McCourtney Road Landfill – Nevada County, CA

McCourtney Road Landfill is founded in an extremely complex geologic and hydrogeologic region of the Sierra Nevada Foothills. Holdrege & Kull has performed a wide variety of tasks at this landfill for the County of Nevada. Since 1996, H&K has provided sampling and monitoring of groundwater wells, surface water, leachate extraction wells, surface impoundments, lysimeters, and leachate pump stations. H&K has prepared quarterly, semi-annual, and annual water quality reports required by the Regional Water Quality Control Board. Most recently, H&K updated the Water Quality Protection Standard (WQPS) and revised the Monitoring and Reporting Program (MRP) to eliminate monitoring points that are no longer needed. H&K is currently customizing monitoring systems, monitoring protocol, and data evaluation protocol; monitoring groundwater surface water, landfill gas, soil pore water, soil vapor, storm water and leachate; performing inter-well and intra-well statistical analysis; managing compliance of a Detection Monitoring Program (DMP) and a Corrective Action Program (CAP); performing iso-contour mapping and settlement calculations; providing financial assurance updates and Post-Closure Maintenance Plan (PCMP) updates; preparing O&M plans; and preparing a Preliminary Closure Plan for surface impoundment decommissioning. H&K also recently negotiated new WDRs with the RWQCB, which resulted in reduced monitoring requirements and the elimination of nine off-site wells from the monitoring requirements.

Past projects performed by H&K at the McCourtney Road Landfill include the following.

  • Performed in-situ permeability testing of proposed final cover material using Boutwell permeameters.
  • Drilled and constructed monitoring, leachate extraction, and perimeter gas wells through the landfill mass and surrounding the landfill; and performed monitoring and sampling of monitoring points.
  • Performed static and pseudo-static stability analyses of a 40-foot high refuse embankment and provided buttress design to increase embankment stability.
  • Performed an extensive investigation in a proposed expansion area and designed a composite base liner for the cell.
  • Investigated a non-permitted “white metals” disposal area. We provided CQA services during closure of the area.
  • Prepared workplans for closure of three other non-permitted disposal areas at the site.
  • Performed a supplemental investigation to fill the “data gaps” noted during review of hydrogeologic data. The supplemental investigation included large scale pump tests, a downhole geophysical survey of all monitoring wells on and surrounding the landfill, a geochemical study of the constituents found in each monitoring well, stereonet analysis of fracture orientation data, and computer analysis of piezometric levels in each well.
  • Developed a fracture controlled hydrogeologic model, based on the supplemental and existing data.
  • Developed project plans and specifications and provided CQA services during closure of two non-permitted waste cells and interim closure of the 90/91 Cell.