Faced with continuing growth and re-development, an aging lime softening plant, and regulatory issues with disinfection by-products, the City of Dania Beach, FL pursued the construction of a new 2.0 mgd nanofiltration process to complement the City’s existing 3.0 mgd conventional lime softening water treatment plant. Efforts to develop a plant that would improve water quality, meet long term needs and raise community awareness involved CDM Smith engineering and construction teams, the City and FloridaAtlanticUniversity.  This paper presents the innovative membrane treatment plant design that was developed to maximize system recovery while providing a high degree of operating flexibility.  This design includes a two stage nanofiltration unit followed by a convertible third and fourth stage reverse osmosis unit to provide the City with the flexibility to meet their concentrate discharge limits when operating at recoveries up to 95 percent by operating in a four stage configuration.  Operating at this higher recovery was tested by FloridaAtlanticUniversity faculty and students, and preliminary design concepts were gained from student design projects, including meeting LEED certification goals.  This plant secured enough credits  to become the first LEED Gold certified water plant in the world.

So what does this mean to a community?  Is this work pursuing?  Why is this type of certification useful for local governments?  In  many cases it sets a public policy example.  It may cut long-term costs (something many utilities do not focus on), and it may improve sustainabilitiy?  What are your thoughts?  Read more in an upcoming JAWWA article.