Center for Urban Waters have taken their research to the highest place on earth. The same techniques used to analyze water quality in Puget Sound are being applied at Everest base camp.
Water samples were collected on the mountain and sent back to PSI researchers Andy James and Justin Miller-Schulze as part of a study on potential human impacts on drinking water. New techniques can identify chemical tracers known as CECs that indicate human sources.
CEC stands for “contaminants of emerging concern,” and the area’s more than 4 million residents inadvertently flush them into Puget Sound every day. They include hundreds—if not thousands—of food additives, pharmaceuticals and other chemicals that pass through leaky septic tanks and wastewater treatment plants. Their impacts on the environment are unknown, but scientists have started using these compounds to trace and identify human sources of pollution.
Miller-Schulze and James were studying the occurrence of CECs like caffeine and ibuprofen that can serve as markers for bacterial pollution from human waste—the equivalent of a human fingerprint at the scene of a crime (or broken sewer main). New techniques can effectively trace these compounds in concentrations as small as the parts per trillion, and far exceed the accuracy of standard tests for E. coli and other bacteria.
Last summer, a team of Seattle-based engineers heard about this work and contacted PSI with an unusual request. Could some of these same analytical techniques be applied to other parts of the globe, in particular to one of the world’s most famous climbing destinations?
The engineers were led by climbers Gary Porter and Dan Mazur who had become alarmed by increasing pollution in the Everest region and were working to improve environmental conditions at the local villages. Once a pristine outpost, Everest base camp now draws thousands of climbers and trekkers, along with mounting garbage and human waste.
Each year, Sherpas haul more than 12 metric tons of human feces from staging areas around Everest to the village of Gorak Shep. Without a modern sanitation system, much of this waste is simply tossed into open pits and may now be finding its way into local drinking water. Tests sponsored by the National Science Foundation in 2012 showed high levels of fecal contamination in one of the village’s major water sources.
The water was clearly tainted, but it was difficult to prove how it got that way. Was the contamination from the many human visitors, or some other source? Perhaps a preponderance of yaks and other livestock in the nearby villages? Standard tests weren’t definitive, and that’s where PSI came in.
Miller-Schulze and James had been doing the same type of research to identify leaky septic tanks in Puget Sound, and the techniques they used for Everest were similar. Last November, a group of climbers and Sherpas gathered samples and shipped them back to the PSI labs at the Center for Urban Waters in Tacoma. The water was full of chemicals that could only have come from achy humans.
“One of the sample sites had levels of Tylenol and ibuprofen comparable to measurements we have made right at the outlets of septic tanks in Kitsap County,” says Miller-Schulze, who did the chemical analysis. “The fact that we are seeing these high levels of anthropogenic drugs reinforces that the source is human.”
For James, an environmental engineer working on new ways to identify pollution sources, the Everest project was a chance to come full circle. A climber himself, he had visited the region years ago as a Peace Corps volunteer and had seen first hand the concentrated levels of tourism there. “Hopefully, climbers and tourists will start taking more responsibility for sanitary conditions on the mountain,” he said. “These studies are a clear demonstration that they are having an impact.”
The project presented some unique challenges. The great distance from the sampling source to the lab meant longer storage times. To minimize degradation, the researchers opted to freeze the samples. That wasn’t difficult on a mountain of ice, but other logistical challenges were harder to overcome. Mailing the samples would have been extremely expensive and impractical, so they were carried by hand, and eventually by plane from base camp all the way to Seattle.
Miller-Schulze cautioned that the initial sample size was small, coming from only four sources, and that the length of time that the samples had to be stored makes them less accurate. However, he said degradation would only lead to fainter readings, not false positives. Concentrations of contaminants would likely be higher at sample sites. The team expects to receive more samples from climbers in March.
The volunteer engineers who approached PSI hope to use the findings to bolster the case for the installation of a biogas waste digester system near Everest base camp. The system would convert the waste into methane gas for cooking fuel for local villagers. The PSI scientists for their part hope to take what they learned and apply it to their work at Sound Citizen, a citizen science program that identifies human-originated compounds such as caffeine and cooking spices in the waters of Puget Sound. The two researchers are also working to identify emerging contaminants that might be harmful to Puget Sound wildlife.