Low Mass Emissions Monitoring Option

1. Low Mass Emissions Monitoring Option Matthew Boze USEPA Clean Air Markets Division Emissions Monitoring Branch June 10, 2004

2. Low Mass Emissions Monitoring Methodology • The LME Methodology (§75.19) may be used in lieu of CEMS or the methods under App D and E to determine and report hourly heat input and NOx mass emissions • The LME Methodology is not an exemption from the monitoring and reporting requirements. • LME isnot the sameas a 25 ton monitoring exemption

3. LME Applicability • Gas and oil fired units only (no solid fuels!) • NOx emissions limitation (§75.19(a)(i)(A)) • Year round reporting units: NOx < 100 tons/year and < 50 tons/control period • Ozone season only reporting units: NOx< 50 tons/control period • SO2< 25 tons/year for ARP affected units

4. Initial LME qualification§75.19(a)(2)(ii) • Initial qualification is based on either: • Historical NOx mass emissions data for the three years (ozone seasons) prior to the year in which LME status is requested; or • When three full years (OS) of data are not available, a combination of any available historical data and projected data totaling three years may be used. • Historical emissions may be calculated using the LME methodology; or be based on Part 60, or State Certified CEMS. • Projected emissions must be calculated using either the appropriate default NOx emission rates from LM-2 or using a conservative estimate of the expected NOx emission rate if a fuel-and-unit specific rate is to be determined.

5. Other Initial Qualification Provisions §75.19(a)(3) • For units that do not qualify for LME based on the last 3 years (or ozone seasons) of data, they may also initially qualify for LME if: • The owner or operator takes an enforceable permit restriction on operating hours such that the unit may not emit more than the allowable tons of NOx from §75.19(a)(i)(A); or • If the actual emissions for the past years is not representative of expected future year emissions due to the recent installation of emissions controls on the unit.

6. On-going Qualification and Disqualification from LME • EPA monitors the emissions as calculated using the LME methodology to verify ongoing qualification with respect to the applicable emissions limitations. • If a LME unit fails to meet the emissions limitation, then: • The LME unit becomes disqualified from LME methodology • The Owner or Operator must install, and certify monitoring systems that meet the monitoring requirements by December 31 of the calendar year following the year that the limit was exceeded. • If the monitoring systems are not installed and certified by the deadline, then the unit must report maximum potential values for NOx emission rate and heat input for every hour of operation until the appropriate systems are installed and certified.

7. Disqualification from LMEDue to Fuel Change • §75.19(b)(3) - If a LME unit changes fuels, such that a fuel other than those allowed for use in the LME methodology is combusted, the unit is disqualified as of the first hour that the new fuel is combusted. • The Owner or Operator must install, and certify monitoring systems that meet the monitoring requirements prior to switching fuels. • If the required monitoring systems are not installed and certified prior to the fuel switch, then the unit must report maximum potential values for NOx emission rate and heat input for every hour of operation until the appropriate systems are installed and certified.

8. Regaining LME Status if Lost • When a unit has been disqualified from the LME methodology, the owner or operator may submit an application to re-qualify as an LME unit only if: • Three years of monitored emissions data is obtained, following the disqualification year, showing that the unit emitted less than the limits specified in §75.19(a)(i)(A); and • The Authorized Account Representative certifies in the application that the unit operation during those monitored years is representative of the projected future operation for the unit.

9. LME Monitoring Option for Determining NOx Mass Emissions • The LME Methodology is based on the combination of • A default NOx emission rate (lb/mmBtu), • Default NOx Emission Rate from table LM-2, or • Fuel-and-unit specific NOx Emission Rate • The heat input (mmBtu) used during the reporting period • Maximum Rated Heat Input Rate, or • Long Term Fuel Flow

10. Default NOx Emission Rate • Table LM-2 of §75.19(c)

11. Fuel-and-Unit Specific NOx Emission Rate • §75.19(c)(1)(iv)(C) • Perform four load Appendix E testing • Use the highest 3-run average NOx emission rate from the testing • For units tested with SCR or SNCR • Use the highest 3-run average NOx emission rate from the testing, or • 0.15 lb/mmBtu whichever is greater

12. Fuel-and-Unit Specific NOx Emission Rate • For units that only operate at base and peak loads (combustion turbines) either: • Use the 3-run App E test average from each load condition, or • Use the 3-run App E test average from the base load, and use base x 1.15 for all hours of peak operation. • Use the 95th percentile value from 3 years of quality-assured NOX emission rate data from a NOX-diluent CEMS • Part 60 or State Certified CEMS may be used • The data from the CEMS is only useable to determine the fuel-and-unit specific NOx emission rate, and CANNOT be used for Part 75 reporting or ongoing LME qualification!!!

13. Fuel-and-Unit Specific NOx Emission Rate • The fuel-and-unit specific NOx Emission Rate may NOT be used until after the fuel-and-unit specific NOx emission rate testing has been completed (§75.19(a)(4)) • Instead you must use either: • The applicable default from Table LM-2, or • The maximum potential NOx emission rate

14. Maximum Rated Heat Input Method • §72.2 defines the Maximum Rated Heat Input as “a unit-specific maximum hourly heat input (mmBtu) which is the higher of the manufacturer’s maximum rated heat input or the highest observed hourly heat input” • Total Heat Input for the quarter is the product of the number of operating hours and the Maximum Rated Heat Input HIqtr = OPHrsqtr x MRHI

15. Long Term Fuel FlowHeat Input Method • Fuel Flow • Qualified fuel billing records • A fuel measurement standard listed in §75.19(c)(3)(ii)(B)(2), or • A fuel flowmeter certified, maintained, and quality assured according to Part 75 Appendix D • GCV • Part 75, Appendix D §2.2 and 2.3, or • Default GCV in Table LM-2 • Pipeline Natural Gas - 1050 Btu/scf • Natural Gas - 1100 Btu/scf • Residual Oil - 19,700 Btu/lb or 167,500 Btu/gal • Diesel Fuel - 20,500 Btu/lb or 151,700 Btu/gal

16. LME NOx Mass Determinations • At the end of each reporting period, the total heat input is apportioned to each operating hour by load • The default NOx emission rate is multiplied by the hourly heat input value to determine the NOx mass emissions (lb/hr) for each hour of operation

17. LME Reports • MDC has a module that can generate the quarterly EDR file: http://www.epa.gov/airmarkets/monitoring/mdc/index.html • An LME tutorial is also available to show you how to use MDC to generate monitoring plans and quarterly reports • email requests to: mdc@pqa.com attn: Nat Rogers • MDC cannot be used to submit your quarterly report. • You must use ETS-FTP to submit EDR’s • Remember: EDR’s are required even when the unit does not operate