Located near Houston on the Texas Gulf Coast, League City is a popular waterfront resort community. Residential and commercial growth recently prompted the city to expand its Southwest Water Reclamation Facility (SWWRF) to accommodate future growth and meet new state water quality standards.

Challenge

A growth-driven need for Tertiary Treatment

League City contracted with CDM Smith to manage the expansion project and design and construct a 4.0 MGD (design) / 12 MGD (peak)treatment facility with an energy, labor, and operational efficient process that would meet exceptionally stringent discharge limits. The facility also needed to ensure Type I or Type II non-potable reuse was available for future irrigation and/or amenity use. The engineering firm analyzed SWWRF’s lift station and collection system capacity under normal and peak wet weather conditions and determined that tertiary filtration was needed. In this dense, high-volume community, space constraints and cost were a priority for this project

Solution

The Forty-X™ Disc Filter — High-Quality, High Volume Filtration in less space

It was determined that two Forty-X Disc Filters from the DAVCO product line of Evoqua would be the ideal solution for meeting stricter effluent requirements and increasing capacity in a small footprint. The Forty-X Disc Filter is a high-rate tertiary filter that fits into a fraction of the footprint required by traditional sand filters and uses an inside-out flow pattern that increases throughput, improves efficiency, and minimizes lifecycle costs. In addition, the system’s robust pressure-assisted seal allows the panel to sustain and operate at a higher head, and its modular design adapts to a broad range of flows and applications including water reuse, tertiary filtration, process water filtration and conventional filter retrofits.

Results

The two Forty-X Disc Filter tank units at the League City facility handle a peak flow rate of 6 MGD while maintaining a consistent effluent quality of < 2mg/l of TSS exceeding the required limit.