Greatly efficient recovery of impacted groundwater and product.
When free product is present in the subsurface, removing it before it spreads further is the priority. High vacuum extraction applies strong negative pressure to monitoring wells, pulling free product and product vapors out of the subsurface and to the surface, where they can be captured and properly disposed of. At The Phoenix Group, each extraction event is planned around the specific conditions at the site.
Dual-phase extraction works by applying vacuum simultaneously to both the saturated and unsaturated zones. This recovers groundwater carrying dissolved contamination and vapors from the soil above the water table in a single operation. In many cases, in-situ chemical injection is used alongside dual-phase extraction to increase treatment efficiency or improve the volume of free product removed. The two methods complement each other well.
Throughout the process, our team provides clear communication about what the extraction data shows and what it means for the project. The information gathered during high vacuum extraction events guides the next steps in remediation, whether that means scheduling additional treatment or evaluating whether the site is ready to transition toward closure.
Not every extraction event produces the same results, and that variability is itself useful data. When free product recovery drops significantly between events, it suggests the recoverable phase is being depleted, and the project may be ready to shift toward a different treatment approach. When recovery remains high, it confirms that additional high vacuum extraction is still warranted. We track those trends across events and adjust recommendations accordingly. Property owners aren't left guessing about where things stand. After each extraction event, we provide a clear summary of what was recovered, what conditions looked like in the field, and what we recommend as the next step.
High vacuum extraction uses a vacuum system connected to monitoring wells to apply strong negative pressure to the subsurface. This draws free product, contaminated groundwater, and vapor-phase contaminants up through the wells to the surface, where they are collected for treatment or disposal. The method is most effective at sites with measurable free product floating on the water table.
Dual-phase extraction applies vacuum to both the saturated zone (groundwater) and the unsaturated zone (soil vapor) at the same time, recovering both liquid and vapor-phase contamination in a single operation. Standard groundwater pumping only targets liquid below the water table, and product skimming only recovers the free product layer at the surface. Dual-phase extraction captures a broader range of contaminants more efficiently.
High vacuum extraction is particularly effective at recovering LNAPL products such as gasoline, diesel, and heating oil that have accumulated on the water table. It also recovers volatile organic compound (VOC) vapors from the unsaturated soil above the water table. The specific products and compounds targeted depend on the site history and the type of release that occurred.
Planning starts with a review of existing site data, including the distribution and thickness of free product, the depth to water, and the soil permeability. That information determines how many wells to pull from, the appropriate vacuum level, and how long to run the system. We mobilize the equipment to the site, connect to the target wells, and monitor conditions throughout the event to ensure the work is proceeding as planned.
We measure free product thickness before and after each event, track the volume of fluid and vapor recovered, and collect samples from the extracted fluid for laboratory analysis where required. This data is compiled into an event report that documents what was removed, how conditions changed, and what it means for the project. The report supports both internal planning and regulatory submittals.
Yes. Combining dual-phase extraction with in-situ chemical injection is a common and effective approach. Extraction removes recoverable free product and vapor, while injection introduces chemical amendments into the residual contamination zone to break down what cannot be pumped out. The two methods address different phases of contamination and together can reduce the overall mass of contaminants more efficiently than either method alone.
High vacuum extraction events are designed to minimize disruption to daily operations. The equipment is typically set up in one area of the site, and the connection points are existing monitoring wells. Most extraction events are completed within a single day or over a short series of days. We coordinate timing with the site operator to avoid conflicts with critical operations whenever possible.
