Austin Water Aims To Rid Treatment Plants Of Zebra Mussels

AUSTIN, TX — Austin Water has achieved a significant milestone in its efforts to manage Zebra Mussels at its three water treatment plants, utility officials said this week.

Utility crews completed inspection and cleaning of the raw water intakes at all three treatment plants and commissioned new systems to deter future infestations this month, according to an advisory issued on Monday.

Zebra Mussels were first detected in Lake Travis in 2017, and have since infested the body of water along with Lake Austin, both sources of Austin’s drinking water. The invasive species attaches to surfaces —such as grates, screens, pipes and valves — leading to interference with operations that increases the energy needed to pump water through the process, officials explained. Presence of the mussels also can affect taste and odor of drinking water.

In response, Austin Water has established a multi pronged approach to managing its raw (lake) water infrastructure, including:

• Routine cleaning and removal of Zebra Mussel shells on screens and other infrastructure;
• use of contracted divers to inspect underwater infrastructure and pressure wash grates and underwater infrastructure at least annually;
• utilization of 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, officials said. 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, according to utility officials. 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, according to the advisory.

“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," Rick Coronado, assistant director of operations at Austin Water, said in a prepared statement. "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.”

Looking toward the future, officials said, 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," Austin Water Director Greg Meszaros said in a prepared statement. "Establishing a sustained approach to managing them is a vital part of our ongoing operations. 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 the utility's Zebra Mussel Mitigation portal.