Air Toxics Safety Net Program (0190 through 0230)
(1)The purpose of the Air Toxics Safety Net Program is to address human exposures at public receptors to air toxics emissions from stationary sources that are not addressed by other regulatory programs or the Geographic Program. It is the Commission’s expectation that the Safety Net Program in OAR 340-246-0190 (Air Toxics Safety Net Program (0190 through 0230)) through 340-246-0230 (Safety Net Source Air Toxics Emissions Reduction Measures in Permit) will apply only rarely.
(2)Subject to the requirements contained in OAR 340-246-0190 (Air Toxics Safety Net Program (0190 through 0230)) through 340-246-0230 (Safety Net Source Air Toxics Emissions Reduction Measures in Permit), the Lane Regional Air Pollution Authority is designated by the Commission as the agency responsible for implementing the Air Toxics Safety Net Program within its area of jurisdiction. The requirements and procedures contained in this rule must be used by the Regional Authority to implement the Air Toxics Safety Net Program unless the Regional Authority adopts superseding rules, which are at least as restrictive as the rules adopted by the Commission.
(3)Selection of Sources. DEQ will select a source for the Air Toxics Safety Net Program if all of the following criteria are met:
(a)DEQ has ambient monitoring information, gathered using appropriate EPA or other published international, national, or state standard methods that concentrations of air toxics have caused an exceedance of at least one ambient benchmark at a site representing expected human exposure to air toxics from the source at a public receptor in a location outside of the source’s ownership or control.
(b)DEQ has information that the source’s air toxics emissions alone have caused an exceedance of at least one ambient benchmark at a site representing expected human exposure to air toxics from the source at a public receptor, in a location outside of the source’s ownership or control. This could be based on emissions inventory, modeling or other information.
(c)The source is not subject to or scheduled for a federal residual risk assessment under the federal Clean Air Act section 112(f)(2) through (6).
(d)The source is not subject to the permitting requirements under OAR chapter 340, division 245.
(e)The source is not subject to an emissions limit or control requirement imposed as the result of modeling or a risk assessment performed or required by DEQ prior to November 1, 2003 for the air toxics that exceed the ambient benchmarks.
(f)The source is located outside of a selected geographic area, as designated in OAR 340-246-0130 (Geographic Program (0130 through 0170)) through 0170.
(4)Air Toxics Science Advisory Committee Review. Before requiring a source to conduct a source-specific risk assessment, DEQ will present its analysis to the ATSAC. Within 120 days, the ATSAC will review the analysis and make a finding. If the ATSAC concurs with DEQ or takes no action, DEQ may proceed under this rule. If the ATSAC objects, DEQ will not proceed until it receives concurrence from the Commission.
(5)Source-Specific Exposure Modeling and Risk Assessment. Upon written notification by DEQ, a source must conduct a risk assessment including exposure modeling for the air toxics measured at levels above ambient benchmarks. The source must use a risk assessment methodology provided by DEQ. This risk assessment will provide the basis for establishing air toxics emissions reductions or demonstrating that at public receptors in areas outside of a source’s ownership or control, people are not being exposed to air toxics at levels that exceed the ambient benchmarks.
(6)Risk Assessment Methodology. DEQ will provide guidance on the methods to be used. The risk assessment methodology will be developed in consultation with the ATSAC and will result in a protocol that:
(a)Uses reasonable estimates of plausible upper-bound exposures that neither grossly underestimate nor grossly overestimate risks;
(b)Considers the range of probabilities of risks actually occurring, the range of size of the populations likely to be exposed to the risk, and current and reasonably likely future land uses;
(c)Defines the use of high-end and central-tendency exposure cases and assumptions;
(d)Develops values associated with chronic exposure for carcinogens; and
(e)Addresses both carcinogenic and non-carcinogenic air toxics and allows for detailed exposure assessments to the extent possible.
Rule 340-246-0190 — Air Toxics Safety Net Program (0190 through 0230),