AWWA WQTC69284

This powerpoint presentation begins by providing a brief overview of the Baldwin Park Operable Unit (BPOU), located in the San Gabriel Valley in southern California, and was declared a Superfund Site in 1984 due to volatile organic compounds (VOC) contamination. Perchlorate was discovered there in 1997. Perchlorate characteristics and perchlorate treatment at BPOU are outlined. A pilot study to evaluate the performance of four different perchlorate-selective IX resins at three utilities in the BPOU is presented and had the following objectives: pilot skids using representative operational conditions; test new resins and those that had high capacities in Cal Domestic pilot studies; assess nitrosamine leaching from the new resins; and, test spent resins for metals leaching (TCLP and California WET). Testing conditions are presented for resins, pilot skid and water quality. Results are provided for: perchlorate breakthrough; nitrosamine leaching; and, spent resin TCLP and California WET testing. Presentation conclusions indicate the following: the four tested tributylamine resins have a high capacity for perchlorate removal, greater than 250,000 BVs water treated, depending on water quality; resin capacity at Valley County was approximately 70% of the capacity at La Puente, based on BVs of water treated, due to higher nitrate concentrations in the source water; the Dow PSR2 performed best at all three plants, however the performances of the four resins were not extremely different; resin selection for the three participating plants may be based on economics and operation considerations; all four resins leached NDBA and one may have leached NDMA, but concentrations declined to below 10 ng/L within one hour of rinsing; the speciation of nitrosamine leaching reflects the functional amine groups present in the resins as observed in the previous Cal Domestic study; and, TCLP and California WET testing indicated that spent resin from the three utilities would not be classified as hazardous waste. Results from this study, including a cost comparison with regenerable ion exchange systems, reveal that single pass ion exchange is a feasible and cost competitive option for perchlorate treatment. Includes tables, figures.