Issue link: http://townofcary.uberflip.com/i/1521780
C A RY, N O RT H C A R O L I N A A N N U A L WAT E R Q U A L I T Y R E P O R T 2 0 2 3 15 C A RY P R OAC T I V E LY I M P L E M E N T S A DVA N C E D T R E AT M E N T T E C H N O LO GY Cary has been actively following the national discussion of PFAS since we first tested for these substances in 2015 as part of UCMR3, or the Unregulated Contaminant Monitoring Rule, and then subsequently tested and detected PFAS in late 2017. Cary proactively studied and pilot tested several water treatment optimization processes known to enhance PFAS removal in early 2018. One such process available for implementation was carbon adsorption with a product called powder activated carbon (PAC), which has multiple benefits for other stages of water treatment along with reducing PFAS. Studies indicated this method was beneficial and effective at further reducing PFAS at low concentration levels. As such, Cary immediately implemented this process continuously as part of our already advanced water treatment process during 2018 and we've been consistently using this process optimization for the past several years to improve PFAS removal, well before PFAS was proposed to be regulated. The combination of PAC with our existing process, including ozonation, provides an even higher level of sophisticated multiple barrier water treatment technology to support advanced treatment of both regulated and unregulated substances for removal from Cary's drinking water. SUBSEQUENT TESTING SHOWS EXTREMELY LOW PFAS LEVELS IN FINISHED DRINKING WATER THAT ARE BELOW THE NEW MAXIMUM CONTAMINANT LEVELS ANNOUNCED BY THE EPA . W H AT I S 1, 4 - D I OX A N E ? 1,4-dioxane is a colorless, flammable liquid often used as a solvent or solvent stabilizer in the manufacture and processing of polyethylene terephthalate (PET), cotton, textile products, automotive coolant, cosmetics, shampoos, and other products. I S 1, 4 - D I OX A N E R E G U L AT E D ? 1,4-dioxane is not currently regulated. However, the EPA has established a health advisory of 35 parts per billion (ppb). Health advisories are not regulatory limits, they provide technical guidance to state agencies and public health officials. I S 1, 4 - D I OX A N E F O U N D I N C A RY 'S D R I N K I N G WAT E R ? The test results demonstrate that 1,4- dioxane levels in our drinking water have been well below the EPA's health advisory. Our Operations and Laboratory staff collect samples from Jordan Lake to monitor the quality of our source water.