Prior to 2008, the city of Dania Beach, Fla., USA, had exceeded the capacity of its nanofiltration plant on several occasions, requiring the city to purchase water. Additionally, while the city had always complied with increasingly stringent disinfectant by-product (DBP) rules, monitored DBP levels in the distribution system were higher than the city desired. To meet increased drinking water demands and improve finished water quality, the city partnered with Water Design-Build Council member CDM Smith on a new treatment process-based expansion that integrates with the city’s existing 3-mgd lime stabilization water treatment plant.
Delivered through design-build, the new nanofiltration/reverse osmosis plant reduces the city’s need to purchase finished, treated water during periods of peak demand and is expected to accommodate at least 20 to 30 years of growth and development. Two innovative, four-stage nanofiltration membrane units treat variable quality raw water sources, achieve high system recovery, and minimize raw water consumption and concentrate disposal costs.
The system provides the flexibility to achieve product water quality goals with variable raw water quality from both the city’s wellfield and the Broward County wellfield, as well as uses the existing sewer collection system, which flows to the city of Hollywood’s wastewater treatment plant for concentrate disposal. To improve the quality and color of finished water delivered to customers, the plant design blends the existing lime-softened water supply with permeate from the nanofiltration process, which is very low in DBP precursors and color.
The state-of-the-art water treatment plant is the first to receive LEED® certification. Green initiatives include optimizing energy performance equipment, using construction materials with high recycled content, and minimizing water use through xeriscaping and low-flow fixtures. Plant construction also included site improvements, new pretreatment equipment and associated yard piping, electrical service with emergency generator, chemical feed and storage facilities, and a degasifier tower. The result is a reliable, cost-effective, and easily operated and maintained facility that meets the city’s water quality and capacity requirements. The facility has been recognized by the U.S. Environmental Protection Agency, Florida Institute of Consulting Engineers, the Design-Build Institute of America in Florida and the National Council of Examiners for Engineering and Surveying.
This article has been republished with permission by CDM Smith. To view the original article, visit the CDM Smith website.