Vapor Intrusion Mitigation of Petroleum Hydrocarbons
at a Residential Complex for Major Petroleum Company
Mattapoisett, MA
Problem:
Gasoline vapors were detected in several condominium basements located within a residential complex situated downgradient of a former gasoline station.
Solution:
ES&M responded quickly and deployed air recirculation units equipped with carbon adsorbers. Cracks in the basement floors and the sumps were sealed to reduce vapor intrusion. Indoor air samples were collected, the results of which were used to conduct an imminent hazard evaluation. While no imminent hazard was present, the results of a risk characterization indicated that further response actions would be necessary. ES&M researched the construction of the condominium complex, and conducted pilot testing. Ultimately, a sub-slab depressurization system that created a vacuum using pre-existing under-drain piping was designed. This resulted in control of the vapor intrusion pathway with minimal inconvenience to homeowners and significant cost savings to our client.
Gasoline vapors were detected in several condominium basements located within a residential complex situated downgradient of a former gasoline station.
Solution:
ES&M responded quickly and deployed air recirculation units equipped with carbon adsorbers. Cracks in the basement floors and the sumps were sealed to reduce vapor intrusion. Indoor air samples were collected, the results of which were used to conduct an imminent hazard evaluation. While no imminent hazard was present, the results of a risk characterization indicated that further response actions would be necessary. ES&M researched the construction of the condominium complex, and conducted pilot testing. Ultimately, a sub-slab depressurization system that created a vacuum using pre-existing under-drain piping was designed. This resulted in control of the vapor intrusion pathway with minimal inconvenience to homeowners and significant cost savings to our client.
Scope of Work:
Project Highlights:
- MCP Phases I through V
- Tier Classification
- Imminent Hazard Evaluation
- Immediate Response Actions
- Remedy Operation Status
- Risk Characterization
- Site Monitoring
- Soil Gas and Indoor Air Evaluations
- Sub slab depressurization
Project Highlights:
- ES&M responded quickly to complaints of petroleum odors in the indoor air of newly constructed residential condominiums. Carbon-based odor abatement units were immediately installed to abate the odors and an indoor air monitoring program was implemented. The results of the air monitoring and sampling documented that an imminent hazard did not exist.
- To further control odors inside the condominiums, we researched the construction of an underdrain system installed by the builder, and designed a sub-slab depressurization system that utilized this piping. This approach minimized both costs to our customer and disturbance to the condominium residents.
- Through negotiations with regulators, ES&M concurrently satisfies both IRA and Phase V/ROS reporting requirements within the State's regulatory framework.
- We have maintained excellent rapport while working inside four private residences. These efforts have clearly benefited our customer and allowed the work to proceed smoothly.
- ES&M has installed vapor barriers in several of the basements, and we monitor differential pressure to assess the efficiency of our system.