Municipal Water Line Extension for PFOA Remediation

Challenge

In 2016, following the discovery of PFOA in groundwater in Hoosick Falls, residents of the west end of Bennington began asking the State of VT to test their well water, given their proximity to a former CHEMFAB Industries plant that manufactured PFOA-containing products. The State discovered more than 400 contaminated wells. Town officials recognized that they needed to respond to this discovery without delay.

Solution

In a matter of days, MSK provided the Town with a comprehensive proposal to extend the Town's municipal water lines to affected residences. The original plan called for the construction of 8 miles of new main and associated individual service lines. Over the next few years, the project grew to over 16 miles of water main and 11 miles of service lines. Much of the water line extension reached into higher-elevation rural areas and required costly technical solutions. Despite the complexity and scale of the project, the Town, facing a public health mandate, moved forward with the plan.

We provided the Town with a preliminary engineering report (PER), including cost projections. The State of VT requested additional work to determine if the Town's current water supply would be sufficient to serve the new connections. The State also asked the Town to examine whether water quality could be maintained in the new line, given that the formation of disinfection by-products is positively correlated with residence time, which would be longer in this extension to low-usage areas. MSK addressed these concerns by developing an extended period simulation model that calculated water aging as well as the influence of the water source. The State approved our plan to connect the entire rural western sector of town to the municipal water system. We obtained necessary easements from landowners, carried out all right-of-way surveys, and provided construction observation and administration services. Construction was completed in 2019.

Following our mapping of all of the water valves in the system, the Town hired us to design a replacement for an aging cast iron water main in the heart of the town's commercial district. The main was located directly under the crown of the state highway and was flanked on both sides by sewer mains. We surveyed and secured private easements along the mile-long stretch of main. We developed existing conditions drawings, completed a phased design plan, and oversaw bidding. Construction was completed over 5 seasons, keeping annual municipal outlays within the capital improvements budget and avoiding bond financing. In the course of providing construction administration services, MSK coordinated nightly shutdowns with private landowners, observed directional drilling under the state highway, and the observed installation of a new pressure-reducing valve vault.

As the West End water line upgrades wrapped up, we completed design for the East End phase, part of a settlement between Vermont and Saint-Gobain over contaminated wells in northeast Bennington. MSK obtained necessary easements from landowners and carried out all right-of-way surveys, construction administration and observation services on over 8.5 miles of new water distribution main and associated individual service lines.

Results

The project was successfully completed in 2021 and has provided clean and reliable drinking water to users. On behalf of the Town, we managed all disbursements and associated accounting, including billing, contractor payments, and record keeping. Our services allowed the Town to focus its resources on a range of other priorities while making timely contractor payment more straightforward.

The project totaled over $25 million over 9 contracts. Over 397 total sites were included.