Auburndale, Florida's Western Regional Wastewater Treatment Plant, installed an Aquionics medium pressure ultraviolet system in 1993 to disinfect treated effluent for a reuse program.
As the population in Florida continues to grow at a rate of 4,500 people each week, the demand for clean water also increases - a fact that has led to widespread and often prolonged water shortages. To combat the problem, Florida promotes reuse of reclaimed water and water conservation as major state objectives.
By using reclaimed water for reuse in place of potable water, the potable water supply can be conserved for human use.
The state has five disinfection levels for treated wastewater, depending on the effluent disposal method or reuse program. For its reuse program, the Auburndale plant must meet the state's "high-level" requirements for public access and edible crop irrigation.
The Auburndale plant was built in 1981 and has a rated capacity of 1.4 mgd. The plant's treatment process is a typical Florida design with the wastewater pumped to the headworks of the plant. The unit processes proceed from screening and grit removal to sequencing batch reactors (SBR) for biological treatment and then to dual media traveling bridge filters that normally reduce turbidity levels to less than 1.0 NTU.
The filtered effluent is discharged to a 15,000-gallon sump and pumped with variable speed drive pumps through the Aquionics UV treatment system. The final effluent is stored in a 250,000-gallon storage tank and used in a municipal lawn sprinkler system and for spray irrigation on approximately 150 acres of orange groves. If the storage tank is full, the flow is diverted to a rapid infiltration basin for groundwater recharge.
The ultraviolet system provides the high level disinfection the water must undergo before it can be pumped back to the environment. The process has no disinfection byproducts or chlorine residual to harm the environment.
In 1997, about 40 percent of Florida's reclaimed water was used for irrigating areas accessible to the public (parks, golf courses, and residential lawns). An additional eight percent of reclaimed water was used to irrigate edible crops.
