Utilization of Passive Samplers for Water Quality Monitoring of Hexavalent Chromium in Water Treatment Plants

The current EPA regulation for total chromium in drinking water is the MCL standard of 0.1 milligrams per liter or 100 parts per billion (ppb) to avoid dermatological effects. With a toxicology study released in 2008 by the Department of Health and Human Services noting that hexavalent chromium is carcinogenic, the EPA is currently reviewing this MCL standard. During this review, the EPA provides monitoring guidance that requires quarterly sampling of surface water for hexavalent chromium. However, these samples monitor the instant in time that they were taken, and do not account for varying concentrations that are time-dependent. This research seeks to develop a method for monitoring hexavalent chromium in water. Using ion exchange technology, passive samplers were developed and installed at the Chandler Water Treatment Plant for a week-long monitoring event. Results show that passive samplers using ion exchange technology provide an accurate assessment of the average concentration of total chromium within the water treatment plant's effluent with 90.3% recovery of Cr(VI) in SIR-100 resin and 62.6% recovery in SIR-700.