Issue link: http://townofcary.uberflip.com/i/1467830
6 2021 WATER QUALITY REPORT KEEPING YOUR WATER SAFE Each year the state certified laboratory at the Cary/Apex Water Treatment Facility performs extensive testing to ensure the safety of your drinking water. In 2021, staff collected and analyzed Cary's drinking water over 100,000 times for many substances such as radioactive, biological, inorganic, volatile organic or synthetic organic substances. The table below shows only those substances that were detected in the water. Unless otherwise noted, the data presented in the table below is from testing performed from January 1 – December 31, 2021. The EPA and the State allow monitoring for certain substances less than once per year because the concentrations of these substances are not expected to vary significantly from year to year. In these cases, the most recent sample results are included, along with the year in which the sample was taken. Some of the data, though representative of the water quality, is more than one year old. During 2021, the Town of Cary was in compliance with all state and national Drinking Water Regulations. WATER TESTING RESULTS SUBSTANCE (UNIT OF MEASURE) YEAR SAMPLED HIGHEST LEVEL ALLOWED (MCL) HIGHEST LEVEL GOAL (MCLG) AMOUNT DETECTED RANGE VIOLATION TYPICAL SOURCE Bromate (ppb) 2021 10 (running annual average) 0 2 (running annual average) 0 – 11 (individual measurements) No By-product of drinking water disinfection Chlorine (ppm) 2021 MRDL = 4 running annual average) MRDLG = 4 2.55 (running annual average) 1.25 – 3.68 (individual sites) No Water additive used to control microbes Chloramines (ppm) 2021 MRDL = 4 (running annual average) MRDLG = 4 2.94 (running annual average) 1.2 – 3.92 (individual sites) No Water additive used to control microbes Fluoride (ppm) 2021 4 4 0.72 No range No Erosion of natural deposits; Water additive that promotes strong teeth; Discharge from fertilizer and aluminum factories Gross Beta (pCi/L) 2017 50 0 4.2 No range No Decay of natural and man-made deposits Haloacetic Acids (HAAs) (ppb) 2021 60 N/A 17 (Maximum LRAA) 0 – 18 (individual sites) No By-product of drinking water disinfection Trihalomethanes (THMs) (ppb) 2021 80 N/A 39 (Maximum LRAA) 22 – 49 (individual sites) No By-product of drinking water disinfection Total Coliform Bacteria (% positive samples) 2021 5% 0% 2% 0 – 2% No Naturally present in the environment Total Organic Carbon (removal ratio) 2021 TT = removal ratio of >1 N/A 1.62 (running annual average) 1.52 – 1.86 (range of monthly) No Naturally present in the environment Turbidity (NTU) 2021 TT = 1 NTU and 95% of samples <0.3 NTU N/A 0.10 NTU and 100 of samples <0.3 NTU 0.03 – 0.10 No Soil runoff SUBSTANCE (UNIT OF MEASURE) YEAR SAMPLED HIGHEST LEVEL ALLOWED (AL) HIGHEST LEVEL GOAL (MCLG) AMOUNT DETECTED (90TH PERCENTILE) SITES ABOVE AL/ TOTAL SITES VIOLATION TYPICAL SOURCE Copper (ppm) 2021 1.3 1.3 0.0988 0/60 No Corrosion of household plumbing systems; Erosion of natural deposits Tap water samples were collected for lead and copper analyses from sample sites throughout community. In the 2021 study, only one sample had detectable lead and it measured 3.1 ppb (well below the action level of 15 ppb).