Austin (KXAN) — More than a year after the city of Austin found that an unchecked invasion of troublesome mollusks known as Zebra mussels was to blame for unpleasant smells and taste in Austin water, the city’s water utility says it has a plan for managing this species in the long term.

The invasive species has spread across Texas over the past decade.

They reproduce quickly and can cause expensive damage as they cling to pipes, grates, and equipment.

Zebra mussels were first confirmed in Lake Travis in July 2017 and have since infested Lake Travis and Lake Austin — the two bodies of water Austin Water draws its water supply from.

Zebra mussels cling to a tire in Lady Bird Lake (KXAN/ Alyssa Goard)

These mussels have spread so prolifically, that the water utility doesn’t have hope of eliminating them entirely, just mitigating their impact.

“We know that Zebra Mussels are here to stay in our water supply,” said Austin Water Director Greg Meszaros in a city release Monday.

“Establishing a sustained approach to managing them is a vital part of our ongoing operations,” Meszaros continued.

The management plan

As of Monday, Austin Water says it has completed inspection and cleaning of the raw water intakes at all three treatment plants and that this month the utility also commissioned new systems to deter future infestations.

One of the measures the department has come up to manage Zebra mussels includes routine removal of the mollusks from things like screens and infrastructure. Austin Water plans to contract divers at a minimum once a year to inspect underwater infrastructure for Zebra mussels. For areas that divers cant access, the water utility plans to use “rovers with cameras” to inspect.

Austin Water said it is amping up protocols “to evaluate taste and odor of drinking water more frequently.”

Zebra mussels affixed to a rock on Lake Travis. (KXAN Photo/ Alyssa Goard).

In the short term, the water utility is installing chemical systems to feed liquid copper sulfate pentahydrate into the pipes that take water from lakes to the treatment plants to keep mussels from clinging to the pipes.

This method feeds a low dose of liquid copper sulfate pentahydrate to kill off Zebra mussels.

Austin Water said there are safeguards to keep these chemical feed systems within the pipeline.

Last month, Austin Water completed a similar operation at the Handcox Water Treatment Plant and finished rolling out chemical feed systems at the Ulrich and Davis Water treatment plants earlier this month.

For a long-term mussel mitigation strategy, 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.