A DRY INJECTION SYSTEM FOR THE EMPLACEMENT OF FILTER PACKS AND ANNULAR SEALS IN GROUND-WATER MONITORING WELLS

The reliability of filter pack and annular seal emplacements, and the degree of integrity of installed seals, are two of the most important factors to be considered when both installing and later utilizing ground water monitoring wells. Numerous, and often costly, problems of using existing methods of installing filter packs and annular seals during the construction of ground water monitoring wells have led to the development of a technique of installing these monitoring well components using a dry injection system. The dry injection system has been used to construct monitoring wells in extremely complex overburden/bedrock environments with a variety of drilling techniques. The system has shown that a high degree of reliability in the, construction of monitoring wells and greater confidence in obtaining representative ground water samples can be achieved over existing methods of filter pack and annular seal emplacement. The system has also been more cost effective than existing methods, especially for deep boreholes and multilevel monitoring system installations.