Related: Portland's Toxic Air Problem
Elevated levels of cancer causing hexavalent chromium continue to circulate in Southeast Portland's air, but the Oregon Department of Environmental Quality said Thursday it has narrowed down a possible source: exhaust stacks at Bullseye Glass.
Bullseye hasn't used chromium in its glass making operations for months, but DEQ officials said they suspect residual chromium in the stacks may be the culprit.
DEQ has been monitoring the air in Portland since a U.S. Forest Service study earlier this year detected highly elevated levels of chromium and other heavy metals.
“We have not seen any of those spikes since May," said Keith Johnson, environmental cleanup manager for DEQ.
"But we have lately begun to see sort of a general elevation of chrome-6 concentration in air over what we would expect from urban ambient amounts,” he added
As a result of the latest tests, DEQ is requiring Bullseye Glass to clean its exhaust stacks of built-up chromium by Sept. 1.
In a press release Thursday, Bullseye said it will continue its plan to install furnace filters, known as baghouses, and continue to comply with DEQ requirements.
"To date, Bullseye has spent approximately $60,000 for professional services on the source test. We expect the program to install baghouses will cost approximately $650,000. In the meantime, we are formulating some new chromium-free green glasses," the release stated.
DEQ officials said they will also be addressing other possible sources of the chromium, such as dust from a nearby cement company.