TPDES Stormwater Annual Report FY2017 | Page 40

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 2016 , February 2017 , May 2017 , and August 2017 . The table below provides a summary of water quality parameters for FY 2017 . Data from FY 2016 is included for comparative purposes .
Water Quality Parameter
FY 2016
FY 2017
Water Temperature ( �C ) Minimum
9.35
19
Maximum
31.1
33.93
Mean
25.3
26.3
Dissolved Oxygen ( mg / L ) Minimum
1.44
2.5
Maximum
8.39
16.6
Mean
6.54
6.79
Specific Conductance ( �s / cm ) Minimum
218.3
197.5
Maximum
1186
1495
Mean
663.4
545.52
pH Minimum Maximum
Mean
7.18
6.93
8.39
8.89
7.66
7.67
Total Phosphorus ( mg / L ) Minimum
0.04
0.03
Maximum
2.21
0.2
Mean
0.22
0.08
E . Coli ( MPN ) Minimum
25
1
Maximum
26,000
82,000
Mean
1757.6
2214.79
Nitrate Minimum
0.10
0.08
Maximum
1.48
0.99
Mean
0.41
0.35
Flow ( ft 3 / s ) Minimum
0.04
0
Maximum
28.6
25.75
Mean
2.96
1.68
Additional analytes may be added in subsequent reporting periods to gauge overall watershed health .
CITY OF ARLINGTON TPDES STORMWATER ANNUAL REPORT – FY 2017
46 | Page