This three-phase project increased wastewater treatment plant capacity from 4 to 6 mgd with provisions for future expansion to 8 mgd. The increased capacity also addresses seasonal demand for reclaimed water. With funding assistance from Mead & Hunt, the project received St. John’s Water District and Florida Department of Environmental Protection cost share grants.
Various plant improvements replaced process equipment, added rotary drum sludge thickeners, odor control, surface water treatment and filtration. New aerator impellors, drives and ‘Oculus’ control system optimize aeration to increase anoxic retention and reduce soluble nitrate. This approach significantly reduced energy consumption and total nitrogen, exceeding expectations with effluent total nitrogen concentrations below 3 mg/l.
Surface water treatment upgrades include chemical feed pumps, flocculation basins and new ‘Aqua Diamond’ filters that replaced traveling bridge sand filters. The new filters increase the average hydraulic capacity from 6 mgd to 12 mgd, providing 6 mgd of reuse augmentation capacity from the surface water.
The plant’s instrumentation and control system was redesigned to incorporate a fiber-optic data highway network and new programmable logic controllers. The I&C upgrades replace outdated equipment, improves monitoring and reporting capabilities, and enhance process automation and control.