Taste and Odor Study of Wright Patman Lake

Although taste and odor problems are not considered a direct threat to public health, they constitute the greatest public relations issue many water utilities face. Consumers generally rely on the taste and odor of their water as an indicator of its safety. In response to local concerns and to prompt stakeholders participation, a survey focusing on taste and odor issues of local water utility customers was conducted by the SRBA. A survey was mailed to local water systems that utilize Wright Patman Lake water. The questions contained in this survey focused on the frequency, magnitude, and timing of taste and odor problems. For purposes of comparison, the survey was also sent to three water utilities that utilized other sources.

The results of the survey show that many of the cities that are serviced by Wright Patman Lake do experience problems with taste and odor, while few complaints were reported at the three utilities that do not use Wright Patman Lake water. The problem seems to occur most frequently during the summer months and subsides in the fall. Because the water produced for the cities serviced by Wright Patman Lake arrives as treated water, standby chlorination is the only chemical treatment utilized by local utilities. Some strategies applied to combat the taste and odor problem are the mixing of ground water and flushing of water mains.

The potential causes of taste and odor problems are thought to be trace amounts of several organic compounds whose sources include certain species of algae, weeds, standing timber, soil and sediment. High levels of chlorophyll indicate that algae may be the dominant factor in Wright Patman Lake.

The need for collection of more data to help to explain why the taste and odor issues exist for Wright Patman Lake is supported by this study. A study of the algae levels and the algae type may be warranted in order to identify which types of algae dominate Wright Patman Lake and to what extent they contribute to the taste and odor issues.

Atrazine Study In Big Creek Lake

March 2002 marks two years of monitoring Big Creek Lake for atrazine, a widely used herbicide. Big Creek Lake, a small, unclassified reservoir of about 700 acres was listed as threatened by contamination on the 2000 303(d) list due to atrazine in finished drinking water.

The Big Creek Lake study is part of a larger project conducted by the TNRCC involving several Texas reservoirs, titled "Targeted Monitoring and BMP implementation in Seven Atrazine Threatened Lakes." The two major components of the project are: (1) surface water quality monitoring to better distinguish the threat of atrazine to drinking water sources, and (2) implementation of best management practices (BMP'S) to reduce the addition of atrazine in the subject watersheds.

The TNRCC Region 5 staff has conducted monthly surface water quality monitoring in Big Creek Lake for atrazine, alacholr, metolachlor and simazine. To eliminate the effects of water treatment, only raw (untreated) water has been sampled. These first two years of data will be reviewed by the TNRCC to assess the degree of atrazine contamination and to determine if further action is warranted.

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