About DEQ’s report on Oregon

Last week, ODA and DEQ also released the 2019-2021 biennial report for the Pesticide Stewardship Partnership. Despite an unnecessary headlining of detections alone in the short fact sheet and the report itself, a deeper look at the data reveals that overall, more than 90% of sites sampled over the last 10 years have shown either improving or non-significant changes based on an analysis of changes in concentrations over time. And this is despite the fact that the PSP sampling strategy is targeted to specific times and locations where pesticides are most likely to be detected.
According to the report, only two pesticides come out as having significant increases in aquatic life benchmark exceedances compared with the last biennium (malathion and diazinon), and those occurred in only one watershed each across the nine that were sampled. In fact, over the last 10 years, including 257 sampling sites, only 8.5% of these sites appear to be associated with any negative trends in water quality connected to pesticide concentrations. We will continue to stress that there are serious flaws with using PSP sampling data to draw any conclusions beyond the local context, since these data reflect targeted attempts to detect pesticides at specific times and locations.
While several charts in the report focus exclusively on detections, the report does point out the lower diversity of pesticides detected in watersheds that are mainly agricultural, compared with those that have mixed, including urban land uses. It also points to significant reductions in specific pesticides detected within each of the PSP watersheds. In the future, we hope to see a shift away from trying to generalize from the data and back toward the data’s intended use: supporting robust and targeted education and outreach to pesticide users, whose volunteerism, trust, and respect are at the heart of this program.

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