TPDES Stormwater Annual Report FY2021 TPDES Stormwater Annual Report FY2021 | Page 57

SUMMARY OF WATER QUALITY IMPROVEMENTS , DEGRADATIONS , AND PROGRESS TOWARD MEASURED REDUCTION IN POLLUTANTS
The City of Arlington assesses improvements and / or degradations in water quality by analyzing Clean Rivers Program ( CRP ) data . The purpose is to monitor changes in and to determine overall watershed health . Assessment of CRP data offers the most comprehensive view of watershed health as it captures chemical , bacteria , and nutrient indicators . Also , CRP program data is collected from sample sites in most of Arlington ’ s watersheds ( including impaired segments of the Trinity River ). An evaluation of the trends in the analytes measured can be used to assess water quality improvements , degradations , and progress .
Quarterly CRP monitoring was conducted in November 2020 , February 2021 , May 2021 , and August 2021 . The table below provides a summary of water quality parameters for FY 2021 . Data from FY 2020 is included for comparative purposes .
A table summary of water quality parameters is outlined below .
Parameter
Fiscal Year 2020
Fiscal Year 2021
Difference
Percent Change
Water Temperature Minimum
9.24
4.88
-4.36
0.47
Maximum
31.1
30.79
-0.31
0.01
Mean
17
17.34
0.34
0.02
Dissolved Oxygen Minimum
4.05
2.45
-1.6
0.4
Maximum
11.59
15.87
4.28
0.37
Mean
7.74
7.77
0.03
0.004
Specific Conductance Minimum
102.4
10.2
-92.2
0.9
Maximum
1212
5360
4148
3.42
Mean
538.35
562.74
24.39
0.05
pH Minimum
6.54
6.55
0.01
0.002
Maximum
8.79
8.8
0.01
0.001
Mean
7.56
7.46
-0.1
0.01
Total Phosphorus Minimum
0.02
0.02
0
0
Maximum
0.335
0.859
0.524
1.56
Mean
0.08
0.08
-0.0004
0.006
E . Coli Minimum
12
1
-11
0.92
Maximum
24196
39726
15530
0.64
Mean
476.42
300.93
-175.49
0.37
Nitrate Minimum
0.05
0.05
0
0
Maximum
1.52
1.32
-0.21
0.14
Mean
0.23
0.21
-0.02
0.1
Flow ( ft 3 / s ) Minimum
0.05
0.05
0
0
Maximum
0.05
0.05
0
0
Mean
0.05
0.05
0
0
Additional analytes may be added in subsequent reporting periods to gauge overall watershed health .
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