Permit Approval for Well #8 in Blackstone, MA
Weston & Sampson was contracted to install a large diameter production well (Well #8) and complete a safe yield assessment in an effort to assess the viability of permitting a new withdrawal at this location. After completing a thorough review of work completed previously by the D.L. Maher Drilling Company, Weston & Sampson contracted D.L. Maher to construct and test a 16” x 12” x 10” test production well in the most favorable small diameter test well location. A 48-hour pumping test was conducted to assess aquifer hydraulics, water quality, and safe yield. The results reveal a site with adequate water quality and high aquifer transmitting capacity. The estimated safe yield of the site is within the range of 500-600 gpm (0.72 to 0.864 MGD). Since this well represented a potential permitted capacity greater than two times the highest yielding well in the Blackstone, Weston & Sampson recommended this site for permitting.
Subsequent to testing, Weston & Sampson was again hired to permit the Well 8 Site for the town. The Request for Site Exam and Pumping Test was submitted in December and approved by the DEP Central Office in February. The approved pumping test plan was then executed in April. Since this site is located approximately 40 feet from Harris Pond, the DEP required additional monitoring of the nearby surface water bodies and a more complex numerical groundwater model to be developed, calibrated, verified, and run to simulate the effects of pumping on the surrounding sensitive receptors as well as the other five production wells located within the same aquifer. This model was developed and calibrated and a variety of simulations were run to predict the Zone II wellhead protection area and the capture area of Well 8 pumping at a rate of 500 gpm (0.72 MGD). The Source Final Report was submitted in November 2010 to document the work completed and permit the source for the above referenced rate.