Tata & Howard provided engineering consulting services to the Town of Monson, Massachusetts for the relocation of the 8-inch diameter water main on Mechanic Street.
The main was originally constructed in 1897 under the streambed; however, after 117 years in this location, the decrease in surface water elevation had exposed the water main. The water level averaged about one inch below the top of pipe, exposing the top portion of the entire section of main that crossed the brook, approximately 15 linear feet of main. Exposure of the water main made it susceptible to freezing during the winter months, which could have resulted in a break and subsequent lost water or contamination from the brook to the Town’s entire water system, potentially resulting in significant costs to residents and to repair, clean, and disinfect the system. The main provides potable water to approximately fifty residents. There were only two gate valves located at the ends of Mechanic Street. As a result, if the main were to fail at the bridge, the entire street would have to be shut down in order to repair the damage, disrupting water service for the 50 serviced residents.
The Mechanic Street Bridge has a history of failure. As a result of a major flood event in 1955, the bridge failed and was completely replaced in 1956. The bridge ran directly over the water main, which posed an additional threat to the main should the failure reoccur. Although the main was unaffected during the previous failure, its weakened condition made it more susceptible to failure in a similar event.
Tata & Howard provided funding assistance and the project qualified for and received a FEMA Hazard Mitigation Grant for 75% of the cost of the project. The work included the preparation of design plans and specifications for the relocation of the 8-inch water main to a self-supporting beam structure attached to the bridge abutments on Mechanic Street. The project also included bidding, permitting, construction administration, and resident observation.
