By Marissa Heffernan / The Daily News
The Department of Ecology is seeking public comment on updates to the state’s water quality standards that would set requirements for oxygen and fine sediment levels in streams and rivers.
According to Ecology, the changes are intended to help support the recovery of salmon, especially salmon roe and young fish.
âSalmon need fresh, clean water to survive,â Ecology’s press release said. “This includes sufficient oxygen and a healthy habitat.”
When fine sediment settles on salmon spawning gravel, it can block the flow of water through the gravel, depriving fish eggs and larvae of oxygen. Currently, state standards do not directly address fine sediment, so Ecology is proposing to clarify what fine sediment protection means.
The draft rule states that water bodies “shall not contain fine sediment from anthropogenic sources at levels which cause adverse effects on aquatic life, their reproduction or their habitat”.
Fine sediments are defined as sediments smaller than 2 millimeters.
Changes to oxygen requirements proposed by Ecology include increasing the required amount of oxygen in water from 9.5 mg / L to 10 mg / L for salmon habitat. The project also includes the addition of a 90% dissolved oxygen and dissolved oxygen saturation requirement, which could be used in place of the milligrams per liter measurement.
Dissolved oxygen saturation reflects how much oxygen water can hold at a given temperature and pressure, and measuring it will help determine the cause of low dissolved oxygen, according to Ecology, “which is the more often due to high water temperature and excess nutrients “.
“We need regulatory changes to support the investments tribal, state and local governments are making to restore Washington’s iconic salmon runs,” said Vince McGowan, Ecology’s water quality program manager, in A press release. âEnsuring that salmon have sufficient oxygen and healthy spawning grounds is essential for salmon recovery. “
People can provide comments on the draft regulatory language online, in public hearings, or by mail. The deadline for comments is December 16. Public hearings will be held Dec. 8-9 online, and written comments can be mailed to the Department of Ecology Water Quality Program c / o Susan Braley, PO BOX 47600 Olympia, WA 98504. Ecology plans to adopt the rules on March 9.