Specifications include, but are not limited to: The New Hampshire Geological Survey (NHGS) within the New Hampshire Department of Environmental Services (NHDES) is seeking bids for the installation of two (2) groundwater monitoring wells to be located in Litchfield and Canaan, New Hampshire, and for the decommissioning of one (1) existing groundwater well located in Franklin, New Hampshire. The newly installed wells will be incorporated into the New Hampshire Groundwater Level Monitoring Network. The preferred method for monitoring well installation will be using 4-1/4” ID (inside diameter) Hollow Stem Augers. Final depths for the groundwater monitoring wells are anticipated to be 40 to 50 feet below ground surface (bgs). The final well depths will be based on field conditions and determined on site. The groundwater monitoring wells are to be constructed with schedule 40, 2-inch ID PVC riser and well screen. Filter pack sand is to be used to fill the bore annulus around the screen to a minimum of two feet above the top of the screen. A bentonite seal will be placed above the filter pack with a minimum thickness of 2-feet. Steel well protective casings will be installed and cemented at the ground surface to protect the wells. Once installed, the wells will be pumped to develop the well filter pack and remove fine sediments from the well. Well decommissioning will be completed by cutting the existing steel riser off below the ground surface and backfilling of the 2.5-inch ID 50-foot length of overburden well riser.
