Moretrench was contacted by NYCDEP after turbid water was noticed seeping from the toe of their Cannonsville Reservoir Dam, in the Catskill Mountains. The problem was determined to be related to an exploratory borehole conducted for a hydroelectric plant project that intercepted an artesian aquifer in the underlying glacial till. Moretrench first installed a series of wells to dewater the artesian unit using the Sonic drilling method. Once the artesian aquifer was depressurized, the owner was able to stop their reservoir draw down and Moretrench was able to grout the borehole to seal off the aquifer. As a geotechnical engineer, my take-away from this project is the dangers of creating very serious problems when drilling exploratory holes around an active dam if your boreholes are not properly abandoned. [Source: Read More about the project at Moretrench. Image: Moretrench]
