SCE Mesa Facility

In support of facility decommissioning, a Phase I Environmental Site Assessment (ESA) was required prior to termination and/or reduction of the client’s land lease in compliance with ASTM E1527-13 guidance, including site inspection, records review, interview and reporting tasks. The Phase I ESA focused on a 120 acre, three-parcel area located on US government owned land that had been developed with industrial manufacturing and support facilities, a helicopter pad, gas station, sewage treatment plant, campground, training centers, medical center and administration buildings. Prior to the client’s use, the property had been part of a Federal facility.

Based on the findings of the Phase I ESA’s and additional environmental requirements specified in the land lease agreement by the landowner, Leighton completed multiple work plans to investigate approximately 130 areas of potential concern (AOPCs). The 2014-2019 Site investigation efforts resulted in the advancement of a total of 860 soil and soil gas borings ranging up to 110 feet in depth, and the installation of 20 groundwater monitoring wells. Reporting included data validation and human health and ecological risk assessments. Timely remedial actions were completed and out-of-the-box remedial strategies were implemented resulting in Client savings over $1 million in lease fees.  

A challenging aspect of this project was the multiple parties involved that contributed comments and provided input into the multiple reports and remedial actions, including the Landowner (via various federal groups and interests), client departments (Real Estate, Environmental, and Facilities), environmental consultants representing other interested parties, the California Coastal Commission, the United States Environmental Protection Agency, the San Diego Regional Water Quality Control Board, and the Department of Toxic Substances Control (DTSC) acting as the lead regulatory agency with oversight of the investigation. Leighton addressed comments from the multiple parties in a timely manner and adhered to client deadlines geared towards fulfilling lease obligations and meeting corporate schedules.