The City of North Miami Beach's water system is the second largest in Miami-Dade County, with infrastructure of water supply, treatment, storage, transmission, and distribution. The water system provides services to approximately 32,800 metered connections in North Miami Beach, Sunny Isles, Miami Gardens, Aventura and portion of Northwest Miami-Dade, serving approximately a population base of over 180,000.

Prior to the expansion, the city owned and operated the Norwood-Oeffler Water Treatment Plant, a traditional lime softening plant with 16 million gallons per day (MGD) capacity. Approximately 12 to 14 MGD was purchased from Miami-Dade Water and Sewer Department through 8 interconnections to meet demand.

The water treatment process included lime softening for hardness reduction, iron and color removal, followed by stabilization, filtration and disinfection. The process also includes the addition of polymer to aid the lime softening process, polyphosphate for corrosion control, and fluoride for dental health. Disinfection is achieved by chloramines, with ammonia added before chlorine. The finished water meets or exceeds all current local, state and federal regulations.

The raw water was supplied by 12 Biscayne Aquifer wells, ranging from 40 to 100 ft deep. The wells are located at the Norwood well field, including 7 wells located on the water plant site, and 5 wells offsite in nearby schools and public parks. The capacity of the wells ranges from 0.6 to 6 MGD, with a total capacity of 27 MGD. These wells are rotated on regular basis.

History of the Water Treatment Plant Expansion Program

To serve all its customers with its own water, and to provide superior water quality to all its customers, the City of North Miami Beach initiated a Water Treatment Expansion Program. Phase I of the expansion project increased treatment capacity from 16 MGD to 32 MGD. After careful feasibility studies and evaluations, the City decided to keep the existing lime softening process, and expand the plant using the state of art membrane technology. Foreseeing limited water resources from traditional Biscayne Aquifer water, the city added the deeper Floridan Aquifer as another raw water source.

Initial capacity for the membrane treatment system is 15 MGD, which includes 9 MGD of Nanofiltration and 6 MGD of low pressure reverse osmosis treated water. The system is expandable to 20 MGD, with additional NF train of 3 MGD and additional RO membrane for 2 MGD. The permeate flow streams of the membrane processes is combined for post treatment/stabilization and subsequently blended with finished water from the existing lime softening process and the filtered raw water blend. The blended finished water is then transferred to a new 4.2 million gallons (MG) and existing 2.0 MG ground storage tanks before it pumped out to the water distribution system. The new membrane plant held a ribbon cutting ceremony in December of 2007.