No Worries for Holliston Water

TTHMs and HAA5s in the water? (Well, not anymore.) What does that mean?
In mid-May, the Town of Holliston Water Department issued a notice to residents that in certain areas of town, from routine samples taken on April 10, certain contaminants, specifically Trihalomethanes (TTHMs) and Haloacetic Acids (HAA5s) exceeded acceptable standards by the Mass. Department of Environmental Protection (MassDEP). The town tested four sites, as they usually do, and the Rockland Street sample showed 88 ppb (parts per billion) for TTHMs (acceptable levels are 80ppb) and 65 ppb for HAA5s (acceptable levels are 60 ppb). Subsequent testing taken on May 11, 2017, after the system had been flushed, showed TTHMs at 58.7 ppb and HAA5s at 23.1 ppb.
While the two chemicals can cause health problems if they are consumed over a lifetime, these chemicals posed no immediate threat to Holliston residents.
“If we took no corrective action and always had those elevated sample numbers, and if you drank that water for 70 years every day, then you have an elevated health risk,” says Holliston DPW Director Sean Reese. If there had been immediate risk, he says, Holliston residents would have been immediately notified. “The way the EPA looks at it, it’s not an emergency. You don’t have to cease drinking the water, and the best way to remove the residuals is to flush the system.”
The immediate steps the Town of Holliston took was manually flushing the system, in addition to automatic hydrant flushers installed on the hydrant that are operated at night. In this way, water moves throughout the system, so there’s no stagnation.
“Basically, (the elevated levels of TTHMs and HAA5s) were a result of disinfecting the water with chlorine,” says Reese. “Since 1900, chlorine has been used primarily in drinking water. It’s very effective with a cost favorable toward any type of municipality.
According to Reese, last summer, during the severe drought, the Town was unable to flush the system. “When you can’t flush the system, you have more chlorine,” he says. “Typically, it’s done in the fall and in the spring, and typically there is a higher chlorine residual in the summertime.
Reese says the town operates the water system “to be most effective.” A well on Central Street, for example, “aesthetically doesn’t have the best water quality. We chemically treat it to make it safe to drink, but it puts out a high amount of iron, so we deal with that issue of rusty water on that side of town. What we’ve done to alleviate that is to become less reliant on Well 5. Now, when we run that well less to lessen the dirty water calls on that side of town, we run the treatment plant on Washington Street, the filtration plant, more. As a result of running that plant, we have a higher chlorine residual. It’s a cleaner water, but when you have a higher chlorine residual out there to fight off potential bacteria, you are more likely to have higher elevations of disinfection byproducts. They take a longer time to form.” The DPW Director explains that in that area of town, where water pipes lead to some dead ends, the water can remain in the pipes longer. This is why flushing is necessary.
Reese says dead-end areas in the system can pose challenges.
“Small towns branched the water main with little thought,” he says. “What you want to have is a loop system, where you have water continually moving,” says Reese. “Any time we try to remove dead ends by looping the water main, it helps the water quality,” says Reese. Any improvements help the system, says Reese, who says a treatment plant for Central Street will actually be on the warrant for the October town meeting. There are also plans, he says, to loop the water main on Hanlon Road and tie that in ideally by late summer. Other issues the town faces, with its old water system, is the need for pipe replacement.
“You have to look at it holistically, what you want to do first and what’s immediate need, based on funding to do that. It’s always a difficult sell when it comes to infrastructure, and it can be a Catch 22, improving the system with minimal disruption.”
Reese points out that municipal water is extremely highly regulated, and the town has become more proactive in its approach to clean water than it was before the DPW was formed, with a more streamlined practice with continuous updates.
Still, issues can arise, and Reese says the Water Department, and the state, want to know if anyone has a problem.
“Anybody who calls has a valid concern. Everybody in this water department – this is their profession. We’ve dedicated our lives to it. The staff is professional, and everybody is out there trying to serve the community to the best of their ability, working with the resources we have,” says Reese. “(Holliston residents) are the consumers of the system; it’s their system. They expect us to operate it efficiently.”
For more information please visit www.townofholliston.us or contact Sean M. Reese, Public Works Director, at (508) 429-0603 or Holliston Water Department, 703 Washington Street, Holliston, MA 01746