Avila Beach's Improved Wastewater Treatment Plant

Avila Beach Community Services District (CSD) operates the Avila Beach Wastewater Treatment Plant (WWTP). The plant was originally designed as a primary clarification plant and later upgraded to include a trickling filter and secondary sedimentation basin. As development has occurred around the town, and with the construction of a large RV park contributing high organic loading, the CSD initiated an improvement project for the WWTP to increase loading capacity while also providing higher quality effluent and site redundancy. Wallace Group was awarded the design contract and worked with the CSD to develop plans for expansion to include a packaged membrane bioreactor system, influent equalization tank, upgraded emergency backup generator, and updated SCADA control system. The site is geographically constrained by a main traffic corridor road on one side and a creek on the opposite side. The design work required creativity to provide the expansion capacity necessary, while preserving access for sludge hauling, chemical deliveries, and service vehicles. The site geology was also an important design consideration. To resolve the high degree of settlement potential caused by the site soils, vibratory pier ground improvements were installed under the concrete equipment pads. The new treatment plant was commissioned in summer 2023 and produced high quality effluent for future recycled water to the adjacent golf course.