Clean Air Mercury Rule

The Clean air Mercury Rule was signed on May 18, 2005.

  • It targets coal-fired electrical generating units larger than 25 MW.
  • It sets nation-wide caps: 38 tons/yr in 2010 (Phase I) and 15 tons/yr in 2018 (Phase II) and beyond (down from an estimated 48 tons in 1999.)
  • Each state has been allocated a cap total for each phase of the program.
  • Each state must demonstrate compliance each year with its caps. The model rule includes a market trading program which states may use, or they can establish emission limits to stay within the caps.
  • Phase I caps are based on existing control technology (for particulates, SO2, and NOX). Phase I also anticipates the further application of these types of controls to eastern sources that must comply with the Clean Air Interstate Rule (CAIR). Mercury reductions under Phase I are considered as a co-benefit of the CAIR program.
  • Even in Phase II, most of the actual reductions will occur in the East, where the coal that is burned is bituminous.
  • Utah’s allowances are: 0.506 tons/yr for Phase I and 0.200 tons/yr for Phase II. This compares with an estimate of 0.142 tons emitted in 1999. This implies that Utah will have a surplus of allowances.
  • Any additional generating capacity will have to fit within these caps.
  • The Ute Indian Tribe, which has jurisdiction over the Bonanza Power Plant, was allocated 0.060 tons/yr for Phase I and 0.024 tons/yr for Phase II (there was no estimate provided for 1999).
  • View a slide show overview (512 KB) of issues associated with mercury.
  • Get some general mercury information.

Public Interest Mercury

The Department of Environmental Quality is concerned about elevated levels of mercury in Utah, and has begun a program to control airborne mercury emissions.

In May of 2005, EPA issued a final rule, Clean Air Mercury Rule (CAMR), to address mercury emissions from coal-fired electric generating units larger than 25 megawatts. By initial estimates, air-born mercury emissions from this source category account for roughly 48% of all domestic mercury emissions. Other sources include gold mines, hazardous waste incinerators, medical waste incinerators, and salvage operations (mercury switches in cars).

Mercury Rules Adopted by Air Quality Board at its March 14, 2007 Meeting

On March 14, 2007, the Utah Air Quality Board adopted a Designated Facilities Plan to address Mercury Emissions at Coal-Fired Electric Generating Units (EGUs.) This Plan, in association with a number of other Rules adopted by the Board (R307- 210, 220, and 224), implements the federal Clean Air Mercury Rule (CAMR) for the State of Utah (excepting areas of Tribal jurisdiction.) Under the CAMR, Utah is allocated a mercury emission budget for each year beginning in 2010. In 2018, the budget changes from 0.506 to 0.200 tons per year. Compliance with these emission budgets will be demonstrated through a nation-wide Cap and Trade program administered by the EPA. In addition to the CAMR provisions, the Air Quality Board adopted a State-only rule (R307-424) that establishes minimum performance criteria for existing EGUs and requires that potential increases in mercury emissions from new or modified EGUs be offset (at a ratio of 1:1.1) by contemporaneous reductions of mercury emissions. These rules work together to set mercury emissions from EGUs in Utah on a downward trend.

Last Updated:


Back to top