Natural Resources: Monitoring Well Decommissioning

Contaminated groundwater sites worldwide are engaged in regular sampling of monitoring wells at a typical cost of $1,500 per well-sampling event.

On most sites, many wells are redundant or geostatistically insignificant and can be decommissioned.
EVS-PRO and MVS's Well Decommission module analyses all available data and quantifies the impact on site assessment quality associated with removing each well. The impact of removing a well is quantified in terms of its impact on the geostatistical plume extent.

During remediation plumes are shrinking and may drift. This can necessitate decommissioning of some wells and adding new wells. C Tech's well decommissioning and DrillGuide© technology provide the tools to properly monitor and guide the remediation efforts at the lowest possible cost.

Here, we demonstrate the process of using the Well_Decommision module.

Well MW7W removed.

Well MW7W removed.

Well MW7B Removed.

Well MW7B Removed.

The two figures above demonstrate that some wells have a profound effect on site assessment.

The final output shows each well colored by its impact on the site contaminant area in square feet.

 

Well decommission final results for Pentachlorophenol Target Isolevel = 5.00 Maximum Area Deviation. Data provided courtesy of U.S. EPA Region 5.

Well decommission final results for Pentachlorophenol Target Isolevel = 5.00 Maximum Area Deviation. Data provided courtesy of U.S. EPA Region 5.

 

EVS-PRO's Well Decommission technology provides a defensible approach to determining candidate wells for decommissioning. Each decommissioned well can save thousands of dollars per year.

The nominal contaminated area is 1,835,263 square feet. Removing MW18B affects area determination by only 0.026%.

Removing MW18B would have an insignificant impact on Site Assessment.

Removing MW18B would have an insignificant impact on Site Assessment.

Removing MW102 would have a profound impact on Site Assessment.

Removing MW102 would have a profound impact on Site Assessment.