MONITORING WELL CLOSURES AND SITE CLOSURES
Unsealed or improperly sealed wells can threaten public health and safety and the quality of the groundwater resources. Therefore, proper abandonment (decommissioning) of a well is a critical final step in its service–life. Proper well abandonment accomplishes the following: 1) eliminates the physical hazard of the well (the hole in the ground); 2) eliminates a pathway for migration of contamination; and 3) prevents hydrologic changes in the aquifer system (e.g., changes in hydraulic head, mixing of water between aquifers, etc.). Proper decommissioning methods will depend on both the reason for abandonment and the condition and construction details of the boring or well.
Typically, monitoring wells that were installed and continue to function as designed, can be abandoned in place. Monitoring wells that are abandoned in place are filled with sealant. Protective casings, riser pipes, tubing, and other appurtenances at the surface that cannot be removed are cut–off below grade after the sealant has properly set. When abandonment is completed below the finished grade, the area of the boring is covered with a layer of bentonite, grout, concrete, or another sealant before backfilling to grade.
Achieving site closure is the ultimate goal for most remediation projects. This is accomplished by developing cleanup goals, negotiating with regulatory agencies, and developing a remediation strategy to achieve the cleanup goals. TITAN Environmental’s seasoned team of experts have achieved site cleanup and closure on many projects throughout California.