The Texas Department of Health has issued a fish consumption advisory for all Texas waters of Caddo Lake due to increased levels of mercury found in fish tissue. In the Caddo Lake area the mercury may be from natural sources, such as geologic formations, as well as stormwater runoff from manufacturing areas around the lake. Metals are possible concerns in this segment. Unfortunately, almost no sampling has occurred in the segment since 1992. It is not clear whether these results reflect permanent conditions or ones that have changed since the 1980s.
Further monitoring is recommended to determine current water quality.
Segment 0402 has a possible concern for dissolved oxygen, fecal coliform bacteria, and the dissolved metals cadmium and zinc. Nutrients are also a concern for this segment. Sluggish flow and organic loading from natural sources, as well as from wastewater discharges, likely contribute to these problems. Metals have not been monitored over a sufficient period of time to provide trends and to determine potential causes. The Texas Department of Health has issued a fish consumption advisory for this segment due to elevated levels of mercury found in fish tissue.