Updated June 20, 2023

The health of the Texas Colorado River downstream from Austin — an ecological system which functions as a massive water filter — has improved from what it was in the 1980’s when it was used as Austin’s dumping grounds.   As a result of actions taken by the Clear, Clean Colorado River Association, the TCEQ set, and enforced, wastewater treatment standards that required best-available technology in order to meet the exceptional aquatic life use, recreational use, and drinking water standards.  However, with the rapid growth in the counties between Austin and Bastrop — both municipal and industrial — the water quality in the river is once again threatened. 

Exceptional Use Water Quality Standards

The water quality standards on the two segments of the river between Austin and La Grange — classified segments 1428 and 1434 on the map –are designated as “Exceptional” for aquatic life use, “Primary Contact 1” for recreational use, and are designated to provide water for use as a public water system for drinking water supply. (TCEQ, Chapter 307- Texas Surface Water Quality Standards Rule Project No. 2016-002-307-OW, Colorado River Basin Designated Uses and Numeric Criteria).

  • Exceptional aquatic life use –  This standard characterizes an condition of the river that includes outstanding natural habitat characteristics, exceptional or unusual assemblage of species, abundant sensitive species, exceptionally high diversity , exceptional high species richness, and a balanced trophic structure.
  • Recreational use – This standard characterizes a condition of the river that is designated for recreational activities that are presumed to involve a significant risk of ingestion of water (e.g., wading by children, swimming, water skiing, diving, tubing, surfing, hand fishing (as defined by Texas Parks and Wildlife Code) and whitewater activities that include kayaking, canoeing, and rafting).

Click here for larger and clearer map

Water Quality Assessment Report

Here is how the TCEQ’s assessment indicates the water quality in the river is changing!  The page below is for the segment of the Colorado River from the confluence of Gilleland Creek to the river bridge at FM-969 at Utley to(for SEGID: 1428, AUID: 1428-01).  The Boring Company, SpaceX, and the Corix/McKinney Roughs wastewater treatment plant are located just upstream from the river bridge at Utley on FM-1209, and the Tesla gigafactory is further up river.

  • Aquatic Life Use – The data for this standard is carried over from the 2010 report, meaning that an evaluation for this standard has not been made since around 2002-2010.  In 2010, and now carried over to the 2020 report, the fish community and macrobenthic community in this segment of the river is listed as “impaired” by TCEQ, yet no action seems to have been taken to correct the impairment, or better characterize with additional studies.  The data quality is listed as “inadequate”, yet nothing has been done to get better data.
  • General Use – The data for this standard indicates that nutrient levels of nitrate and total phosphorus in this segment of the river are at a level that is of “concern”.   This is a common concern in all of the segments down to La Grange, TX.

The Scientific Data does not support TCEQ’s findings!

Unfortunately, though the river is showing impairment, TCEQ continues to allow more, and more wastewater to be disposed of in the river; allow more and more nutrients such as phosphates and nitrates;  and allows more and more bacteria to contaminate the river.  As a result of having not conducted adequate  studies to demonstrate that the river IS HEALTHY — and meeting the use standards — TCEQ is not able to make an affirmative statement about the river’s status.

The only affirmative statement by TCEQ is that “Segment No. 1428 is not currently listed on the State’s inventory of impaired and threatened waters (the 2022 CWA § 303(d) list)”. This statement is found in its Notice of Application and Preliminary Decision for TPDES Permit for Municipal Wastewater when a draft permit is issued.

Environmental Stewardship strongly objects to TCEQ’s ongoing statement above since this statement implies that the river is meeting exceptional standards. To the contrary, there are numerous citations of ecological/biological, physical, and chemical impairment concerns that have been repetitively listed for this section of the river since 2002 and earlier. The evidence shows that for more than twenty (20+) years concerns have been raised about impairment of fish and macrobenthic communities, as well as physical and chemical that do not support water quality standards, yet these concerns have not been adequately investigated.

Environmental Stewardship asserts that segment 1428 is likely impaired according to the 2020 and 2010, 2008, 2006, and 2002 Texas Integrated Reports, and should either be on the 303(d) list of impaired streams, or assumed to be impaired, and should be subject of management strategies to remedy the impairments and a proper anti-degradation review be done base on the best available science.

In reviewing the 2020 Texas Integrated [Assessment] Report for the Colorado River (Basin 14) it is clear that concern for impaired fish and macrobenthic communities in these segments of the river may not only be currently impaired, but many of these impairments are carried forward from the 2002 report — when they were initially listed — “due to inadequate data for this method of assessment”.

Even more concerning is that many of the impairments that were listed in the 2020 report, were de-listed on July 7, 2022, after new guidelines were adopted that gave TCEQ a get-out-of-jail-free card to cover its failure to conduct the studies required to make an affirmative determination (see pages 2-3). No justification for these delistings is found in the record.

The following sample page from the Integrated Report tells the story:    

  • First, fish and macrobenthic communities (collections of these species) are listed as “Impaired fish community in water” and “Impaired macrobenthic community in water”, and have been listed that way from as early as the  2002 Integrated Report.
    • ID = Inadequate Data (meaning that studies that have been needed to demonstrate compliance, or non-compliance, with the use standard have not been done).
    • CF = Carried Forward (note the box is ticked).  In fact, my research shows these items as having been carried forward from as early as the 2008 Integrated Report).
    • CN = Use Concern
  • Second, Nutrient levels (Nitrate and Phosphorus) have likewise been listed as concerns.
    • AD = Adequate Data (meaning that there is adequate data to make the screening level concern justified.
    • CS = Concern for Screening level.

Environmental Stewardship evaluated the 2002, 2006, 2008, 2010, 2020, and 2022 reports in detail as described in the summary that follows below: 

Sample page from Texas Integrated Reports – Assessment Results for Basin 14 – Colorado River Basin.

Reports and Exhibits that Support our Findings

The following information has been compiled by Environmental Stewardship to support our findings:

  • Summary of  Supporting Evidence: Supporting evidence for issues raised by Environmental Stewardship in comments to TECQ regarding Gapped Bass/The Boring Company, and Corix/McKinney Roughs wastewater TPDES permit applications
  • Timeline:  Timeline for Listing and Assessment of Colorado River (Basin 14) Segment 1428 — impairments listed since 2006 in the Texas Integrated Reports
  • Exhibits in Support of Evidence:Exhibits in Support of Evidence for Issues raised by Environmental Stewardship in comments to TCEQ regarding Gapped Bass/The Boring Company, and Corix/McKinney Roughs wastewater TPDES Permit Applications and Draft Permits
  • 2004-08 Studies: General area description and references to studies conducted to document the status of the Austin-Bastrop Reach of the Colorado River (Colorado-Lavaca Basin and Bay Expert Science Team Report, March 1, 2011)
  • Assessment Guidelines:
    • 2002 Guidance for Assessing Texas Surface and Finished Drinking Water Quality Data  These  are the guidelines that were in place when the 2002 data were evaluated to assess Segment 1428 with the Fish and Macrobenthic data that were determined in 2002 to be a cause for concern for impairment of these two communities of aquatic organisms.   According to Table 13 below, even if the Dissolved Oxygen, Toxics in Water, and Habitat Assessment met the screening criteria, the fact that both benthic and fish bioassessment data indicated non-attainment of the designated Aquatic-Life Use, the final assessment should likely have been that the Aquatic-Life Use designation was Not Supported placing the segment on the 303(d) list of impaired  streams.  Once on the 303(d) list, a Total  Maximum  Daily  Load  (TMDL)  management  plan  should  have  been  put  in  place  to  restore  this  segment  of  the  Colorado  River  to  Fully  Supported  status.  


    • 2008 Guidance for Assessing and Reporting Surface Water Quality in Texas     Table 3-7 below is the same table as Table 13 above from the 2002 assessment guidelines.  Had these guidelines been followedthe Fish and Macrobenthic data  that were determined in 2002 to be a cause for concern for impairment of these two communities of aquatic organisms would have lead to the same determination.   According to Table 3-7 below, even if the Dissolved Oxygen, Toxics in Water, and Habitat Assessment met the screening criteria, the fact that both benthic and fish bioassessment data indicated non-attainment of the designated Aquatic-Life Use, the final assessment should likely have been that the Aquatic-Life Use designation was Not Supported placing the segment on the 303(d) list of impaired  streams.  Once on the 303(d) list, a Total  Maximum  Daily  Load  (TMDL)  management  plan  should  have  been  put  in  place  to  restore  this  segment  of  the  Colorado  River  to  Fully  Supported  status.
    • 2008 Surface Water Quality Monitoring Program  In 2008, the Surface Water Quality Monitoring (SWQM) Program, established in 1967 by the Texas Water Quality Board and subsequently moved to the Texas Commission on Environmental Quality, encompassed the full range of activities required to obtain, manage, store, assess, share, and report water quality information to other TCEQ teams, agency management, other agencies and institutions, local governments, and the public. Primary statutory authority for the SWQM Program is provided under Section 26.127 of the Texas Water Code (TWC), which states, “The executive director has the responsibility for establishing a water quality sampling and monitoring program for the state. All other state agencies engaged in water quality or water pollution control activities shall coordinate those activities with the Commission.” As such, it was the Executive Director’s responsibility to properly collect and assess data for the individual segments and, where data were lacking, to cause the data to be collected so that each segment could be properly assessed to determine if its use was fully supported, or if remedial management actions were warranted.
    • 2022  Guidance for Assessing and Reporting Surface Water Quality in Texas   On July 7, 2022 TCEQ adopted new guidance that allowed many of the assessment data, including the impairment of Fish and Macrobenthic invertebrate communities to be de-listed, no longer appearing in the assessment data.   Until 2022, these data were carried forward from the previous assessment without TCEQ taking action to collect the bioassessment data needed to confirm that these communities were, or were not supported.   See:  Summary of Evidence, and Timeline in Reports and Exhibits that support our Findings (above).


  • Fish and Macrobenthic Communities have been TCEQ listed1 as “impaired … in water “as “TCEQ 08cause[s]” for concern in numerous Assessment Units (AUID) of Segment 1428 since 2002 when they were initially listed. Both are “use concerns” (CN) based on “inadequate data (less than 4)” (ID). The methods of assessment for these parameters for Aquatic Life Use were listed in 2020 as “regional” and “qualitative”, respectively.
  • These two biological parameters of concern that relate to aquatic life use have been carried forward for at least 20 years without having been further evaluated to determine whether to rate them as fully supporting (FS), nonsupport (NS), or no concern (NC).
  • Fish Community, as an Aquatic Life Use Method, and the lower segment of the Colorado River, were delisted from the July 7, 2022, TCEQ Water Quality Report. Dissolved oxygen concerns in the upper segment of the Colorado river were also delisted from the same report.
  • Segment 1428 was included in “intensive biological and physical data collection activities conducted in 2004-2007” and reported in 2008. Aquatic habitat and use data were collected at 10 sites from Longhorn Dam to Wharton. Fifty (50) species of fish were collected in the entire lower basin (see 2004-08 Studies link above).
  • Nutrient screening for Nitrate and Total Phosphate have been TCEQ listed as General Use “in water” “TCEQ cause” of concern based on the concentration levels that these compounds are found in water. (See Documents cited in footnotes 1 and 2). Neither have been caried forward from previous assessments. Both are “screening level concerns” (CS) based on adequate data (AD). The method of assessment for these General Use parameters have been by Nutrient Screening Levels. Orthophosphorus was listed in this group until 2020.
  • Both nitrate and phosphorus have been chemical parameters of concern for at least 20 years but continue to be assessed and included because the data indicates an ongoing concern that is short of being characterized as nonsupport (NS) that would trigger a Category 5c response.
  • The Nitrate and Total Phosphate concerns in lower segment of the Colorado River were also delisted from the July 7, 2022, TCEQ Water Quality Report.
  • Category 5c concerns, like bacteria in this Segment, are included on the 303(d) list and require additional data or information to be collected and/or evaluated for one or more parameters before a management strategy, normally TMDLs for chemical parameters, is selected.


  • Fish and Macrobenthic Communities have been a TCEQ cause based on impairment in water concerns that have not been investigated for at least 20 years by collecting biological field data to determine whether to rate them as fully supporting (FS), nonsupport (NS), or no concern (NC).
  • Without a holistic biological assessment of these biological indicators of the status of aquatic life use, there is no ability for TECQ, or the public, to determine whether management strategies for constituents in discharges to this segment of the river — such as nitrogen and total phosphate — are degrading the water quality in this Colorado River segment to an extent that the aquatic life use has also been degraded, or not degraded.
  • The Executive Director has asserted,
    • “no significant degradation of water quality is expected in the Colorado River below Lady Bird Lake/Town Lake which has been identified as having exceptional aquatic life use”,
  • That assertion for both the Tier 1 and Tier 2 antidegradation review cannot be reliably concluded given the uncertainty in the data and the agency’s levels of evaluations of the conditions in the River below Lady Bird Lake/Town Lake.

Here is a link to the 2020 Texas Integrated Water Quality Assessment Report  for the three segments of the Colorado River that hold an “exceptional” aquatic use standard;  Lake Travis, and segments 1428 and 1434 between Austin and La Grange, TX.

Recommended Actions

It is time for the Texas Commission on Environmental Quality, and the Texas Parks and Wildlife Department to update their assessments of how well the Aquatic Life Use and General Use standards are being met in Segments 1428 and 1434 of the Colorado River.  

  • It is imperative that best-available-technology be updated and applied to new and existing wastewater treatment permits in these segments.  
  • The wastewater treatment technology being employed needs to be reviewed and upgraded to ensure that  best available technology (BAT) or best available technology economically achievable (BATEA) are required to be used.  
  • Updated standards should require the water quality of effluents to be such that they do not degrade the water quality in the segments, but rather contribute to the objective of maintaining a sound ecological environment that is fishable and swimmable.


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