Zebra mussels threaten river, not tap water

It’s not likely that San Marcos tap water will have the “fishy” smell that plagued Austin’s municipal supply in recent days, a city official says, because the system has been engineered to prevent infestation by invasives like Zebra mussels. 

However, drinking water isn’t the only thing at risk. It may be just a matter of time, another expert says, before the invasives show up in the San Marcos River and even Spring Lake.

The city has drawn 80 percent of its drinking water from Lake Dunlap, downstream from Canyon Lake, since 2000. Tom Taggart, the city’s director of public services, said the intake at Lake Dunlap is equipped with a chemical feed that kills the mussels with sodium permanganate.