Tacachale Solvent Site Assessment, Remediation, and Permitting
   Florida

Overview
Video and geophysical logging of three Floridan aquifer potable supply wells at the Tacachale facility were conducted by Water & Air and the St. Johns River Water Management District (SJRWMD) to determine possible routes by which chlorinated and non-chlorinated volatile chemicals released at or near the land surface were entering the site's deeper water supply. Well logging results identified several holes in the casing of one of the wells at approximately 350 feet below the land surface.

As a result of these findings, TCUP limited pumping was negotiated and approved by the SJRWMD to allow the supply wells, which had previously been shut off, to be temporarily brought back on-line for hydrologic testing. Hydrologic aquifer performance testing (APT) confirmed that the damaged well casing was transmitting water and possibly chemicals from upper aquifers to the deeper Floridan aquifer. Subsequently, this well was abandoned through high pressure grouting to prohibit the exchange of water and chemicals from upper aquifers to the Floridan aquifer.

Details

• Groundwater and Soil Assessment
• Groundwater Modeling
• Remedial design
• Construction specifications and management
• Regulatory agency coordination
• Permitting

Results
Water & Air used APT results and groundwater modeling to demonstrate to the WMD that withdrawing groundwater from the remaining two wells would not cause vertical leakage from upper aquifers to the lower Floridan aquifer. Based on APT and modeling results, a CUP was issued. Water & Air also designed and supervised the installation of a granular activated carbon (GAC) treatment system to polish groundwater extracted from the remaining potable wells prior to water being delivered to the facility for consumptive use.