What is LME?

40CFR Part 75 provides an alternative monitoring methodology that may be used instead of CEMS for gas and oil fired units with very low mass emissions (§75.19(a)). The low mass emissions, or LME, methodology does not require continuous monitoring of emissions or heat input. Instead, hourly SO2, NOx, and CO2 emissions are estimated using fuel-specific default emission rates. Hourly heat input is either estimated from records of fuel usage, or is reported as the maximum rated heat input for each unit operating hour.

LME methodology may be used by any gas- or oil-fired unit which meets the requirements of §75.19(a). Ozone-season only reporters should begin using the methodology on the first hour of the ozone season reporting period. LME units must demonstrate annually that the unit continues to emit no more than the allowed tons of NOx and/or SO2.


LME Table Defaults

If the affected unit combusts only natural gas and/or fuel oil, use Table LM-1 in §75.19(a) to determine the appropriate SO2 emission rate for use in calculating hourly SO2 mass emissions. A lower fuel-specific SO2 emissions factor may be used in lieu of the value from Table LM-1 if a permit condition is in place.

Use Table LM-2 to obtain the appropriate default NOx emission factor. Alternatively, you may calculate a fuel and unit specific NOx emission rate following the instructions in §75.19(c)(1)(iv)(A).

For Acid Rain Program units that only combust natural gas and/or fuel oil use Table LM-3 to determine the appropriate CO2 emission rate. Units that combust other fuels should derive a fuel and unit specific CO2 emission rate following the instructions in either §75.19(c)(1)(iii)(A) or §75.19(c)(1)(iii)(B).


LME-Specific Measured Parameters and Applicable Monitoring Methods

Tags: emissions, LME, monitoring

Last update: 2016-06-23 19:22