Challenge. Define and address environmental impacts to soils and groundwater to allow redevelopment of property as the city’s new central public library

Solution. A 2-acre property with an electrical substation in downtown Austin, the Seaholm Substation site is part of a larger decommissioned power generation and distribution complex with activities dating back to the 19th century. To prepare the site for reuse as the location of the new central public library, INTERA prepared a Texas Voluntary Cleanup Program (VCP) application and performed a site investigation and subsequent response action.


As part of the investigation, we reviewed historical reports, performed groundwater sampling of existing wells, collected soil samples from over 80 borings, evaluated the analytical results, and prepared an Affected Property Assessment Report for submittal to the Texas Commission on Environmental Quality (TCEQ). While groundwater monitoring results indicated no concentrations of chemicals greater than the applicable Texas Risk Reduction Program (TRRP) residential assessment levels; the investigation did identify soil impacts from polychlorinated biphenyls (PCBs), semi-volatile organic compounds (SVOCs), arsenic, and lead. During the remedial action, INTERA provided contractor oversight, confirmation sampling, evaluation of analytical results, waste management and tracking, project documentation, and planning and coordination. After removing some 30,000 cubic yards of waste for off-site disposal, we documented the remediation activities in a Response Action Completion Report to document the remediation which was submitted to the TCEQ and accepted without comment. Although the Toxic Substances Control Act (TSCA) cleanup requirements were not initially applicable due to the low concentrations of PCBs in site soils collected and analyzed as part of the investigation, confirmation soil sampling after the remedial action did show PCBs at greater than 50 mg/kg (the threshold for TSCA applicability). INTERA’s expertise in working with TSCA requirements for performance based cleanups enabled us to address the PCB issues in an efficient manner and meet the required schedule. After the successful excavation, removal, and disposal of contaminated soils, a Certificate of Completion was issued by the TCEQ. Our efforts cleared the way for the construction and opening of Austin’s new central public library in late 2016.