Background
Colorado’s Environmental Justice Act directs the Air Quality Control Commission to impose enhanced modeling and monitoring requirements for new and modified sources of affected pollutants in disproportionately impacted communities. In 2023, the Commission revised Regulation 3 to create two monitoring pathways for those communities.
Sources in cumulatively impacted communities scoring above the eightieth risk percentile under Colorado EnviroScreen must conduct source-specific monitoring. Sources in other disproportionately impacted, socioeconomically vulnerable communities instead pay a one-time fee to fund Division-administered community monitoring. GreenLatinos, 350 Colorado, and Earthworks challenged the rule, and the district court upheld it.
The Court’s Holding
The court of appeals affirmed. It held that the statute’s undefined requirement for “enhanced” monitoring did not require every source in a disproportionately impacted community to conduct onsite, source-specific monitoring. The Commission reasonably concluded that the revised rule heightened monitoring requirements beyond prior practice and had discretion to use a fee-funded community-monitoring program for some sources.
The court also found a reasonable record basis for using EnviroScreen and the eightieth-percentile threshold to prioritize communities with greater cumulative burdens. Finally, it held that the Environmental Justice Act did not require the Commission to identify hazardous air pollutants beyond benzene, toluene, ethylbenzene, and xylene; identifying additional pollutants was discretionary.
Key Takeaways
- “Enhanced monitoring” under the Environmental Justice Act does not compel source-specific monitoring for every source in a disproportionately impacted community.
- The Commission may use collected fees for Division-administered community monitoring rather than require each covered source to operate monitors.
- The Commission reasonably relied on EnviroScreen and an eightieth-percentile threshold to tailor monitoring obligations.
Why It Matters
The decision gives the Commission substantial latitude to implement Colorado’s environmental-justice air-permitting requirements through tiered monitoring programs. It also confirms that courts will defer to a reasonable agency policy choice supported by a discernible rationale in the rulemaking record.