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FACT SHEET: Fish Toxicity and Groundwater Contamination Episodes at the OSU Food Toxicology & Nutrition Laboratory What has the task force learned about the problem? What can be ruled out as the possible cause of the fish toxicity? Why does DHS think it is safe to use my well water for cooking and drinking? How do I know if I have a shallow well and what does that mean for my drinking water? Is it possible that there will be another episode? In the spring of 2000, Oregon State University researchers began finding an unusually high rate of liver cancer in untreated ("control") fish at the Food Toxicology and Nutrition Laboratory, located approximately one mile east of Corvallis on Highway 34. A number of other unusual effects were found in the fish, including high mortality, altered growth, kidney damage, anemia, and various physical deformities. A task force was organized in the spring of 2000 to investigate the high level of fish toxicity. The task force consisted of representatives from the Oregon Department of Human Services (DHS), the Department of Environmental Quality (DEQ), Oregon State University (OSU) and the Linn and Benton County Health Departments. The primary goals of the task force were to determine whether a groundwater contaminant caused the fish toxicity and what the potential health risk might be to people who live in the area and drink well water. Through a process of elimination, OSU determined it is likely that the fish toxicity was caused by a chemical contaminant in the lab's water supply. However, no contaminant was found to explain the fish kills or the increased incidence of other unusual effects. Tests of the lab's well water did detect very low levels of some pesticide and petroleum compounds. The interagency task force agrees that the detected contaminants are typical for shallow groundwater (less than 40 feet). The levels are significantly below regulatory standards for drinking water developed by the Environmental Protection Agency and DEQ. What has the task force learned about the problem? While the causative agent remains uncertain, the task force has been able to characterize several important aspects of the fish toxicity events. The events were determined to be episodic in nature and were not the result of long-term hazardous conditions. No unusual events have occurred in the past 18 months in the fish lab or associated aquifer, during which time the task force has taken the steps described below:
In 2000, health officials at DHS issued a recommendation regarding the use of water from wells that potentially draw from the same shallow groundwater as the fish lab. The recommendation cautioned people living nearby to consider using bottled water for drinking and cooking. It was issued because of the potential exposure to hazardous material from drinking well water. With the information from the task force investigation and the lack of unusual fish toxicity in the past 18 months, DHS is removing the recommendation because there is no evidence that the causative agent remains in the groundwater. The concentrations of those contaminants that were detected in the groundwater were well below regulatory standards and should not pose a threat to human health. The fish toxicity events are part of a larger issue that affects people who receive their drinking water from shallow wells in the Willamette Valley and other regions of the country. Shallow wells have been found to be more vulnerable to bacterial and chemical contamination. How do I know if I have a shallow well and what does that mean for my drinking water? A shallow well (40 feet or less in depth) can be easily contaminated. For people that use well water for drinking and cooking, alternate methods to reduce exposure to contaminants can be taken. Although DHS has removed the bottled water recommendation, some people may choose to continue using bottled water or consider treatment options for their well. The shallow groundwater in the area around the OSU Fish Lab is susceptible to low levels of contamination from multiple land uses. The shallow groundwater aquifer around the OSU Fish Lab is similar to other groundwater systems throughout the Willamette Valley. The Willamette Valley's shallow sand and gravel aquifer has an extensive history of water quality problems. The lack of a significant clay layer to block the downward flow of contaminants means that they can become easily polluted. In addition, water that passes through coarse gravel may not have enough contact with fine soil to filter chemicals and bacteria. Contamination can come from spills, landscaping, residential septic systems, agricultural practices and other sources. Shallow wells that are close (less than 100 feet) from surface water, such as a stream or river, are also susceptible to surface water because it can migrate into the groundwater. If you would like to know more about the different treatment options to reduce contamination in your well, contact the OSU Well Water Program web site at http://wellwater.orst.edu or Dennis Nelson at 541-726-2587 ext. 21. Is it possible that there will be another episode? It is possible that another fish toxicity event may occur. OSU has committed to keeping the community informed and will continue to monitor trout in the lab. If an event should occur, DHS and the county health departments will alert users of the groundwater. Although no agency can guarantee that unusual fish toxicity won't occur in the future, there is nothing to indicate that the groundwater poses a public health hazard. Where can I call if I have other questions or need more information? Please see the contact information at the top of this page. |
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