Plumewatch is a computational implementation of established atmospheric dispersion principles. It estimates when chemical odors from wood treatment plants in Alexandria and Pineville, Louisiana may affect surrounding areas, using free weather data from the National Weather Service API.
Permit-Only Data Policy: To ensure regulatory transparency, this model operates under a strict permit-only data policy. All emission quantities and source types (fugitive vs. stack) are derived exclusively from the Louisiana Department of Environmental Quality (LDEQ) Electronic Document Management System (EDMS). Every forecast is directly traceable to authorized emissions listed in public regulatory filings.
How it works: The model employs a modified Gaussian plume framework that recalculates hourly based on real-time wind vectors from NWS, temperature inversion detection using the Brutsaert (1975) emissivity equation, and a solar-elevation-scaled heating model for surface volatilization rates.
Modeled Emission Sources:
Facility 1 — Alexandria (3600 Koppers Road) — LDEQ Permit #2360-00032-07. Treats railroad ties with creosote using 4 high-pressure cylinders at 140°F. Emits 18.67 tons/year of VOCs, dominated by 9.26 tons/year of naphthalene (7.41 tons from ground-level fugitive emissions alone). Also emits cresol (0.14 t/yr), quinoline (0.36 t/yr), PAHs (0.26 t/yr), and phenol (0.09 t/yr). Operates 24/7/365 with ~7-8 cylinder unloading events per day. Unloading events are modeled as a statistically distributed probability across operating hours, rather than real-time event tracking. Fugitive emissions are strongly temperature-dependent due to naphthalene's vapor pressure (roughly doubles every 15°F).
Facility 2 — Pineville (74 Wadley Street) — LDEQ Permit #2360-00004-07. Treats utility poles with creosote, pentachlorophenol (Penta), DCOI, and CCA using 3 treatment cylinders and 2 dry kilns. Emits 78.68 tons/year of VOCs — 4× more than Alexandria. The kilns dominate (61.68 t/yr), releasing acetaldehyde (2.10 t/yr), formaldehyde (0.86 t/yr), and methanol (0.82 t/yr) — compounds with distinct pungent/sharp odor profiles — from elevated stacks. Ground-level emissions include cresol (1.62 t/yr — 11× more than Alexandria), naphthalene (0.84 t/yr), and diesel vapors from the Penta/DCOI carrier solvent. Diesel is blended onsite with preservative concentrates before treatment. The facility stores over 103,000 gallons of creosote and 62,000 gallons of diesel in tank farms that exhibit diurnal breathing losses (vapor expansion) during afternoon warming. Operates 24/7/365. Sits on the Pineville bluff at 103 ft elevation — during calm, stable conditions, heavy compounds (diesel, cresol) are subject to downslope drainage flow into the valley below.
Temperature Inversions: Normally, air temperature decreases with altitude, allowing emissions to rise and disperse. During a temperature inversion, a warm air layer sits above cooler surface air, trapping emissions near the ground. This is detected through proxy signals: dewpoint-temperature convergence, overnight temperature trends, wind speed, and NWS forecast discussion analysis.
Terrain: The model incorporates local elevation data from USGS. The Alexandria facility sits at 72 ft in the Red River valley floor — one of the lowest points in the area where cold air and emissions pool. The Pineville plant sits 30 feet higher on the Pineville bluff at 103 ft. During calm winds and inversions, emissions from the elevated Pineville plant are subject to downslope drainage flow into the valley, while the Alexandria plant's emissions pool in place. The Red River valley also channels north-south airflow, concentrating odors along the valley axis.
Limitations & Conservative Bias: To maintain scientific integrity, the model intentionally excludes uncharacterized sources. While additional potential area sources may exist, only emissions documented in public LDEQ permit filings are included in the scoring algorithm. This ensures that every forecast is directly traceable to authorized emissions in public regulatory records.
Disclaimer: This is an experimental tool based on publicly available weather data and general atmospheric modeling principles. It does not measure actual air quality or emissions, and does not monitor regulatory compliance. It provides a statistical estimate of odor likelihood based on permitted emission limits and forecasted meteorological conditions. Actual conditions may differ from estimates. All facility data is sourced from public LDEQ permit records. This tool is not affiliated with any government agency or the wood treatment facilities.