Dartmouth’s water treatment system has been switched from chlorine to chloramines as of March 22, Interim Department of Public Works Director Tim Barber told the Select Board at an April 5 meeting.

Switching to chloramine treatments is expected to reduce chemicals in the water, officials said.

The project has been in the works for years, and was expected to wrap up last spring.

But it was set back by staffing issues at the department.

In November 2019, Dartmouth borrowed nearly $1.3 million from the Massachusetts Clean Water Trust for improvements to reduce levels of trihalomethanes (TTHMs) — a byproduct of chlorine disinfectants — in the water.

TTHMs and haloacetic acids have been found in the town’s water supply in levels just above state standards intermittently since 2013.

Over many years, drinking high levels of TTHMs may result in liver, kidney, or central nervous system problems, or an increased risk of cancer.

But chloramines don’t form the same chemical byproducts.

In 2017, June Town Meeting approved a budget of $1.5 million to address the town’s water quality issues, and the project was started in June 2019. 

New Bedford has already changed its water supply disinfectant to chloramine.

The switch “should help with some water quality issues,” Director of Development Cody Haddad said at Monday’s Select Board meeting.

“We went online March 22, the day I came down with Covid,” Superintendent of Water and Sewer Steven Sullivan told the board.

He commended the DPW employees who worked to bring the new system online in his absence.

“They’ve taken the bull by the horns and done a great job without me being there,” he noted, adding that “things are starting to fall into place.”

“If we continue this and do our job, we’ll be getting rid of the trihalomethane and haloacetic acid problem we’ve been having in town for many years,” he said.

Select Board members approved posting information about the change to the town’s website to let residents know what’s going on.

They also said the town should change its water bills from six month to quarterly billing as soon as possible.

Sullivan noted that although the department currently doesn’t have the personnel to accomplish quarterly billing, a future capital improvement plan could allow residents to go online and look at their water bill breakdowns on a quarterly basis.

“I think that’s important,” said Select Board Vice Chair Shawn McDonald. “One of the major concerns that I get is these water bills.”

To find out more, visit www.town.dartmouth.ma.us/home/news/chloramine-faqs.