Except as specified in § 63.1085(f) and paragraphs (c) and (d) of this section, if a leak is detected, you must comply with the requirements in paragraphs (a) and (b) of this section unless repair is delayed according to § 63.1088.
(a) Repair the leak as soon as practical but not later than 45 calendar days after you received the results of monitoring tests that indicated a leak. You must repair the leak unless you demonstrate that the results are due to a condition other than a leak.
(b) Once the leak has been repaired, use the monitoring requirements in § 63.1086 within 7 calendar days of the repair or startup, whichever is later, to confirm that the heat exchange system has been repaired.
(c) Beginning no later than the compliance dates specified in § 63.1081(a), if a leak is detected using the methods described in § 63.1086(e), you must repair the leak to reduce the concentration or mass emissions rate to below the applicable leak action level as soon as practicable, but no later than 45 days after identifying the leak, except as specified in § 63.1088(d). Repair must include re-monitoring at the monitoring location where the leak was identified according to the method specified in § 63.1086(e)(3) to verify that the total strippable hydrocarbon concentration or total hydrocarbon mass emissions rate is below the applicable leak action level. Repair may also include performing the additional monitoring in paragraph (d) of this section to verify that the total strippable hydrocarbon concentration is below the applicable leak action level. Actions that can be taken to achieve repair include but are not limited to:
(1) Physical modifications to the leaking heat exchanger, such as welding the leak or replacing a tube;
(2) Blocking the leaking tube within the heat exchanger;
(3) Changing the pressure so that water flows into the process fluid;
(4) Replacing the heat exchanger or heat exchanger bundle; or
(5) Isolating, bypassing, or otherwise removing the leaking heat exchanger from service until it is otherwise repaired.
(d) Beginning no later than the compliance dates specified in § 63.1081(a), if you detect a leak when monitoring a cooling tower return line according to § 63.1086(e)(1)(i), you may conduct additional monitoring of each heat exchanger or group of heat exchangers associated with the heat exchange system for which the leak was detected, as provided in § 63.1086(e)(1)(ii). If no leaks are detected when monitoring according to the requirements of § 63.1086(e)(1)(ii), the heat exchange system is considered to have met the repair requirements through re-monitoring of the heat exchange system, as provided in paragraph (c) of this section.
[67 FR 46271, July 12, 2002, as amended at 85 FR 40421, July 6, 2020]