JHA performed indoor air and sub-slab soil gas testing on behalf of the client to determine the extent of a vapor encroachment concern (VEC) for potential contaminants indicated in JHA’s prior Phase I ESA of the site. Investigation results detected volatile organic compounds (VOCs) which required the installation of a 2,000-2,500 standard cubic feet per minute (scfm) sub-slab depressurization (SSD) system for the safety of on-going tenant activities. JHA procured and managed all subcontractors required for the design, installation, maintenance, and operations of the SSD system. Final design included: details specifying the size and placement of sumps for adequate sub-slab soil gas extraction, the size and quantity of piping needed to remove soil gas from under the concrete building slab, the number and size of blower systems required to effectively remove sub-slab soil gas, and the air permitting requirements for the anticipated quantity of VOCs released into the atmosphere. JHA also coordinated system testing and installation activities with multiple active operational facilities to prevent scheduling hangups. The testing of the VEC, design and installation of the SSD system, and bringing the system into full operation, was completed between four- and five-months’ time.
JHA also performed continued air sampling and testing, air permit compliance, piping inspections and repairs, and mechanical maintenance on the SSD system. JHA provides a continuous summary of all testing and sampling activities, maintenance activities, and VOC discharge activities in a year-end summary report for the client.