Project Summary

Clients: US Army Corp of Engineers
Contract Value: $75,000

The former Atlas D Missile Site 4 is a nationally recognized project being monitored by USACE Headquarters, Wyoming congressional representa-tives, and the Assistant Secretary of the Army. Activities at this former Department of Defense facility resulted in volatile organic compound (VOC) contamination in groundwater and soil vapor at the site and downgradient, where the contaminated groundwater has reached a well field that supplies drinking water to the City of Cheyenne., Wyoming.

LTM Tasks

  • Developed LTM program by collecting samples from existing wells and using the sample results, well locations, and well constructions details to select wells for the program
  • 125 wells were evaluated; 70 were selected for the LTM program, which began in 2010
  • Collect semi-annual groundwater sampling of LTM program wells
  • Validate the data to QA Level 4 to ensure they usable to meet the data quality objectives
  • Prepare LTM reports that summarize the analytical results and provide trend analyses, water-level maps, and other pertinent evaluations to assess changes in contaminant concentrations and locations
  • Based on the LTM results and other analyses, many additional wells have been installed at the site; many of these are nested—with three discrete intervals screened at one location
  • In fall 2016, xx well locations were sampled from 162 discrete depth intervals