The Carlisle Mosquito Online

Friday, January 24, 2003


Carlisle School wastewater plant site still uncertain

The most immediate task for the Carlisle School Building Committee is the selection of the best location for a new wastewater plant needed by the school. Possible sites for the plant include the slope to the right of Spalding Field, next to the planned discharge/leaching field on the lower Banta-Davis Land off Bedford Road, or at the back of the Banta-Davis Land.

The present school septic system has been in technical failure under Title 5 regulations for several years and is pumped out monthly. The septic system is not in physical failure, however. The school now needs a wastewater treatment facility rather than a septic system due to increased enrollments which have increased flow rates at the school. The new facility must also serve any possible future expansion of the school, including a possible second school (see article on page 9).

Costs rise with distance

Paul Clinghan of engineering design firm HTA estimated the cost of the plant at between $1 million and $1.25 million depending on site conditions encountered, such as the cost of digging a trench in an area with ledge. Clinghan said if the wastewater plant is sited close to the school, the cost for construction would be around one million dollars; if further away, the cost would rise above a million. He said HTA can do a detailed engineering cost estimate for the plant once a site is finalized.

A sewage pipe would run from the school to the wastewater treatment plant where it would go through a pre-treatment tank and a flow equalization tank to the wastewater plant. The treated effluent would then be piped down to the discharge field at the Banta-Davis Land. The plant is expected to take up about a half-acre site, with the building itself to be approximately 32x42 feet.

Members of the recreation commission attended the January 13 meeting of the building committee to give their input on the plant's location so it would have the least impact on town playing fields. Mark Spears of the RecCom told the committee that if a playing field were used for the plant, the cost of replacing the field would be $100,000. The RecCom and the building committee will visit the possible sites on January 24 with the design engineer.

Daily maintenance

The wastewater treatment plant will require daily maintenance and would need to be tested on a regular basis. The school could contract the work to an outside company for management of the system at an annual cost of around $50,000, said Clinghan. Instead, the school maintenance department could choose to have someone licensed to do the daily maintenance work.

2003 The Carlisle Mosquito