Pulsed Bed Sand Filter Help Re-use Wastewater
"If I had a chance to talk with them," he says, "I'd tell them 'Don't worry. Everything will be fine here while you're away. We're taking care of the treatment plant. The water's OK.'"
Helping the wastewater treatment plant run problem-free is a Hydro-Clear pulsed bed sand filter, supplied by <%=company%>.
The filter is gravity flow and consists of six cells, three having been added in a recent expansion. The filtering medium is a 10-in. bed of fine sand, and the compartmentalized underdrain is designed to allow pulsing of the bed and efficient backwashing.
The filter is equipped with a Chemical Clean cycle to clear the bed of grease and oil. This is accomplished by soaking the bed with an emulsifying detergent, and then backwashing the grease and oil out of the filter bed and restoring the sand to its original condition.
Planned Development
Julington Creek is a 4,200-acre planned community, featuring woodlands, lakes, library, a recreational facility, and 18 holes of golf. Developed according to Florida's CDD (Community Development District) program, the community is located in south suburban Jacksonville, close to the east bank of the St. Johns River. The community includes about 1,600 homes, with plans to "build out" to 6,500 in the next 15 years.
The wastewater plant currently treats about 350,000 gallons a day with influent BOD averaging 180 milligrams per liter; suspended solids about 160mg/L.
It's a simple, efficient process, with all treatment processes in above ground concrete structures. Wastewater enters the plant through bar screens and then passes to a modified sequencing batch reactor, where biological treatment and nitrification take place. Digested sludge is hauled and spread wet on near-by fields.
Approximately 10 batches of biologically treated wastewater are sent to the Hydro-Clear filters, each day. Filtered effluent is chlorinated and stored in a holding tank. Effluent quality is less than one milligram per liter suspended solids, and less than one NTU turbidity (permitted levels are 5 mg/l SS and 3NTU).
Alum is available for phosphorus removal, but so far that process step hasn't been necessary.
Effluent Reused
During normal weather, the filtered wastewater irrigates the community's golf course; there are plans to use it on median strips and landscaping.
In wet weather, the water is dechlorinated and discharges under a permit to the St. Johns River.
"This is very environmentally friendly plant," says Brightwood. "Our processes enable us to produce an excellent quality water."
Project design engineer is England, Thims and Miller (Jacksonville) and Ortega Industrial Contractors (Jacksonville) was the contractor. Operator is OMI for JCP Utilities. Ellis K. Phelps & Co. (Apopka, FL) represents USFilter on this project.