The Atmospheric Release on January 5, 2001 from a Chemical Facility in Geismar, LA


This incident was initiated by a power outage within the facility that resulted in a loss of the instrument air supply for the plant. Loss of instrument air resulted in control valves defaulting to their failed (loss of power) positions. The power loss also resulted in the shutdown of the motor driven chlorine compressor and the loss of power to the instrumentation and control system for the facility.

The incident caused two atmospheric releases: 1) an emission of hydrogen chloride (HCl) at the Perchloroethylene Production Facility in the North section of the plant; and 2) an emission of chlorine gas (Cl2) at the Chlorine Production Facility in the South section of the plant. The locations of the releases are shown in the map (Figure 1).

EnviroComp's Role

We were retained by the attorneys representing the facility. Our work included accident reconstruction, characterization of the emission rates of HCl and Cl2 (e.g., intensity and duration), calculation of the main meteorological parameters affecting the release, use of the ALOHA model to simulate the concentration impact, and visualization of the results. We also examined and critiqued the work performed by the plaintiffs' experts.

Our simulation modeling results for Cl2 are presented in the figure below (Figure 2). Our simulations clearly show that the ground-level concentrations caused by both releases are below well-established levels of concern (ERPG) beyond the facility's property fence line.


Figure 1 Figure 2