Concerned residents of the Lake Washington area, including some in Kenmore, are working together to hold the Washington State Department of Transportation accountable for the arsenic levels in the old State Route 520 bridge.

Letters have been sent to the Federal Highway Administration (FHWA) and United States Department of Transportation Inspector General asking for a federal investigation into WSDOT and its contractor, Kiewit/General/Manson (KGM).

A press release issued by People for an Environmentally Responsible Kenmore (PERK), the Green River Coalition and Laurelhurst Community Club last week documents how the residents and organizations came across conflicting reports of the level of arsenic in the concrete in the old SR 520 bridge through open records requests. Some documents list very low levels of arsenic (less than 0.2 ppm), while others list 50-65 ppm.

The old floating bridge is currently being demolished over Lake Washington, leading residents to raise health concerns.

“It involves the whole lake, not just Kenmore,” Janet Hays, a Kenmore resident, said.

The concerned citizens met with WSDOT and KGM in July, when representatives of both organizations allegedly denied the higher level despite documents indicating they knew there were 50-65 ppm in March.

Also in July, a request for the records leading WSDOT and KGM to arrive at the 50-65 ppm figure was filed, but Green River Coalition Co-Founder Greg Wingard said they have yet to receive that documentation.

“They have to provide us with the data,” he said. “If they don’t, we’ll sue them.”

Since the press release and letters were sent out Tuesday, Wingard received an email from the Department of Ecology saying they were starting to look into the amount of arsenic in the bridge. PERK President Elizabeth Mooney received an email Wednesday from FHWA Washington Division Environmental Program Manager Sharon Love saying the administration is working on a formal response to the concerns.

Mooney said, at the very least, she would like to see air and water monitoring in the area near the demolition to see if any traceable amounts of arsenic or other contaminants are found.

A call to WSDOT for comment has not been returned.