Challenge. Obtain environmental closure of property selected as site of new bus and commuter rail operation and maintenance facility

Solution. After another contractor performed Phase I and II environmental site assessments (ESAs), INTERA led the additional investigation and remediation activities required to obtain site closure under the Texas Commission on Environmental Quality’s (TCEQ) Voluntary Cleanup Program (VCP). The site was a 28-acre property with a history of industrial activities that dated back over 40 years. The Phase II ESA identified impacts to soil and groundwater, with RCRA metals, volatile organic compounds, and total petroleum hydrocarbons (TPH) being the primary contaminants of concern (COCs). We performed an affected property assessment that included installation of 16 groundwater monitor wells and over 60 soil borings. This fieldwork was performed on an expedited schedule over a 3-week period to support the property transaction. INTERA also performed concrete bulk sampling to investigate potential impacts to waste storage areas and building slabs. The results of the assessment were documented in an Affected Property Assessment Report. The completion of the environmental closure for the site was critical to obtaining project funding from the Federal Transportation Authority to enable construction of the new facility. Our assessment efforts determined that there were four small areas of affected soil that had concentrations of COCs above the applicable critical protective concentration limits (PCLs), including cadmium, benzo(a)pyrene, dibenzo(a,h)anthracene, pentachlorophenol, and TPH. INTERA prepared and submitted a Self-Implementation Notice (SIN) to facilitate a removal action for the four affected soil areas. We provided remediation oversight including contractor supervision, confirmation sampling, and project documentation/reporting. The remedial actions were documented in a Response Action Completion Report (RACR) that was submitted to the TCEQ and quickly approved. For groundwater, four analytes (arsenic, 1,4 dichlorobenzene, pentachlorophenol, and trichloroethene) exceeded the critical PCLs established for the site. INTERA prepared a Response Action Plan to address the groundwater through natural attenuation, as documented by periodic groundwater monitoring. When results of the monitoring showed that concentrations had been reduced to below PCLs, we prepared a comprehensive report documenting the results and met with the TCEQ to request discontinuation of groundwater monitoring and approval of environmental closure of the property. The TCEQ subsequently issued a final Certificate of Completion for the site. INTERA’s efforts on this Brownfields project played a key role in meeting Cap Metro’s schedules for finalizing the property transaction, preparing the site for redevelopment through the implementation of remediation and demolition activities, and obtaining federal funding to support construction of this now fully operational facility.