Forensic Analysis of Horizontal Well Systems

Project Location: Eastern New York
Client: Public Utility – Airport
Contamination: Jet Fuel
Site Size: 10+ Acres
Project Description: Having contracted with a large Environmental Remediation firm to design and install several horizontal well deployed AS and SVE systems to remediate their large plume of JP fuel, the client became concerned that the systems were not functioning as reported (and hence, remediation was not progressing as stated), prompting them to seek a third party expert opinion. Their concerns were in part confirmed by extreme localized bubbling of pooled rainwater near the equipment compound, whereas no bubbling in any other area of treatment was seen. The client asked us for help.

We were requested to forensically review the contractor’s installation and each system’s performance to determine if 1) the contractor’s stated levels of performance were accurate, and 2) if not, what could be done to bring overall performance to required levels.

Employing our VAPOR™ forensic evaluation software with special measurement instruments and techniques, we were able to determine the actual volume of flow to, and from, each well. By modeling each well’s head and tail pressure or vacuum along with its total flow rate, we were able with SPARGE™ and EXTRACT™ to determine if each HAS well was able to sparge air over its full length, and whether.

Each HSVE well was withdrawing air volume incrementally where required. Each field-measured value was then compared to the contractor’s design value as supplied on his construction prints, as well as to copies of several previous months’ system performance status reports.

We found significant problems with both the HAS and HSVE systems, including grossly oversized blowers, large well header leaks, a HSVE well placed below the local water table, and general poor operating and reporting practices. We generated a guidance document that provided the client with our findings, clear documentation of deficiencies, and suggestions for resolution.

Following our report, the client required the contractor to excavate several areas and repair fractured well headers. Blower speeds were changed, wasteful bypass valves were closed, and reporting practices were revised to represent actual system performance. Necessary revisions to all systems were completed over the span of several months, resulting in an immediate and quite noticeable increase in subsurface remediation, leading to the completion of site clean up within the stipulated 5-year term.