The City of Arlington MS4 permit now requires targeted BMPs be developed and implemented when an MS4 drains to an impaired waterbody – waterbodies with established TMDLs and those without . While the requirements to address TMDL ’ s appeared in the City ’ s renewed permit in August 2019 , the City has identified development and implementation of a comprehensive TMDL program to be fully implemented by the end of the permit term in 2024 . Goals include identifying areas of focused effort , creating measurable goals to reduce the discharge of pollutants of concern to impaired and TMDL waters , identifying benchmarks for program effectiveness , and monitoring and assessing progress toward reaching benchmarks . The City has outlined TMDL program goals that are to be completed on a yearly basis over the permit term in its Stormwater Management Program ( SWMP ). Reporting on the progress of Year 2 goals associated with the TMDL program are outlined below .
Monitoring or Assessment of Progress : Year 1 and Year 2 Goals
Year 2 includes the implementation of seven ( 7 ) program goals , in addition to the continuation of the Year 1 goal . The City ’ s MS4 permit indicates that Permittees may evaluate progress toward meeting the benchmarks established by choosing one of the following options as outlined in the permit : ( 1 ) evaluating program implementation measures ; OR ( 2 ) assessing improvements in water quality . The City has chosen to utilize option 2 which states :
The permittees may assess improvements in water quality by using available data for segment ad assessment unites of waterbodies from other reliable sources , or by prosing and justifying a different approach such as collection additional instream or outfall monitoring data , etc . that may be acquired from TCEQ , local river authorities , partnerships , and / or other local efforts as appropriate .
Year 1 Goal : Monthly Bacteria Monitoring by the City and its Co-Permittee
In 2016 , in anticipation of the promulgation of TMDL bacteria regulations , Environmental Management Group began a monitoring for bacteria impacts in Arlington watersheds . The program ( Interim Monitoring & Reduction Program ) was initially developed to monitor the presence of bacteria ( E . coli ) at the eight ( 8 ) current CRP locations . CRP sites are monitored for indicator bacteria once per quarter , however , in order to fully represent stream flow conditions and presence of bacteria , the EM Group began monitoring these sites on a monthly basis . CRP sites were chosen originally because the sites were identified by the TCEQ as impaired waterbodies not suitable for contact recreation due to the high presence of indicator bacteria .
The program was expanded in 2018 to include 5 additional sample locations including the Trinity River for a total of thirteen ( 13 ) bacteria monitoring locations . As such , it is practical for the City to assess progress toward established benchmarks by assessing any improvements in water quality by using the available data for segments and assessment units of the waterbodies from our own collected data as well as data available from other reliable sources , namely the Trinity River Authority of Texas ( TRA ).
Additionally , with the promulgation of the Permit , co-permittees ( University of Texas – Arlington ( UTA )) will also participate in assessing improvements in water quality . during the permit term , UTA will be responsible for monitoring monthly , those portions of the applicable AUs that traverse those portions of the MS4 within their jurisdiction – a total of four ( 4 ) monitoring locations . Water grab samples shall be taken to an accredited laboratory and sampled for the presence of E . coli bacteria . Laboratory results are submitted to the City of Arlington Environmental Management Group once available . It is important to note , however , that the City of Arlington will be responsible for addressing the TMDL and impaired waterbody requirements outlined in the renewed Permit for the MS4 in its entirety – including the portions located within UTA ’ s jurisdiction – for the current permit term ( 2019- permit expiration ).
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