Environmental assessment of Las Vegas Wash and Lake Mead artificial wetlands demonstration project

摘要

The effective use of artificial wetlands for treatment of municipal wastewater is well documented; however, design and economic data for artificial wetlands development are limited (Gersberg et al., 1984a). This is due partly to regional differences in climate, soils, and vegetation and partly to the desired waste treatment. As a result, specific treatment levels and cost benefits relative to the use of an artificial wetlands for a particular site cannot be evaluated adequately without a pilot demonstration project. Las Vegas Wash receives sewage effluent from the Las Vegas metropolitan area and has been designated as a wetlands community park. Las Vegas Wash is located in the Mojave Desert and a wetlands in this area is very unique. Unfortunately, the existing wetlands have been essentially lost due to erosion. Wetlands restoration is currently under consideration for both sewage treatment and erosion control. The effort proposed here is for a pilot wetlands demonstration for treatment of sewage effluent in Las Vegas Wash. Historically, substantial reductions in nutrient concentrations occurred in the Las Vegas Wash. These reductions were due to some combination of mechanisms associated with but not directly related to the historical wetlands as described in the u22Historical Backgroundu22 section of this proposal. The proposed demonstration will be an artificial (managed) wetlands; and therefore, it will not functionally be representative of the historical wetlands in Las Vegas Wash.