| (i) For each out-of-order period less than 24 hours, the maximum one-hour average HRVOC concentrations from the 24-hour period immediately prior to the out-of-order period must be used. (ii) For each out-of-order period of 24 hours or greater, the maximum one-hour average HRVOC concentrations from the 24-hour period immediately prior to the out-of-order period must be used for the time period from the initial outage of the monitoring system to time of collection of the first manual sample required by this paragraph. The results of each manual sample must be used for the time period from collection of that sample to the collection of the subsequent sample, or to the time that the continuous monitoring system is on-line and within the required performance specifications. (B) For periods that only the analyzer system is out of order and the sampling system (i.e., HRVOC sparging or stripping system) is still functioning within normal specifications, the owner or operator may elect to collect the manual samples required by this paragraph using the sampling system of the continuous HRVOC monitoring system. (c) When periodic sampling is required, the owner or operator of the cooling tower heat exchange system shall determine the speciated HRVOC concentration as soon as this information is available, but no later than seven days after the sample(s) have been collected. Samples collected in a TedlarTM bag must be analyzed no later than 72 hours after the samples have been collected. The samples must be analyzed according to the procedures in Test Method 18, 40 CFR Part 60, Appendix A, and/or Method TO-14A, published in "U.S. EPA Compendium for Determination of Toxic Organic Compounds in Ambient Air (1996)," United States Environmental Protection Agency Document Number 625/R96/010B. (d) In lieu of subsections (a)(2) - (5) and (b)(2) - (5) of this section, the owner or operator of cooling tower heat exchange systems in which no individual heat exchanger has 5.0% or greater HRVOC in the process-side fluid, shall determine total strippable VOC and the HRVOC concentration in the cooling tower water at least once per month, with an interval of not less than 20 days between samples, according to the air-stripping method in Appendix P. If the total strippable VOC concentration in the cooling tower water is 50 ppbw or greater, the owner or operator shall determine the total strippable VOC weekly and the HRVOC concentration weekly. The additional sampling for the total strippable VOC concentration and HRVOC concentration continue until the total strippable VOC concentration drops below 50 ppbw. (e) In lieu of using a continuous flow monitor as described in subsections (a)(1) and (b)(1) of this section, the owner or operator of a cooling tower heat exchange system may: (1) use the maximum potential flow rate based on manufacturer's pump performance data, assuming no back pressure; or (2) install, calibrate, operate, and maintain, in accordance with the manufacturer's recommendations, a monitor to continuously measure and record each cooling water pump discharge pressure to establish the total dynamic head of the cooling water system. The owner or operator of the cooling water system must establish, use, and demonstrate in the QAP required in §115.766(i) of this title (relating to Recordkeeping and Reporting Requirements, a calculation methodology that will provide, on a continuous basis, the cooling water circulation flow rate (in gpm) based on the following: cooling water discharge pressure for each pump; the manufacturer's certified pump performance data; and the number of pumps in operation. This calculated flow rate will then be used to determine the hourly emission rate in pounds per hour, as required by §115.766(a)(3) of this title. (f) Minor modifications to the monitoring and testing methods in this section may be approved by the executive director. Monitoring and testing methods other than those specified in this section may be used if approved by the executive director and validated by 40 CFR Part 63, Appendix A, Test Method 301 (December 29, 1992). For the purposes of this subsection, substitute "executive director" in each place that Test Method 301 references "administrator." (g) In lieu of using the monitor location described in subsections (a), (b), and (h) of this section: (1) the owner or operator of cooling tower heat exchange systems in which a single cooling tower services both HRVOC and non-HRVOC process units, or a single cooling tower that services multiple types of heat exchange systems (i.e., jacketed reactor or finite volume system), may: (A) install a flow monitor or monitors, meeting the requirements of subsections (a)(1) and (b)(1) of this section at a point that represents the flow of cooling water from only the HRVOC-containing process units; and (B) monitor the total strippable VOC or HRVOC concentration, in accordance with subsection (a), (b), (d), or (h) of this section at a point leaving the HRVOC-containing process unit and prior to mixing with cooling tower water from other units; or (2) the owner or operator of cooling tower heat exchange systems may elect to monitor cooling water flow rate at a location that is representative of the total flow rate to the cooling tower. (h) In lieu of the requirements of subsection (a) of this section, the owner or operator of a cooling tower heat exchange system in dedicated service to a finite volume system, as defined in §115.760(b) of this title, with HRVOC and with a design capacity to circulate 8,000 gallons gpm or greater of cooling water may elect to comply with the following requirements: (1) install, calibrate, operate, and maintain a continuous flow monitor on each inlet of each cooling tower. Each monitor must be calibrated on an annual basis to within ±5.0% accuracy. When the cooling tower flow monitor is down, flow measurements must be used for the most recent 24-hour period in which the flow measurements are representative of cooling tower operations during monitor downtime; (2) determine the speciated strippable HRVOC concentration by collecting samples from each inlet of each cooling tower at least once per month in accordance with the air-stripping method in Appendix P; (3) determine the total strippable VOC concentration by collecting samples from each inlet of each cooling tower at least twice per week in accordance with the air-stripping method in Appendix P with an interval of not less than 48 hours between samples; (4) if the concentration of total strippable VOC is equal to or greater than 50 ppbw in the cooling tower water, collect an additional sample to determine total strippable VOC, speciated HRVOC, and total HRVOC from each inlet of the affected cooling tower at least once daily in accordance with the air-stripping method in Appendix P. The additional sampling to determine total strippable VOC, speciated HRVOC, and total HRVOC must continue on a daily basis until the concentration of total strippable VOC drops below 50 ppbw; (5) install, calibrate, operate, and maintain a continuous monitoring system to monitor the inventory level of the HRVOC in the finite volume system; (6) develop, implement, and follow a written monitoring plan to satisfy the requirements of paragraph (5) of this subsection. The monitoring plan must include: (A) specifications for all monitors used to satisfy the requirements of paragraph (5) of this subsection; (B) the normal hourly variation in the inventory level for the continuous monitoring system; (C) all process information, design specifications, and engineering calculations, used to establish the normal hourly variation in the inventory level; and (D) at a minimum, quarterly inspections of the continuous monitoring system to ensure proper operation; (7) if the hourly inventory level monitored in accordance with paragraphs (5) and (6) of this subsection is not within the normal hourly variation in the inventory level established as required in paragraph (5) of this subsection, except during maintenance activities, then the owner or operator must perform sampling for total strippable VOC as specified in paragraph (3) of this subsection within 24 hours. If the concentration of total strippable VOC is equal to or greater than 50 ppbw in the cooling tower water, then the owner or operator shall perform daily sampling to determine total strippable VOC, speciated HRVOC, and total HRVOC in accordance with paragraph (4) of this subsection until the concentration of total strippable VOC drops below 50 ppbw; and (8) upon written request by the executive director, the monitoring plan required in accordance with paragraph (6) of this subsection must be submitted within 30 days for review. The executive director may require additional or alternative monitoring requirements. |
