Assessing Toxicity in Ambient Water and Sediment in Seven Texas Water Bodies

Related Links:

TMDLs: Improving Water Quality

Atlas of Texas Surface Waters

Counties:	Brazos, Brewster, Cameron, Harris, Jefferson, Kinney, Maverick, Presidio, Terrell, Val Verde, Webb, Willacy, Zapata
Parameter:	Toxicity in water and sediment
Basins:	Neches-Trinity Coastal, San Jacinto River, Brazos River, Nueces–Rio Grande Coastal, Rio Grande
Segments:	0702A, 1007A, 1209A, 1209B, 2201, 2304, 2306

Alligator Bayou

• Project Overview
  (PDF. Help with PDF)
• Background and Goals
• Summaries
• Final Reports
• Posters
• For More Information

Background
and Goals

Water quality data assessed in 1999 indicated that toxic conditions might exist in the water or the sediment of seven water bodies at various locations in Texas. Toxicity in water and sediment are conditions that are measured to determine if a water body can support a healthy aquatic community.

To determine the potential of water bodies to be toxic to aquatic life, sensitive aquatic organisms are exposed to water and sediment samples under laboratory conditions. These sensitive organisms serve as surrogates for the species indigenous to the water body being tested. However, there is not always a positive correlation between toxicity observed in the laboratory and actual toxic conditions in the water body being tested. Also, the laboratory tests used to determine the potential for toxicity do not identify the specific chemical toxicants responsible for the observed effects.

The goal of this project was to confirm the presence of toxicity and to determine its causes, where present. Summaries of the results for each water body assessed during the project are provided below.

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Summaries

These summaries are provided as PDF files. (Help with PDF.)

• Project Overview
• Summary Test Results
  
  • Alligator Bayou, Segment 0702A
  • Vince Bayou, Segment 1007A
  • Bryan Municipal Lake and Fin Feather Lake, Segments 1209A and 1209B
  • Arroyo Colorado, Segment 2201
  • Rio Grande Below Amistad Reservoir, Segment 2304
  • Rio Grande Above Amistad Reservoir, Segment 2306

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Final Reports

These summaries are provided as PDF files. (Help with PDF.)

• Alligator Bayou, Segment 0702A (12.7 MB)
• Vince Bayou, Segment 1007A (6 MB)
• Bryan Municipal Lake and Fin Feather Lake, Segments 1209A and 1209B (6.4 MB)
• Arroyo Colorado, Segment 2201 (4.3 MB)
• Rio Grande Below Amistad Reservoir, Segment 2304 (2.5 MB)
• Rio Grande Above Amistad Reservoir, Segment 2306 (2.2 MB)

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Posters

These posters were presented at the SETAC 24th Annual Meeting in North Ammerica, November 2003. They are provided as PDF files. (Help with PDF.)

• An Assessment of the Presence and Causes of Ambient Toxicity in Seven Texas Waterbodies
• Toxicity Identification Evaluation: Porewater and Sediment Approach for Alligator Bayou
• Toxicity Indentification Evaluation: Arsenic in Sediment of Finfeather Lake
• A Case Study of the Rio Grande Toxicity Project

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For More Information

For more information about the the project, please call Andrew Sullivan at 512/239-4587. Or e-mail us at tmdl@tceq.state.tx.us, and reference the Toxicity Assessment project in the subject line.

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