Brownsfield Redevelopment

San Leandro, California

WEST provided complete site investigation, risk evaluation, remedial action plan preparation, as well as completion documentation for the redevelopment of a 44 acre assemblage of commercial, industrial and residential properties in San Leandro, California. The properties were remediated in coordination with the San Leandro Redevelopment Agency and the California Regional Water Quality Control Board for a residential development.

WEST performed site investigations that included the advancement of approximately 90 soil borings, five monitoring wells and the collection of approximately 300 soil and groundwater samples. The results of the investigations revealed that historical operations on the properties resulted in releases of chemicals to soils and groundwater including tetrachloroethene (PCE), trichloroethene (TCE), and petroleum hydrocarbons.

In addition, off-site releases at several nearby properties resulted in impacts to shallow groundwater. The Site cleanup proceeded under the Polanco Redevelopment Act. Application of the Polanco Redevelopment Act provided a statutory mechanism for the redevelopment agency and the purchasers to obtain immunities from state environmental laws following the completion of the cleanup.

WEST prepared the Remedial Action Plan (RAP) that included a health based risk assessment, soil leaching evaluations, development of cleanup goals and action plan. The remedial activities completed included the excavation and on-site treatment and reuse of approximately of 8,000 cubic yards of PCE and petroleum impacted soil and installation and operation of a groundwater ozone sparging system. Sampling following implementation of the remedial activities con-firmed that PCE in groundwater had been reduced approximately 80 percent in approximately eight weeks. WEST was able to demonstrate that the residual concentrations of PCE in groundwater did not pose a threat to use of the property and that no further remedial actions were warranted.

The completion of the remedial actions was approved by the California Regional Water Quality Control Board and the Polanco Act immunities adoption and No Further Action letter was issued approximately 14 months after WEST began investigations.