DEPARTMENT OF PUBLIC HEALTH AND ENVIRONMENT
Air Quality Control Commission
REGULATION NUMBER 8
CONTROL OF HAZARDOUS AIR POLLUTANTS
5 CCR 1001-10
PART C.
Colorado State Standards for Hazardous Pollutants
I.
Repealed
II.
Statements of Basis, Specific Statutory Authority and Purpose for Part C
II.A.
August 21, 1997
This Statement of Basis, Specific Statutory Authority and Purpose complies with the requirements
of the Colorado Administrative Procedures Act, section 24-4-103, C.R.S.
Basis
This Commission action repeals Regulation No. 8, Part C, section II, [5 CCR 1001-10 (1997)],
which set forth an emissions standard and emission testing requirement for all stationary sources
of hydrogen sulfide.
Specific Statutory Authority
The Commission adopts these regulation revisions under its general authority found in section
25-7-105(1), C.R.S. and under the specific authority of sections 25-7-106(l)(c), and 25-7-109(1)
and (2), C.R.S.
Purpose
Regulation No. 8, Part C, section II imposed an emission standard on all stationary sources of
hydrogen sulfide. The Commission initially adopted this rule in September 1978 and later
amended it in May 1994. Subsequently, the Colorado General Assembly enacted changes to
section 25-7-103(11), C.R.S. (1996 Supp.). These changes prohibited emission control
regulations that “include standards that describe maximum ambient air concentrations of
specifically identified air pollutants....”
The existing rule barred emissions of hydrogen sulfide into the ambient air that would cause the
one-hour average ambient air concentrations of hydrogen sulfide to exceed 142 micrograms per
standard cubic meter (0.10 ppm). The Commission concludes that this existing rule is
inconsistent with the legislative intent expressed in the 1995 statutory changes, and perhaps
unenforceable. Accordingly, the Commission in this rulemaking deletes the existing rule in its
entirety. The Commission did not include the existing rule as part of the state implementation
plan, so this action is not a revision of that plan.
The Commission anticipates that the Division and interested parties will continue to work together
to evaluate the need for regulation of hydrogen sulfide and the appropriate regulatory mechanism
if such need exists.
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II.B.
Lead Emission Standard Removal
Adopted:
March 18, 2010
The Commission intends to maintain and update its Regulation Number 8, Part C.
Statutory Authority
This Statement of Basis, Specific Statutory Authority and Purpose complies with the requirements
of the Colorado Administrative Procedures Act, C.R.S. Section 24-4-103, and the Colorado Air
Pollution Prevention and Control Act, C.R.S. Sections 25-7-109, 110, 110.5 and 110.8.
Specifically, C.R.S. Sections 25-7-109(1),(2)(h) and (4), authorize the Commission to adopt,
promulgate, and from time to time modify or repeal emission control regulations requiring
effective practical air pollution controls for hazardous air pollutants, including lead, as well as
broader, general authority to adopt regulations pertaining to hazardous air pollutants.
Basis
Colorado’s Regulation Number 8, Part C includes an outdated lead emission standard. In 2008,
EPA promulgated a more stringent lead NAAQS. The following table compares Regulation
Number 8, Part C’s lead emission standard to the lead NAAQS.
Old Lead (Pb) NAAQS
Reg 8, Part C
Current Pb NAAQS
Pb Emission Standard
1.5 ug/m3 – quarterly avg.
1.5 ug/m3 – monthly avg.
0.15 ug/m3
monthly avg.
–
rolling
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While the numerical lead standard was intentionally duplicative of the old lead NAAQS codified in
Title 40 CFR Part 50, the averaging period used to demonstrate attainment differed (see above
table).The difference in averaging periods (one month compared to 3 months) is insignificant
compared to the difference in order of magnitude in numerical standards. Thus, the new lead
NAAQS is considered more stringent and thus more protective than the state-only standard.
Subject sources are required to model compliance with the Regulation Number 8, Part C’s lead
emissions standard and the lead NAAQS in order to demonstrate compliance with both.
Purpose
The Commission intends to remove the Regulation Number 8, Part C lead emission standard and
compliance demonstration requirement to eliminate duplicative and inconsistent lead standards,
due to the recent promulgation of a new lead NAAQS (discussed above).
In addition, subsequent to the promulgation of the lead emission standard and compliance
demonstration in Regulation Number 8, Part C, the law changed. The Colorado General
Assembly enacted changes to Section 25-7-103(11), C.R.S. (1996 Supp.). These changes
prohibited emission control regulations that “include standards that describe maximum ambient
air concentrations of specifically identified air pollutants....”
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This removal ensures compliance with the Legislature’s directive to avoid emission control
regulations with maximum ambient air concentrations for any specifically identified air pollutant.
The Commission did not include the existing rule as part of the state implementation plan, so this
action is not a revision of that plan.
Findings pursuant to C.R.S. Sections 110.5(5)(a) and 110.8
The purpose of these revisions is to ensure consistency with EPA’s adoption of a more stringent
lead standard. Therefore, these revisions do not exceed or differ from the federal act or rules.
These revisions are not intended to reduce air pollution and do not result in a demonstrable
reduction in air pollution; prior to this rulemaking, lead sources were required to comply with the
federal lead standard so there is no effect on air pollution. Public health and the environment are
sufficiently protected by the lead NAAQS. These revisions benefit the regulated community and
the public by eliminating confusion caused by differences between state and federal
requirements.
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