Refineries handle large volumes of flammable and toxic materials in a small footprint, and the people downwind of them include the plant’s own workers, mutual aid crews and the surrounding community. When something releases, the first questions are always the same: where is it going, how far, and will that change in the next few minutes?
The hazards
- Toxic gas releases. OSHA lists oil and gas refining among the places hydrogen sulfide (H2S) is found. H2S is heavier than air, can travel along the ground and collects in low-lying areas. (OSHA)
- Releases during fires and explosions. At the Philadelphia Energy Solutions refinery on June 21, 2019, the U.S. Chemical Safety Board found that 5,239 pounds of highly toxic hydrofluoric acid were released, 3,271 pounds of it into the atmosphere. (CSB final report, 2022)
- Smoke from large fires. NOAA notes that ALOHA, the standard U.S. plume model, does not model smoke or other byproducts of combustion. (NOAA) For smoke, the wind field and forecasts are what tell you where it is heading.
Why the wind map matters at a refinery
A single weather station gives one wind speed and direction for the whole site. Inside a refinery the air does not behave that way: it speeds up, slows down and swirls around tanks, columns and buildings, and it bends with any hills, river valleys or bluffs nearby. The LR-x® 3D wind field model, based on U.S. Army Research Laboratory technology, accounts for terrain and structures and can show eddy currents that concentrate a plume around buildings. That helps pick safer approach routes, muster points and staging areas. How the 3D wind field model works.
What LR-x® adds to the emergency plan
- H2S and chlorine release modeling. LR-x® models hydrogen sulfide and chlorine releases with ALOHA, drawing color-coded threat zones from current weather. Changing weather is applied to the model automatically.
- Any chemical ALOHA can model. ALOHA’s chemical library covers over 500 pure chemicals and some common chemical solutions, a subset of NOAA’s CAMEO Chemicals database. (NOAA ALOHA Technical Documentation)
- Three additional forecasts, about every 2 minutes, so the team can see a wind shift coming instead of reacting to it.
- A fixed site configuration that runs the 3D wind field continuously (24/7) and can connect to fixed atmospheric sensors placed around the plant.
- Tier II data showing what nearby facilities report storing, with contacts, which matters when a release could reach a neighbor’s site.
- KML export. LR-x® exports the real-time plume model, the real-time 3D wind field model and the three forecast models as KML files you can use in ArcGIS, on top of your plot plans and pre-plan layers.
- What-if scenarios for drills and pre-planning, run against the site’s real terrain.
Who uses it
Refinery emergency response teams and safety staff, the local fire department and hazmat team that respond with them, mutual aid partners, and the Local Emergency Planning Committee (LEPC) that plans for the community around the plant. Under EPCRA, facilities submit their Tier II chemical inventories each year to the LEPC and the local fire department. (EPA)
See also: tank farms and terminals, chemical plants and all facility types.
Incidents described on this page are cited from public investigation reports. They are examples of the hazards these sites face, not LR-x® deployments.