2023 Water Quality Report 2023 Water Quality Report | Page 2

TABLE A | REGULATED SUBSTANCES
2023 WATER QUALITY REPORT page 2

TABLE A | REGULATED SUBSTANCES

Substances that are regulated or are required to be monitored and were detected in Arlington tap water in 2023
SUBSTANCE UNITS AVG . LEVEL
MIN . LEVEL
MAX . LEVEL
MCL MCLG POSSIBLE SOURCE OF SUBSTANCE
Arsenic ppb 0.70 ND 1.30 10 NA
Barium ppm 0.053 0.049 0.057 2 2
Naturally present or byproduct of agricultural and industrial activities
Discharge from metal and chemical factories , well drilling operations
Cyanide ppb 60.0 ND 120 200 200 Discharge from metal and chemical factories Bromate 1 ppb < 5 < 5 6 10 10 Byproduct of drinking water disinfection Fluoride ppm 0.554 0.305 0.777 4 4 Water additive promoting strong teeth
Nickel ppb 1.2 1.10 1.30 100 100
Naturally present or byproduct of metal and industrial processes
Nitrate
ppm
0.509
0.358
0.672
10
10
Runoff from fertilizers or livestock feedlots
Nitrite
ppm
< 0.05
ND
0.142
1
1
Runoff from fertilizers or livestock feedlots
Chloramines 2
ppm
3.7
3.6
3.8
MRDL = 4
MRDLG = 4
Water additive used to control microbes
Total Trihalomethanes 2
ppb
12.1
10.3
14.2
80
NA
By-product of drinking water disinfection
Haloacetic Acids ( HAA5 ) 2
ppb
6.5
5.5
7.6
60
NA
By-product of drinking water disinfection
Atrazine
ppb
0.1
ND
0.1
3
3
Runoff from herbicide use on row crops .
1
Compliance is based on a calculated running annual average of the quarterly averages .
2
Compliance is based on a calculated annual average of all samples at routine sites .
SUBSTANCE UNITS ACTION LEVEL
NO . OF SITES EXCEEDING ACTION LEVEL
90 % PERCENTILE
DETECTED RANGE
POSSIBLE SOURCE OF SUBSTANCE
Lead ( 2023 ) 3 ppb AL = 15 0 1.02 ND-5.34
Copper ( 2023 ) 3 ppm AL = 1.3 0 0.154 0.015-0.357
Corrosion of household plumbing systems
Corrosion of household plumbing systems
3
Instead of MCLs for lead and copper , EPA requires that 90 % of water samples obtained from customers ’ taps contain less than the Action Level for each metal .
TOTAL ORGANIC CARBON ( TOC )
SOURCE
WATER SOURCE
AVG . LEVEL
MIN . LEVEL
MAX . LEVEL
UNITS
POSSIBLE SOURCE OF SUBSTANCE
Total Organic Carbon ( TOC ) Pierce Burch ( PB ) Treatment Plant
Total Organic Carbon ( TOC ) John Kubala ( JK ) Treatment Plant
Raw
5.9
4.8
7.6
ppm
Naturally present
Drinking
3.5
2.9
4.0
ppm
in the environment
1.2 1.0 1.3 removal ratio *
Raw
5.7
4.4
7.1
ppm
Naturally present
Drinking
3.2
2.9
3.4
ppm
in the environment
1.2 1.0 1.6 removal ratio *
* 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 .