Overview
Video and geophysical logging of three Floridan aquifer potable water supply wells at the Tacachale facility was conducted by Water & Air and the St. Johns River Water Management District (SJRWMD) to determine possible contamination routes of chlorinated and non-chlorinated volatile chemicals of 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, a Temporary Consumptive Use Permit (TCUP) for limited pumping was negotiated and approved by the SJRWMD to allow the supply wells, which had previously been shut off, to be temporarily used 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.
Task Summary
- Conducted groundwater and soil assessment.
- Modeled groundwater conditions.
- Created remedial design.
- Developed construction specifications and management.
- Coordinated with regulatory agency.
- Compiled and submitted permit application.
Results
Water & Air used APT results and groundwater modeling to demonstrate to the SJRWMD that withdrawing groundwater from the remaining two wells would not cause vertical leakage from upper aquifers to the lower Floridan aquifer and a Consumptive Use Permit (CUP) was issued. Water & Air also designed and supervised the installation of a granular activated carbon treatment system to polish groundwater extracted from the remaining potable water supply wells prior to water being delivered to the facility for consumptive use.
