R 336.2160 Mercury low mass emitter monitoring methodology.

Rule 1160. (1) Unless the federal MATS is an applicable requirement, beginning April 16, 2015, the monitoring methodology shall meet all of the requirements of this rule. (2) The owner or operator of an affected unit that emits less than 464 ounces (29 pounds) of mercury per year may use the mercury low mass emitter monitoring methodology after performing initial certification testing. The owner or operator of the affected unit shall perform the initial certification testing and ongoing quality assurance as described in subrules (2) and (3) of this rule. The initial test shall be performed within 60 days of the effective date of these rules or 90 days prior to the compliance date, whichever is later. (3) For the initial certification testing, the following shall apply: (a) The owner or operator shall perform mercury emission testing to determine the mercury concentration, for example, total vapor-phase mercury, in the effluent. (b) Testing shall be performed using 1 of the following mercury reference methods: ASTM D6784-02, adopted by reference in R 336.2150, Method 29, method 30A, or method 30B of Part 60, adopted by reference in R 336.1299. A test shall consist of a minimum of 3 runs at maximum routine load while firing fuel or fuels with the highest mercury content. (c) The minimum run time shall be 1 hour if method 30A is used. If method 29, ASTM D6784-02, or method 30B is used, paired samples are required for each test run and the runs shall be long enough to ensure that sufficient mercury is collected to analyze. When method 29 or ASTM D6784-02 is used the test results shall be based on the vapor-phase mercury collected in the back half of the sampling train. For each method 29, ASTM D6784-02, or method 30B test run, the paired trains shall meet the relative deviation requirement specified in method 30B. If the relative deviation specification is met, the result of the 2 samples shall be averaged arithmetically. (d) If the unit is equipped with flue gas desulfurization or add-on mercury emission controls, the controls shall be operating normally during the testing, and for the purpose of establishing proper operation of the controls, parametric data shall be recorded. (e) A complete test plan and test notification shall be provided to the department 30 days prior to the testing. (4) Based on the results of emission testing, the following equation shall be used to provide a conservative estimate of the annual mercury mass emissions for the unit: E = N · K · CHg · Qmass Where: E = Estimated annual mercury mass emissions in ounces per year. N = 8760 hours or the maximum number of operating hours per year allowed by the unit's federally enforceable permit. K = 9.978 x 10-10 ounces-scm/µg-standard cubic foot (scf). CHg = Highest mercury concentration (µg/scm) from any test run or 0.05 µg/scm, whichever is greater. Qmass = Maximum potential flow rate. (a) If the estimated annual mercury mass emissions are 464 ounces per year or less, the unit is eligible to use the monitoring methodology of this rule, and mercury continuous emission monitoring is not required. (b) The results of the testing performed under this rule shall be submitted as a certification application to the department, not later than 45 days after the test is completed. The calculations demonstrating that the unit emits less than 464 ounces per year shall be provided, and the default mercury concentration that will be used for mercury mass emission reporting shall be specified. (c) Following initial certification the following steps shall be taken: (i) The default mercury concentration used to estimate the unit's annual mercury mass emissions shall be reported for each unit operating hour and shall be used to calculate hourly mercury emissions. (ii) The mercury emission testing described in this rule shall be repeated periodically for the purpose of quality assurance, as follows: (A) If the results of the certification testing under this rule show that the unit emits 144 ounces (9 pounds) per year or less, the first retest is required by the end of the fourth quarter following the calendar quarter of the certification test. (B) If the results of the certification test under this section show that the unit emits more than 144 ounces per year but less than 464 ounces per year, the first retest is required by the end of the second quarter following the calendar quarter of the certification test. (C) Retesting shall be required either by the end of the second or fourth quarter following the quarter of the previous test, depending on the results of the previous test. To determine whether the next retest is required within 2 or 4 quarters, substitute the highest mercury concentration from the current test or 0.50 µg/scm, whichever is greater, into the equation under subrule (3) of the rule. If the estimated annual mass emissions exceed 144 ounces, the next test is due within 2 quarters. If the estimated annual mass emissions are 144 ounces or less, the next test is due within 4 quarters. (d) The updated mercury default concentration shall be applied beginning with the first unit operating hour after the completion of the retest. (e) If the unit is equipped with flue gas desulfurization system or add-on mercury controls, the owner or operator shall record the parametric data for each unit operating hour. (f) An additional retest is required when there is a change in coal rank of the primary fuel or other significant fuel change. (g) At the end of each calendar year, if the cumulative annual mercury mass emission from an affected unit exceeds 464 ounces, the owner or operator shall install, certify, operate, and maintain a mercury continuous emission monitoring system, or sorbent trap monitoring system, not later than 180 days after the end of the calendar year in which the emissions exceeded 464 ounces.