- If the stack samples described in Step 2 were analyzed for hexavalent chromium, the SEF based on the hexavalent chromium enrichment factors (as defined in Step 2) shall be used in this calculation.
- If the stack samples were not analyzed for hexavalent chromium, then the SEF based on the total chromium enrichment factor shall be used in this calculation.
• Calculate the “violation" dust metal concentration limit (DMCLv) using Equation 3 if EF95% is determinable, or using Equation 6 if EF95% is not determinable.
- Chromium is treated as a special case. The “violation" kiln dust chromium concentration limit is set for total chromium, not for hexavalent chromium. The limit for total chromium shall be calculated using the Tier III (or Tier II) metal limit for hexavalent chromium.
- If the stack samples taken in Step 2 were analyzed for hexavalent chromium, the EF95% based on the hexavalent chromium enrichment factor (as defined in Step 2) should be used in this calculation.
- If the stack samples were not analyzed for hexavalent chromium, the EF95% based on the total chromium enrichment factor shall be used in this calculation.
• Submit certification of compliance.
• Steps 2-4 shall be repeated for recertification, which is required once every 3 years (see s.
NR 666.103(4)).
(5) Monitor metal concentrations in kiln dust for continuing compliance, and maintain compliance with all compliance limits for the duration of interim license.
• Metals to be monitored during compliance testing are classified as either “critical" or “noncritical" metals.
- All metals shall initially be classified as “critical" metals and be monitored on a daily basis.
- A “critical" metal may be reclassified as a “noncritical" metal if its concentration in the kiln dust remains below 10% of its “conservative" kiln dust metal concentration limit for 30 consecutive daily samples. “Noncritical" metals shall be monitored on a weekly basis.
- A “noncritical" metal shall be reclassified as a “critical" metal if its concentration in the kiln dust is above 10% of its “conservative" kiln dust metal concentration limit for any single daily or weekly sample.
• Noncompliance with the sampling and analysis schedule prescribed by this method is a violation of the metals controls under s.
NR 666.103.
• Follow the sampling, compositing, and analytical procedures described in this method and in other appropriate methods, as they pertain to the condition and accessibility of the kiln dust.
• Follow the same procedures and sample at the same locations as were used for kiln dust samples collected to determine the enrichment factors (as discussed in Step 2).
• Samples shall be collected at least once every 8 hours, and a daily composite shall be prepared according to appropriate procedures.
- At least one composite sample is required. This sample is referred to as the “required" sample.
- For QA/QC purposes, a facility may elect to collect 2 or more additional samples. These samples are referred to as the “spare" samples. These additional samples shall be collected over the same time period and according to the same procedures as those used for the “required" sample.
- Samples for “critical" metals shall be daily composites.
- Samples for “noncritical" metals shall be weekly composites. These samples can be composites of the original 8-hour samples, or they can be composites of daily composite samples.
• Analyze the “required" sample to determine the concentration of each metal.
- This analysis shall be completed within 48 hours of the close of the sampling period. Failure to meet this schedule is a violation of the metals standards of s.
NR 666.103.
• If the “conservative" kiln dust metal concentration limit is exceeded for any metal, refer to Step 8.
• If the “conservative" kiln dust metal concentration limit is not exceeded, continue with the daily or weekly monitoring (Step 5) for the duration of interim license.
• Conduct quarterly enrichment factor verification tests, as described in Step 6.
(6) Conduct quarterly enrichment factor verification tests.
• After certification of compliance with the metals standards, a facility shall conduct quarterly enrichment factor verification tests every 3 months for the duration of interim license. The first quarterly test shall be completed within 3 months of certification (or recertification). Each subsequent quarterly test shall be completed within 3 months of the preceding quarterly test. Failure to meet this schedule is a violation.
• Simultaneous stack samples and kiln dust samples shall be collected.
• Follow the same procedures and sample at the same locations as were used for kiln dust samples and stack samples collected to determine the enrichment factors (as discussed in Step 2).
• At least 3 single (noncomposited) runs are required. These tests need not be conducted under the operating conditions of the initial compliance test; however, the facility shall operate under the following conditions:
- It shall operate at compliance test production rate.
- It shall burn hazardous waste during the test, and for the 2-day period immediately preceding the test, such that the feedrate of each metal for pumpable and total hazardous wastes consist of at least 25% of the operating limits established during the compliance test.
- It shall remain in compliance with all compliance parameters (see s.
NR 666.103(3)(a)).
- It shall follow a normal schedule of kiln dust recharging.
- It shall generate normal marketable product from normal raw materials during the tests.
(7) Conduct a statistical test to determine if the enrichment factors measured in the quarterly verification tests have increased significantly from the enrichment factors determined in the tests conducted in Step 2. The enrichment factors have increased significantly if all 3 of the following criteria are met:
• By applying the t-test described in Appendix A, it is determined that the enrichment factors measured in the quarterly tests are not taken from the same population as the enrichment factors measured in the Step 2 tests;
• The EF95% calculated for the combined data sets (i.e., the quarterly test data and the original Step 2 test data) according to the t-distribution (described in Appendix A) is more than 10% higher than the EF95% based on the enrichment factors previously measured in Step 2; and
• The highest measured kiln dust metal concentration recorded in the previous quarter is more than 10% of the “violation" kiln dust concentration limit that would be calculated from the combined EF95% .
If the enrichment factors have increased significantly, the tests to determine the enrichment factors shall be repeated (refer to Step 11). If the enrichment factors have not increased significantly, continue to use the kiln dust metal concentration limits based on the enrichment factors previously measured in Step 2, and continue with the daily and/or weekly monitoring described in Step 5.
(8) If the “conservative" kiln dust metal concentration limit was exceeded for any metal in any single analysis of the “required" kiln dust sample, the “spare" samples corresponding to the same period may be analyzed to determine if the exceedance was due to a sampling or analysis error.
• If no “spare" samples were taken, refer to Step 9.
• If the average of all the samples for a given day (or week, as applicable) (including the “required" sample and the “spare" samples) does not exceed the “conservative" kiln dust metal concentration limit, no corrective measures are necessary; continue with the daily and/or weekly monitoring as described in Step 5.
• If the average of all the samples for a given day (or week, as applicable) exceeds the “conservative" kiln dust metal concentration limit, but the average of the “spare" samples is below the “conservative" kiln dust metal concentration limit, apply the Q-test, described in Appendix A, to determine whether the “required" sample concentration can be judged as an outlier.
- If the “required" sample concentration is judged an outlier, no corrective measures are necessary; continue with the daily and/or weekly monitoring described in Step 5.
- If the “required" sample concentration is not judged an outlier, refer to Step 9.
(9) Determine if the “violation" kiln dust metal concentration has been exceeded based on either the average of all the samples collected during the 24-hour period in question, or if discarding an outlier can be statistically justified by the Q-test described in Appendix A, on the average of the remaining samples.
• If the “violation" kiln dust metal concentration limit has been exceeded, a violation of the metals controls under s.
NR 666.103(3) has occurred. Notify the department that a violation has occurred. Hazardous waste may be burned for testing purposes for up to 720 operating hours to support a revised certification of compliance. Note that the department may grant an extension of the hours of hazardous waste burning under s.
NR 666.103(3)(g) if additional burning time is needed to support a revised certification for reasons beyond the control of the owner or operator. Until a revised certification of compliance is submitted to the department, the feedrate of the metals in violation in total and pumpable hazardous waste feeds is limited to 50% of the previous compliance test limits.
• If the “violation" kiln dust metal concentration has not been exceeded:
- If the exceedance occurred in a daily composite sample, refer to Step 10.
- If the exceedance occurred in a weekly composite sample, refer to Step 11.
(10) Determine if the “conservative" kiln dust metal concentration limit has been exceeded more than 3 times in the last 60 days.
• If not, log this exceedance and continue with the daily and/or weekly monitoring (Step 5).
• If so, the tests to determine the enrichment factors shall be repeated (refer to Step 11).
• This determination is made separately for each metal. For example,
- Three exceedances for each of the 10 hazardous metals are allowed within any 60-day period.
- Four exceedances of any single metal in any 60-day period is not allowed.
• This determination should be made daily, beginning on the first day of daily monitoring. For example, if 4 exceedances of any single metal occur in the first 4 days of daily monitoring, do not wait until the end of the 60-day period; refer immediately to Step 11.
(11) The tests to determine the enrichment factor shall be repeated if: (1) More than 3 exceedances of the “conservative" kiln dust metal concentration limit occur within any 60 consecutive daily samples; (2) an excursion of the “conservative" kiln dust metal concentration limit occurs in any weekly sample; or (3) a quarterly test indicates that the enrichment factors have increased significantly.
• The facility shall notify the department if these tests shall be repeated.
• The facility has up to 720 hazardous-waste-burning hours to redetermine the enrichment factors for the metal or metals in question and to recertify (beginning with a return to Step 2). During this period, the facility shall reduce the feed rate of the metal in violation by 50%. If the facility has not completed the recertification process within this period, it shall stop burning or obtain an extension. Hazardous waste burning may resume only when the recertification process (ending with Step 4) has been completed.
• Meanwhile, the facility shall continue with daily kiln dust metals monitoring (Step 5) and shall remain in compliance with the “violation" kiln dust metal concentration limits (Step 9).
10.6 Precompliance Procedures
Cement kilns and other industrial furnaces that recycle emission control residue back into the furnace shall comply with the same certification schedules and procedures (with the few exceptions described below) that apply to other boilers and industrial furnaces. These schedules and procedures, as set forth in s.
NR 666.103, require no later than the effective date of the rule, each facility submit a certification which establishes precompliance limits for a number of compliance parameters (see s.
NR 666.103(2)(c)), and that each facility immediately begin to operate under these limits.
These precompliance limits shall ensure that interim license emissions limits for hazardous metals, particulate matter, HCl, and Cl2 are not likely to be exceeded. Determination of the values of the precompliance limits shall be made based on either (1) conservative default assumptions provided in this Methods Manual, or (2) engineering judgement.
The flowchart for implementing the precompliance procedures is shown in Figure 10.6-1. The step-by-step precompliance implementation procedure is described below. The precompliance implementation procedures and numbering scheme are similar to those used for the compliance procedures described in Subsection 10.5.
(1) Prepare initial limits and test plans.
• Determine the Tier III metal emission limit. The Tier II metal emission limit may also be used (see s.
NR 666.106).
• Determine the applicable PM emission standard. This standard is the most stringent particulate emission standard that applies to the facility. A facility may elect to restrict itself to an even more stringent self-imposed PM emission standard, particularly if the facility finds that it is easier to control particulate emissions than to reduce the kiln dust concentration of a certain metal (i.e., lead).
• Determine which metals need to be monitored (i.e., all hazardous metals for which Tier III emission limits are lower than PM emission limits, assuming PM is pure metal).
• Follow appropriate procedures for preparing waste analysis plans for the following tasks:
- Analysis of hazardous waste feedstreams.
- Daily and/or weekly monitoring of kiln dust concentrations for continuing compliance.
(2) Determine the “safe" enrichment factor for precompliance. In this context, the “safe" enrichment factor is a conservatively high estimate of the enrichment factor (the ratio of the emitted metal concentration to the metal concentration in the collected kiln dust). The “safe" enrichment factor shall be calculated from either conservative default values, or engineering judgement.
• Conservative default values for the “safe" enrichment factor are as follows:
- SEF = 10 for all hazardous metals except mercury. SEF=10 for antimony, arsenic, barium, beryllium, cadmium, chromium, lead, silver, and thallium.
- SEF = 100 for mercury.
• Engineering judgement may be used in place of conservative default assumptions if the engineering judgement is defensible and properly documented. The facility shall keep a written record of all assumptions and calculations necessary to justify the SEF. The facility shall provide this record to the department upon request and shall be prepared to defend these assumptions and calculations.
Examples of situations where the use of engineering judgement is appropriate include:
- Use of data from precompliance tests;
- Use of data from previous compliance tests; and
- Use of data from similar facilities.
(3) This step does not apply to precompliance procedures.
(4) Prepare certification of precompliance.
• Calculate the “conservative" dust metal concentration limit (DMCLc) using Equation 5.
• Submit certification of precompliance. This certification shall include precompliance limits for all compliance parameters that apply to other boilers and industrial furnaces (i.e., those that do not recycle emission control residue back into the furnace) as listed in s.
NR 666.103(2)(c), except that it is not necessary to set precompliance limits on maximum feedrate of each hazardous metal in all combined feedstreams.
