Waterways at Pipestone National Monument have been found to contain a harmful mix of pollutants/NPS

Editor's note: This updates to explain the time lag between the sampling and the announcement of the finds.

A harmful mix of chemical and bacterial pollutants, including high levels of E. coli, were found in water samples taken from Pipestone Creek at Pipestone National Monument in Minnesota.

The results were announced Monday by the National Park Service and U.S. Geological Survey, some five years after the initial samples were collected. The length of time it took to announce the results stemmed from samples being sent to at least five different labs, the time it took to write the report, and a peer-review process, said Pipestone Superintendent Lauren Blacik in an email Monday.

"At the time the samples were taken there were warnings to the public about the water quality on a wayside along the creek and in the Circle Trail Guide," added the superintendent. "Since the study was finalized, we have added more prominent warning signs along the creek."

According to the a report on the findings, the samples were taken because "three reaches of Pipestone Creek, including the section flowing through [the monument], are on the Environmental Protection Agency’s list of impaired waters for turbidity and fecal coliform bacteria in high enough numbers to indicate a potential health hazard."

The samples, from Pipestone Creek, the pipestone quarries, and Winnewissa Falls, were analyzed for more than 250 potential water-quality parameters and contaminants.

Researchers detected 13 pesticides, five pharmaceuticals (acetaminophen, gabapentin, gemfibrozil, metformin, and oxycodone), caffeine, methylparaben, two algal toxins, three fecal indicator bacteria, and Mycobacterium avium subspecies paratuberculosis, a parasitic bacterium that can cause disease in cattle, in creek and/or quarry samples.

Among the most concerning findings is that fecal coliform and E. coli were detected in all creek samples and exceeded recommended levels, the release said. These bacteria are an indication of fecal contamination and can be associated with some gastrointestinal diseases. The presumed source of this bacteria is cattle manure. 

Three other pathogens were detected in the water near Winnewissa Falls: Cryptosporidium, Legionella, and ruminant Bacteroides. There are no maximum recommended levels associated with these organisms; however, Cryptosporidium and Legionella can cause illness in humans. Ruminant Bacteroides is an indicator of manure contamination. Other findings that exceeded water-quality benchmarks included dissolved oxygen and turbidity, total nitrogen, nitrate, and phosphorus, and the pesticide atrazine.  

Upstream of the monument, Pipestone Creek has been channelized into a judicial ditch, which is heavily impacted by agricultural and stormwater runoff, the release said.

The monument has taken the initial steps of posting signs warning of the potential health hazards posed to the public and strongly recommends against entering the Pipestone Creek. Some state and local government agencies have programs to incentive best practices to reduce contamination, and park staff said they hope to work with others to improve water quality in the creek over time.

Traditionally, the Pipestone Creek sustained people following wild game, and its waters likely drew people to the quarries. To many, this water is a sacred resource, intertwined with the health of the people, plants, animals, and the pipestone itself.