UPDATED: Hazmat investigation still underway after 100 fish killed in stream

Update at 5:35 p.m. — The Arlington Dept. of Environmental Services said via Twitter Thursday evening that “people and their pets should continue to avoid entering” Four Mile Run. Authorities are still investigating the incident and may be adding some harmless dye to the water as part of the investigation.

Update: Harmless dye may be seen in Four Mile Run in the area of this incident as the investigation proceeds. People and their pets should continue to avoid entering the stream. https://t.co/6RVLSZIHar

— Arlington Department of Environmental Services (@ArlingtonDES) September 8, 2022

Earlier: There are “no ongoing hazards to humans and their pets” after a hazmat incident in Four Mile Run.

That’s according to the Arlington County Fire Department, in a Twitter post this morning. ACFD said about 100 fish found dead in the stream on Wednesday, between S. Walter Reed Drive and S. Taylor Street. A chemical odor was also reported.

People and pets were encouraged to avoid the waters between the Shirlington area and the Potomac after the fishkill was discovered. The fire department says it has identified “a likely source” that caused the incident.

ACFD and Arlington’s Dept. of Environmental Services worked together on the hazmat investigation.

#Final – Hazmat crews identified a likely source that resulted in approximately 100 fish killed in Four Mile Run in the area initially reported. There are NO on going hazards to humans and their pets from this incident.

— Arlington Fire & EMS (@ArlingtonVaFD) September 8, 2022