Marin County Dry Cleaner Remediation

Citadel EHS implemented and manages the remediation of a high-priority dry-cleaning site in Marin County, under the oversight of the San Francisco Bay Regional Water Quality Control Board (SFBRWQCB). The site, which is among SFBRWQCB's highest-priority cases, was impacted by chlorinated volatile organic compounds (VOCs) contamination in soil, soil vapor, and groundwater from historical dry-cleaning operations. The remediation implemented by Citadel addressed impacted soil, soil vapor, and groundwater with VOC impacts that extended approximately half a mile off-site.

Key remedial actions undertaken included:

• Soil Excavation: Excavation and removal of PCE-impacted soil from the former dry-cleaning area.
• Soil Vapor Extraction: Localized SVE to treat residual soil vapor.
• In-Situ Chemical Reduction (ISCR): Two rounds of ISCR injections (approximately 65 injection borings per event) of treatment amendments in groundwater to accelerate the breakdown of PCE and its breakdown products.
• On and off-Site Sewer Lateral Removal: Removal of an abandoned sewer lateral to eliminate a preferential pathway for contaminant migration.
• Ongoing monitoring of groundwater and soil vapor to assess natural degradation trends.

The project also involved significant stakeholder engagement and environmental litigation related to historical contamination and alleged off-site impacts. Citadel EHS provided technical support, remediation expertise, and expert consultation throughout the litigation process, contributing to a unanimous 12-0 jury verdict in favor of the client. The case was subsequently recognized among the Daily Journal's Top Defense Verdicts of 2022.

Highlights:

• SFBRWQCB Oversight
• Remediation of PCE-Impacted Dry Cleaner Source Area and ½ Mile Groundwater Plume
• Litigation Support
• 99% reduction of PCE in Soil Vapor
• 85%+ Reduction of PCE in Groundwater
• Mitigation of Offsite Vapor
• Facilitating Low-Income Residential Redevelopment