When thinking of the most challenging types of sites an environmental consultant may encounter, do any come to mind that involve subsurface obstructions, and what alternatives are there to sonic drilling that would help you overcome these challenges? Certain types of subsurface obstructions limit the efficacy of the consultant’s traditional toolkit to assess and remediate soil and groundwater contamination. Before breaking the news to your client that you’re going to need to involve a sonic drilling rig to install remediation wells, consider how horizontal directional drilling techniques can be used to overcome these difficult conditions.
Subsurface obstructions can include:
- Liners or geotextiles
- Buried waste
- Former building foundations or basins
- Soil blending treatment areas that have been mixed with concrete
- Exclusion zones where penetration of the surface has been prohibited
Whether it be a military facility with a buried storage drum area, a waste pond with a liner, a landfill subject to a ROD that precludes vertical drilling, a former industrial site where the former building foundations remain in place, or a commercial facility where soil blending was performed and concrete was mixed into the backfill, the site conditions can pose quite a challenge, even to experienced consultants. These types of site conditions can often limit remediation options, require expensive specialized equipment, or involve costly restoration efforts.
Alternatives to Sonic Drilling
Traditional solutions to deal with these subsurface obstructions typically come at the cost of significant compromises, but what are the alternatives to sonic drilling to overcome these obstructions?
Sonic vertical drilling rigs can be used to penetrate concrete in the subsurface but comes at a significant financial cost. Liners and geotextiles can be easily penetrated but can involve a difficult regulatory approval process and may require costly restoration efforts. In-situ remediation system designs can be adapted to be moved away from areas of buried waste but can result in significantly reduced remediation system performance due to the inability to place remediation wells in the areas containing the highest concentration of contaminants.
Alternatively, horizontal directional drilling techniques can be used to overcome such site conditions and accomplish the following:
- By placing wellheads and staging equipment outside of sensitive areas and boring horizontally beneath the obstructions; one can completely avoid perforating liners/geotextiles, disturbing buried waste, boring through thick concrete, or breaching exclusion zones.
- Provide more precise targeting of areas of high contaminant concentration.
- Place significantly more screens within the plume, allowing for more effective remediation system performance.
How do you evaluate potential solutions when site conditions render traditional remediation tools difficult to use? Call our horizontal remediation well experts at 1-877-788-4479 or email us at drilling@directionaltech.com to learn more or to discuss how together we can create the most successful outcome for your client.