​Rules that we all must play by........
             My first question is --------- Do you think a plant wants to have CEMS? 
All of the data below i got from the EPA and I went through and tried to cut it to show just what we need.​

 What is Part 75 and who must comply with it ?
The Part 75 rule, which is found in Volume 40 of the Code of Federal Regulations (CFR), was originally published in January, 1993. The purpose of the regulation was to establish continuous emission monitoring (CEM) and reporting requirements in support of EPA’s Acid Rain Program (ARP), which was instituted in 1990 under Title IV of the Clean Air Act. The Acid Rain Program regulates electric generating units (EGUs) that burn fossil fuels such as coal, oil and natural gas and that serve a generator > 25 megawatts. For these units, Part 75 requires continuous monitoring and reporting of sulfur dioxide (SO2) mass emissions, carbon dioxide (CO2) mass emissions, nitrogen oxides (NOx) emission rate, and heat input. The SO2 component of the ARP is a “cap and trade” program, designed to reduce acid deposition by limiting SO2 emission levels in the “lower 48" states of the U.S.A.
In October, 1998, EPA added Subpart H to Part 75, which provides a blueprint for the monitoring and reporting of NOx mass emissions and heat input under a State or Federal NOx emissions reduction program. The Agency anticipated that such programs were likely to come into existence, due to growing concern over health hazards associated with NOx emissions from power plants and large industrial sources. NOx is a precursor to ozone and fine particulate matter formation. Subpart H was first adopted as the required monitoring methodology for NOx mass emissions and heat input under the NOx Budget Trading Program (NBP).​​​

​​Why is continuous monitoring necessary?
Emissions monitoring and accounting are the backbone of cap and trade programs. Because the emission allowances are based on the total mass of a pollutant emitted over a certain time period, emissions must be monitored continuously during the compliance period. It is therefore essential to have a reliable measurement method for the commodity being regulated and traded---in this case, emissions— to ensure that the goal of achieving actual, measurable emissions reductions in a cost-effective manner is met. Part 75 provides the necessary measurement method, and gives value to the traded commodity by:
• Ensuring that the emissions from all sources are consistently and accurately measured and reported. In other words, a ton of emissions from one source is equal to a ton of emissions from any other source;
• Requiring a complete record of emission data to be produced for each unit in the program (i.e., data are obtained for every hour of unit operation);
• Verifying that emission caps are not exceeded, thereby ensuring that emissions are not underestimated and that emission reduction goals are being met.

​​Conduct Quality Assurance/Quality Control Procedures
After certification, the following periodic performance evaluations of all monitoring systems must be conducted, to ensure the continued accuracy of the emissions data:
• The quality-assurance tests for CEMS include daily assessments (e.g., calibration error tests), quarterly assessments (e.g., linearity checks), and semi-annual (or annual in most cases) relative accuracy test audits (RATAs);
• For Appendix D fuel flowmeters, annual accuracy tests are required; and
For all required continuous monitoring systems, a written quality assurance (QA) plan must be developed and followed. The quality control plan includes step-by-step procedures for each of the required QA tests, as well as procedures for calibration adjustments, preventive maintenance, audits, recordkeeping and reporting.

​​What is a continuous emission monitoring system (CEMS)?
A continuous emission monitoring system, or CEMS, consists of all the equipment needed to measure and provide a permanent record of the emissions from an affected unit. Examples of CEMS components include:
• Pollutant concentration monitors (e.g., SO2 or NOx monitors).
• Diluent gas monitors, to measure %O2 or %CO2
• Stack gas volumetric flow rate monitors
• Sample probes
• Sample (“umbilical”) lines
• Sample pumps
• Sample conditioning equipment (e.g., heaters, condensers, gas dilution equipment)
• Data loggers or programmable logic controllers (PLCs)
• DAHS components that electronically record all measurements and automatically


​​3.4.1 Determining lb/mmBtu emission rates
To calculate NOx emission rates in terms of mass per unit of heat input (lb/mmBtu), NOx concentration data, diluent gas (CO2 or O2) concentration data, and a fuel-specific “F-factor” are required. The F-factor relates the volume of stack gas or CO2 produced by combustion to the heat content of the fuel combusted. For example, typical units for an F-factor are dry standard cubic feet of stack gas per million Btu of heat input (dscf/mmBtu), or standard cubic feet of CO2 per million Btu (scf CO2 /mmBtu). Fuel-specific F-factors are listed in Appendix F of Part 75. These factors are based on the thermodynamic principles of combustion. Since F-factors are derived assuming that fuel and air are mixed in an exact stoichiometric ratio and that combustion is complete, the NOx emission rate equations include corrections for excess air.
3.4.2 Determining pollutant mass emission rates
To determine pollutant emission rates in terms of mass per unit time (e.g., lb/hr or tons/hr) the pollutant concentration is multiplied by the stack gas flow rate and an appropriate conversion constant. A correction for moisture may also be required. The hourly pollutant mass emission rate in lb/hr may also be calculated by multiplying the heat input-based emission rate (lb/mmBtu) by the heat input rate (mmBtu/hr).
3.4.3 Determining heat input rate, in mmBtu/hr
To determine the hourly heat input rate (mmBtu/hr), the stack gas flow rate (scfh) is divided by the appropriate F-factor (scf/mmBtu), and a correction for excess air is applied, using the measured diluent gas concentration. A moisture correction may also be required.

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