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8 2021 WATER QUALITY REPORT EMERGING CONTAMINANTS UNREGULATED SYNTHETIC OR NATURALLY OCCURRING CHEMICALS THAT ARE NOT COMMONLY MONITORED BY WATER UTILITIES ARE KNOWN AS CONTAMINANTS OF EMERGING CONCERN. Cary is committed to providing high-quality, safe drinking water and closely follows the scientific study of contaminants of emerging concern. More than 100,000 chemicals are registered in the United States, and new chemicals and microorganisms continue to be identified. Some of these contaminants can be detected at extremely low levels (parts per trillion – ppt) by continuously improving test methods. For reference, Jordan Lake holds 70.1 billion gallons or 8.97 trillion ounces of water. Therefore, 1 ppt is approximately the equivalent of one 9-ounce glass of water into the entirety of Jordan Lake. The health significance of these trace contaminants is often under review and the subject of further study and research. The fact that a substance is detectable doesn't mean it is immediately harmful. The EPA issues a health advisory for contaminants of emerging concern when research indicates a potential health impact. Health advisories provide information to the public so state and local agencies can take appropriate action to protect public health. The potential health impacts are usually risk- based, where a small amount of a substance, consumed regularly over a long period of time, may increase the risk of certain diseases for some portion of the population. Cary regularly tests the drinking water for the following contaminants of emerging concern: Per and polyfluoroalkyl substances (PFAS), and 1,4-dioxane. PFAS are a class of man-made chemicals used for consumer product applications such as waterproof and stainproof fabrics, nonstick cookware, some food packaging materials and fire suppression foams. In 2021, Cary tested the drinking water four times for 39 PFAS compounds. Four PFAS compounds were detected. Perfluorooctanoic acid (PFOA) and Perfluorooctane sulfonic acid (PFOS) were not detected. 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. In 2021, the drinking water was tested for 1,4-dioxane sixteen times. The average amount detected was <0.07 ppb and results ranged from <0.07 to 0.18 ppb which is below the US EPA's health advisory of 35 ppb. Cary consistently feeds powdered activated carbon which has been effective at reducing PFAS in drinking water. Cary plans to further improve the water treatment process. Upgrades include changing the filter media from sand and anthracite coal to granular activated carbon as well as converting the existing chemical filtration process to a biological filtration process. These innovative treatment technologies are designed to further reduce contaminants of emerging concern from our drinking water. However, complete elimination of all emerging contaminants is not technologically feasible at this time. HOW SMALL IS ONE PPT? 1 PPT IS APPROXIMATELY THE EQUIVALENT OF ONE GLASS OF WATER INTO THE ENTIRETY OF JORDAN LAKE. ONE GLASS OF WATER

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