Keeping Oregon’s waterways safe from pollution is no small task in today’s world. Seemingly endless sources of contamination can foul streams and rivers. For example, past decades of industrial operations left behind chemical contaminants that today still confound clean-up efforts in Portland Harbor. Heavy metal mine tailings can seep into streams, increasing mercury levels in fish. But these so-called point sources of pollution are only the conspicuous culprits. The largest source of water pollution in Oregon is surface water runoff, or non-point source pollution, and it’s more difficult to contain because its sources are not traceable to a single pipe or leaky mine.
Jeff Jenkins, an Oregon State University toxicologist, knew a decade ago that it was just a matter of time before a particular non-point source of pollution in California would soon be a concern in Oregon. California Fish and Game officials had found that early-season use of organophosphates, a class of neurotoxin pesticides that were used to combat insect pests in tree fruits, were toxic to some sensitive aquatic organisms considered indicators of stream health. The same pesticides were being used at the time throughout the 24,000 acres of fruit orchards in Hood River’s watershed.
In the late 1990s, Jenkins learned from Gene Foster, a toxicologist at the Oregon Department of Environmental Quality and an OSU graduate, that organophosphate levels had exceeded water quality standards in Hood River samples. The standards include hundreds of measures designed to protect aquatic life, often based on the most sensitive species. In addition, there was concern for winter steelhead in the area that could be harmed indirectly by a reduction or contamination of their food supply.
Two of the most potent organophosphates in question were the neurotoxins chlorpyrifos and azinphos-methyl. They control pests by disrupting nerve transmission and the ability to reproduce. Chlorpyrifos was used to control insect pests on pear, apple, and cherry trees early in the season, when the weather could still be rainy and the potential for runoff was high. Azinphos-methyl was typically used in the drier summer months to rid the orchards of codling moth. About 74 percent of all apples grown in the valley and 68 percent of all pears were sprayed with an organophosphate to keep codling moths in check. It was only a matter of time before Oregon’s $160 million tree fruit industry would face a tough decision.
Jenkins hoped that DEQ’s findings would engage the community of Hood River growers rather than be perceived as the beginning of a regulatory crackdown. “My goal was that stakeholders, particularly the ones considered polluters, should have a say in the matter to facilitate a faster solution,” Jenkins said. “Of equal importance was the chance to use monitoring data as the basis for science-based dialogue among all stakeholders, including the Hood River Watershed Group, the irrigation districts, and the Confederated Tribes of the Warm Springs who have treaty rights to the Hood River.”
Jenkins developed a monitoring strategy detailing to stakeholders where, how, and why they were monitoring. Hood River Soil and Water Conservation District personnel conducted sampling, using protocols developed by OSU. Three days a week for four seasons (from 2000 through 2003) they monitored water in three strategic locations: the lower valley, where DEQ had found high levels initially; a site that received both agricultural and urban runoff; and an agricultural site in the upper valley. Jenkins’s lab developed new analytical methods to handle the samples cost-efficiently. Water quality standards for these chemicals are quite stringent, and at a few times in a few samples, the researchers found levels more than twice the legal limit as mandated by federal water quality standards.
“Once these issues get on growers’ radar screens, water quality ranks up there with their other decision making criteria,” Jenkins said. “Times are changing, and growers in Hood River are a good example of proactive change.” The process helped increase the awareness of growers about organophosphates, altered how they were using the products, and supported their interest in finding alternatives with lower impacts on aquatic resources. Eventually growers and researchers at OSU’s Mid-Columbia Agricultural Research and Extension Center worked together using the local measurements to develop best management practices tailored to the Hood River Valley. “When offering alternatives to practices, I feel it has more legitimacy if it’s based on local data developed with local input,” Jenkins said.