A boil water advisory has been issued for several Bergen County towns after E. coli was discovered in the drinking water.

The advisory was issued to Veolia customers in Cliffside Park, Edgewater, Fairview, Fort Lee, Leonia, Ridgefield and Palisades Park, the company said on Thursday, July 21.

E. coli was confirmed in samples taken July 19 and 20, following a water main break at the Ridgefield plant, the company said.

"Veolia is continuously monitoring and testing the system and we will inform you as soon as the boil water advisory is lifted," the company said.

E. coli are bacteria whose presence indicates that the water may be contaminated with human or animal wastes. Human pathogens in these wastes can cause short-term effects, such as diarrhea, cramps, nausea, headaches, or other symptoms. They may pose a greater health risk for infants, young children, the elderly, and people with severely compromised immune systems.

These bacteria can make you sick and are especially a concern for people with weakened immune systems. Bacterial contamination can occur when increased run-off enters the drinking water source (for example, following heavy rains). It can also happen due to a break in the distribution system (pipes) or a failure in the water treatment process.

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