Contamination in some waterways, as expected, will draw new scrutiny, while results from other newly tested waters will show they do meet the standards for their intended uses. Increased monitoring also can assist with getting water bodies removed from the list. Removal may occur for a number of reasons for instance, tighter wastewater discharge permitting requirements that reduced contaminant loadings to the waters, improved septic systems, banned chemicals, or better environmental safeguards at construction sites. In Austin, a fish consumption advisory for Town Lake, a segment of the Colorado River that runs through the city, was lifted late last year when tissue samples of fish indicated that levels of the banned pesticide chlordane would no longer raise health concerns. And in the Panhandle, the Canadian River above Lake Meredith and the Lower Prairie Dog Town Fork of the Red River have been reassessed for fecal coliform bacteria contamination.
Testing shows that both can now fully support safe recreation.
Studies now show that mercury concentrations in these waters fall well below levels that would cause a concern for human health. The additional waters being studied for contaminants reflect the state s goal to monitor and assess more waters that have not been studied and to classify previously unclassified waters as to their quality and uses. They also are standardizing collection methods and sharing the data.