City of Alexandria Responds to Lake Cook Contamination

Page archived as of May 28, 2021

This news release has been updated to include detail about fishing at Lake Cook.

City of Alexandria Responds to Lake Cook Contamination

For Immediate Release: May 14, 2021

On May 12, the City of Alexandria was notified and responded immediately to a fish kill and an oil-like substance at Lake Cook, a City-owned and operated lake located near Eisenhower Avenue. Lake Cook is adjacent to Cameron Run Regional Park, which is operated by the Northern Virginia Regional Park Authority (NOVA Parks). The Virginia Department of Environmental Quality, Alexandria Fire Department and Fire Marshal’s Office, and the Department of Transportation & Environmental Services determined the contamination was caused by excessive chlorine entering Lake Cook from Cameron Run Regional Park, which includes a splash park, with a play pool and a wave pool. Approximately 60,000 gallons of chlorinated water from the play pool entered the lake over the course of 9 to 12 hours through a piped connection that the operator thought connected directly to the sanitary sewer, rather than the lake facility. 

Approximately 150 fish and one bird were killed due to chlorine exposure, and their removal is in progress. To help keep residual material from entering Lake Cook, the City placed booms (floating beams used to contain spills) on the surface of the water at the discharge point of Lake Cook and the walking bridge. The Fire Marshal’s Office issued a notice of violation for the illegal discharge of chlorinated pool water and a blue substance used as a stain on the pool deck. NOVA Parks has indicated that it will take actions to ensure that such a discharge error cannot reoccur in the future.

Lake Cook is a designated fishing spot in Alexandria and in response to this incident, the City has posted signs that all fishing at Lake Cook should be catch and release only until further notice. 

Contact the City immediately using Alex311 if you see or smell anything out of the ordinary in Alexandria’s waterways. If you suspect the spill to be hazardous, please dial or text 911.

For inquiries from the news media only, contact Andrea Blackford, Senior Communications Officer, at  or 703.746.3959.

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