340-245-0230 Toxic Air Contaminant Monitoring Requirements (1) An owner or operator of a source that chooses to perform toxic air contaminant monitoring under OAR 340-245-0050 must submit an application for a Toxic Air Contaminant Permit Addendum and a Toxic Air Contaminant Monitoring Plan, developed in consultation with and approved by DEQ in a Toxic Air Contaminant Permit Addendum, before beginning toxic air contaminant monitoring. Toxic air contaminant monitoring must be conducted for a period of not less than 12 months with at least 12 months of valid data with greater than 75 percent data completeness per quarter. (2) Public involvement requirements. DEQ shall work with the owner or operator to develop public information concerning an approved Toxic Air Contaminant Monitoring Plan and the timeline for the approved Toxic Air Contaminant Monitoring Plan. (3) Toxic air contaminant monitoring requirements. The owner or operator must submit a Toxic Air Contaminant Monitoring Plan in accordance with OAR 340-245-0030 that includes but is not limited to: (a) Identification of all toxic air contaminants that will be monitored; (b) A description of all proposed monitoring locations; (c) A description of the monitoring and analysis protocols for each toxic air contaminant to be monitored, including at a minimum: (A) The monitoring equipment and methods to be used for each toxic air contaminant; (B) The sampling methods, including sample handling and custody storage requirements; (C) The frequency of sampling at each monitoring location; the duration of each sample (i.e., the length of time in hours that each sample runs), and time of year; (D) Analytical methods and the analytical method detection limits and reporting limits to be used for each toxic air contaminant; (E) Quality assurance and quality control measures to be taken and who will be performing these measures; and (F) Descriptions of security measures to protect the monitoring equipment; (d) A description of how to determine and account for the ambient concentration of each toxic air contaminant being monitored that results from all causes other than the source under consideration, including natural and unknown causes; (e) A description of how and where meteorological monitoring will be performed and the meteorology equipment used; and (f) A description of how the data will be reduced and how often the results will be reported to DEQ. (4) Reporting Requirements. The owner or operator of a source that has been issued a Toxic Air Contaminant Permit Addendum or operating permit that includes air monitoring requirements must report to DEQ the following information: (a) Monthly monitoring result reports, no more than 30 days after all monitoring data becomes available for the month to which the data applies. The reports must include but is not limited to: (A) Ambient toxic air contaminant concentrations, all daily risks and all monthly average risks from all monitoring locations specified in the Air Monitoring Plan; (B) Meteorological data summary; (C) Daily production data; and (D) A description of any excess emissions or upset conditions that may have affected the ambient toxic air contaminant concentrations monitored, including conditions outside the property boundary that may affect ambient air (i.e., forest fires, house fires, train derailments, accidental spills, etc.); (b) An air monitoring final report, no more than 60 calendar days after completing all Toxic Air Contaminant Monitoring Plan requirements that also includes a description of any process changes that have occurred during the air monitoring period that may affect the results of the monitoring. (5) Air monitoring results. (a) Upon completion of the air monitoring, the owner or operator must submit to DEQ an assessment of risk based on the air monitoring data and other relevant information; (b) For all toxic air contaminants that are not monitored, or for which monitoring results were inconclusive, the owner or operator must use the modeled concentrations of those toxic air contaminants and add the risk from the modeled concentrations to the risk from the monitored concentrations to arrive at a total risk from the source; and (c) Upon receipt of air monitoring data and assessment of risk under subsections (a) and (b), DEQ will review the submittal and approve or deny it in accordance with the procedures OAR 340-245-0100(4). Statutory/Other Authority: ORS 468.020, 468.065, 468A.025, 468A.040, 468A.050, 468A.070, 468A.155, 468A.135 & 468A.337 Statutes/Other Implemented: 468.065, 468A.025, 468A.040, 468A.050, 468A.070, 468A.155, 468A.010, 468A.015, 468A.035, 468A.337 & 468A.335 History: DEQ 18-2021, amend filed 11/17/2021, effective 11/17/2021 DEQ 197-2018, adopt filed 11/16/2018, effective 11/16/2018