Employee error was largely to blame for Austin issuing a three-day citywide boil-water notice in February, an internal investigation finds.
The Austin Water report, released Tuesday, confirms two initial findings by the city-owned utility: that the overnight shift at the Ullrich Water Treatment Plant didn't respond to repeated alarms that water was becoming sludgy, and that they didn't reach out to higher-ups to avoid the plant's mandatory shutdown Feb. 5.
The investigation lays out a clearer timeline of what led to the city issuing the boil-water notice. It was the city's third notice in four years and ultimately led to the resignation of Austin Water Director Greg Meszaros.
Turbidity — cloudiness that occurs when particles build up in water — reached unsafe levels at the Ullrich plant on the night of Feb. 4 and into the next morning. The report found:
- A buildup of solids started roughly around 10 p.m. in a single basin where water is filtered and clarified. Ullrich had three overnight staffers, who began testing and monitoring levels in the basin shortly after. The report said the employees were convinced the turbidity issues were related to leaks in older iron pipes, which had caused previous issues, and focused on finding leaks.
- At around 2:30 a.m., the water overtopping the basin "looked similar to the water in the Colorado River during the 2018 flood." At that point, the report says, "the basin should have been shut off immediately to prevent high turbidity water from reaching the filters."
- The sludgy water flowed to the filters, which functioned for about an hour and a half before becoming overloaded. The investigation found the water sent to those filters was "10-100 times more turbid than typical for 5 hours until [the basin] was finally taken off-line at 7:38 a.m."
- At 8 a.m., the turbidity of the plant's treated water exceeded the level that would trigger a boil-water notice.
- At 9:30 a.m., the plant was shut down.
- Roughly 10 hours later, at 7:30 p.m., the city issued its boil-water notice.
After Ullrich was shut down, the city moved its water-treatment operations to two other plants.
Austin Water told KUT that ultimately no contaminants were found in the water tested at the Ullrich plant. The utility has said it's taken measures to avoid future errors at the plant.
The Austin Water Oversight Committee will meet Thursday to discuss the internal investigation. The Austin City Council has called for an independent audit of the incident.