A release from the city of Round Rock states that on June 17, city officials found and reported this unauthorized discharge, pointing to contractor work done the previous day as part of a project to expand capacity at the East Brushy Creek Regional Utility Authority Wastewater Treatment Plant. The discharge is believed to have overflowed from a manhole upstream of the wastewater treatment facility.
City utility crews became aware of the discharge in an inspection of the area prompted by dead fish sighted at low water crossings near CR 122 and CR 123. On-site Texas Commission on Environmental Quality officials estimated that roughly 250 fish were killed as a result of the discharge, according to the city.
At the time, the city stated that its contractor had been working on a line in the plant located between the plant’s new preliminary treatment unit and an existing aeration basin, and the wastewater flow to that line was shut off. While the line was shut off, wastewater backed up into the collection system's main interceptor along Brushy Creek, causing the overflow, according to the city, most likely in the evening hours of June 16.
City staff is still working to determine how long the overflow drained into the creek and total volume of discharge. The event does not appear to be connected to increased inflows that caused the plant to discharge higher-than-permitted levels of organic solids into the creek in March. The ongoing issue of increased inflow is currently being addressed by the city of Round Rock and its regional partners.
Signs advising residents to stay out of Brushy Creek downstream of the plant have been placed along creek entrances since March due to these previous increases of inflow. Such advisories remain in place, and any additional advice from the TCEQ will be communicated by the city if advised to do so.
