Full Description

The Membrane Concentrate Pilot Wetland Project is being conducted by the City of Oxnard Water Division toassist with the City's water resources master planning process and implementation of the Groundwater RecoveryEnhancement And Treatment (GREAT) Program. Proposed water production technologies will generate brineconcentrate that will require disposal. One conceptual alternative could be to use the membrane concentrate as awater source to brackish or salt marsh wetlands.CH2M HILL is conducting the Membrane Concentrate Pilot Wetlands Project to determine if membraneconcentrate could be used for regional benefit, including assisting with restoration of the Ormond Beach wetlandssystem. The project consists of twelve 1.1 m2 wetland tanks comprised of six wetland types and two replicates.The pilot wetlands include a water storage tank, constant head tank, and all associated piping. The wetland typesinclude five flow-through mesocosms (surface flow (SF) high marsh, SF low marsh, horizontal subsurface flow(SSF), peat-based vertical upflow (VF), and submerged aquatic vegetation (SAV)), and a saltgrass evaporationsystem. The evaporation cells receive concentrate inflow, but are operated to achieve a zero discharge.Of the wetland types selected, the SF high marsh, SF low marsh, and the SAV cells represent the major brackishwater plant communities known to exist within the existing Ormond Beach wetlands. Plants were obtained fromnative plant nurseries. The primary water source is reverse osmosis (RO) membrane concentrate from the Port Hueneme WaterAuthority's Brackish Water Research Desalination Facility. Preliminary data available from project Phases reported in this paper indicate the following:native wetland plants adapted to salt and brackish water conditions exhibited normal, even vigorous growth;parameters of greatest concern such as selenium and nitrate-nitrogen significantly decreased to environmentallysafe levels within the wetland, mostly in the VF and SFLM wetlands;concentrations of many inorganic water quality parameters did not decline during the study, but some, such ascalcium, alkalinity, and total hardness declined in the SAV wetlands; and,treatment by the marshes in general yielded a brackish water with significantly reduced contaminant levelsthat, with further testing and regulatory approval, may be used for regional benefit, including assisting with restoration of regional estuarine wetlands. Includes 8 references, tables, figure.

Product Details

Edition: Vol. - No. Published: 03/01/2005 Number of Pages: 11File Size: 1 file , 430 KB