Section 11-59-4 - Ambient air quality standards(a) The numerical ambient air quality standards below limit the time-averaged concentration of specified pollutants dispersed or suspended in the ambient air of the State, but these standards do not in any manner authorize the significant deterioration of existing air quality in any portion of the State.(b) Limiting concentrations specified for a calendar year or a calendar quarter shall not be exceeded. Limiting concentrations specified for one-hour, three-hour, eight-hour, and twenty-four-hour periods shall not be exceeded more than once in a calendar year.(c) In the ambient air the concentration of carbon monoxide measured by a reference method shall not exceed: (1) An average value of ten milligrams per cubic meter of air during any one-hour period; and(2) An average value of five milligrams per cubic meter of air during any eight-hour period.(d) In the ambient air the average concentration of nitrogen dioxide measured by a reference method during a calendar year shall not exceed seventy micrograms per cubic meter of air.(e) In the ambient air the concentration of particulate matter as particles with an aerodynamic diameter less than or equal to a nominal ten micrometers measured by a reference method shall not exceed: (1) An arithmetic mean of fifty micrograms per cubic meter of air during a calendar year; and(2) An average value of one hundred fifty micrograms per cubic meter of air during any twenty-four-hour period.(f) In the ambient air the average concentration of ozone measured by a reference method during any eight-hour period shall not exceed one hundred fifty-seven micrograms per cubic meter of air.(g) In the ambient air the average concentration of sulfur dioxide measured by a reference method shall not exceed: (1) An average value of eighty micrograms per cubic meter of air in a calendar year;(2) An average value of three hundred sixty-five micrograms per cubic meter of air in any twenty-four-hour period; and(3) An average value of one thousand three hundred micrograms per cubic meter of air in any three-hour period.(h) In the ambient air the average concentration of lead measured as elemental lead by a reference method during a calendar quarter shall not exceed 1.5 micrograms per cubic meter of air.(i) In the ambient air the average concentration of hydrogen sulfide measured by a reference method shall not exceed thirty-five micrograms per cubic meter of air (twenty-five parts per billion) in any one-hour period.[Eff 11/29/82; am 4/14/86; am and comp 6/2 9/92; am and comp 11/26/93; am and comp 9/15/01] (Auth: HRS §§ 342B-3, 342B-31; 42 U.S.C. §§7410, 7416; 40 C.F.R. Parts 50, 51) (Imp: HRS § 342B-31; 42 U.S.C. §§7407, 7409, 7410, 7416; 40 C.F.R. Parts 50, 51)