Case Studies
J.S. Held Acquires Shechter & Everett to Expand Forensic Accounting Capabilities for Family Law Disputes in Florida
Read MoreA developer initiated grading activities for a multi-family residential redevelopment project on a four-acre property in Santa Ana, California, in 2016. During construction, the project contractor identified petroleum hydrocarbons. Impacted soil was excavated and staged, and an initial soil sample collected at 15 feet indicated gasoline-range total petroleum hydrocarbons (TPH-g) and fuel-related volatile organic compounds (VOCs).
Our experts were retained to monitor VOC vapors in accordance with South Coast Air Quality Management District Rule 1166 and to oversee additional excavation activities. Further assessment of the extent of impacts was required to define the limits of the affected soil.
Our experts evaluated site conditions and conducted an additional assessment by excavating seven potholes around the perimeter of the initial excavation and collecting supplemental samples. Gasoline-range hydrocarbons and VOCs were detected in three of the seven locations at the north end of the excavation. Based on these findings, excavation boundaries were expanded to address remaining impacted soils.
The excavation was enlarged to approximately 70 by 100 feet and extended to a depth of 19 feet, where groundwater was encountered. A total of approximately 3,200 cubic yards of soil was removed and disposed of off-site as non-hazardous waste. Our team collected 73 confirmation samples from multiple depths along excavation sidewalls and bottom, as well as from eight additional perimeter potholes. Results demonstrated that the affected soil had been removed, and the excavation was backfilled with engineered fill, allowing construction to resume.
In 2018, our experts conducted verification sampling of soil, soil vapor, and groundwater from five borings installed around the excavation limits to a depth of 20 feet. Soil and groundwater samples were analyzed for VOCs, TPH-g, TPH-d, and TPH-mo, and soil vapor probes were installed at depths of 5 and 17 feet. Results indicated:
Our experts determined that remaining hydrocarbon contaminants were below screening levels for direct exposure and did not impact groundwater. Soil vapor results at shallow depths indicated that vapors were not migrating toward the surface, and the vapor intrusion risk was determined to be unlikely.
> Environmental Risk and Compliance
Our team provides expert advice in the identification and mitigation of risk in environmental matters and develops solutions to deliver ongoing EHS regulatory compliance and independent monitoring.
> Environmental, Health, and Safety
J.S. Held provides environmental, health, and safety consulting and expert services spanning environmental damage and remediation, environmental due diligence, energy transition, toxicology and epidemiology, industrial hygiene, product stewardship and product liability, and human health and safety.
