Utah Administrative Code

The Utah Administrative Code is the body of all effective administrative rules as compiled and organized by the Division of Administrative Rules (see Subsection 63G-3-102(5); see also Sections 63G-3-701 and 702).

NOTE: For a list of rules that have been made effective since October 1, 2019, please see the codification segue page.

NOTE TO RULEFILING AGENCIES: Use the RTF version for submitting rule changes.

R307. Environmental Quality, Air Quality.

Rule R307-424. Permits: Mercury Requirements for Electric Generating Units.

As in effect on October 1, 2019

Table of Contents

R307-424-1. Purpose and Applicability.

The purpose of R307-424 is to regulate mercury emissions from any coal-fired electric generating unit (EGU). R307-424 applies to any coal-fired electric generating unit as defined in 40 CFR 60.24.

R307-424-2. Part 70 Permit.

Sources meeting the applicability requirements of R307-424-1 above, and also meeting the applicability requirements of R307-415-4, are required to obtain a mercury (Hg) budget permit in accordance with R307-224-2(1)(a).

R307-424-3. Offset Requirement: Mercury.

Sources meeting the applicability requirements of R307-424-1 above and making application for an approval order under R307-401 shall, in addition to any other requirement for obtaining such approval order, obtain an enforceable offset for any potential increase in mercury emissions in accordance with the following:

(1) The permitted increase in mercury emissions, considering the application of any control method or device, shall be offset by mercury emission credits at a ratio of 1 to 1.1 respectively.

(2) The averaging period for such determinations shall be a 12-month period.

(3) Mercury emission credits must be obtained from an EGU located within the State of Utah, excluding any EGU located on Indian lands within the State.

(4) To preserve reductions in mercury emissions as credits for use in offsetting potential increases, the director must identify such credits in an order issued pursuant to R307- 401 and shall provide a registry to identify the person, private entity or governmental authority that has the right to use or allocate the banked emission reduction credits, and to record any transfers of, or liens on, these rights.

(5) Any emission offsets shall be enforceable by the time a new or modified source commences construction, and, by the time a new or modified source commences operation, any emission offsets shall be in effect and enforceable.

(6) The quantity of mercury emission reductions to be used for credit will be determined in accordance with 40 CFR part 75, or will be based on the best available data reported to the director. To the extent that the EGU has been subject to the requirements of part 75, mercury emissions data shall be the average of the 3 highest annual amounts over the most recent 5-year period. Mercury emission reductions made prior to December 31, 1999 shall not be creditable for such purpose.

(7) R307-424-3 shall not apply to any EGU for which a valid approval order was issued prior to November 17, 2006.

R307-424-4. Emission Rates.

(1) By no later than December 31, 2012, the owner or operator of any EGU with an input heat capacity in excess of 1,500 MMbtu per hour and having commenced operations prior to November 17, 2006, shall demonstrate compliance with at least one of the following:

(a) A maximum emission rate of 6.50 X 10-7 pounds mercury per million btu heat input; or

(b) A minimum of 90% control of total mercury emissions.

(2) Compliance with (1) above shall be based on an annual averaging period beginning January 1 and ending December 31.

(a) Beginning January 1, 2013, compliance shall be determined using the monitoring and recordkeeping requirements incorporated under R307-224-2. Upon completion of each year's fourth quarterly report, an assessment shall be made for the entire calendar year and reported to the director within 30 days.

(b) Where it is necessary to determine the mercury content of the coal or coals burned, the owner or operator shall use the appropriate ASTM method, and shall measure at least one representative sample each month. Records of such testing shall be kept for a period of at least five years, and shall be made available to the director upon request.

(3) Should an EGU be unable to achieve the maximum emission rate or the minimum control efficiency described in (1) above, despite proper operation of the unit in conjunction with a baghouse as well as wet or dry flue gas de-sulfurization, the owner or operator may petition the director for a modification to the compliance limitation for the unit in accordance with R307-401.

(a) Such petition shall be received no later than the date upon which the compliance assessment required under (2)(a) above is due.

(b) Any such determination by the director will be made on a case-by-case basis, taking into consideration energy, environmental and economic impacts and other costs. It will be based on the best information and analytical techniques available.


air pollution, electric generating unit, mercury

Date of Enactment or Last Substantive Amendment

May 9, 2007

Notice of Continuation

May 15, 2017

Authorizing, Implemented, or Interpreted Law

19-2-101; 19-2-104(1)(a); 19-2-104(3)(e); 40 CFR 60.24

Additional Information


For questions regarding the content or application of rules under Title R307, please contact the promulgating agency (Environmental Quality, Air Quality). A list of agencies with links to their homepages is available at http://www.utah.gov/government/agencylist.html or from http://www.rules.utah.gov/contact/agencycontacts.htm.