CORVALLIS - An interagency team of scientists studying fish liver cancer and other fish health problems at an Oregon State University research facility east of Corvallis has estimated an "area of highest potential groundwater concern" around the laboratory.
He estimated area extends north and south of Highway 34, from the Willamette River east approximately two miles to the vicinity of Terra Circle, and southeast along Peoria Road to the old Dixie School.
Although there is not yet direct evidence linking a known groundwater contaminant to the fish problems, persons living within the area of concern should consider drinking bottled water as a precaution, recommended Duncan Gilroy, public health toxicologist with the Oregon Health Division. Use of bottled water outside the area is probably not necessary.
This spring, OSU researchers discovered an unusually high rate of liver cancer and other effects in a number of untreated "control" fish at the Food Toxicology and Nutrition Laboratory, located one mile east of Corvallis on Highway 34. The OSU researcher s previously had experienced a mass fish kill of thousands during December of 1998. Subsequent analysis of the trout's diet, the source and biology of the fish, and laboratory infrastructure and procedures revealed no possible method of contamination, oth er than the source of the lab's water, which is pumped from the groundwater through a series of wells.
Scientists with Oregon Health Division and the Oregon Department of Environmental Quality have been studying the hydrology of the area, and have made some approximations about groundwater movement and the dimensions of the groundwater area providing wate r to the OSU laboratory. A number of private wells also are within this area.
"The area is based largely on groundwater modeling and is only an estimate at this point," emphasized Dennis Nelson, groundwater coordinator for the Health Division's Drinking Water Program. "But it will help identify which households should consider usi ng bottled water."
The area estimated by the agencies is not necessarily an area of groundwater contamination, pointed out Bill Mason, a hydrogeologist with DEQ. Numerous tests of the groundwater thus far have revealed no contaminants that could be responsible for the fish cancer and other effects.
"The task force wants people to understand that the area we have estimated is NOT an area of known groundwater contamination," Mason said. "It is simply an area where private wells could be drawing the same water as the wells at the OSU lab."
Mason said conservative assumptions were used in defining the area of concern, and it is likely that some wells within the area draw water from a different part of the aquifer than the OSU lab. For example, another Oregon State fish laboratory, located l ess than a mile away, has had no apparent problems with its fish.
Scientists with OHD and DEQ have not ruled out the possibility that stream water seeping into the groundwater could carry a contaminant. They therefore also recommend that residents having wells within approximately 100 feet of the East Channel or Muddy Creek consider using bottled water, especially during high water levels in the winter and spring.
Larry Curtis, chair of the Department of Environmental and Molecular Toxicology at OSU, said it is possible that a groundwater contaminant appears only sporadically and could be triggered by high water. The December 1998 incident at the lab that killed t housands of fish occurred during a prolonged rainy period, added Curtis, who chairs the interagency task force.
Curtis said the team is continuing its effort to identify potential contaminants that could have caused the health problems in the fish. The Environmental Protection Agency's national laboratory in Las Vegas is assisting the team in the analysis of addit ional water samples and tissue from the affected fish.
In the meantime, residents who live inside the area of concern should consider using bottled water for drinking and cooking, said OHD's Gilroy.
"Until we know more about what is going on, using bottled water is a sensible precaution," Gilroy said. "We will continue to provide the community with updates as they develop."
A fact sheet with additional details about the fish laboratory and groundwater testing is available by calling the Oregon Health Division at 503-731-4015, or accessing it on the .