Soil vapor extraction (SVE) is a remediation technology for cleaning up contaminated soil and groundwater. However, SVE has significant limitations and drawbacks, particularly when it comes to its environmental impact.
In this blog post, I’ll talk about SVE, exploring what it is, how it works, and why it’s not as effective as it can or should be.
What is soil vapor extraction?
The process typically involves installing extraction wells or trenches in the contaminated area, which are connected to a vacuum system. The vacuum system creates pressure that draws the VOCs out of the soil and into a contained filter.
The extracted vapors are then treated using a variety of methods, including granular activated carbon (GAC) filtration. However, this is where the process can fall short.
The Problem with SVE: Bypassing the GAC Filter
One of the most significant issues with SVE is that operators may bypass the GAC filter drums, releasing pollutants directly into the atmosphere. This is a concern, as VOCs are known to contribute to air pollution, climate change, and negative health effects.
By bypassing the GAC filter, SVE operators are essentially sidestepping a critical step in the cleanup process. This not only fails to address the underlying contamination issue but also causes pollution. During our recent trip to the San Juan Basin in New Mexico, we observed five SVE units that were either inoperable, disconnected, or the GAC filters had been bypassed with the vacuum turned on.
Image: SVE unit where the GAC filter is not attached to the vacuum
Regulatory Failures: A Lack of Oversight
Despite the environmental risks associated with SVE, regulatory agencies have failed to provide adequate oversight. We observed multiple units which were not connected to the GAC filters. While this will remove some contaminants from the soil, it’s immediately releasing these pollutants into the atmosphere which can negatively impact the planet and human health. In the case SVE units are operating as intended, we have not been able to access the maintenance or completion records. We could not find any information detailing what happens to GAC filters once they are disposed. If these records do exist, we were unable to locate them using the normal search process.
Some of the key regulatory failures include:
– Inadequate monitoring and enforcement: Regulatory agencies often rely on operator self-reporting, which can lead to underreporting and non-compliance.
– Lack of clear guidelines and standards: The EPA and state agencies have failed to establish clear guidelines and standards for SVE operations, allowing operators to exploit loopholes and bypass some safety measures.
– Insufficient public disclosure: Regulatory agencies often fail to provide adequate public disclosure of SVE operations, making it difficult for communities and enforcement agencies to hold operators accountable.
These regulatory failures have consequences, including the continued release of VOCs into the atmosphere and exposure to communities living in close proximity.
Conclusion
Soil vapor extraction is sometimes touted as a solution to oil and gas spills that contaminate soil. However, like with any technology designed to remediate pollution, the success of the remediation is dependent on proper operation of the technology. In cases like we observed, where the operator is bypassing the GAC filter, pollutants are being pumped into the atmosphere and causing more pollution. The problems at the sites were due to the operator’s failures to maintain them properly. However, other problems exist with allowing operators to implement these “solutions” without oversight. What happens to the GAC filters? How are they disposed of? Are they inspected by regulatory agencies?
The lack of regulatory oversight allows operators to prioritize profits over New Mexicans and our environment. We have to prioritize more effective solutions. We must require operators to be financially responsible for the entire cleanup cost of every site they own rather than passing this cost onto us.
