Shell Norco Chemical Plant West Site – Emissions Trend

This page assembles 5 consecutive years of EPA Toxics Release Inventory Form R filings for Shell Norco Chemical Plant West Site, spanning 2019–2023. Each annual total aggregates on-site air emissions, surface-water discharges, land disposal, and off-site transfers reported by the facility under EPCRA Section 313, which requires disclosure whenever a listed chemical is manufactured, processed, or otherwise used above threshold quantities.

Reported releases opened at 20.1K in 2019 and closed at 17.4K in 2023 – a decrease of 13.0% over the window. The chart below stacks the four TRI release media (air, water, land, off-site) and overlays the yearly total. The top contributor by cumulative mass is Benzene at 19.4K, followed by Toluene at 13.7K.

Because TRI figures are estimated, not metered, year-over-year deltas can reflect methodology revisions, ownership changes, or shifts in what a facility classifies as reportable, not only physical emission changes. Treat the trajectory as a disclosure record, and cross-reference with the EPA Enforcement and Compliance History Online (ECHO) system for the fuller regulatory picture on this chemicals facility.