Active Mountaintop Gas Station Remediation Site

MAE2 was selected to design and build a remediation system for a gas station site in a small mountain town.

The geology of the area is fractured bedrock and the gasoline and MTBE contamination traveled through the fractures and impacted several nearby drinking wells. The consultant conducted a multiple day test at the site. MAE2 used this data to design a system that would prevent the contamination from moving off site and eliminate the source area. This meant the system would need to operate a large number of wells at high vacuum in order to remove the free product and create influence in the fractures to prevent the plume from traveling.

MAE2 used the pilot test data to design and provide written specifications for a Multi Phase Extraction and Groundwater Treatment system. The system needed to remove and treat TPH-Gasoline concentrations as high as 160,000 PPB and MTBE concentrations of 3,500 PPB.
The system uses 3 high vacuum rotary claw pumps, providing over 700 ACFM flow at 20” HG vacuum, to extract impacted groundwater and vapors. The pumps can be run simultaneously or independently depending upon the operational needs of the site.

The extracted groundwater from the individual wells passes through an 18 point custom manifold and settles out in a 220 gallon knock out tank. A progressive cavity transfer pump sends the water to a 20 GPM Oil Water Separator to remove any free product gasoline. A centrifugal transfer pump sends the water through a bag filter to remove solids and particles from the water before being treated by an oversized Removable Tray Air Stripper. The stripper is oversized to provide additional residence time to treat the MTBE. The water is pumped through another bag filter and then two 250 LB Liquid carbon vessels before being discharged to a mountain stream.

Finally the system will provide runtime hours, vacuum trends, and water flow totals recorded through the PLC control panel. The cellular connection allows full system control and data through easy to use web browser access. This is a vital because the town is remote and susceptible to power outages. The system can be restarted without requiring a time consuming trip, maximizing runtime.

This Gas Station Site remediation System uses the following components and subsystems

Rotary Claw Vacuum Pump
Removeable Tray Air Stripper
PLC Control panel
Bag Filter
Carbon Filtration
Oil Water Separator
Vapor Liquid Separator
Centrifugal Transfer Pump
Progressive Cavity Transfer Pump