Vapor intrusion investigation and mitigation in a residential neighborhood

About this project

client
Confidential
location
Minnesota
completion date
2016

To evaluate vapor intrusion near a site with groundwater impacted by chlorinated solvents, primarily trichloroethylene (TCE), our client hired Barr to assist with a large-scale vapor intrusion investigation in a residential area. Using a tiered approach following the Minnesota Pollution Control Agency’s (MPCA’s) risk-based guidance, we first performed a desktop screening-level vapor-intrusion study to determine that vapor intrusion represented a potential concern and required further investigation.

Barr then collected soil-gas and groundwater samples in public rights-of-way to further evaluate the potential vapor intrusion risk and define areas where building-specific data was needed. This information indicated that building-specific data was needed from approximately 300 properties.

As part of the building-specific sampling effort, Barr communicated with property owners and building occupants regarding sampling, obtained access agreements, and scheduled appointments. Each property was assigned a “property coordinator,” a Barr staff member who followed the property through the life cycle of the project, including communicating with property owners and building occupants, obtaining access agreements, scheduling sampling appointments, and communicating sampling results. Due to the large number of properties, communications with property owners and other property-specific data were documented in a database for frequent reporting to our client and regulatory agencies.

This personalized approach resulted in participation from 95 percent of property owners. Barr’s sampling technicians used manually operated drills, vapor-pin sample ports, leak-testing methods, and Summa canisters to collect sub-slab soil gas samples. Indoor air sampling was also completed at selected locations.

Based on the results, active sub-slab depressurization mitigation systems were installed at more than 185 properties. Barr observed the installations and also observed and documented post-installation diagnostic testing to confirm the effectiveness of each system.

Key team members

Sara Ramsden

Vice President
Senior Environmental Engineer

Eric Blodgett

Environmental Engineer

Sara Gaffin

Vice President
Senior Geological Engineer

Mary Sands

Vice President
Senior Chemical Engineer

Related Contaminated site management projects

Park and landscape design for Mouse River enhanced flood protection project
Design of abutment wall extension at Dells hydro station
Coffee Creek trout stream restoration
Dry-stack tailings management
Tailings basin expansion and closure options
Investigation and remediation of jet-fuel release
Snowpack monitoring and lake drawdown for Minnesota watershed district
Redevelopment services for Surly destination brewery
Penn Avenue sinkhole investigation and rehabilitation
Monitoring of constructed wetland for groundwater remediation
Landslide stabilization design for an underground coal mine
Advanced oxidation process pilot evaluation for municipal drinking-water system
RICE applicability analysis and audit
Responding to wind-farm tornado damage
Environmental liability assessment at manufacturing facility
Evaluation of wind-turbine foundation following fire damage
Groundwater modeling for wellhead-protection-plan amendment
Multi-site PFAS remedial investigation and remediation
Sediment removal from beneath Vermillion River bridge
Monitoring and maintenance of remediation system at wood-treating site
Monitoring of end-pit lake at oil sands mine
Flood risk reduction of suburban lakes
Letter of map revision for Minnesota city
Options study and design to restore biomass fuel-handling system
Mine remediation and reclamation
West River Parkway landslide repair
FERC relicensing of Ford Lake Dam
Groundwater compliance assistance for CCR Rule
Floodproofing of utility switchyard
Concept-level design of wastewater discharge option
Flood mitigation at refinery
Wetland replacement assistance for highway project
Environmental support for post-fire cleanup at industrial facility
Permitting and compliance services for oilseed-processing plant
Lilydale Regional Park stormwater management and slope stabilization
PFOS investigation at municipal wastewater plant
Response to denatured ethanol release
Aquatic invasive species (AIS) management in a Wisconsin lake
Solar-energy-system compliance
Berm-failure study at saltwater disposal well site
Remedial investigation, negotiation, and design for Superfund site
Preliminary feasibility study for PFAS-related water quality concerns
Rockford dam removal
Groundwater modeling and remedial improvements at closed landfills
Stressor-identification report for an impaired urban stream
Post-flood stream assessment and natural channel design
Support for decommissioning and demolition of manufacturing facility
Water reuse evaluation for zero liquid discharge at manufacturing facility
Water-quality and structural monitoring for channel dredging
Spillway redesign at Cedar Falls Hydro Generating Station
Air-quality services for steel company
Flood risk management system upgrades and FEMA certification
PMF modifications at hydroelectric plants
PMF study for the Dead River
PFAS mass balance and sample collection
PFAS treatment during power plant decommissioning
TMDL study and water quality assessment for a suburban stream
Gas processing equipment, outage procedure and fitness-for-service evaluation
Permitting and nondegradation services for sugar-beet facility
PFAS stack testing services for a manufacturing client
AWIA risk and emergency compliance for urban drinking water
Environmental assessment program for highway safety improvements
CFD modeling of stormwater tunnels
Environmental services at manufacturing facility
Assessment of PFAS use
Air permitting assistance for manufacturing coating facility
Air permitting assistance for pharmaceutical facility
Design of repairs to leaking reservoir
Water reuse system design
Trichloroethylene (TCE) investigation and remediation
RCRA waste tank inspection, certification, and closure
Air permitting assistance for reaction-injection molding operation
Environmental permitting and engineering design for biomass carbon production
Road raise and conceptual design
Reasonably available control technology analysis for refinery
Flood-control-system upgrades and certification
Landslide stabilization protects architectural treasures
Strategy for collecting lake-morphometry data
Tailings facility dam safety review
Engineering services for industrial landfill expansion and closure