PHYSICOCHEMICAL PARAMETERS FOR CHEMICALS ASSOCIATED WITH FATE AND TRANSPORT OF MUNITIONS

The US Army Environmental Center (USAEC) has developed a test program to identify and quantify the emissions that result from weapons firing and from the use of pyrotechnic devices. The test program is divided into three distinct areas: characterization of smoke and pyrotechnic emissions, a firing point emission study, and an exploding ordnance emission study. One of tasks associated with this program is to develop a database of physicochemical parameters for chemicals listed by USAEC.

The objective of this task is to define the physical/chemical properties required for fate and transport modeling of chemicals typically associated with munitions and their respective emissions. The U.S. Army Engineer Research and Development Center (ERDC) is gathering such data on chemicals identified by USAEC and seeking to fill data gaps.

The physicochemical parameters of chemicals listed obtained from a variety of sources (literature and other data bases). For those chemicals lacking sufficient parameters information, the physicochemical parameters may be obtained from other sources such as the Environmental Protection Agency's ASTER (Assessment Tools for the Evaluation of Risk) program.

For each chemical, major parameters that effect fate/transport of chemical in the environment will be gathered and added to the database. Other parameters may be required depending on the details of the reaction pathways considered, e.g., whether oxidation, photolysis, and biodegradation are explicitly considered as reaction paths rather than lumped decay (from half life). Additionally, for explosives-related compounds, decay in soil and groundwater is dependent on local conditions (e.g., redox). However, for many military unique or relevant compounds, process information in this detail will not be available, thus, lumped process decay will usually be the approach. If specific process rate information is available, then it will be included.

This presentation will describe the data requirement for fate and transport simulations of munitions compounds. The available sources of physicochemical data will be described. The data gaps and step-by-step data analysis and estimation techniques for the missing parameters for selected chemicals will be explained and illustrated.