MCM 8 : MONITORING , EVALUATION , AND REPORTING
The City of Arlington maintains a comprehensive monitoring program to protect water quality of receiving waters within the MS4 and comply with permit requirements . The City of Arlington has elected to perform the required storm event discharge monitoring under Section IV , Section A . 1 : NCTCOG Regional Wet Weather Characterization Program ( RWWCP ) as supplemented by dry weather monitoring and local monthly grab sampling .
Screening and monitoring efforts include dry weather screening , Inner-City Creek Sampling ( Monthly / CRP ), wet weather monitoring ( RWWCP ), and industrial and high-risk runoff monitoring .
I . Dry Weather Monitoring
The City ’ s dry weather screening program focuses on detecting the presence of illicit discharges , eliminating illicit connections , and assessing dry weather water quality changes . In the fourth reporting period ( 4RP ), the historical dry weather database ( developed in 2003 ) was integrated with current GPS MS4 mapping activities to provide a clearer picture of the location of the City ’ s outfalls and other stormwater infrastructure . As a result , dry weather sampling was suspended to avoid incorrect and / or improper screening . Re-implementation of the program was initiated in late FY2016 on June 16 , 2016 , after the rainy season .
Screenings continued in FY 2019 to meet TCEQ requirements to screen all areas of the MS4 during the permit term , but not necessarily every outfall . Environmental Specialists within the Environmental Management Group are responsible for conducting all dry weather screening activities . Dry weather screening occurs when there has been no significant precipitation ( less than 0.10 inches ) within 48 hours to ensure flow is not from rainfall runoff . Tests and observations are made when the flow is first observed and again within 24 hours , but no sooner than four hours to increase the potential to detect illicit flows .
The dry weather outfall screening summary for this reporting period is outlined below . |
Watershed |
Number of outfalls screened / verified |
Number of Outfalls with Flow |
Illicit Connections or Discharges |
Unable to Access |
Rush |
107 |
23 |
0 |
0 |
Lower Village |
35 |
1 |
0 |
5 |
Upper Village |
4 |
0 |
0 |
0 |
Fish |
29 |
10 |
1 |
0 |
Trinity Tributaries 31 4 0 4
II .
Cottonwood 7 1 1 0 Johnson 129 8 1 3 Walnut 0 0 0 0
Lynn 0 0 0 0 Bowman Branch 9 1 0 0
Total 351 47 3 12 Monthly Inner-City Creek Sampling – In Situ
Since 1988 , the City of Arlington Environmental Management staff has , on a monthly basis , conducted sampling activities in its inner-city creek system . The purpose of monthly inner-city creek sampling is to determine and / or detect the present of illicit discharges . Over time , sites have been added , discontinued , or moved to provide a
47 | Page