Soil contamination poses significant environmental and health risks, especially when volatile organic compounds (VOCs) seep into the subsurface. For industries and communities aiming to remediate impacted sites, soil vapor extraction (SVE) is a powerful and proven technique.
At General Carbon, we are committed to providing cutting-edge solutions for environmental remediation, and SVE plays a vital role in our efforts to restore cleaner groundwater and soil. In this guide, we explore what SVE is and how we can help with soil remediation efforts.
What Is Soil Vapor Extraction (SVE)?
Soil vapor extraction (SVE) is an in-situ (on-site) remediation technology used to remove VOCs in vadose zone soil (unsaturated soil). SVE systems involve the use of a vacuum that pulls vapors from underground. Then, the extracted vapors, or off-gases, are treated to remove harmful levels of contaminants.
There are a handful of treatment options involved in SVE that capture chemicals and allow clean air to exit into the atmosphere. Some of the treatment options include:
- Adsorption: Vapors are pumped through granular activated carbon filters that separate the contaminants from the air.
- Biofiltration: Microorganisms are added to break down extracted vapors into gases, such as carbon dioxide.
- Thermal oxidation: Vapors are destroyed by heating them to high temperatures.
How Does SVE Work?
The SVE process involves the following steps:
- Site assessment: Engineers evaluate soil properties, contamination levels, and the depth of volatile pollutants.
- Installation of extraction wells: A network of wells is strategically placed in the contaminated area to a depth above the water table in order to optimize vapor removal.
- Application of vacuum pressure: A vacuum system attached to the extraction wells pulls volatile contaminants in vapor form from the soil to the ground surface for treatment.
- Vapor treatment: The extracted vapors are processed through activated charcoal filters, thermal oxidation, or biofiltration to remove hazardous components.
- Monitoring and optimization: Continuous monitoring ensures efficiency and regulatory compliance, with system adjustments made as needed.
SVE is often used together with air sparging to treat contaminated soil. While the SVE process involves the treatment of dry soil above the water table via the use of extraction wells and a vacuum system, air sparging treats groundwater-soaked soil below the water table using injection wells and an air compressor that pumps air underground to extract contaminant vapors.
How Long Does the SVE Process Take?
SVE can last from several months to several years and varies from site to site. Cleanup time depends on several factors, including:
- Contaminant type and concentration: Highly volatile contaminants extract faster than less volatile ones. If extracted soil gas concentrations are high, SVE will take longer.
- Contaminated area: If the contamination site is large or deep, treatment will take longer.
- Soil characteristics: Dense or moist soil can slow the movement of vapors, while soil with high permeability allows for quicker vapor movement.
Benefits of SVE
SVE poses little risk to site workers and the community. During the process, chemical vapors are securely contained, and treatment of the contaminants does not involve harmful chemicals. Plus, only air that is deemed clean by air quality standards will be released into the atmosphere.
On top of SVE being a safe remediation technology, here are some additional benefits to using SVE systems as a form of remediation for a contaminated site:
- Minimal site disturbance: Since it is an in-situ technology, excavation is not required, which preserves the site’s integrity.
- Cost-effective: SVE is typically inexpensive to implement and can treat large soil volumes at reasonable costs.
- Ease of use: SVE systems are easy to install and can be easily monitored.
- Pairs with other remediation techniques: As previously mentioned, SVE can easily be coupled with other systems, such as air sparging and soil fracturing.
- Fast-acting: Depending on site conditions, significant contaminant reduction can be achieved within months to a few years.
Applications of Soil Vapor Extraction
Now that you have an understanding of what soil vapor extraction is, here are some possible applications of this technology:
- Industrial spill cleanups
- Gas and fuel leak remediation
- Manufacturing site decontamination
- Dry cleaner site remediation
Environmental Protection and Sustainability
SVE is a common and proven remediation technology, and the Environmental Protection Agency (EPA) considers it to be a primary remedy for the treatment of VOCs in soil under their Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). By preventing pollutants from migrating into groundwater sources, this remediation method helps preserve local ecosystems and drinking water supplies. Additionally, by using activated carbon and other treatment technologies, emissions are controlled, reducing the environmental footprint of the remediation process.
How General Carbon Can Help With Soil Remediation
Soil Vapor Extraction is an essential tool in environmental remediation. When paired with activated carbon filtration, it provides a comprehensive approach to tackling soil and groundwater contamination. And General Carbon is here to help.
Not only can we supply you with activated carbon, but we can also custom fabricate treatment systems designed for soil vapor extraction solutions. Our expertise ensures that your adsorption equipment is tailored to the specific needs of your site, maximizing efficiency and effectiveness in contaminant removal.
Contact us today for more information on SVE and how General Carbon can assist with your remediation needs!