Despite a change in Dartmouth’s treatment system last year, the water main on Reed Road is still experiencing water quality issues — and the State Department of Environmental Protection is getting involved to bring the water supply up to standard.

The Water Department reported on Dec. 21 that it found high levels of haloacetic acids — a byproduct of chlorine disinfection, also called HAA5 — within the water main that stretches from Reed Road to the tank located on Old Fall River Road.

In their latest test, the department reported the average levels over the last 12 months to be at 64 parts per billion. The standard — a safety measure determined by the state — is 60 ppb.

All residents connected to the Reed Road system have been notified, according to Steve Sullivan, the Superintendent of Water and Sewer.

“The goal is to get it below 60 consistently,” he said. “That’s what we’re working on now.”

Sullivan noted that engineers are currently collaborating on how to solve the issue and that the state is requiring his department to provide reports and updates.

“During this planning period, the Department expects the Town to collect water quality data from its sources, including the purchased finished water from New Bedford, to further inform its decision-making,” a notice from MassDEP read.

“The state is requiring us to come up with something and we will,” Sullivan said.

According to MassDEP, high levels of exposure to some of the chemicals in HAA5 have been known to cause adverse developmental and reproductive effects, including toxicity to the liver, kidneys, neurological and reproductive systems.

While the Reed Road averages are higher than the set standard, residents do not need to boil water or take any other corrective actions, the water department reported.

“If the water was unsafe to drink, people would know,” he said.

This was the third violation of 2021 for the Reed Road water main. In May, the department reported high levels of trihalomethanes (TTHMs) and found that water exceeded the standard for HAA5s in August. 

E. coli, which is a fecal indicator, was also found in untreated water samples back in September.

According to Sullivan, those wells are still offline and will reactivate when 99% of bacteria are removed.

As a result of the latest report, MassDEP issued the Town of Dartmouth a notice of noncompliance, meaning that a public water supplier violated an enforceable standard.

“Unfortunately, HAA5 levels during the second and third quarters of 2021 significantly increased, resulting in [maximum contaminant level] violations during both quarters plus the fourth quarter,” MassDEP’s letter read.

To lower the levels, Sullivan said the town is working to flush the lines over the next few weeks and will retest the quality.

Last year, the town switched its treatment system from chlorine to chloramines, which officials say should reduce levels of HAA5.

In 2017, Town Meeting also approved a budget of $1.5 million to address the water issue. The conversion process began in June 2019, but 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 an aeration system and other improvements in order to reduce levels of TTHMs in the water townwide.

Aside from the well closures, Sullivan said the new townwide system has “been helping a bit.” 

He noted that a recent individual reading for the Reed Road site came in at 31 ppb for HAA5s — well below the state standard of 60 ppb.

According to the department, the system transition can take a “considerable amount of time to move throughout the entire water system,” but that HAA5 levels have continually decreased since May 2021.

The main issue, he said, is “residence time” — the time that water spends in a particular place — due to the low volume of municipal water users on that main.

On average, Sullivan said, the water sits in the Reed Road main for around four days. The department’s main on Chase Road, meanwhile, is typically cycled through every two hours.

“It’s a large water main with not a lot of usage,” Sullivan said. “It’s just a water main that loops around.”

According to the superintendent, the longer the water sits, the more it allows disinfectant byproducts such as HAA5s and TTHMs to build up in the main.

Once warmer weather arrives, the Water Department will reinstitute daily flushing on Reed Road, which officials say should “move water through the system at a faster rate and speed up the full transition to chloramines.”

“The state is all over us and they’re not going to let us go until we fix the problem,” Sullivan said. “My goal before I retire is to get this done so the next guy doesn’t have to deal with this.”

A copy of the Town of Dartmouth and MassDEP’s notice is attached to this story.