Several Delaware County communities are being advised to boil their water due to the potential for contamination caused by a water main break Thursday afternoon. 

People in Upper Chichester, Lower Chichester, Marcus Hook and Twin Oaks should bring their water to a rolling boil for at least minute before using it for drinking, making ice, cooking and personal hygiene, the Chester Water Authority said in an advisory issued Thursday evening. 

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There is an increased chance that the water contains disease-causing organisms, officials said. That’s because the main break caused a drop in water pressure in an active construction site at Bethel Avenue and Route 322, in Upper Chichester, allowing the potential for the water to become contaminated via back flow. 

The break involved a 24-inch main and a failed valve that required crews to manually cut the water off before repairs could proceed, according to county spokesperson George Basile. Partial service is expected to return by the end of Friday, but the issue may take 48 hours to fully resolve.  

Two water filling stations are available to people under the advisory. They are located at the Upper Chichester Township Municipal Building, 8500 Furey Road in Upper Chichester, and the Marcus Hook Borough Administrative Office building at 1111 Market St. in Marcus Hook. People should bring their own containers. 

CWA is also delivering bottles of water to residents upon request. Anyone impacted can call 610-876-8181 for assistance.

The cause of the main break is being reviewed by specialty contractors, and contamination has not been confirmed in the affected areas, water authority officials said.

While the advisory is in effect, customers may experience low to no water pressure.

“CWA understands the disruption the water main break has caused for our customers and the community,” Executive Manager Darryl Jenkins said in a statement. “Our crews and partners are working tirelessly to resolve the issue as quickly and safely as possible. We appreciate the public’s patience and cooperation as we restore service.”

Chichester School District closed its schools and offices Friday in response to the alert, saying the requirement makes it “impossible” to serve students breakfast or lunch in a safe manner.

The water authority said it collaborated with the Delaware County Emergency Management Division to ensure first responder service is not be impacted. 

More information can be found by calling the CWA’s Customer Service Department at (610) 876-8181 or (800) 793-2323.

This story has been updated with comment from Delaware County officials.