TNRCC Issues Proposed Rules On Emissions Events Reporting

  • The Texas Natural Resource Conservation Commission (TNRCC) recently released proposed rules that would significantly strengthen the reporting and compliance rules for upsets, maintenance, startup and shutdown activities for Texas facilities. In addition, TNRCC proposes to repeal the existing reporting rules almost entirely.

    The proposed rules, which are intended to implement amendments to the Texas Clean Air Act during the last legislative session, would have the following impacts:

    • reduce the exemptions from authorized emissions limits for upsets and unscheduled maintenance, startup and shutdown activities;
    • require that maintenance, startup and shutdown activities be scheduled, noticed in advance to the TNRCC, with limits on when scheduled activities can occur outside of authorized emissions limits;
    • allow the TNRCC to require facilities deemed to have "excessive emissions events" to file a corrective action plan or obtain a permit to capture the emissions events; and
    • increase the current amount of reporting and recordkeeping for emissions events and scheduled maintenance, startup and shutdown activities.
  • A public meeting on the proposed rules is scheduled for May 21, 2002 and written comments are due May 28, 2002. To view a copy of the proposed rules, click here.

    A more detailed summary of key changes in the proposed rules is provided below. For more information, please contact Maddie Kadas (512) 478-7966 ([email protected]) or Rob Brager (410) 230-3855 ([email protected]).

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    1. Emissions Events: Upsets and Unscheduled Maintenance, Startup and Shutdown Activities.

    Under the proposed rules, "emissions events," which would be defined as "any upset event or unscheduled maintenance, startup, or shutdown activity that results in unauthorized emissions from an emissions point" in excess of reportable quantities (RQ) must be reported as soon as practicable, but not later than 24 hours. An "upset event" would be defined as "an unplanned or unanticipated occurrence or excursion of a process or operation that results in unauthorized emissions." To be exempt from authorized emissions limits (i.e., permit, rules, or orders of the TNRCC), the emissions events would have to be reported and satisfy all of the following criteria:

    • be caused by a sudden breakdown of equipment or process, beyond the control of the owner or operator;
    • not stem from any activity or event that could have been foreseen and avoided and could not have been avoided by good design, operation, and maintenance practices;
    • good air pollution control practices were maintained;
    • prompt action was taken to achieve compliance once the operator knew or should have known that applicable emission limitations were being exceeded;
    • the amount and duration of the unauthorized emissions and any bypass of pollution control equipment were minimized;
    • all emission monitoring systems were kept in operation, if possible;
    • the owner or operator actions in response to the unauthorized emissions were documented by logs or other evidence;
    • the unauthorized emissions were not part of a frequent or recurring pattern indicative or inadequate design, operation or maintenance;
    • the percentage of a facility's total annual operating hours during which unauthorized emissions occurred was not unreasonably high; and
    • unauthorized emissions did not cause or contribute to a condition of air pollution.


    In addition, a follow-up report of the emissions event would have to be filed within two weeks of the event. The facility would be required to maintain records of the emissions event for 5 years, including any emissions below the RQ.

    2. Scheduled Maintenance, Startup and Shutdown Activities.

    The rules also include reporting requirements for certain scheduled maintenance, startup or shutdown activities ("MSS"). A scheduled MSS is defined as "a maintenance, startup, or shutdown activity that will not and does not result in the emission of at least a reportable quantity of unauthorized emissions and the activity is recorded as required or if the maintenance, startup, or shutdown activity results in the emission or at least a reportable quantity of unauthorized emissions and (A) the owner or operator of the facility provides prior notice and a final report; (B) the notice of final report includes the information required; and (C) the actual emissions do not exceed the estimates submitted in the notice."

    Scheduled maintenance, startup and shutdown ("MSS") events that are expected to exceed an RQ would only be exempt from authorized emissions limitations if the facility gives 10 days prior notice of the MSS event to the TNRCC and can show all of the following:

    • the periods of unauthorized emissions from a scheduled MSS could not have been prevented through planning and design;
    • the unauthorized emissions from a scheduled MSS are not part of a recurring pattern indicative of inadequate design, operation, or maintenance;
    • if the emissions from the scheduled MSS were caused by a bypass of control equipment, the bypass was unavoidable to prevent loss of life, personal injury or severe property damage;
    • good air pollution control practices were maintained;
    • the frequency and duration of scheduled MSS operations during which unauthorized emissions were released were minimized;
    • all emissions monitoring systems were kept in operation, if possible;
    • the unauthorized emissions were documented by logs or other evidence;
    • the unauthorized emissions did not cause or contribute to a condition of air pollution.
  • In response to the initial 10-day notice, the Executive Director may specify the amount, time and duration of emissions allowed during the scheduled MSS activity and may require the owner or operator of the facility to submit a technical plan explaining how emissions will be minimized during the MSS activity. In addition, if the information on the initial notice of the MSS activity is different than what actually occurred during the MSS activity, a follow-up report with correct information would have to be filed within two weeks of the event. The facility must maintain records of the MSS activity for five years.

    3. Excessive Emissions Events.

    Finally, the proposed rules would also require the TNRCC to determine whether a facility's emissions events are "excessive" based on the following criteria:

    • the frequency of a facility's emissions events;
    • the cause of the emissions events;
    • the quantity and impact on human health or the environment of the emissions event;
    • the duration of the emissions event;
    • the percentage of a facility's total annual operating hours during which emissions events occur; and
    • the need for startup, shutdown and maintenance activities.

Facilities that are deemed to have "excessive" emissions events will be required to either develop a corrective action plan or, when the emissions are sufficiently frequent, quantifiable and predictable and the emissions meet permitting criteria, file a letter of intent to obtain authorization for the emissions.