Toxic air contaminants: monitoring | Colorado Department of Public Health and Environment

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On this page: Overview | Upcoming public participation opportunities | Phase 2 site selection (complete) | Phase 1 site selection (complete) | Contact us

Overview

The Air Pollution Control Division monitors toxic air contaminants as required by state law. The division has established seven air toxics monitoring sites across Colorado.

The division began operating the first three sites on January 1, 2024:

Grand Junction, Mesa County.
Commerce City, Adams County.
La Salle, Weld County.

The division began operating four more sites on July 1, 2025.

Pueblo, Pueblo County.
Colorado Springs, El Paso County.
Canon City, Fremont County.
Wheat Ridge, Jefferson County.

The division asked for input to help inform the location of all seven monitoring sites. The division selected monitoring site locations to cover both urban and rural areas, with priority to sites within disproportionately impacted communities. Findings from the sites can be found on the division’s online Air Toxics and Ozone Precursor Data Repository.

Learn more about air toxics

Upcoming public participation opportunities

Public meetings on air toxics monitoring report

The division held public meetings in July to review the first year of the state’s air toxics monitoring program. The division installed monitors at three new air monitoring sites around Colorado to gather air toxics measurements. The division shared preliminary results and trends observed from these new air monitoring sites during 2024. The division is seeking written comments on what questions the public would like the division to try to address when the division publishes the report in October 2025. The new monitors and annual reports are required under House Bill 22-1244: The Public Protections from Toxic Air Contaminants Act.