Concerns about the presence of heavy metals like lead and arsenic in the river after several dams were breached were first voiced by residents and Siskiyou County officials in March.
But a new round of monitoring from early May suggests those metals concentrations, many of which are naturally occurring, are dropping as decades of sediment continues to wash down the river.
“The metals really are associated with the sediments. They’re bound up in the sediments. And so, as the sediment concentrations come down, the metal concentrations are also coming down,” said Matt St. John, an environmental program manager at the North Coast water quality board.
The new water quality monitoring testing was done on May 1 and 2 by the Klamath River Renewal Corporation, the organization in charge of dam removal. According to St. John, the results were provided to him on a provisional basis last week. A full report prepared by KRRC is expected in the coming weeks, he said.
“The bottom line is from the standpoint of those heavy metals -- you mentioned aluminum, arsenic and lead -- they’re all below water quality standards and really don’t present any kind of public health concern at all,” he said. “They’re really at background or baseline levels.”
The presence of metals caused such concern from residents around the Klamath River that the Siskiyou County Board of Supervisors declared a local emergency in late March and requested that Governor Gavin Newsom declare a state of emergency in order to provide federal and state assistance to the county.
Gov. Newsom did not fulfill the request, according to staff from his office.
This month construction crews broke ground on the deconstruction of Iron Gate and J.C. Boyle dams after receiving authorization to remove them by the Federal Energy Regulatory Commission.
St. John with the North Coast Regional Water Quality Control Board said, based on a recent visit he made, river conditions appear good in spite of the demolition work.
Correction: a previous version of this story misidentified the organization preparing the next Klamath River water quality report.
