Vapor Intrusion Mitigation / Sub-Slab Depressurization

ALPINE has been designing and installing sub slab depressurization systems and vapor/gaseous intrusion mitigation systems since 2000. As an early entrant into this field, which is, only now beginning to become mainstream, our engineers pioneered proprietary methods for control of negative pressure field extension in new construction. Our experience in design and install is wide ranging from the smallest of residential properties, to factories, to sprawling strip malls.

We have designed and installed systems for the removal of chlorinated solvents (i.e. perchloroethylene (PCE) (perk), trichloroethylene (TCE), etc.), gasoline, fuel oil, radon, and methane. Our design approach involves a three-step process:

• Collect site-specific use information. This is an important step used to balance space function with system cost. For example, it is desirable to minimize visible piping in a retail space; so higher capacity fans can be incorporated to minimize visible piping.

• Perform site-specific pressure field extension testing. This phase involves coring holes through the concrete floor and testing the pressure field created with a series of test fans to determine the sub slab aggregate gradient to be used in the system deign.

• Use the data collected in the first two phases to create drawings and a specification identifying the equipment and layout of the system.