Lake Hopatcong residents’ drinking water contained coliform bacteria, according to samples taken in June by the township’s Municipal Utilities Authority (MUA).

A letter received by community residents from the MUA on Monday stated that out of 10 samples taken during June, five contained the bacteria. According to the letter, “usually, coliforms are a sign that there could be a problem with the system’s treatment or distribution system (pipes). Whenever we detect coliform bacteria in any sample, we do follow-up testing to see if other bacteria of greater concern, such as fecal coliform or E. coli, are present. We did not find any of these bacteria in our subsequent testing.”

The letter stated that those with a severely compromised immune system, infants, pregnant women or the elderly may be at increased risk and should seek medical advice about drinking the water.

According to the letter, the bacteria detected did not constitute an emergency. In that case, residents would have been notified within 24 hours.

Further tests have been performed, and the problem has been resolved, the letter concluded.

Residents who have questions may contact Rich Tuttle, director of municipal utilities, at 973-208-6145.

Tuttle could not be reached for comment. Patch will provide more information as it becomes available.