ONTARIO SMOG
MICHAEL NEAL
31 credentialed testers in Ontario.
MICHAEL NEAL
Paolo Estrada
Paul Rothwell
Phill Backstrom
Ralph Glass
rosendo quezada
todd wells
Vernon Donahe
Clean Truck Check applies to heavy-duty vehicles that operate in California — including out-of-state trucks based here that run loads west.
Source: FMCSA MCMIS carrier census, US Census County Business Patterns 2021.
OpenStreetMap-tagged truck stops, services areas, and HGV-marked fuel stations within 25 miles of Ontario. Useful for routing a service stop around your CTC test.
+6 more within 25 miles.
Source: © OpenStreetMap contributors. Last updated 2026-05-18.
Annual aggregate readings from EPA Air Quality System monitors within about 25 miles of Ontario, reporting year 2025. Clean Truck Check exists to reduce real-world emissions from heavy-duty vehicles — the numbers below are the local baseline those rules are designed to improve.
Source: EPA Air Quality System (AQS) API. Reporting year 2025. Last fetched 2026-05-18.