Concentrations of sulfur dioxide in ambient air as measured by an approved method for each averaging time must not exceed the following concentrations:
(1) Annual average: 0.02 ppm as an annual arithmetic mean for any calendar year at any site as measured by the reference method described in appendix A of 40 CFR part 50 or by an equivalent method designated in accordance with 40 CFR part 53.(2) 24-hour average: 0.10 ppm as a 24-hour average concentration more than once per calendar year at any site as measured by the reference method described in appendix A of 40 CFR part 50 or by an equivalent method designated in accordance with 40 CFR part 53.(3) 3-hour average: 0.50 ppm as a three-hour average concentration more than once per calendar year at any site as measured by the reference method described in appendix A of 40 CFR part 50.(4) 1-hour average: 0.075 ppm as a three-year average of the annual 99th percentile of the daily maximum 1-hour average concentration recorded at any monitoring site as determined by appendix T of 40 CFR part 50 as measured by a reference method based on appendix A or A-1 of 40 CFR part 50, or by a Federal Equivalent Method (FEM) designated in accordance with 40 CFR part 53 . [NOTE: This rule is included in the State of Oregon Clean Air Act Implementation Plan that EQC adopted under OAR 340-200-0040.]
[NOTE: View a PDF of referenced EPA Methods by clicking on "Tables" link below.]
Or. Admin. Code § 340-202-0070
DEQ 37, f. 2-15-72, ef. 3-1-72; DEQ 8-1988, f. & cert. ef. 5-19-88 (corrected 9-30-88); DEQ 24-1991, f. & cert. ef. 11-13-91; DEQ 4-1993, f. & cert. ef. 3-10-93; DEQ 14-1999, f. & cert. ef. 10-14-99, Renumbered from 340-031-0020; DEQ 6-2001, f. 6-18-01, cert. ef. 7-1-01; DEQ 11-2013, f. & cert. ef. 11-7-13; DEQ 7-2015, f. & cert. ef. 4/16/2015; DEQ 13-2019, amend filed 05/16/2019, effective 5/16/2019Statutory/Other Authority: ORS 468.020 & 468A
Statutes/Other Implemented: ORS 468A.025 & 468A.035