Water near Cosmopolis will be turning red, but there is no need for alarm.

The Washington State Department of Health is alerting the public that they will be doing testing as part of an effort to determine the impact of pollution on shellfish in Grays Harbor.

March 18-21, officials from the Washington State Department of Health, the Quinault Indian Nation, and federal and state agencies will conduct a dye study in the Chehalis River.

On March 19, red dye will be added to treated wastewater from Cosmo Specialty Fibers’ treatment plant. The dye may be visible in the water; however, it is not harmful to people, marine life or the environment.

Scientists will monitor its movement over the next few days and pinpoint where pollution may come in contact with shellfish in the harbor.

The Department of Health is responsible for the safety of commercially harvested shellfish in the state.

The Office of Environmental Health and Safety uses national standards to classify all areas.

USGS scientists conducted a dye-tracer study in June 2016 on the Missouri River about 10 miles downstream of Fort Peck Dam, Montana. The public can expect to see the Yellowstone River turn a similar color in the vicinity of the injection site when scientists conduct a dye study near Glendive, Montana in late June, 2017.(Credit: Pat Braaten, USGS. Public domain.)