Evaluation of Landfill Conditions and Potential Impacts on Water Resources in Rural Clark County, NV

Affiliation(s) PI Project period Funded by
DHS Pohlmann, Karl F 10/01/2011 - 09/30/2012 US Department of Agriculture

Project Description

Task 1. Assessments of Closed Rural Landfills including: Compilation of existing data in collaboration with SNHD staff; spatial analysis of landfill sites will be conducted using imagery and GIS data acquired from the Clark County GIS Department; SNHD staff will benefit from exposure to spatial analysis tools and improved familiarization with available GIS datasets; Field Surveys. Sites will be visited in conjunction with SNHD staff to provide reconnaissance descriptions of current conditions and collection of data needed for evaluation of cover, management, and monitoring systems. Working together with DRI on these field surveys will provide SNHD staff with invaluable hands-on experience in evaluation of landfill conditions at representative sites. Task 2. Evaluation of Conditions at Reid Gardner Generating Station This task will assess current hydrogeological and cover conditions at the Reid Gardner landfills and evaluate the potential for transport of contaminants from the landfills to the Muddy River via groundwater and surface water systems. Essentially the same activities specified for Task 1 will be carried out; however, the ongoing operations and the much larger scale of this facility will require that the scope of investigations at Reid Gardner be larger and as a result will require more time and resources to accomplish the project objectives. Task 3. Guidance for the Design and Evaluation of ET Covers in Clark County DRI will draw upon experience as a key institution in the U.S. EPA's Alternative Cover Assessment Program (ACAP) to develop guidance for cover design and evaluation that meets the needs of SNHD and other responsible agencies in Clark County. In addition to general guidance, specific guidance will provided for landfills that warrant substantial attention as determined during earlier phases of this project or that are of particular concern to SNHD. Successful design of water balance covers requires knowledge of the interaction between the site climate and the soil-and-plant system that comprises the final cover. This guidance will include specific details regarding sampling, analysis, and evaluation of barrow soils for final landfill cover application. Methods for evaluating nearby mature plant communities will be described to support of selection of appropriate revegetation efforts. Construction methods for water balance covers differ from many other earthworks projects and the guidance document will provide detailed and practical suggestions derived from experience at many other landfill sites. These methods will provide cover systems with appropriate water storage capacity, revegetation requirements, and long-term stability. Evaluation methods, including basic numerical modeling methods, will be described.