Summary Table of Completed TMDLs and Implementation Plans
(In alphabetical order by name of water body or region)
|TMDL Allocation||Implementation Plan|
(Click on the project for more information.)
|Impairments Addressed in Project||Water-Quality Segments Addressed in Project||TCEQ Date of TMDL Adoption||TMDLs Adopted||EPA Date
|TMDLs Approved||TCEQ Date
|TMDLs Addressed by I-Plan|
|1||1||Original 3/23/01; Revised 6/14/02||1||10/30/02
Legacy Pollutants: DDE, Chlordane, Toxaphene—2202
Legacy Pollutants: DDT, DDD, dieldrin, endrin, lindane, hexachlorobenzene, heptachlor, heptachlor epoxide—2202
|8||1*||07/25/03||8||05/13/04||8||Same activities as in I-Plan approved 9/14/01|
|Brays Bayou in the Houston Metropolitan Area
Bacteria—1007B, 1007C, 1007E, 1007L
|Buffalo and Whiteoak Bayous
Bacteria—1013, 1013A, 1013C, 1014, 1014A, 1014B, 1014E, 1014H, 1014K, 1014L, 1014M, 1014N, 1014O, 1017, 1017A, 1017B, 1017D, 1017E
|Clear Creek Above and Below Tidal
|Clear Creek Above and Below Tidal
Trichloroethane, Dichloroethane—1101, 1102
|4||2*||Original 2/9/01; Revised 6/14/02||4||05/09/03||4||10/12/01||4|
|Clear Creek Above Tidal
|Clear Creek and Tributaries
Bacteria—1101, 1101B, 1101D, 1102, 1102A, 1102B, 1102C, 1102D, 1102E
|Colorado River Below E.V. Spence Reservoir
Chloride, Total Dissolved Solids—1426
|Cottonwood Branch and Grapevine Creek
DDD, DDE, DDT, PCBs, Chlordane, Dieldrin, Heptachlor epoxide - 841A
|Eastern Houston in the Houston Metropolitan Area
Bacteria—1006F, 1006H, 1007F, 1007G, 1007H, 1007I, 1007K, 1007M, 1007O, 1007R
|2||1||Original 11/17/00; Revised 6/14/02||2||05/09/03||2||8/10/01||2|
|Fort Worth Legacy
DDE, PCBs, Chlordane, Dieldrin—806A
DDE, PCBs, Chlordane, Dieldrin—829A
|Greens Bayou in the Houston Metropolitan Area
Bacteria—1016, 1016A, 1016B, 1016C, and 1016D
|Guadalupe River Above Canyon Lake
|Halls Bayou in the Houston Metropolitan Area
Bacteria—1006D, 1006I, 1006J
|Houston Metropolitan Area Bacteria—See entries for Eastern Houston and Brays, Greens, Halls, and Sims Bayous|
|Houston Ship Channel Nickel
Nickel—1001, 1005, 1006, 1007, 1013, 1014, 1016, 1017, 2426, 2427, 2428, 2429, 2430, 2436
|14||14*||Original 8/11/00; Revised 6/14/02||14||05/09/03||14||7/13/01||14|
to take action
on this TMDL
Bacteria—1004E, 1008, 1008H, 1009, 1009C, 1009D, 1009E, 1010, and 1011
|Lake O’ the Pines
|Lower Sabinal River
|Lower San Antonio River
|North Bosque River
Nutrients (narrative)—1226, 1255
Zinc in Oyster Tissue—2482
|Orange County Watersheds
Bacteria, Dissolved Oxygen, pH—0508, 0508A, 0508B, 0508C, 0511, 0511A, 0511B, 0511C, and 0511E
|Petronila Creek Above Tidal
Chloride, Sulfate, Total Dissolved Solids—2204
is not needed.
|Sims Bayou in the Houston Metropolitan Area
|Upper San Antonio River
Bacteria—1910, 1910A, 1911
|Upper Oyster Creek
|Upper Oyster Creek
|Upper Gulf Coast Oyster Waters
Bacteria—2421, 2422, 2423, 2424, 2432, 2439
|Upper Trinity River
|# of Impairments Addressed in Project||# of Segments Addressed in Project||# TMDLs Adopted||# TMDLs Approved||# TMDLs Addressed by I-Plan|
|170 TMDLs for 114 segments||167 TMDLs for 113 segments||63 TMDLs for 37 segments
*More than one project addresses the water-body segment or segments; each segment is counted only once in the total number of segments addressed by TMDLs.
^The number of impairments (TMDLs) reported in the summary table is greater than the number shown in the title of the TMDL report. This is due to a change in EPA reporting requirements that was made after the TCEQ’s report of this project was completed and published (see below under "How TMDLs Are Counted").
The EPA requires one TMDL for each impairment listed in a water body. An impairment is the combination of the use that is affected (such as support of aquatic life) with the pollutant or condition of concern (such as mercury or low dissolved oxygen). For example, if Jones Creek was listed as not meeting the aquatic life use because of low dissolved oxygen concentrations, and not meeting the fish consumption use because of mercury in fish tissue, two TMDLs would be required for Jones Creek.
Prior to 2008, the number of impairments was reported by water-quality segment, as required by EPA guidance. During that period, the TCEQ used the term “water body” synonymously with “water-quality segment” when reporting how many segments were addressed by TMDLs.
In 2008, the EPA began requiring the TCEQ to develop and record one impairment (and TMDL) for each assessment unit within a water-body segment. Consequently, the TCEQ reports multiple TMDLs (impairments) where once it would have counted only one. The TCEQ continues to report the number of water bodies addressed through TMDLs by water-quality segment.
A water-quality segment is a geographic portion of a river, lake, or bay that has relatively homogeneous chemical, physical, and hydrological characteristics. A segment is assigned a unique number for the purpose of categorization and provides a basic unit for managing water quality. In some cases, a segment may be the same as the entirety of the water body; for example, a small lake may not be divided into multiple numbered segments.
An assessment unit is a further geographic subdivision of a segment. For example, Segment 0200 may have five assessment units.
Projects Develop Multiple TMDLs
To be most efficient with resources of time and money, the TMDL Program may addresses the same pollutant in multiple water bodies through a single project, or may addresses multiple similar pollutants (such as three different pesticides) in one segment through a single project. Hence, a single project may produce many TMDLs.
Federal law requires that the EPA take formal action to approve or disapprove any TMDLs adopted by the states. So, on any particular date, the number of TMDLs adopted by the Commission may differ from the number approved by the EPA. Similarly, there is a lag time between the completion of a TMDL and the Commission’s approval of the plan to implement the TMDLs. That means that the number of TMDLs and I-Plans will not usually match, since TMDLs and I-Plans are being completed all the time.