06-096 C.M.R. ch. 113, § 5 - Quantification of Offset Credits for Credit Generators

A. Offset credits shall be quantified in an average hourly or daily emission rate expressed in pounds.

B. Quantification of offset credits shall follow the two-step process provided below, including quantification of the base credit and adjustment of the base credit for compliance assurance.

C. Step One: Replicable methods must be used to establish the baseline which reflects the lower of actual or allowable emissions and which serves as the level below which emission reductions are considered surplus, and to quantify base credit reflecting the real emission reduction below baseline. Replicable methods must include the following, as appropriate, for the specific offset credit application:

(1) Continuous Emission Monitoring System (CEMS): Direct determination through the use of a certified CEMS; or

(2) Mass Balance Calculations: Mass balance calculations which are a function of process and control equipment parameters, inventory records, usage and disposal records, activity levels, and/or throughput production consistent with good engineering practice and methods as approved by the Department and EPA; or

(3) Stack Testing: Calculations based on direct measurement of emissions by use of a test method contained in 40 C.F.R. Part 60 Appendices; or

(4) Capture and Control Efficiencies: Testing of capture and control efficiencies using approved testing methods, mass balance, and corresponding calculations as approved by the Department and EPA; or

(5) Parametric Monitoring: Parametric monitoring programs approved by the Department where the owner or operator identifies one or more indicators of the performance of an applicable control device or process at a pollutant-specific emission unit subject to this Chapter, and, for each indicator identified, provides a credible demonstration of the validity of the indicator monitored which includes the following:

(a) The demonstrated relationship between the indicator and emissions from the emissions specific unit; and

(b) The demonstrated margin of compliance with the applicable emission standard; and

(c) The potential variability of emissions under normal and anticipated operating conditions; or

(6) Emission Factors: Use of EPA-approved emission factors for pollutants and for estimates of capture and controls, with and emission calculation methods described in "Compilation of Air Pollutant Emission Factors, EPA, AP-42 Volume 1: Stationary and Area Sources," including the most recent supplements at the time of application; and "Guidance for Procedures for Emission Inventory Preparation," U.S. EPA 450/4-81-02, as is appropriate for the application under consideration.

D. Step Two: Emission reductions will be certified by the Department as offset credits after application of a compliance assurance multiplier reflecting the method of measurement used to determine the base credit numerical value. The applicable compliance assurance multiplier will be determined as provided in the table below.

Method of Measurement	Compliance Assurance Multiplier
Continuous Emission Monitoring System (CEMS)	0.95
Mass Balance Calculations	0.95
Stack Testing	0.85
Capture and Control Efficiencies	as set by the Department and EPA
Parametric Monitoring	0.50 - 0.85, as determined by the Department and EPA
Emission Factors	0.50 - 0.85, as determined by the Department and EPA

Notes

06-096 C.M.R. ch. 113, § 5