Greenhouse Gas Emissions and Energy Management for Manufacturing in Colorado (GEMM 1)

The GEMM 1 rule requires facilities to conduct an energy and greenhouse gas emissions audit that will assess ways to reduce greenhouse gas emissions and save energy. The Air Pollution Control Division must approve plans for the audit, including who will do the audit and what it will cover.

GEMM 1 facilities were required to submit a Greenhouse Gas Best Available Emissions Control Technology and Energy Best Management Practices Audit Plan by December 31, 2022 to the Air Pollution Control division for review. Each plan was developed by a third-party auditor who met division guidance for auditor selection. Audits must be done by a professional who does not work at the facility.

The audit plans must describe:

• Which greenhouse gas emitting equipment would be audited.
• Who would be on the audit team.

Audits are required to:

• Use the federal Interagency Working Group’s “social cost” of greenhouse gases available at the time of the audit to consider economic impacts.
  • The social cost of greenhouse gases is an estimate, in dollars, of the economic impacts that come from releasing one ton of greenhouse gases in a given year.
• Include ways for facilities to reduce air pollution in nearby communities.
• Cover which control measures are possible, how much they will cost, and what the energy, environmental, and economic impacts would be.

After the 2022 audits were completed, the facilities submitted an Audit Report to the division for review. The division reviewed the plans and issued determinations in 2023. These determinations indicate each source's compliance status. The Colorado Air Quality Control Commission approved those determinations in summer 2023. 

• Based on the GEMM 1 rule, if a facility’s audit were to show it was not using the best controls to save energy and reduce greenhouse gas emissions, the facility must:
  • Reduce the same amount of emissions that those best controls would achieve, and reduce an additional 5% in total greenhouse gas emissions.
• If the audit showed a facility was already using the best controls, the facility is still required to reduce greenhouse gas emissions by an additional 5%.
• The division provided each facility a greenhouse gas emissions limit. The facility must stay below that limit each year through one or more of the following actions:
  • Reducing greenhouse gas emissions directly at the facility.
  • Installing an onsite renewable energy project that reduces the greenhouse gas emissions from the facility’s energy use.
  • Providing proof of greenhouse gas credits awarded by the division.

Facilities must send a compliance action plan to the division within 120 days of the Commission’s approval, stating:

• The timeline and actions that will be used to meet the annual emissions limit.
• How the facility will improve air quality for nearby communities, as recommended in the audit.
• Starting in 2025, each facility must show the division how it will meet the 5% reduction requirement for that year. 

• GCC Rio Grande
• EVRAZ
• CEMEX
• Holcim
• Past Determination Public Meeting Recordings

All rulemaking documents are available online. The final rule is available online (see Regulation Number 27).