AWWA WQTC64110

This slide presentation outlines a project concerning brackish groundwater wells that contained detectable concentrations of 1,2,3- Trichloropropane (TCP). Mission Basin Desalting Facility finished water concentrations exceed 5 ng/L, the California DHS Notification Level. The project objective: was to identify the best treatment technology for removing TCP to less than 5 ng/L. The challenge was that no treatment technologies have been demonstrated in these conditions for this purpose. Experimental approach and results included: bench-scale experiments to validate promise of treatment technologies to meet effluent TCP goals; granular activated carbon (GAC) experiments involved two sets of isotherm experiments to determine TCP adsorption capacity in reverse osmosis (RO) permeate; RO experiments involved flat-sheet experiments treating brackish groundwater to determine the extent of TCP rejection with higher pressure membranes (i.e. CPA3 vs. ESPA1); and, pilot testing of RO followed by GAC to validate operational performance. Conclusions of bench-scale experiments included: bottom line for treatment technology assessment; GAC proven to achieve target effluent TCP goals; RO shows promise, but may not meet TCP goals; and, next step was pilot testing of GAC to remove TCP in RO effluent. Includes tables, figures.