PITTSBORO — Pittsboro could have clean drinking water within about a year, according to water treatment experts, but only if the town’s board of commissioners act later this month to approve …
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PITTSBORO — Pittsboro could have clean drinking water within about a year, according to water treatment experts, but only if the town’s board of commissioners act later this month to approve modification of its water treatment plant.
CDM Smith, an engineering and construction company which provides water solutions for government and private clients, has worked with the town of Pittsboro for more than two years — compiling data and preparing recommendations to mitigate the town’s two water system deficiencies: capacity limitations that stifle development plans and a filtration system insufficient to address the town’s increasingly polluted drinking water.
The latter problem has received widespread attention across the state and around the country after scientists and researchers discovered in recent years that Pittsboro’s water — drawn from the Haw River — was teeming with carcinogenic per- and polyfluoroalkyl substances known as PFAS.
In tandem with a town-sponsored task force that worked throughout 2020 to identify short-term solutions to the water contamination issue, CDM Smith has been devising a long-term solution involving Pittsboro’s water treatment plant.
During Monday’s Pittsboro Board of Commissioners meeting, two CDM Smith engineers, Reed Barton and William Dowbiggin, presented the company’s findings at the commissioners’ first meeting of the new year, and recommended infrastructure changes that could resolve both of Pittsboro’s water problems.
“The project approach is to move forward with advanced treatment and expansion of the water treatment plant,” Barton said.
The changes would help to address both water “quality, meaning issues in the Haw River ... and quantity, dealing with growth that’s coming to the town,” Barton said.
Right now, Pittsboro’s water treatment plant has a capacity of 2 million gallons per day, but projections indicate that incoming development will push the town’s water demands in excess of that level by 2023 at the earliest.
“But whether it’s by 2023 or 2025,” Barton said, “additional capacity will be needed at the water plant.”
As Chatham Park and other Pittsboro developments reach their construction goals, the town will need water capacity to exceed 14 mgd within the next 40 years. But CDM Smith recommended an initial project to expand capacity to 6 mgd, which could support the town’s needs until 2040.
More challenging than simple expansion, however, will be to equip the water treatment plant with filtration systems robust enough to remove the Haw River’s many harmful chemicals. In the last year, CDM Smith conducted studies on Pittsboro’s drinking water to isolate the most effective filtration systems. The team identified three combinations of filtration types capable of removing at least 90% of all PFAS compounds along with 1,4-dioxane, broad spectrum personal care and pharmaceutical products (PPCPs) and bromide/brominated disinfection byproducts (DBPs) — all of which are known to cause cancer.
The first “treatment train” option, as Barton called it, was a combination of granular activated carbon (GAC) and ion exchange (IX) filtration. The treatment systems alone would cost $11 million to $13 million. When coupled with $31 million for facility expansion, the project would cost at least $42 million.
The town could also elect for a modification of option one — GAC+IX paired with ultraviolet photolysis and an advanced oxidation process (UV/AOP). That option would cost an estimated $45 million to $48 million, including expansion.
Finally, low-pressure reverse osmosis (LPRO) could solve the town’s water problems, but it would cost significantly more than options one and two — between $59 million and $67 million. LPRO would also require the town to attain extra permitting and navigate time-sapping government hurdles.
With that in mind, CMD Smith recommended the commissioners select GAC+IX.
“It provides superior performance and can achieve 90% PFAS removal,” Barton said. “It can be incorporated into the existing water treatment plant pretty readily, requiring less space compared to RO.”
Also, because it requires fewer permits than an RO system, GAC+IX can be installed on a shorter timeline, and it wastes less water in the treatment process compared to RO.
If the commissioners chose to pursue a GAX+IX system, Barton said, they could achieve cleaner water within as little as 12 months. Implementation would involve a two-fold process: installing a 1 mgd GAC treatment addition to the current plant to be operable in about a year while designing full expansion to a 6 mgd facility with GAC+IX to meet growing demand for water by 2025.
The drawback, however, is the town would likely have to pay out-of-pocket to begin construction. The design-build style it requires does not qualify for federal loads.
“The reason (this option) is so much more expedited is it basically means we have to pay cash or find some other mechanism to keep us away from … intensive funding cycles,” Pittsboro Town Manager Chris Kennedy said.
But Kennedy encouraged the board not to discount the option. “I think we can swing it,” he said, either with available on-hand funds or through regular bank loans.
Still, the presentation was met with some apprehension from the commissioners.
“I remain concerned about the idea that — well, the fact — that RO is the most effective option in terms of removing all the contaminants,” Commissioner John Bonitz said.
Kennedy, however, argued that while RO is the leading water filtration technology available, the GAC+IX combination achieved similar results.
“We wanted to find every way to say yes to RO ...” he said of town staff, who reviewed the presentation before it was given to the commissioners. “It’s the best technology. And, you know, that’s what we want to provide to our citizenry, the best technology available. But we found them both to be very comparable.”
The CDM Smith representatives seconded Kennedy’s assessment, reiterating that GAC+IX proved as effective as RO in the company’s year-long study of Haw River water.
“And so, with the lower cost and just the expediency with which we could install a solution, it seemed like GAC+IX was the proper path forward,” Kennedy said.
The commissioners did not vote on a decision, though, but elected to defer official action until its next meeting on Jan. 25.
Town staff presented the commissioners with two site planning recommendations on Monday, both of which the board approved.
• A 7-acre vacant parcel at 1696 Hillsboro St. will be developed to house a 10,000 square-foot medical office to be used as a dialysis center.
• The property located at 56 Sanford Road will be developed into a two-story, 4,000 square-foot restaurant to be located within the downtown SoCo development. As part of this site plan request, the developers also requested approval of a sewer allocation request in the amount of 7,178 gallons per day which was granted.
Reporter D. Lars Dolder can be reached at email@example.com and on Twitter @dldolder.
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