Precision Castparts is investigating whether PCBs that went into Johnson Creek previously, during six decades of operations in Southeast Portland, now pose significant risks to human health and the environment, according to the Oregon Department of Environmental Quality, which is monitoring the study.
DEQ said Polychlorinated biphenyls – a class of manmade chemicals known as PCBs – in Johnson Creek came from the Precision Castparts metal fabrication plant at 4600 S.E. Harney Street, where the company initially set up operations in 1956. The creek runs just south of the plant near the Clackamas-Multnomah County Line.
In 2016, when Pamplin Media first reported PCBs measured in the waterway, DEQ said it could not "definitively" identify the source of the toxins. But in early June, DEQ spokeswoman Laura Gleim said her agency no longer has any doubts that the PCBs had spilled from a storm sewer on the Precision plant property. She said DEQ also is keeping an eye on underground contamination from the plant that is polluting an aquifer running toward the city of Milwaukie.
Precision Castparts, which produces a variety of products for the aerospace industry, has responded to the discovery by treating its stormwater runoff since 2016 to prevent further contamination at the site from reaching the creek, she said.
"It's important to note that contamination is no longer migrating from the site into Johnson Creek, and the groundwater doesn't pose a current health risk to people," Gleim pointed out. "We're still gathering data to develop a full characterization for the site, which will take some time."
Precision Castpart's portion of the investigation is expected to wrap up later this year, according to company spokesman David Dugan. Gleim said DEQ will wait until Precision Castparts completes its study before determining "if there is a risk to human health or the environment."
Although Precision Castparts is responsible for conducting the risk assessment, Gleim said the state agency will oversee the study, review it, and approve it only if it meets the state's standards.
DEQ takes samples of the groundwater in the area four times per year. No PCBs have been reported in the groundwater.
Every year, a handful of Coho and Chinook salmon are spotted in the creek, according to the Johnson Creek Watershed Council. In 2018, the City of Portland removed some contaminated soils from the creek near the plant to improve fish habitat, and to reduce erosion. The city is expected to release a report on that work this summer.
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