The Surface Water and Treatment System facility consists of lime-softened clarification, dual media filtration, ultrafiltration membrane filtration, and reverse osmosis (RO) membrane treatment. This system treats water from Lake Granbury in Granbury, Texas, which has elevated levels of chlorides ranging from 50 to 1,400 mg/L. As designed, the system was unable to meet an increase in production demand. Accordingly, efforts were undertaken by the Brazos Regional Public Utility Agency and Enprotec / Hibbs & Todd to evaluate options for retrofit and expansion of the existing system. The SWATS facility UF system is comprised of 5 treatment trains and was originally designed to produce 8 MGD with Hydranautics HydraCAP UF membranes in 2001. As a result of excessive fiber breakage and performance challenges, the facility elected to retrofit the system in 2008 to accommodate Norit X-Flow membranes. With the 2008 retrofit, the system was supposed to produce 10.0 MGD. As a result of this retrofit effort in 2008, the 5 treatment trains were fully populated with 80 modules per train, thereby eliminating the possibility of future expansion. The purpose of this project was to expand the SWATS facility to meet increased production demand of 10 MGD, with consideration of potential further future expansion. With this expansion, the intent was to engineer a custom design to allow for reuse of existing support systems to the fullest extent possible, including stainless steel frames, piping, chemical cleaning systems, feed pumps, pre-strainers, compressors, valves, and instrumentation. This paper will discuss preliminary design considerations for optimizing reuse of existing equipment and consideration of flow pattern, operations, and physical differences between various modules. As part of this work, pilot testing was performed to both meet regulatory approval requirements for an alternative membrane module and to evaluate UF performance with the aim to eliminate lime softening. Lastly, the execution of the retrofit will be discussed, including final system design, unexpected challenges, coordination of the retrofit process, operational downtime and staging, controls integration, and other site modifications.
This presentation is available to AMTA Members only.
- Jason Nay / Libbie Linton, P.E. / Alain Richard / Joshua Berryhill, P.E.
- WesTech Engineering, Inc. / Brazos Regional Public Utility Agency / Enprotec/Hibbs & Todd, Inc. (eHT)
- AMTA/AWWA Membrane Technology Conference, Long Beach, CA
- AMTA/AWWA Membrane Technology Conference
- Membrane, Ultrafiltration, Design, Pretreatment, Case Study, Optimization, Retrofit