Due to the volatile nature of solvent and petroleum-related contaminants, the vapor intrusion pathway is often relevant during an environmental investigation at a manufacturing facility, dry cleaner, or gas station etc . The concern is that vapors, which off-gas from a contaminant body, will seep into a building and create unsafe conditions for the inhabitants. If groundwater or soil contaminant concentrations exceed vapor intrusion screening levels in close proximity to a building structure (existing or future), additional vapor characterization may be necessary.
To further assess the vapor intrusion pathway, a soil gas (subsurface vapor) sample can be collected from a shallow vapor well (approximately three to five feet deep) immediately outside the footprint of the building or from a Vapor Pin®. A Vapor Pin® allows for the collection of a soil gas sample directly beneath a foundation floor (known as a sub-slab vapor sample) by installing a brass pin into the floor and then drawing a sub-slab vapor sample through the pin. Vapor wells can also be utilized at a vacant property where a future structure is planned. Edge drilling can provide and install vapour pins and wells across Western Australia in any location to help with your environmental sampling requirements.
Multilevel Groundwater and soil Vapour wells are engineered technologies installed in single boreholes above and/or below the water table to obtain data from different depth intervals. The technologies may consist of various pipes, liners, access ports, sampling pumps, pressure sensors, and sealing mechanisms that are installed temporarily or permanently in boreholes drilled into unconsolidated sediments or bedrock.
MLS systems facilitate 1) ongoing measurement and monitoring of depth-discrete water pressures (hydraulic heads) and 2) repeated collection of depth-discrete groundwater samples for chemical testing. Commercial MLS systems are available with as few as three ports (CMT System) to more than 20 ports (MP Westbay and Solinst Waterloo Systems). An essential design element of all MLS systems is that they must prevent hydraulic connection of the various monitored intervals within the wellbore.
While installed primarily in water-saturated sediments and rock, MLS systems can also be installed in the vadose zone for the collection of depth-discrete soil gas samples. Hybrid MLS systems can be constructed with some ports in the vadose zone and some ports in the saturated zone.