So, you are thinking that a horizontal well will be the appropriate remediation technology for one of your project sites. Now what do you do? There are many manuals and resources to install a vertical system, but where do you get that standard information on horizontal wells so that you can design your horizontal remediation well project?
Designing a horizontal remediation well should start with a call to an experienced environmental horizontal well driller. The environmental horizontal well driller will first ask for a background history of the site. The typical questions are: how was the property contaminated, what is the contaminant, and how long has the property had this problem? Did you have a specific application in mind for the remediation? Any remediation technology that has been used with a vertical well can be adapted to horizontal wells. The answer to each of these questions begins before designing a horizontal remediation well.
For example, if the site is a gas station with a product leak that has been undetected for many years that has migrated under the building and off site under a right-of-way or state/city road, this would be an appropriate application for a horizontal remediation well.
The next stage when designing a horizontal remediation well will require answering the following questions:
- Revisit discuss the remediation strategy and determine if it is feasible and does our previous experience designing and installing horizontal wells provide us with ways to improve the process?
- Do you have a site plan?
- Do you have a site plan showing the plume?
- What is the depth and location of the plume?
- Does the site have access constraints such as property boundaries, business activities that cannot be interrupted, buildings or areas within the buildings with security clearance that cannot be accessed or other site specific demands?
- Are there underground utilities that may affect the design of horizontal well layout?
- If the horizontal wells are being installed at a shallow depth, are there footers or foundations that need to be considered?
After these questions and perhaps a few others that were prompted by responses, the design for the horizontal well layout begins. This design for the horizontal remediation well layout is critical to the project’s success.
An initial horizontal well placement design is stretched out knowing that the design will be tweaked and changed until actual horizontal well installation. As an experienced environmental horizontal well driller, we have had to adjust or modify many designs in the field because of unforeseen and unpredictable obstacles and circumstances.
Before proceeding to the field, the initial horizontal well placement design goes through another battery of questions and feasibility for the type of horizontal remediation system that will be installed. For our hypothetical gas station that was mentioned early, the consultant has asked us to design and install two horizontal air sparge wells and one horizontal soil vapor extraction well. This is when our engineers and PhD Hydrogeologist begin to design the horizontal well screen.
Once the horizontal well screen is designed, the horizontal well placement is again reviewed for critical components that will ensure the productivity and efficiency that our clients have stipulated.
The design for the horizontal remediation well placement and the design for the horizontal remediation well screen are now complete and the project is ready for the remedial construction phase.
Directional Technologies, Inc. has been installing horizontal remediation wells since 1993. Our experience as an environmental horizontal driller has allowed us to continue to improve the efficiency of horizontal remediation wells when they are designed and installed properly.