BREWER – There is good news and bad news for the city’s water department.

The good news is that the lead and copper rates are the lowest they have been in a dozen years. The bad news that is in August and September tests showed the presence of coliform bacteria.

The bacteria formed because not enough disinfectant was added to the water, a problem quickly addressed by staff, Water Department Supervisor Mike Riley said Friday.

“In this case we put in a little too little,” he said. City workers “boosted the disinfectant levels and at the same time flushed … that pipe that was having a problem.”

Five retests of the city’s water have been conducted over the last couple of weeks and “all of those came back negative,” Riley said. “The problem was localized and temporary. There has been no detection since.”

Coliform bacteria are naturally occurring and typically have higher rates in the late summer and early fall “because there is a lot of activity in the ponds [that supply the city’s water]. That creates more of a demand” for the disinfectant.

Adding too much disinfectant would cause taste and odor problems, and not enough allows the bacteria to grow.

“It’s a balancing act,” Riley said.

To comply with federal laws, the city is posting a public notice in the Bangor Daily News to inform consumers of the problem and how it has been addressed.

The water is safe to drink for most, but “people with severely compromised immune systems, infants and some elderly may be at increased risk,” the notice states, adding that those with health concerns should contact their doctor.

“The good news is we passed our lead and copper rule for the first time in 12 years,” Riley said. “Those levels have come down consistently over the last several months, ever since we began using soda ash.”

Soda ash, or sodium carbonate, provides corrosion control by making “the lead less likely to leach out of the pipes,” Riley said.

The federal Environmental Protection Agency has been monitoring lead and copper levels of the water department for years, with testing twice a year.

“We actually fell below the lead action level,” Riley said. “If we fall below that again next spring, we’ll be able to go on reduced monitoring” with only annual testing.

“Eighteen months ago we made a change to a different chemical [and] that seems to be doing the trick,” he said.

Those with questions about the bacteria or the lead and copper results may call Riley at 989-4214.

nricker@bangordailynews.net

990-8190