2019 Water Utilities Consumer Confidence Report 2019 Water Utilities Consumer Confidence Report | Page 2

Table A. Regulated Substances. These substances are regulated or are required to be monitored and were detected in Arlington tap water in 2019 Substance Atrazine Barium Cyanide Bromate 3 Fluoride Nitrate as Nitrogen Nitrite as Nitrogen Chloramines 2 Total Trihalomethanes 2 Haloacetic Acids (HAA5) 2 Substance Lead (2018) Copper (2018) 1 1 Units Avg. Min. Max. ppb ppm ppb ppb ppm ppm ppm ppm ppb ppb 0.05 49.5 66.6 <5 0.54 0.450 <0.05 3.2 12.5 5.8 0.00 45.0 45.3 <5 0.225 0.26 ND 3 11.9 5.5 0.10 3 3 54.0 200 200 87.9 200 200 <5 10 10 0.809 4 4 0.834 10 10 0.1098 1 1 3.5 MRDL=4 MRDLG=4 12.9 80 NA 6.1 60 NA Units ppb ppm Total Organic Carbon (TOC ) Units PB Plant (raw) PB Plant (drinking) PB Removal ratio 4 JK Plant (raw) JK Plant (drinking) JK Removal ratio 4 ppm ppm ratio ppm ppm ratio Action No. Sites > Level Action Level AL = 15 AL = 1.3 Avg. 5.1 2.5 1.4 4.9 2.5 1.4 Substance-Radioactive Radium 228 Beta/Photon Emitters Gross Alpha Particle Activity pCi/L pCi/L pCi/L 0 0 Min. Max. 4.5 6.2 2.3 2.9 1.2 1.7 4.0 5.7 2.1 2.9 1.0 1.7 PB Plant JK Plant 2017 2018 1.43 <1.0 4.8 4.5 <2.0 <3.0 MCL MCLG 90 %-tile Range 2.62 0.203 ND-6.29 ND-0.294 MCL MCLG Violation Possible Source No No No No No No No No No No Runoff from herbicide used on row crops Naturally present Discharge from metal/plastic/fertilizer factories Byproduct of drinking water disinfection Highest Single Measurement % of samples less than 0.3 NTU Instead of MCLs for lead and copper, EPA requires that 90 percent of water samples obtained from customers’ taps contain less than the Action Level for each metal. Sampling is required every 3 years. 2 Water additive promoting strong teeth Runoff from fertilizers Runoff from fertilizers Water additive used to control microbes 3 By-product of drinking water chlorination By-product of drinking water chlorination th Violation Possible Source No No Corrosion of household plumbing systems Violation Possible Source (PB = Pierce-Burch Plant) No Naturally present in the environment (JK = John F. Kubala Plant) No Naturally present in the environment Violation Possible Source 5 50 15 NA NA NA No No No Decay of natural and man-made depos- its. Testing for radiological substances required every 3 years. Units Avg. Min. Max. MCL MCLG NTU % 0.06 99.97 0.02 99.93 0.70 100% TT=1.0 TT=95% 0 0 Violation Possible Source No No Soil runoff Compliance is based on a calculated annual average of all samples at routine sites. Compliance is based on a calculated running annual average of the quarterly averages. 4 Corrosion of household plumbing systems Microbiological contaminants In 2019, Tarrant Regional Water District analyzed all raw water sources for cryptosporidium and in January 2019, Lake Arlington was found to have 0.36 oocysts per liter. All other months in 2019 had no detections. Cryptosporidium is a pathogen which may be found in water contaminated by feces. Although filtration removes cryptosporidium, it cannot guarantee 100% removal. Turbidity for both Plants 5 1 5 Removal ratio is the percent of TOC removed by the treatment process divided by the percent of TOC required by TCEQ to be removed. Compliance is based on a running annual average of ratios. If the annual average removal ratio is greater than or equal to 1.0, the system is in compliance. Turbidity has no health effects, however it can interfere with disinfection and provide a medium for microbial growth. Turbidity may indicate the presence of disease-causing organisms, including bacteria, viruses and parasites that can cause symptoms such as nausea, cramps, diarrhea and associated headaches. TABLE DEFINITIONS Action Level (AL) The concentration of a contaminant which, if exceeded, triggers treatment or other requirements which a water system must follow. | < less than the amount listed. | ≥ equal to or greater than the amount listed. | Maximum Contaminant Level Goal (MCLG) The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety. | Maximum Contaminant Level (MCL) The highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the MCLGs as feasible using the best available treatment technology. | Maximum Residual Disinfectant Level Goal (MRDLG) The level of a drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contamination. | Maximum Residual Disinfectant Level (MRDL) The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants. | NA Not applicable | ND (Not Detected) No level of the parameter was detected. | NE Not established | NTU (Nephelometric Turbidity Units) A unit used when measuring turbidity, a measure of the cloudiness of the water. | pCi/L (picocuries per Liter) A measure of radioactivity in the water. | ppb (parts per billion, ug/L) A unit of measurement roughly equal to 1 drop in 100,000 gallons. | ppm (parts per million, mg/L) A unit of measurement roughly equal to 1 drop in 100 gallons. | TT (Treatment Technique) A required process intended to reduce the level of a contaminant in drinking water. | Level 1 Assessment A study of the water system to identify possible problems and determine (if possible) why total coliform bacteria were found. | Level 2 Assessment A very detailed study of the water system to identify potential problems and determine (if possible) why an E. Coli Maximum Contaminant Level (MCL) violation has occurred and/or why total coliform bacteria were found on multiple occasions. | Raw Water Water that has not yet been treated for consumption. 2