# Title 33.1 — Department of Environmental Quality

## Article 33.1-15 — Air Pollution Control

## Chapter 33.1-15-02 — Ambient Air Quality Standards

### § 33.1-15-02-01. Scope.

The ambient air quality standards as presented in this chapter pertain to the ambient air within the
boundaries of North Dakota.
History: Effective January 1, 2019.
General Authority: NDCC 23.1-06-04; S.L. 2017, ch. 199, § 1
Law Implemented: NDCC 23.1-06-04; S.L. 2017, ch. 199, § 21
### § 33.1-15-02-02. Purpose.

It is the purpose of these air quality standards to set forth levels of air quality for the maintenance of
public health and welfare and to provide guidance to governmental and other parties interested in
abating air pollution. Since the ambient air in North Dakota is generally cleaner than these standards,
the standards are not a permit for the unnecessary degradation of air quality.
History: Effective January 1, 2019.
General Authority: NDCC 23.1-06-04; S.L. 2017, ch. 199, § 1
Law Implemented: NDCC 23.1-06-04; S.L. 2017, ch. 199, § 21
### § 33.1-15-02-03. Air quality guidelines.

In keeping with the purpose of these ambient air quality standards, the quality should be such that:
1. The public health will be protected including sensitive or susceptible segments of the
population.
2. Concentrations of pollutants will not cause public nuisance or annoyance.
3. Agricultural crops, animals, forest, and other plant life will be protected.
4. Visibility will be protected.
5. Metals or other materials will be protected from abnormal corrosion or damage.
6. Fabrics will not be soiled, deteriorated, or their colors affected.
7. Natural scenery will not be obscured.
History: Effective January 1, 2019.
General Authority: NDCC 23.1-06-04; S.L. 2017, ch. 199, § 1
Law Implemented: NDCC 23.1-06-04; S.L. 2017, ch. 199, § 21

### § 33.1-15-02-04. Ambient air quality standards.

1. Particulates and gases. The standards of ambient air quality listed in table 1 and table 2
define the limits of air contamination by particulates and gases. Any air contaminant which
exceeds these limits is hereby declared to be unacceptable and requires air pollution control
measures. The stated limits include normal background levels of particulates and gases.
2. Radioactive substances. The ambient air shall not contain any radioactive substances
exceeding the concentrations specified in article 33.1-10.
3. Other air contaminants. The ambient air shall not contain air contaminants in concentrations
that would be injurious to human health or well being or unreasonably interfere with the
enjoyment of property or that would injure plant or animal life. The department may establish,
on a case-by-case basis, specific limits of concentration for these contaminants.
History: Effective January 1, 2019.
General Authority: NDCC 23.1-06-04; S.L. 2017, ch. 199, § 1
Law Implemented: NDCC 23.1-06-04; S.L. 2017, ch. 199, § 21
### § 33.1-15-02-05. Methods of sampling and analysis.

Air contaminants listed under table 1 shall be measured by the method or methods listed in title 40
Code of Federal Regulations parts 50 and 53. Hydrogen sulfide sampling equipment and methods must
be approved by the department. Hydrogen sulfide analyzers must be designed for use as ambient air
quality monitors and must be capable of meeting performance specifications as determined by the
department.
The sampling and analytical procedures employed and the number, duration, and location of
samples to be taken to measure ambient levels of air contaminants shall be consistent with obtaining
results which are precise, accurate, and representative of the conditions being evaluated.
History: Effective January 1, 2019.
General Authority: NDCC 23.1-06-04; S.L. 2017, ch. 199, § 1
Law Implemented: NDCC 23.1-06-04; S.L. 2017, ch. 199, § 21
### § 33.1-15-02-06. Reference conditions.

The standards of ambient air quality listed in table 1 are corrected to a reference temperature of
twenty-five degrees Celsius [298 degrees Kelvin] and a reference pressure of seven hundred sixty
millimeters of mercury [101.3 kilopascals].
History: Effective January 1, 2019.
General Authority: NDCC 23.1-06-04; S.L. 2017, ch. 199, § 1
Law Implemented: NDCC 23.1-06-04; S.L. 2017, ch. 199, § 21
### § 33.1-15-02-07. Concentrations of air contaminants in the ambient air restricted.

1. No person may cause or permit the emission of contaminants to the ambient air from any
source in such a manner and amount that causes or contributes to a violation in the ambient
air of those standards stated in section 33.1-15-02-04.
2. Nothing in any other part or section of this article may in any manner be construed as
authorizing or legalizing the emission of air contaminants in such manner as prohibited in
subsection 1.
History: Effective January 1, 2019.
General Authority: NDCC 23.1-06-04; S.L. 2017, ch. 199, § 1

Law Implemented: NDCC 23.1-06-04; S.L. 2017, ch. 199, § 21

Table 1. AMBIENT AIR QUALITY STANDARDS
Standards
Air Contaminants (Maximum Permissible Concentrations)
Inhalable 150 micrograms per cubic meter, 24-hour average concentration. The
Particulates standard is attained when the expected number of days per calendar
PM year with a 24-hour average concentration above 150 micrograms per
cubic meter, as determined in accordance with 40 CFR 50, Appendix K,
is equal to or less than one.
PM 12.0 micrograms per cubic meter annual arithmetic mean concentration. The
2.5
standard is met when the 3-year average of the annual mean
concentration, as determined in accordance with 40 CFR 50,
Appendix N, is less than or equal to 12.0 micrograms per cubic meter.
35 micrograms per cubic meter 24-hour average concentration. The
standard is met when the 3-year average of the annual 98th percentile
24-hour concentration, as determined in accordance with 40 CFR 50,
Appendix N, is less than or equal to 35 micrograms per cubic meter.
Sulfur Dioxide 0.075 parts per million (196 micrograms per cubic meter) 1-hour average
concentration. The standard is met when the 3-year average of the
annual 99th percentile of the daily maximum 1-hour average
concentration is less than or equal to 0.075 parts per million, as
determined in accordance with 40 CFR 50, Appendix T.
0.5 parts per million (1,309 micrograms per cubic meter of air) maximum
3-hour concentration, not to be exceeded more than once per calendar
year.
Hydrogen 10.0 parts per million (14 milligrams per cubic meter of air), maximum
Sulfide instantaneous (ceiling) concentration not to be exceeded.
0.20 parts per million (280 micrograms per cubic meter of air), maximum
1-hour average concentration not to be exceeded more than once per
month.
0.10 parts per million (140 micrograms per cubic meter of air), maximum
24-hour average concentration not to be exceeded more than once per
year.
0.02 parts per million (28 micrograms per cubic meter of air), maximum
arithmetic mean concentration averaged over three consecutive
months.
Carbon 9 parts per million (10 milligrams per cubic meter of air), maximum 8-hour
Monoxide concentration not to be exceeded more than once per year.
35 parts per million (40 milligrams per cubic meter of air), maximum 1-hour
concentration not to be exceeded more than once per year.
Ozone 0.070 parts per million (137 micrograms per cubic meter of air) daily maximum
8-hour average concentration. The standard is met when the 3-year
average of the annual fourth-highest daily maximum 8-hour average
concentration at an ambient air quality monitoring site is less than or
equal to 0.070 ppm, as determined in accordance with 40 CFR 50,
Appendix P.
Nitrogen 0.053 parts per million (100 micrograms per cubic meter of air), maximum

Standards
Air Contaminants (Maximum Permissible Concentrations)
Dioxide annual arithmetic mean.
0.100 parts per million (188 micrograms per cubic meter) 1-hour average
concentration. The standard is met when the 3-year average of the
annual 98th percentile of the daily maximum 1-hour average
concentration is less than or equal to 0.100 parts per million, as
determined in accordance with 40 CFR 50, Appendix S.
Lead 0.15 micrograms per cubic meter of air, arithmetic mean averaged over a
3-month rolling period. The standard is met when the maximum
3-month mean concentration for a 3-year period, as determined in
accordance with 40 CFR 50, Appendix R, is less than or equal to
0.15 micrograms per cubic meter.
History: Effective January 1, 2019; amended effective July 1, 2020.

Table 2. NATIONAL AMBIENT AIR QUALITY STANDARDS
Standards
Air Contaminant (Maximum Permissible Concentrations)
Sulfur oxides 0.030 parts per million (80 micrograms per cubic meter of air) maximum
(sulfur dioxide) annual arithmetic mean concentration, not to be exceeded in a
calendar year.
0.14 parts per million (365 micrograms per cubic meter of air) maximum
24-hour concentration, not to be exceeded more than once per
calendar year.
The standards in Table 2 will remain in effect until one year after the effective date of the designation for
the one-hour sulfur dioxide standard pursuant to Section 107 of the Federal Clean Air Act except for
areas designated nonattainment with respect to the standards in Table 2 and areas not meeting the
requirements of a state implementation call with respect to requirements for the national ambient air
quality standards in Table 2. The standards in Table 2 will apply to those areas until that area submits,
and the environmental protection agency approves, an implementation plan providing for attainment of
the one-hour sulfur dioxide standard.
History: Effective January 1, 2019.
