AUSTIN, Texas -- Water quality tests we obtained through a public information request show Austin Water faced problems treating water several days before notifying the public.

  • Water quality tests show water problems started several days before informing the public
  • Data indicates problems started three days before boil water notice

The data, which is included in Austin Water’s Surface water Monthly Operating Reports, indicates signs of struggling among the utility’s water treatment plants three days before the citywide boil water notice.

Murky water from the Colorado River, which is called turbidity and measured in units known as NTU, is what Austin Water says quickly overwhelmed its three water treatment plants and eventually leading to the citywide boil water notice.

This graph above shows how raw water quality changed throughout October for Austin's three water treatment plants. On most days, it's rated a one or two, but the signs of the muddy floodwaters began to show up almost a week before the utility issued its boil water notice. Turbidity measurements first increased at Davis Water Treatment Plant to 4 NTU on October 16, 2018, before reaching 383 NTU four days later. Ullrich Water Treatment Plant saw the highest raw water intake turbidity, measured at 387 NTU on October 21, 2018.

That afternoon, Austin Water held a rare Sunday news conference to ask the public to conserve water. By then, the water treatment plants were already struggling.

The graph above shows how the abnormally murky water impacted treatment. Handcox Water Treatment Plant, located on Lake Travis and formerly known as Water Treatment Plant 4, went from its usual production of about 26 million gallons of water a day to down to seven million gallons in a matter of four days. At Ullrich, the city's largest plant, water production dropped by half its normal rate on October 20, 2018, two days before the boil water notice.

Davis suffered a slight slump that weekend, but it was able to quickly increase production to make up for the lack of output from the other two water treatment plants.

Austin Water issued its Boil Water Notice on October 22, 2018. By then, the utility's treatment plants appear to have been on the mend based on their treated water outputs. However, the lack of water treatment ability over the weekend caused many of the city's reservoirs to reach extremely low levels. At the time, utility managers said the city’s potable water supply reached a point where water pressure in several areas was about to drop to unsafe levels. That could have led to bacteria growth in the distribution system and water main breaks, utility managers said.

With the notice behind them, utility leaders say they needed to issue it to warn the public the water could end up contaminated and, perhaps more importantly, to ensure everyone cut back their usage immediately.

Information for this news report comes from the first of several public information requests we’ve filed. Additional stories looking into the factors leading to Austin’s first ever citywide boil water notice and how it was handled will be forthcoming.