AUSTIN, TX – Austin Water has achieved a significant milestone in its efforts to manage Zebra Mussels at its three water treatment plants. The utility has completed inspection and cleaning of the raw water intakes at all three treatment plants and commissioned new systems to deter future infestations this month.
Zebra Mussels were first detected in Lake Travis in 2017 and have since infested Lake Travis and Lake Austin, which are the source of Austin's drinking water. The invasive species attaches to surfaces such as grates, screens, pipes and valves, interferes with operations and increases energy required to pump water through the process. Their presence also can affect taste and odor of drinking water.
In response, Austin Water has established a multipronged approach to managing its raw (lake) water infrastructure, including:
- Routine cleaning and removal of Zebra Mussel shells on screens and other infrastructure;
- Using contracted divers to inspect underwater infrastructure and pressure wash grates and under water infrastructure at least annually;
- Using rovers with cameras to inspect pipelines and underwater infrastructure not readily accessible by divers;
- Enhancement of protocols to evaluate taste and odor of drinking water more frequently; and
- Installation of chemical systems to feed liquid copper sulfate pentahydrate into the water pipes to deter infestation in the pipes that take water from the lakes to the water treatment plants.
Austin Water completed construction and commissioning of chemical feed systems at Ullrich Water Treatment Plant and Davis Water Treatment Plant in early October 2020. A similar system began operation at Handcox Water Treatment Plant in September 2019. The systems will feed a low dose of liquid copper sulfate pentahydrate to kill off any Zebra Mussels in the pipes and deter others from attaching to the water treatment infrastructure. Austin Water worked to get these temporary systems at Davis and Ullrich water treatment plants in operation quickly and is beginning construction to enhance the systems by adding bulk storage tanks, buried piping, containment structures and other elements.
"Austin Water is working to counteract the impacts of this invasive species in a responsible way with the health and safety of our employees, customers and environment at the forefront. These chemical feed systems include safeguards to ensure chemicals remain within the pipeline. Additionally, our robust treatment processes continue to remove chemicals from the water and provide high quality drinking water every day," said Rick Coronado, Assistant Director of Operations at Austin Water.
Looking toward the future, Austin Water is working to design a Copper Ion Generator system that will use electricity and copper electrodes to release copper ions into the raw water pipelines. This proposed system will eliminate the need to deliver, handle, and store large amounts of copper sulfate chemicals onsite.
"We know that Zebra Mussels are here to stay in our water supply. Establishing a sustained approach to managing them is a vital part of our ongoing operations," said Austin Water Director Greg Meszaros. "This work is an important part of our mission to maintain a resilient utility that provides high quality services to our customers amidst changing conditions."
For more information and a video about Austin Water's Zebra Mussels mitigation efforts, visit
https://www.austintexas.gov/department/zebra-mussel-mitigation.
