Anaconda, Montana

WET developed and implemented a stormwater collection and sampling project for the Anaconda-Deer Lodge County municipal stormwater system. The objective was to collect stormwater samples in the existing infrastructure during storm events at the ARWW&S OU. The primary purpose of this sampling effort was to meet the requirements of the ARWW&S OU Record of Decision (ROD) elements (EPA 1998).

WET was tasked with measuring the quantity and quality of stormwater runoff from representative areas of concern in the OU where stormwater may be impacted by metals contaminated runoff. Baseline data were collected for use in the stormwater monitoring program to be implemented following completion of the remedy.

The specific field investigation activities to address the above objectives included:

  • Surface water sampling of main stem and tributary streams and drainages during storm events using automated devices
  • Automated sampling of stormwater within the municipal storm water system
  • Manual sampling and field parameter measurement of stormwater runoff on an opportunistic basis during or following storm events
  • Measurement of stream discharge through direct and indirect methods
  • Collection of concurrent precipitation data

The goal of this investigation was to collect screening and enforcement quality data for use in the remedial design for the ARWW&S OU. Specifically, the data collected during this investigation provided the information required for completing the surface water remedial design component for remedial design units (RDUs) where runoff may impact surface water. The data collected during this investigation was also utilized in the development of a performance monitoring program for the forthcoming ARWW&S OU Monitoring and Maintenance Plan.