NEBRASKA ADMINISTRATIVE CODE

Title 129 - Department of Environmental Quality

Chapter 4 - AMBIENT AIR QUALITY STANDARDS

4-1 The following ambient air quality standards ar e applicable in the State of Nebraska:

001 Particulate Matter

001.01 PM 10 – Primary and secondary standards

Level: 150 micrograms per cubic meter Averaging time: 24-hours Form: Not to be exceeded more t han once per year on average over 3 years

(Attainment of these standards is determined in accordance with Appendix K of 40 CFR Part 50 (versi on July 1, 2012); which is adopted and incorporated herein)

001.02 PM 2.5 – Primary and secondary standards

Level: 15.0 micrograms per cubic meter Averaging time: Annual Form: Annual mean averaged over 3 years

Level: 35 micrograms per cubic meter Averaging time: 24-hour Form: 98th percentile averaged over 3 years

(Attainment of these standards is determined in accordance with Appendix N of 40 CFR Pa rt 50 (version July 1, 2012); which is adopted and incorporated herein)

002 Sulfur dioxide

002.01 Primary standard

Level: 75 parts per billion Averaging time: 1-hour Form: 99 th percentile of 1-hour daily ma ximum concentrations averaged over 3 yearsTitle 129

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4-2 002.02 Secondary standard

Level: 0.5 parts per million Averaging time: 3-hours Form: Not to be exceeded more than once a year

(Attainment of this standard is det ermined in accordance with Appendix T of 40 CFR Part 50 (version July 1, 2012); which is adopted and incorporated herein)

003 Nitrogen dioxide

003.01 Primary standard

Level: 100 parts per billion Averaging time: 1-hour Form: 98 th percentile aver aged over 3 years

003.02 Primary and secondary standards

Level: 53 parts per billion Averaging time: Annual Form: Annual mean

(Attainment of this standard is dete rmined in accordance with Appendix S of 40 CFR Part 50 (version July 1, 2012); which is adopted and incorporated herein)

004 Carbon monoxide – Primary standards

Level: 9 parts per million Averaging time: 8-hours Form: Not to be exceeded more than once per year

Level: 35 parts per million Averaging time: 1-hour Form: Not to be exceeded more than once per year

(Attainment of this standard is det ermined in accordance with 40 CFR 50.8. (version July 1, 2012); whic h is adopted and incorporated herein)

005 Ozone – Primary and secondary standardsTitle 129

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4-3 Level (1997 standard): 0. 08 parts per million (0.08 ppm) Averaging time: 8-hour Form: Annual fourth-highest da ily maximum 8-hour concentration averaged over 3 years

(Attainment of this standard is dete rmined in accordance with Appendix I of 40 CFR Part 50 (Version July 1, 2012); which is adopted and incorporated herein)

Level (2008 standard): 0.075 par ts per million (0.075 ppm) Averaging time: 8-hour Form: Annual fourth-highest dai ly maximum 8-hour concentration averaged over 3 years

(Attainment of this standard is dete rmined in accordance with Appendix P of 40 CFR Part 50 (Version July 1, 2012); which is adopted and incorporated herein)

006 Lead – Primary and secondary standard

Level: 0.15 micrograms per cubic meter Averaging time: Rolling three-month average Form: Not to be exceeded

(Attainment of this standard is dete rmined in accordance with Appendix R of 40 CFR Part 50 (Version July 1, 2012); which is adopted and incorporated herein)

007 Total reduced sulfur

Level: 10.0 parts per million (10.0 ppm) Averaging time: 1 minute Form: Maximum average concentration

Level: 0.10 parts per million (0.10 ppm) Averaging time: 30-minutes Form: Maximum rolling average

007.01 Except as provided in 007.01A and 007.01B these standards apply only where human exposure occurs.

007.01A Ambient concentrati ons of total reduced su lfur (TRS) emissions occurring as a result of natural activi ties that have no associated economic benefits, such as seasonal stratification or turnover of lakes and lagoons, and the release of water uncontaminated by process or industrial activity fromTitle 129

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4-4 lakes, reservoirs, lagoons and water impoundment systems shall not constitute violation of the st andards contained in section 007.

007.01B The Department shall provi de reasonable opportunity for any owner or operator of any source causing or contributing to a violation of the standards in 007 to develop and implement a program to eliminate such violations prior to ta king enforcement action.

007.02 Unless otherwise approved by the Director, the levels of TRS in the ambient air shall be measured using a TRS thermal converter in conjunction with an SO2 monitor. The SO2 monitor s hall be designated as an EPA reference method or equivalent method in accordance with 40 CFR Part 53. In combination, the monitor must meet or exceed t he following minimum specifications:

007.02A Lower detection limit of 0.4 ppb (parts per billion);

007.02B Zero Drift less than 0.5 ppb in 24 hours and less than 1 ppb in 7 days at constant conditions;

007.02C Span Drift of less than 0.5 perc ent of the reading in 24 hours and less than 1 percent of the reading in 7 days at constant conditions;

007.02D Precision of 0.5 per cent of the reading; and

007.02E Linearity of 1 per cent of full scale.

007.03 A rolling average shall be considered valid if there is data for at least 75 percent of the period in question. In t he event that less than 100 percent of the data are available, the rolling average shal l be computed on the basis of the data available using the number of dat a available as the divisor.

007.04 The standards are atta ined when all of the following conditions are met:

007.04A The one-minute concentration is less than or equal to 10.0 ppm, rounded to one decimal place (fractional parts equal to or greater than 0.05 ppm must be rounded up);

007.04B The 30-minute rolling arithmetic mean concent ration is less than or equal to 0.10 ppm, rounded to two decimal places (fractional parts equal to or greater than 0.005 ppm must be rounded up);

Enabling Legislation: Neb. Rev. Stat. §§81-1504(1)(2), 81-1505(1)(12)

Legal Citation: Title 129, Ch. 4, Nebraska Department of Environmental Quality