Vapor Extraction Systems in California
Encon Environmental designs and installs vapor extraction systems for sites across California, providing sub-slab and soil vapor extraction solutions where remedial excavation is not practical or would significantly disrupt existing buildings and operations.
By drawing soil vapors through a network of conveyance piping and treating them at a thermal oxidizer or other control unit, vapor extraction systems can provide long-term remediation even at fully built-out properties.
- Sub-slab and soil vapor extraction systems for complex sites.
- Conveyance piping networks beneath pavement and buildings.
- Integration with thermal oxidizers and other treatment technologies.
What Is a Vapor Extraction System?
Vapor extraction systems are remediation systems that remove contaminated soil vapors from the subsurface and treat them above ground—often where excavation is not feasible or would interfere with existing buildings and infrastructure.
In a typical soil vapor extraction (SVE) system, a series of extraction wells and conveyance piping is installed below grade and, where needed, beneath building slabs. Vapors are drawn through this network under vacuum and routed to a thermal oxidizer or other treatment unit, where they are destroyed before discharge.
This approach is particularly useful at developed properties where impacted soil is located beneath structures or paved areas, or where long-term vapor control is needed to support continued use or redevelopment.
- Buildings or critical infrastructure overlie impacted soils.
- Deep impacts make excavation cost-prohibitive.
- Vapor intrusion into buildings is a concern.
- Long-term remediation is anticipated at the site.
- Regulators require active vapor control in addition to monitoring.
System Design: Wells, Conveyance Piping, and Thermal Oxidizers
The effectiveness of a vapor extraction system depends heavily on how wells and piping are laid out. Encon’s engineers and field staff design extraction well networks and conveyance piping routes to maximize coverage of the impacted zone while respecting site access and structural constraints.
Extraction wells are installed in strategic locations across the property. Conveyance piping is then installed in trenches that branch out from the main compound, running beneath pavement and, where needed, under buildings. All branches are ultimately routed to a central treatment area where the thermal oxidizer or other control unit is installed.
Valving is used to adjust the system over time—allowing more extraction in target areas, throttling back zones that have responded, and balancing vacuum across the site as conditions change.
- Subsurface extraction wells located in key source and plume areas.
- Trenched conveyance piping networks beneath slabs and pavement.
- Central compound for blowers, thermal oxidizer, and controls.
- Manifolds and valves for zone-by-zone flow adjustment.
- Monitoring points to evaluate system performance and coverage.
Temporary and Long-Term Vapor Extraction Solutions
Not every site needs a permanent treatment compound. For locations where a shorter-term extraction program is expected, Encon can design systems with permanently installed subsurface piping and wells paired with a temporary thermal oxidizer or treatment unit.
In these cases, the treatment equipment is brought to the site for the duration of the active remediation period and removed once cleanup goals are met, while the below-grade piping and wells remain in place for future use or contingency if needed.
For sites with longer timeframes—such as former industrial facilities or refineries being transitioned to office or commercial use—Encon can design more robust long-term systems. These systems can operate over extended periods, supporting redevelopment while remediation continues in the background.
- Temporary systems for short-term extraction campaigns.
- Long-term systems for extended remediation at complex sites.
- Sub-slab depressurization approaches for occupied buildings.
- Phased system expansion as additional areas are identified.
- Decommissioning and site restoration when goals are met.
Integrating Vapor Extraction with California Cleanup Programs
Vapor extraction rarely operates in isolation. Encon integrates these systems with broader cleanup strategies that may include remedial excavation, bio-remediation and chemical injection, UST removal, and soil and groundwater testing and analysis.
Our designs reflect California regulatory expectations for soil vapor and vapor intrusion, and are coordinated with local agencies so that performance monitoring, reporting, and end points are clearly defined. As system data accumulates, we adjust operations, document progress, and help position sites for risk-based closure or continued redevelopment.
- Phase II Environmental Site Assessments and follow-up investigations.
- Remedial excavation in accessible source zones.
- Bio-remediation and in-situ chemical injection programs.
- UST cleanup fund and low-risk closure strategies where applicable.
- Long-term monitoring and vapor intrusion evaluations for buildings.
Need a Vapor Extraction System for a California Site?
Whether excavation is not feasible, vapor intrusion is a concern, or regulators are calling for active vapor control, Encon Environmental can design and implement a vapor extraction system tailored to your property and project schedule.
