AWWA MTC61115

The St. Johns River Water Management District (SJRWMD) and CH2M HILL conducted an extensive pilot study involving the use of integrated membrane systems to produce potable water from the St. Johns River. The study identified treatment processes and costs involved in using the St. Johns River as an alternative water supply. This source is one alternative being evaluated to offset a large water supply deficit projected in eastern central Florida. The raw water source for the pilot study was Lake Monroe in Sanford, Florida. This lake is part of the St. Johns River system, and is characteristic of typical Florida surface water with low turbidity and high dissolved organics. In addition, the lake periodically becomes brackish from saline groundwater inflow during low rainfall periods. Prior to testing, a preliminary raw water characterization study identified the treatment requirements necessary for St. Johns River water and a potential treatment facility to be located in the reach between Titusville and DeLand on the St. Johns River. The basis of this study was to evaluate pretreatment technologies that would sufficiently reduce the organic and turbidity levels in the water (e.g., coagulation, clarification, and filtration) so that effective salt removal could be conducted with reverse osmosis (RO) membranes. The purpose of this study was to demonstrate the treatability of this source water, identify the appropriate technology and basic design parameters for treatment, and determine both the capital and operational costs for this potential facility. The intent is that the information in this report will assist an entity in implementing a surface water treatment facility in this reach of the St Johns River and facilitate the next step for a water supply project of this type. The findings of this study are that the source water in this reach of the St. Johns River is treatable and can be used as a source for potable drinking water. All of the technologies identified and selected by the stakeholders for testing in this study demonstrated feasibility and can be recommended for use on this water.