Public Water Supply Quality
The Town of Shrewsbury derives their municipal water supply from a series of eight ground water wells in which mineral deposits of iron and/or manganese,a mineral occurring naturally in water and soil in the Northeast, are present. A sequestering agent has been used to keep the the manganese in solution since December 1989. Despite the sequestering agent and other approaches, over time these minerals have accumulated in various aspects of the water distribution system. With concerns over rising manganese levels and potential effects on our residents, the Town pilot tested various technologies for manganese removal and committed to building a full-size Biological Treatment Facility to treat all well sources at a central location.
The Home Farm Water Treatment Plant construction started in July 2017 and was completed in October 2018. However, the filtration plant will not address the minerals that have already accumulated in the water mains and other aspects of the distribution system. To clear the minerals in the water mains, the Town has developed a Unidirectional Flushing project with the help of Tata & Howard.
In addition to this, as part of required EPA testing, Hexavalent Chromium also known as Chromium-6 was detected in our system registering results between 3-4 parts per billion (ppb), which is well under the EPA and MassDEP standards of 100 ppb for total Chromium, adding together trivalent chromium (Chromium-3) and hexavalent chromium (Chromium-6). Three wells were identified as the culprits: Home Farm 6-1, 6-3 and 6-4, containing medium to high levels of chromium-6. The Town developed a two prong strategy of minimizing usage of those wells, and establishing a new well away from the property on Sewall St. Concurrently, the biological treatment process that was piloted on site showed favorable results, but needed to be cut short due to monitoring well flow issues. The latest readings for finished water in July of 2019 show 3.5 ppb. After the new replacement wells take the place of Home Farm 6-1 and 6-3, hex chrome levels should be between 1-2 ppb, and in all probability below 1 ppb.