U.S. Army Corps of Engineers | Engineer Research and Development Center | Environmental Laboratory
INTRODUCTION
The Training Range Environmental Evaluation and Characterization System (TREECS) has been developed for the Army with varying levels of capability to forecast the fate of munitions constituents (MC), such as high explosives (HE), perchlorate, and heavy metals, within and transported from firing/training ranges to surface water and groundwater. The overall objective was to provide the range manager with tools to assess whether MC concentrations in receiving media (surface water, sediment, and groundwater) will exceed protective health benchmark concentrations. Additionally, the tools can help with range management strategies to avoid exceeding protective benchmarks. Currently TREECS has two tiers for assessments. Tier 1 consists of screening-level methods that require minimal data input requirements and can be easily and quickly applied by range managers or their local environmental staff to assess receiving media concentrations. Surface water and/or groundwater MC concentrations exceeding protective health benchmarks at receptor locations would constitute further study and possibly corrective actions. Assumptions, such as steady-state conditions, are assumed to provide conservative or worst case estimates under Tier 1. If a Tier 1 analysis indicates that protective benchmarks could be exceeded, then there would be cause to proceed to Tier 2 to obtain a more definitive assessment.
Although Tier 2 assessment methods require more detailed site data and more knowledge and skill to apply, they can be applied by local environmental staff that have a cursory understanding of multi-media fate and transport modeling. The Tier 2 approach allows for time-varying analyses. A time-varying analysis should provide more accurate predictions with generally lower concentrations due to mediating effects of transport phasing and dampening. Tiers 1 and 2 focus on contaminant stressors and human and ecological health end-point metrics.
OBJECTIVE
The objective was to develop a client-based, modeling, data delivery, and analysis system that integrates range munitions usage with multimedia and multi-pathway fate/transport modeling to forecast range soil MC concentrations and MC mass export to off-range surface water and groundwater, as well as MC concentrations in surface water, sediment, and groundwater at potential receptor locations. The system was specifically developed to support the Army’s Operational Range Assessment Program (ORAP) Phase II. However, the system can also be used on other sites where MC migration is of concern, as well as for evaluating range use management alternatives to reduce future MC concentrations in receiving media.
APPROACH
The general approach in developing the TREECS system has been to analyze and incorporate existing tools whenever possible for use in training range environmental risk evaluation. In addition, TREECS develops innovative adaptations of those tools and new tools that are appropriate and which can be easily applied to assess ranges. Assumptions were required in order to reduce and constrain the problem set to something that can be easily and quickly modeled and evaluated with limited data and effort, while providing a conservative estimate. The system has been developed for Windows PC client application with an emphasis on a minimal amount of user input while maximizing the user's ability to quantify risks associated with MC. GIS tools have been incorporated into the system in order to provide the user with the ability to use detailed spatial information to characterize the site for input data required for their analyses. Linkages to chemical constituent databases and a protective health benchmark database are included to provide information required to conduct an analysis.