Horizontal remediation wells extend and expand the capabilities of groundwater extraction systems, compared to arrays of vertical wells.
In horizontal remediation wells, a screened section of casing is placed in the zone targeted for groundwater extraction. The screened casing is connected to blank casing leading to the ground surface. Water from the surrounding formation enters the screened section and is pumped to the surface using a submersible pump. In general, the basic principles behind vertical and horizontal systems are the same.
The similarities between vertical and horizontal systems end here. Horizontal wells can treat a much larger area, even crossing an entire contaminant plume, than vertical wells. Since only one pump is needed, the equipment, labor, operation, and maintenance costs are typically reduced over a multiple-pump vertical well system. And, since multiple vertical wells must all be connected and manifolded, they incur an additional cost that is not needed for a horizontal installation.
The design and materials for groundwater extraction wells vary considerably depending on site-specific circumstances such as yield rate, grain-size distribution, type of contaminant, and length and depth of the well. Well material options typically considered are:
Each of the above materials has particular advantages and disadvantages related to cost, strength, resistance to corrosion or degradation, or ease of installation. The design and materials specification for remediation system installation must also cover groundwater filtration. Typical options to prevent silting of wells include EnviroFlex or other integrated filter screens.
If you have questions about the advantages of applying horizontal directional drilling and horizontal wells to your groundwater extraction system, please contact our environmental remediation experts.