The new polymer chemical feed system is nearly complete at Ullrich Water Treatment Plant, and it will help remove silt from the water supply during extreme flooding events—such as in October 2018, when the Colorado River system flooded and high levels of silt washed into the Highland Lakes, Austin's source for drinking water. Silt can raise the turbidity of water, making it cloudy and dark brown in appearance.
“We expect to see extreme flooding events in our watershed more frequently due to the effects of climate change,” Austin Water Director Greg Meszaros said in a statement. “Austin Water is committed to making improvements to our water treatment systems to be prepared to respond to these changing conditions.”
According to Austin Water, floods have typically only caused turbidity to spike for one to two days, but the 2018 flood events caused a weeklong boil-water advisory as the utility attempted to lower turbidity in the city's water supply. During the crisis, the water's turbidity levels were around 80 times higher than normal.
An October 2019 report from the city of Austin, Travis County and Hagerty Consulting Inc. assessing the previous year's flooding event called for polymer-based treatment systems to be installed at all three of the city's water treatment facilities. Engineering and design of the first system has been underway at Ullrich for the past two years, and construction of similar systems at the Davis and Handcox plants will occur over the next two years. According to Austin Water, materials are available at the Davis and Handcox plants to provide temporary polymer feed services in the interim should the need arise.
