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 water treatment operations and increases the amount of energy required to pump water through the process. Their presence also can affect taste and odor of drinking water.

In the fall of 2020, Austin Water achieved a significant milestone in its efforts to manage Zebra Mussels at its three water treatment plants.  The utility completed inspection and cleaning of the raw water intakes at all three treatment plants and commissioned new systems to deter future infestations this month. These steps are part of the multipronged approach to managing Austin Water’s raw (lake) water infrastructure, which includes:

  • 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.

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.

Timeline

  • 2017 - Zebra Mussels first detected in Lake Travis
  • 2018 - Divers inspect underwater infrastructure at three water treatment plants
  • 2019 - Begin ongoing cleaning of underwater infrastructure by divers
  • 2019 - Enhance protocols to evaluate taste and odor of drinking water more frequently
  • 2019 - Begin Copper Sulfate Pentahydrate chemical feed at Handcox Water Treatment Plant
  • 2020 - Begin Copper Sulfate Pentahydrate chemical feed at Davis and Ullrich water treatment plants
  • 2022 (projected) - Complete Copper Ion Generator systems at three water treatment plants
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