CobbFendley provided the design and construction of a new 13 MGD lift station and approximately 6,000 linear feet of HDPE force main from the new lift station to the proposed Cibolo Creek Municipal Authority (CCMA) wastewater treatment plant. The 13 MGD lift station included two 16-foot diameter wet wells each 37 feet deep, with room on the site for a third wet well in the future. The wet wells were circular and cast-in-place construction. The project was designed to convey existing flows and upgrade for ultimate design in the future. Two pumps were installed in the existing condition with room for a third and fourth when flow conditions warrant additional pumping capacity. The pumps are 1,200 to 3,000 GPM variable frequency drive to convey a wide range of flow in the existing condition. The elevation of the wet well, valve vault, and emergency generator was set at two feet above the 100-year floodplain, requiring the site to be elevated above natural ground and graded back to the existing grade at IH-10. The site layout accommodates equipment traffic for regular service as well as maintenance to the station. Odor control using air scrubbers was designed. Several installation methods were required, consisting of open cut (30+ feet deep) and jacking and boring for creek crossings.
To address the installation risks, thorough planning, and engineering analysis were undertaken to perform proper execution of the open cut and jacking and boring methods, minimizing potential disruptions to the surrounding environment and local communities. Extensive pump selection analysis and testing were conducted to confirm that the chosen pumps would effectively handle both the low-flow and high-flow conditions, promoting optimal system performance and reliability throughout the project’s lifespan.
Additionally, CobbFendley was responsible for Project Management, Negotiation, Title Coordination, Closing/Escrow, and Condemnation Support for the acquisition of 26 easements for the wastewater facility.