Air quality is an increasingly important environmental issue for both residential and commercial spaces. Energy efficiency improvements have led to more tightly sealed buildings with reduced ventilation rates, which can potentially cause air pollutants to build-up in poorly ventilated spaces. Furthermore, the USEPA and state environmental regulatory agencies have increased emphasis on investigating the fate and transport of volatile organic compounds (VOCs) in soil vapor, and their possible impact on indoor air quality.
D&B has provided soil vapor intrusion study and air contaminant exposure assessment services to numerous private sector clients, authorities, municipalities and federal and state agencies in conjunction with investigation of a variety of sites including among others:
- Active and closed landfills.
- Active and abandoned manufacturing facilities.
- Former Manufactured Gas Plant (MGP) sites.
- Petroleum storage facilities.
- Dry Cleaning businesses.
The air monitoring and sampling programs conducted by D&B range from the collection of a single sample from a single building to collection of numerous samples from multiple structures up to 1 mile from a project site. The characterization of indoor air quality is an essential element in the investigation of contaminated sites because contaminants often migrate through subsurface soil and groundwater migration pathways to off-site locations. Site contaminants can then enter buildings and other living spaces where direct exposure to the contaminants can occur.
After collection and validation of the soil vapor and indoor air data has been completed, a qualitative risk/exposure assessment is typically prepared by one of D&B’s Certified Industrial Hygienists (CIH). This is to determine if the identified Contaminants of Concern (COCs) pose an unacceptable risk to human health based on current and anticipated use of the building/structure, potential receptors and potential contaminant migration pathways. Remedial actions are undertaken if the exposure assessment identifies an unacceptable risk. Remedial actions may range from increasing ventilation of a building to complete removal of a contaminant source located upgradient of the affected building.