Table A . Regulated Substances . These substances are regulated or are required to be monitored and were detected in Arlington tap water in 2021
Substance |
Units |
Avg . |
Min . |
Max . |
MCL |
MCLG |
|
Atrazine |
ppb |
0.05 |
ND |
0.10 |
3 |
3 |
Runoff from use as a common herbicide and pesticide |
Barium |
ppm |
0.041 |
0.041 |
0.041 |
2 |
2 |
Discharge from metal & chemical factories , well drilling operations |
Cyanide |
ppb |
125.5 |
111 |
140 |
200 |
200 |
Discharge from metal and chemical factories |
Bromate 1
|
ppb |
< 5 |
< 5 |
< 5 |
10 |
10 |
Byproduct of drinking water disinfection |
Fluoride |
ppm |
0.228 |
0.112 |
0.564 |
4 |
4 |
Water additive promoting strong teeth |
Chromium |
ppb |
0.7 |
ND |
1.40 |
100 |
100 |
Discharge from metal and chemical factories |
Nitrate |
ppm |
0.455 |
0.155 |
0.883 |
10 |
10 |
Runoff from fertilizers or livestock feedlots |
Nitrite |
ppm |
< 0.05 |
ND |
0.219 |
1 |
1 |
Runoff from fertilizers or livestock feedlots |
Chloramines 2
|
ppm |
3.1 |
2.5 |
3.3 |
MRDL = 4 |
MRDLG = 4 |
Water additive used to control microbes |
Total Trihalomethanes 2
|
ppb |
6.6 |
5.5 |
7.3 |
80 |
NA |
By-product of drinking water disinfection |
Haloacetic Acids ( HAA5 ) 2
|
ppb |
5.2 |
4.6 |
5.8 |
60 |
NA |
By-product of drinking water disinfection |
Substance |
Units |
Action Level |
No . Sites > Action Level |
90 th
% -tile
|
Detected Range |
Possible Source |
Lead ( 2020 ) 3
|
ppb |
AL = 15 |
1 |
1.203 |
ND-22.5 |
Corrosion of household plumbing systems |
Copper ( 2020 ) 3
|
ppm |
AL = 1.3 |
0 |
0.164 |
ND-0.353 |
Corrosion of household plumbing systems |
Total Organic Carbon ( TOC ) |
Units |
Avg . |
Min . |
Max . |
Possible Source |
PB Plant ( raw )
PB Plant ( drinking )
PB Removal ratio 4
|
ppm ppm ratio |
5.2
3.1
1.2
|
4.7
2.7
1.0
|
6.3
3.7
1.4
|
( PB = Pierce-Burch Plant )
Naturally present in the environment
|
JK Plant ( raw )
JK Plant ( drinking )
JK Removal ratio 4
|
ppm ppm ratio |
5.0
2.8
1.3
|
4.5
2.5
1.0
|
5.6
3.1
1.5
|
( JK = John F . Kubala Plant )
Naturally present in the environment
|
Radioactive Substances |
PB Plant
2017
|
JK Plant
2021
|
MCL |
MCLG |
Possible Source |
Radium 228 |
pCi / L |
1.43 |
< 1.0 |
5 |
NA |
|
Beta / Photon Emitters |
pCi / L |
4.8 |
5.2 |
50 |
NA |
Decay of natural and man-made deposits . |
Gross Alpha Particle Activity |
pCi / L |
< 3.0 |
< 3.0 |
15 |
NA |
|
Microbiological contaminants - Tarrant Regional Water District analyzed all raw water sources for cryptosporidium and there were no detections of cryptosporidium for any month in 2021 . 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 Units Avg . Min . Max . MCL MCLG Possible Source
Highest Single Measurement |
NTU |
0.09 |
0.03 |
. 95 |
TT = 1.0 |
0 |
Soil runoff |
% of samples less than 0.3 NTU |
% |
99.01 |
97.77 |
100.00 |
TT = 95 % |
|
|
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 .
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 .
4
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 .
5
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 . ND ( Not Detected ) No level of the parameter was detected . | NA Not applicable | 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 .
Winners of the Value of Water Mini- Poster contest 2021
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