By Laura Hayes, Contributing Writer
SHREWSBURY — In Shrewsbury’s Home Farm Treatment Plant, there are purple-tinted pipes with white labels. Those pipes are the new home of the town’s PFAS pilot program.
“We’ve been proactive about this in Shrewsbury, engaging in voluntary testing since the fall of 2019,” said Shrewsbury’s Water and Sewer Superintendent Dan Rowley during a May 11 Board of Selectmen meeting.
PFAS is short for per- and polyfluoroalkyl substances. A number of items have these compounds in them, like firefighting foam and non-stick cookware, Rowley said.
According to the Massachusetts Department of Environmental Protection (MassDEP), elevated levels of certain PFAS chemicals may lead to developmental effects in fetuses and infants. They can also impact the thyroid, liver, kidneys, immune system and certain hormones.
Rowley said the most recent PFAS detection level in Shrewsbury in April was 15.5 nanograms per liter (ng/l).
“It’s like having a trillion dollars in the bank and taking $20 out,” Rowley said in an interview with the Community Advocate, contextualizing the measurement. “That’s how small it is.”
Shrewsbury water treatment operations evolve through the years
Rich Fox has worked in Shrewsbury’s water department for decades. When he started working for the department, there wasn’t a water treatment plant.
“We had a barrel of fluoride at each well and a little pump, and you pumped the fluoride into water from each individual well,” Fox said.
In those days, Fox had a one-page list from the Massachusetts Department of Environmental Protection of samples to test for. That list is now 11 pages.
Officials take early action to take local PFAS measurements
As part of its ever-expanding water quality monitoring, Shrewsbury actually tested for PFAS under the third Unregulated Contaminant Monitoring Rule in 2015.
At that time, PFAS weren’t detected, Rowley said. Since then, though, the testing has improved to the point where PFAS are now being tested at a parts per trillion scale.
In 2019, MassDEP reached out to a number of communities, including Shrewsbury, to see whether they would voluntarily test their water for PFAS. Shrewsbury ended up being one of 21 participating communities, Rowley said.
Fox said that, especially after discovering the contaminant hexavalent chromium in their water, the town decided to participate because it wanted to know in advance if there was something in the water that could be potentially harmful.
“It’s one of those things that it’s a question that you know could have ramifications, but on the flip side, we wanted to be prepared, knowing if this was found in a lot of water systems, equipment, people to do piloting wouldn’t be available,” Rowley said.
By October 2019, Shrewsbury had gone through two rounds of testing and had an average PFAS detection of 13.56 ng/l.
Last October, MassDEP released a maximum contaminant level of 20 ng/l for the sum of six compounds under the umbrella PFAS categorization.
Because the town’s levels were above 10 ng/l, but lower than 20 ng/l, Shrewsbury is required to test its treated water every month.
Now there are regulations that require water systems to test for PFAS, and Shrewsbury would have already been obligated to have tested its system by April 1, Rowley said.
“I really think we’ve shifted the management of our water system from really kind of reactive to proactive,” Rowley said.
Shrewsbury gears up for PFAS study
Currently, Shrewsbury’s consultants Tata & Howard, Inc. and sub-consultants Blueleaf Inc. are getting the equipment and materials for their study ready.
Shrewsbury was approved by MassDEP to conduct this pilot study in March, and Rowley estimated that the study would take about six months.
The pilot study is being housed in Shrewsbury’s Home Farm Treatment Plant on Main Street, which was built in 2018 to treat manganese in the town’s water. All of the water in the town is pumped through the plant.
Rowley explained that the water will be filtered through the aforementioned pipes, which will collect samples.
The samples will be taken at different points in the filtration process, and at the end, the town will be able to tell what mechanisms are most effective at filtering out PFAS chemicals.
With that information in hand, an analysis of the operating cost and the cost of ongoing maintenance will be conducted.
The treatment plant may have to expand, ideally on its same site, to build the infrastructure to filter out the PFAS, Rowley explained.