Regional Intermunicipal Interconnection Evaluation, MA

Through a grant from the Pioneer Valley Planning Commission, Tata & Howard was retained by the City of Northampton Department of Public Works (Northampton) and the City of Easthampton Water Works (Easthampton) to complete a Regional Intermunicipal Interconnection Evaluation for the Easthampton, Hatfield, Northampton, Southampton, and Williamsburg water systems.  The purpose of the study is to evaluate potential water distribution system intermunicipal connections and emergency water supply.  A combined water distribution system regional hydraulic model was developed and used to evaluate the hydraulic feasibility and impacts of the proposed interconnections.  The study evaluated the needed infrastructure improvements, system available supply and demands, and available supply through the potential interconnections.

Potential interconnection locations between Northampton and Easthampton were considered at four locations, between Northampton and Hatfield, between Northampton and Williamsburg, and between Easthampton and Southampton.  Infrastructure recommendations at the locations include construction of new water mains, meter pits, flow meters, pressure reducing valves (PRV) and portable pumping systems. The Massachusetts Department of Environmental Protection (MassDEP) Water Management Act (WMA) permitted and registered pumping volumes for each system’s sources was evaluated for potential supply to other communities.  Northampton and Easthampton have surplus supply, while Hatfield, Williamsburg, and Southampton are approaching their WMA permit or registration allowable withdrawal volumes.

The study determined the following:

• Three of the four potential interconnection locations between Northampton and Easthampton could be utilized in an emergency by isolating portions of Northampton’s system. An interconnection that could serve all of Northampton would require a pumping system.
• A pressure reducing valve would be required to supply Hatfield from Northampton and a pumping system would be required to supply Northampton from Hatfield.
• Due to the location of the Williamsburg interconnection along Northampton’s transmission main route, and the limited amount of water available from Williamsburg, an interconnection from Williamsburg to Northampton is not feasible.

There is an existing hydrant to hydrant interconnection between Easthampton and Southampton that has been utilized to supply water to Southampton during periods of high summer demands. To supply the entire Southampton system, a pumping system would be required, and a PRV would be required to maintain adequate pressures if Southampton were to supply Easthampton.