Baltimore wastewater treatment plant spills 21 million gallons of partially treated wastewater

The Anne Arundel County Department of Health issued an advisory on May 30, 2025, for the headwaters of the Patapsco River to the mouth of Bodkin Creek due to a large effluent overflow of over 21 million gallons of partially treated wastewater from the Patapsco Wastewater Treatment Plant in Baltimore, Maryland.

A structural issue led to the bypass of nitrogen-reducing equipment, and the wastewater did not meet the standards for discharge. A preliminary report was recently updated to reflect that raw sewage did not enter the wastewater.

The Department of Health has issued an advisory against direct water contact for the next seven days due to the risk of wastewater affecting Anne Arundel County Recreational Waters. People coming in contact with the affected water are advised to immediately wash well with soap and warm water.

The overflow was initially reported to the Anne Arundel County Department of Health at 11:00 p.m. on Thursday, May 29, 2025, and listed as ongoing. Officials at Baltimore City DPW provided updated information on May 30, 2025, that the wastewater treatment plant was fully operational at 6:00 p.m. on May 29, 2025.

After a rainfall, all Anne Arundel County beaches are under a no swimming and no direct water contact advisory for at least 48 hours due to predicted high bacterial levels.

Anyone fishing in the Patapsco River and neighboring waterways should be cautious and consider wearing gloves, and if there is any water contact, wash hands with soap and warm water as soon as possible.