$2,000,000 Gained on Building Sale
Los Angeles California
An owner of an industrial building was trying to sell his property, and because a prospective buyer learned of a potential vapor intrusion, he was offering the owner $2M less than the asking price. The tenant was a furniture manufacturer. After one day of VaporSafe™ continuous monitoring, indoor spatial and temporal concentration patterns suggested that an indoor source might be the culprit. For instance, TCE concentrations were only elevated during working hours and only in areas where personnel were working. The net result is that with only a few field days, the occupants (many of whom were young women) were protected from exposure risks, the mystery (which prevailed following several rounds of conventional assessment) were resolved, and the seller received an offer for the full asking price. Lesson
: Continuous monitoring can quickly and accurately identify sources of elevated concentrations. For real property transactions, time is critical, and
as such, a few days of monitoring can help expedite the transaction.
Entry Point Determination
Mid Atlantic US
After years of evaluation with traditional methods at a very large industrial facility, TCE entry point locations remained elusive. Within a few hours after VaporSafe™ continuous monitoring began, spatial and temporal patterns revealed that highest concentrations were in the basement where two sumps were located. The consultant covered the sumps with visqueen and within a few hours VaporSafe™ confirmed a drop in indoor concentrations to safe levels. Lesson
: Continuous monitoring rapidly responds to simple building modifications which can help pinpoint vapor entry locations.
Rapid Dry Cleaner Site Closure
With only two days of VaporSafe™ testing for both chemistry and pressure, it was demonstrated that indoor concentrations were safe during working hours as well as when upward advective flow conditions prevailed, resulting in no further action. Regulators reviewed the information and concluded that no further action was required. Lesson
: Continuous vapor concentration combined with pressure monitoring can be used to rapidly achieve site closure.
Residential Vapor Intrusion Mitigation Mystery Solved, Southern California
At a site where a sub-slab depressurization (SSD) system had been in operation, yet indoor concentrations still exhibited periodic TCE risk exceedances using current assessment methods, a continuous monitoring platform was deployed. Within one day of VaporSafe™ operation project personnel determined that concentrations varied widely throughout the day. A few weeks into the monitoring campaign the SSD was turned off to study potential impacts, which was expected to include a rise on indoor TCE concentrations. To the surprise of project personnel, SSD operation increased VI risks! Lessons
: SSD can actually increase risk if not properly designed, if preferential pathways are not accounted for, and if appropriate chemistry testing is not performed during implementation.
Preventing Exposures During School Construction, East Coast US
A school overlying a documented VOC release was undergoing construction that included breaking the concrete and the potential for building occupant exposures. VaporSafe™ was used to automatically track concentration distributions before, during and after construction, and to immediately send out alerts when risk thresholds were exceeded to ensure that personnel and students were not exposed. Lesson
: Continuous monitoring and automated response during construction represents a pragmatic and prudent option for protecting building occupants from fugitive emissions and VOC exposures.
Analysis of Vapor Intrusion at a Large San Diego, California Military Facility
Southern CaliforniaThe Department of Defense manages hundreds of buildings that reside over volatile contaminant groundwater plumes. At one very large (172,000 sq. ft.) facility located in San Diego, the client was struggling with understanding why after spending years of investigation and mitigation, they still had a TCE vapor intrusion issue. VaporSafeTM was deployed for a one week monitoring campaign. Every day dramatic increases in concentrations were observed in the late morning. It was determined that this indoor concentration increase coincided with a drop in barometric pressure and resulting increase in pressure differential between the subsurface and indoors. Lesson
: Upward vapor flow can be caused by drop in barometric pressure and increase in pressure differential. This has significant implications with respect to conventional monitoring methods. For more information, see Hosangadi et