Pflugerville water plant expansion battles pipeline leak and membrane failures ahead of December completion

Pflugerville water plant expansion battles pipeline leak and membrane failures ahead of December completionThe Texas city is maintaining an 8 MGD operational cap under modified Stage 1 restrictions as contractors work to repair a defective joint on a new raw water line and replace failing membrane equipment.

A hydrostatic pressure test revealed a defective joint on a newly installed section of the raw water pipeline, requiring contractors to excavate and repair the line.

The city's water treatment plant is capped at an 8 MGD operational limit due to aging membranes and the recent failure of a critical equipment piece that took one of five treatment trains offline.

Substantial completion of the expansion is slated for October, with final completion in late December, ultimately raising the plant's rated capacity to 30 MGD.

A scheduled plant shutdown from May 27 to June 10 will allow contractors to complete a header pipe installation, paving the way to bring a new 42-inch secondary raw water line online by the end of June.

The City of Pflugerville, Texas, is advancing a critical expansion of its water treatment plant and raw water intake systems, though the project is currently navigating construction defects and equipment failures. During a May 26 city council meeting, water utility officials detailed the challenges keeping the city under modified Stage 1 water restrictions, capping operational treatment at 8 million gallons per day (MGD). Assistant Director of Water Operations Shelby Granger and Director Matt Rector reported a setback on the new raw water pipeline near the river pump station. A recent hydrostatic pressure test revealed a leak caused by a defective joint installation on a newly laid pipe segment. Contractors are currently excavating the site to repair the joint and rebury the line. The city has been relying on a 24-inch emergency bypass line to maintain flows. However, scour has caused the concrete anchor blocks holding the bypass in place to settle and shift downstream, prompting close monitoring. To resolve the reliance on the bypass, the city scheduled a facility shutdown from May 27 to June 10. During this window, contractors aim to complete a critical header pipe installation at the pump station. If successful, this will allow the city to bring a new 42-inch secondary raw water line online by the end of June without requiring further shutdowns. Once the 42-inch line is operational, crews will finish repairing the existing 30-inch raw water line. Back at the water treatment plant, capacity remains tightly constrained. While the plant has a rated design capacity of 17.7 MGD, peak treatment capacity is currently limited to 10.5 MGD, with average daily operations capped at 8 MGD. Granger attributed this to the age of the facility's membrane filters—some of which are in their eighth or ninth year of a 10-year rated life. The situation was further complicated by a recent equipment failure that took one of the plant's five membrane trains offline. Utility staff had anticipated potential failures and proactively stocked critical parts, allowing them to manage the outage while maintaining the 8 MGD output. Granger noted that public conservation efforts have been highly successful, preventing any significant spikes in usage despite the constraints. Relief is on the horizon for the utility. Substantial completion of the water treatment plant expansion is anticipated by October, with final completion expected in late December. Once fully online, the expanded facility will feature a rated capacity of 30 MGD, effectively ending the current operational bottlenecks. Officials noted the expanded capacity could eventually open the door to potential water sales to neighboring municipalities like Hutto. Until then, Pflugerville will maintain its modified Stage 1 restrictions, which target curbing peak irrigation demand between 2:00 a.m. and 6:00 a.m. to keep storage tanks topped off.