The Carlisle Mosquito Online

Friday, March 4, 2005


ConsCom is happy with new wasterwater plan

The Carlisle Conservation Commission (ConsCom) gave its blessing to the latest modifications in plans for the wastewater treatment system designed to serve the Carlisle Public Schools and meet the requirements for an expanding classroom population. The School Building Committee had requested the changes in an effort to reduce the high cost of the original proposal. The overrun had been revealed when the lowest bid for that plan came in at $2.2 million or about $900,000 above the amount approved by the voters at the 2003 Town Meeting. The Board of Selectmen had already endorsed the new approach at a special meeting on January 19.

Following a brief introduction by School Business Manager Steven Moore, who has estimated that the revised plan could shave about $350,000 off the eventual cost, Hoyle Tanner & Associates' engineer Ben Horner tacked up the revised proposal at ConsCom's February 10 meeting. The plan showed the treatment plant moved from its original location near the Corey Building to a site behind the Recreation Committee's proposed tennis courts on the town's Banta-Davis Land. He explained that raw sewage from the school will now be pumped via a force main, six feet in diameter, which will cross Pages Brook in a "strongly reinforced sleeve." This change will eliminate the requirement for an expensive roadway that would have been needed to access a plant at the original school site and will leave present recreational facilities in place. Moore satisfied commission concerns about possible threats to wetland resources during construction activities by describing a "highly controlled quality assurance process."

There were a number of questions about the potential for expansion in the distant future. Would the treatment plant be modular? What would be the maximum load for the leaching field? Moore was not prepared to provide specific numbers at that time. However, he did say, "We know there's excess capacity in the present planIt's definitely built for school growth." To a question about the danger of pressure problems during school vacations and summer recess, Assistant Project Manager Mark Thompson conceded that "lack of enough stuff going through the system" can prove to be a problem but, in what he termed a "dog-food solution" he assured them that if properly monitored, the problem could be managed relatively easily.

Since none of the proposed modifications were considered major from an environmental standpoint, except that relocation of the treatment facility from the area adjacent to the school to Banta-Davis meant that the nature of the material flowing through the force main would be untreated rather than pre-treated, the commission not only saw no real drawbacks, but expressed enthusiasm for the revisions. Better yet, from Moore's point of view, they indicated they would be happy to accept the original plans as basic project documentation along with the set of construction conditions they had already imposed. All they needed at this time were detailed specifications describing the changes, which could then be referenced in the final version. Moore said he would provide the completed paperwork within two weeks, and the public hearing was closed.

2005 The Carlisle Mosquito