DUE Diligence


GSI brings perspective and insights from decades of working on a broad scope of projects, which significantly enhances our ability to evaluate environmental conditions and assess potential liability on a wide range of property types.

Environmental uncertainties can pose significant risks for property transactions and related financing, insurance underwriting, and future land use planning. Our due diligence practice is grounded in our significant experience on environmental projects across many industries, geographic regions, and market sectors. Our technical experts work efficiently to identify, evaluate, and manage potential environmental impacts to soil and sediment, soil vapor, groundwater, and surface water. Our technical experts work efficiently and effectively with multi-disciplinary teams to integrate environmental liability analysis with acquisition, merger, and capital improvement projects.

GSI routinely supports due diligence efforts by performing environmental compliance audits and Phase I ESAs compliant with ASTM standards and EPA’s All Appropriate Inquiry Rule. By identifying potential environmental impacts and compliance issues, we provide assessments of potential environmental liabilities and risk management options, referenced to cost materiality thresholds if desired, prior to property acquisition or disposition. Our due diligence practice is augmented by Phase II investigations, remediation cost estimation, and third-party cost allocation for litigation.

Related practice areas include:


Phase I ESA Review and Environmental Cost Liability Estimation

Confidential, Northern California

On behalf of the Buyer, GSI was retained to review Phase I documentation prepared by a third party. GSI’s review and research identified a tetrachloroethene (PCE) groundwater plume emanating from a former, upgradient dry cleaner facility possibly encroaching on the Subject Property. GSI’s findings and cost estimates for potential vapor intrusion mitigation at this future development site contributed to the Buyer’s successful purchase negotiation with the Seller.

Phase I ESAs and Limited Compliance Audits for Oil and Gas Assets

Multiple Locations, Southern California.

GSI conducted Phase I ESAs and limited compliance audits for a portfolio of oil and gas assets, some of which had been in production for more than 100 years. We were first retained by the lender, which was performing due diligence in support of restructuring existing contracts with the lease holder, and were later hired by a potential buyer to assess the environmental liabilities associated with the assets. GSI tailored our assessment to efficiently and effectively combine the Phase I ESA and compliance review to evaluate the assets relative to the Phase I standard, as well as to a specified materiality threshold for environmental issues that did not meet the level of a “recognized environmental condition.”

Contact Us