DEPARTMENT OF NATURAL RESOURCES AND ENVIRONMENTAL CONTROL
Division of Air and Waste Management
Air Quality Management Section
Secretary’s Order No.: 2003-A-003
RE: Proposed AQM Amendments:
Regulation 3, Section 11: PM10 and PM2.5 Particulates
Date of Issuance: January 13, 2003
Effective Date of the Amendment: February 11, 2003
I. Background
On Tuesday, November 26, 2002, a public hearing was held in the Priscilla Building Conference Room of DNREC, 156 S. State Street, Dover to receive comment on proposed amendments to Regulation 3, Section 11 – PM10 and PM2.5 Particulates of the Delaware Regulations Governing the Control of Air Pollution. With respect to Delaware’s Air Quality Standards referenced in this particular Regulation, the Department proposes to revise the same by reverting them back to their pre-November 1999 form. This action is necessary in response to the March 26, 2002 Court of Appeals decisions that vacated EPA’s standards that were set forth in the 62 FR 38711, dated July 18, 1997. That decision resulted in the standard contained in DNREC’s November 3, 1999 State Implementation Plan (SIP) submittal being less restrictive than the current PM10 National Ambient Air Quality Standards (NAAQS). As a result, EPA cannot approve Delaware’s SIP revision containing a less restrictive PM10 NAAQS standard than the 1987 standard. The impacts of proposed amendments are minimal. Further, the proposed changes will not change the annual and 24-hour average concentration standards of 50 g/m3 and 150 g/m3, respectively. The changes are primarily a technical, procedural change in the Department’s methodology of determining concentrations from monitored data.
With respect to comments received by the Department concerning this proposed amendment, there was written correspondence received from Judith M. Katz, Director, Air Protection Division, at Region III of the EPA, confirming that EPA cannot process a SIP revision which contains a less restrictive PM10 standard than the 1987 standard. Proper notice of the hearing was provided as required by law.
After the hearing, the Department performed an evaluation of the evidence entered into the record in this matter. Thereafter, the Hearing Officer prepared his report and recommendation in the form of a Hearing Officer’s Report to the Secretary dated January 8, 2003, and that memorandum is expressly incorporated herein by reference.
II. Findings and Conclusions
On the basis of the record developed in this matter, it appears that AQM has provided a sound basis for the proposed amendments to Regulation No. 3, Section 11.
III. Order
It is hereby ordered that the proposed amendments to Regulation No. 3, Section 11, be promulgated in final form in accordance with the customary statutory procedure.
Reasons
The amendment of Regulation 3, Section 11, which reverts these specific Air Quality Standards back to their pre-November 1999 form, will aid the State of Delaware in regaining approval from the EPA with respect to its SIP revision. Additionally, these amendments will assist the Department in furtherance of the policy and purposes of 7 Del. C., Ch. 60.
John A. Hughes, Secretary
REGULATION NO. 3
AMBIENT AIR QUALITY STANDARDS
09/11/99
Section 1 - General Provisions
1.1 Air Quality Standards are required to assure that ambient air quality shall be consistent with established criteria and shall serve to effectively and reasonably manage the air resources of the State of Delaware.
1.2 At such time as additional pertinent information becomes available with respect to applicable air quality criteria, recommendations shall be incorporated and the air quality standards shall be subject to revisions.
1.3 The absence of a specific ambient air quality standard shall not preclude actions by the Department to control contaminants to assure protection, safety, welfare, and comfort of the people of the State of Delaware.
1.4 Air Quality Standards are defined by frequency distribution presentations and arithmetic averages. The characteristic parameters describing the frequency distribution are the geometric mean and 99th percentile.
a. The geometric mean is defined as the Nth root of the product of N numbers. Assuming a log-normal cumulative frequency distribution, the 50th percentile value will be equal to the geometric mean.
b. The arithmetic average (mean is defined as the sum of a set of values divided by the number of values.
c. The 99th percentile for a group of numbers is defined as that value which is exceeded by one percent of the numbers.
1.5 The ambient air quality values stated herein shall apply to all areas outside a source property line.
1.6 The sampling and analytical procedures and techniques employed to determine ambient air concentrations of contaminants shall be consistent with methods which result in a representative evaluation of the prevailing conditions. The following methods shall be used directly or employed as reference standards against which other methods may be calibrated;
a. Ambient concentrations of total suspended particulates shall be determined by the reference high volume method in accordance with 40 CFR, Part 50, Appendix B, June 29, 1979.
b. Ambient concentrations of sulfur dioxide shall be determined by the reference or equivalent method in accordance with 40 CFR, Part 50, Appendix A, June 29, 1979.
c. Ambient concentrations of carbon monoxide shall be determined by the reference method in accordance with 40 CFR, Part 50, Appendix C, June 29, 1979.
d. Ambient concentrations of ozone corrected for interferences due to nitrogen oxides and sulfur dioxide shall be determined by the reference method in accordance with 40 CFR, Part 50, Appendix D, June 29, 1979.
e. Ambient concentrations of methane and non-methane hydrocarbons shall be determined by the reference method in accordance with 40 CFR, Part 50, Appendix E, June 29, 1979.
f. Ambient concentrations of nitrogen dioxide shall be determined by the reference method in accordance with 40 CFR, Part 50, Appendix F, June 29, 1979.
g. Ambient concentrations of hydrogen sulfide shall be determined by gas chromatographic separation - flame photometric detection.
h. Ambient concentrations of lead shall be determined by the reference method in accordance with 40 CFR, Part 50, Appendix G, June 29, 1979.
i. Ambient concentrations of PM10 particulate shall be determined by a reference method in accordance with 40 CFR, Part 50, Appendix J, or an equivalent method.
j. Ambient concentrations of PM2.5 particulate shall be determined by the reference method based on 40 CFR, Part 50, Appendix L, as found in the Federal Register dated July 18, 1997, on page 38714 – 38752.
1.7 Air quality standards are expressed in metric units with the approximate equivalent volumetric units in parentheses. The standard conditions for air ambient monitoring is 760 mm. Hg and 25oC. The formula to convert metric units to parts per million (ppm) is:
ppm (vol) = Fg/m3 X .024465 or mg/m3 X 24.465 X 10-6
----------------- ---------------------
MW MW
MW is molecular weight of the contaminant being measured.
02/01/81
Section 2 - General Restrictions
2.1 No person shall cause the Air Quality Standards specified in this Regulation to be exceeded.
02/01/81
Section 3 - Suspended Particulates
3.1 The Primary Ambient Air Quality Standards for Particulate Matter are:
a. An annual geometric mean of 75 micrograms per cubic meter not to be exceeded, based upon twenty-four hour average concentrations.
b. A value of 260 micrograms per cubic meter not to be exceeded more than once per year, based upon twenty-four hour average concentrations.
3.2 The Secondary Ambient Air Quality Standards for Particulate Matter are:
a. An annual geometric mean of 60 micrograms per cubic meter as a guideline for achieving the secondary standard based upon twenty- four hour average concentrations.
b. A value of 150 micrograms per cubic meter not to be exceeded more than once per year, based upon twenty-four hour average concentrations.
02/01/81
Section 4 - Sulfur Dioxide
4.1 The Primary Ambient Air Quality Standards for Sulfur Oxides measured as Sulfur Dioxide are as follows:
a. An annual arithmetic average value of 80 Fg/m3, (0.03 ppm) not to be exceeded, based upon twenty-four hour average concentrations.
b. A twenty-four average value of 365 Fg/m3 (0.14 ppm) not to be exceeded more than once per year based upon twenty-four hour average concentrations.
4.2 The Secondary Ambient Air Quality Standards for Sulfur Oxides measured as Sulfur Dioxide are as follows:
a. A three-hour average value of 1300 micrograms per cubic meter (0.5 ppm), not to be exceeded more than once per year.
02/01/81
Section 5 - Carbon Monoxide
5.1 The average concentration of carbon monoxide taken over any consecutive eight (8) hours shall not exceed a value of 10 milligrams per cubic meter (9 ppm) more than once per year.
5.2 The average concentration of carbon monoxide taken over any one (1) hour period shall not exceed 40 milligrams per cubic meter (35 ppm) more than once per year.
09/11/99
Section 6 - Ozone
6.1 1-hour primary and secondary ambient air quality standards for ozone
The average number of days per calendar year with a maximum one hour average value exceeding 235 Fg/m3 (0.12 ppm) shall be equal to or less than one, averaged over three consecutive years. This standard shall be applicable to New Castle and Kent Counties.
6.2 8-hour primary and secondary ambient air quality standards for ozone
The average of the fourth highest daily maximum 8-hour average ozone concentration is less than or equal to 0.08 ppm, averaged over three consecutive years. This standard applies to all Counties in Delaware.
02/01/81
Section 7 - Hydrocarbons
7.1 The hydrocarbons standard in subsection 7.2 is for use as a guide in devising implementation plans to achieve the ozone standard.
7.2 The average concentration of hydrocarbons, exclusive of methane, taken over a three (3) hour period from 6:00 to 9:00 a.m., local time, shall not exceed 160 micrograms per cubic meter (0.24 ppm) more than once per year.
02/01/81
Section 8 - Nitrogen Dioxide
8.1 The annual arithmetic mean concentration of nitrogen dioxide shall not exceed 100 micrograms per cubic meter (0.05 ppm).
02/01/81
Section 9 - Hydrogen Sulfide
9.1 The average concentration of hydrogen sulfide taken over any consecutive three (3) minutes shall not exceed 0.06 ppm.
9.2 The average concentration of hydrogen sulfide taken over any consecutive 60 minutes shall not exceed 0.03 ppm.
02/01/81
Section 10 - Lead
10.1 The 24 hour concentration of lead averaged over a calendar quarter shall not exceed 1.5 micrograms per cubic meter.
09/11/99
Section 11 - PM10 and PM2.5 Particulates
The Primary and Secondary Ambient Air Quality Standards for Particulate Matter, measured as PM10 are:
150 micrograms per cubic meter (Fg/m3), 24 hour average concentration. The standards are attained when the 99th percentile 24-hour concentration, as determined in accordance with 40 CFR, Part 50, Appendix N, as found in the Federal Register dated July 18, 1997, on page 38759, is less than or equal to 150 micrograms per cubic meter (Fg/m3) expected number of days per calendar year with a 24-hour average concentration above 150 Fg/m3, as determined in accordance with 40 CFR, Part 50, Appendix K, is equal to or less than one.
50 micrograms per cubic meter (Fg/m3), annual arithmetic mean. The standards are attained when the expected annual arithmetic mean concentration, as determined in accordance with 40 CFR, Part 50, Appendix KN, as found in the Federal Register dated July 18, 1997, on page 38759, is less than or equal to 50 Fg/m3.
11.2 The Primary and Secondary Ambient Air Quality Standards for Particulate Matter, measured as PM2.5 are:
65 micrograms per cubic meter (Fg/m3) 24-hour average concentration. The 24-hour primary and secondary PM2.5 standards are met when the 98th percentile 24-hour concentration, as determined in accordance with 40 CFR, Part 50, Appendix N, as found in the Federal Register dated July 18, 1997, on page 38757 - 38758, is less than or equal to 65 Fg/m3
15.0 micrograms per cubic meter (Fg/m3) annual arithmetic mean concentration. The annual primary and secondary PM2.5 standards are met when the annual arithmetic mean concentration, as determined in accordance with 40 CFR, Part 50, Appendix N, as found in the Federal Register dated July 18, 1997, on page 38756 - 38757, is less than or equal to 15.0 Fg/m3