Air - Details 

Emissions monitoring is conducted to determine the concentration of a gas or particulate matter in the air. It can be done by the state to demonstrate compliance with its State Implementation Plan (SIP); or it can be performed by a specific facility to show that it is meeting applicable emissions standards. This part of the tour focuses on air-emissions monitoring requirements contained in the following four federal air-pollution-control regulatory programs:

• Operating permit provisions under Title V of the 1990 Clean Air Act (CAA) Amendments (40 CFR 70)
• Acid Rain Program (40 CFR 72)
• New Source Performance Standards (40 CFR 60)
• Hazardous Air Pollutants program (40 CFR 63)

Operating permit provisions under Title V of the 1990 Clean Air Act (CAA) Amendments (40 CFR 70): 40 CFR 70 contains requirements for new operating permit provisions under Title V of the 1990 CAA Amendments. A Title V operating permit is required for new and existing facilities that:

• Are considered a "major stationary source," which varies according to the pollutants emitted and the attainment designation of the area where the source is located; this means sources that:
  • Emit or have a PTE (potential to emit) 10 tons or more per year of a hazardous air pollutant (HAP) as defined under any Section 112 of the CAA, or 25 tons per year of any combination of HAPs
  • Emit or have a PTE of 100 tons per year of any regulated air pollutant
  • In non-attainment areas, have the potential to lead to ozone formation, carbon monoxide, or particulate matter in amounts greater than regulated thresholds; or
• Are subject to a New Source Performance Standard (NSPS) or a National Emission Standard for Hazardous Air Pollutant (NESHAP) (However, EPA allows States to decide whether to require Title V permits of non-major sources that are subject to a NSPS or NESHAP.); or
• Are subject to the Acid Rain Provisions (However, EPA allows States to decide whether to require Title V permits of non-major sources that are subject to the Acid Rain Provisions.); or
• Are required to have a pre-construction review permit under the Prevention of Significant Deterioration (PSD) or the New Source Review (NSR) Program (In most cases, these will already be major sources. In addition, many states have minor NSR programs applicable to facilities that are not subject to Title V because they are not major sources.)

The regulations require that Title V permits contain conditions regarding applicable monitoring and testing requirements, including periodic monitoring; the use, maintenance and installation of monitoring equipment or methods; and recordkeeping. Monitoring records must be maintained for at least five years from the date of monitoring sample. In addition, the permit must specify conditions for reporting, including the submission of the required monitoring reports at least every six months and the prompt reporting of upset conditions.

Acid Rain Program (40 CFR 72): This program was developed to reduce sulfur dioxide and nitrous oxide emissions by requiring affected facilities to account for each ton of emissions from each regulated unit. It may apply to your power plant if it is a unit listed in 40 CFR 73.10 (i.e., a fossil-fuel-fired combustion device), or if it is a utility unit (i.e., a unit owned or operated by any entity that sells electricity). If your campus power plant does not meet the criteria defining an affected facility, then the Acid Rain Program does not apply to your operation. If, however, the program does apply, then you must implement certain monitoring requirements established by the EPA, including Soc, volumetric flow, NOx, dilute gas, opacity, and CO₂.

If the affected unit is over 25 megawatts or is a new unit under 25 megawatts that uses fuel with a sulfur content greater than 0.05 percent by weight, then the owner/operator is required to measure and report emissions under the Acid Raid Program. In this case, the owner/operator must install continuous emissions monitoring systems (CEMS) on the unit (unless otherwise specified in the regulations), which include:

• An SO₂ (sulfur dioxide) pollutant concentration monitor
• A NO_x (nitric oxide or nitrogen dioxide) pollutant concentration monitor
• A volumentric flow monitor
• An opacity monitor
• A diluent gas (O₂ or CO₂) monitor
• A computer-based data-acquisition and handling system for recording and performing calculations with the data

Other requirements applicable to affected units/facilities include: performance certification tests for equipment monitoring, quality assurance/control, and recordkeeping and reporting.

New Source Performance Standards (NSPS): The New Source Performance Standards (NSPS) contained in 40 CFR 60 address a variety of different types of new or modified stationary air-emission sources. Sources covered by NSPS range from Portland cement plants and petroleum refineries to primary zinc smelters and grain elevators. Each source type is addressed in a separate NSPS Subpart. For example, the General Provisions (which apply to all NSPS sources) are contained in 40 CFR 60 Subpart A. These standards apply to the owner or operator of any stationary source that contains an "affected facility" whose construction or modification is commenced after the date of publication of this part of any standard applicable to that facility (or, if earlier, the date of publication of any proposed standard).

If an owner or operator is subject to the NSPS, the following requirements contained in the General Provisions listed below apply. (You should note that more stringent requirements contained in individual NSPS Subparts may apply for a specific source. If that is the case, then such requirements would supercede those of the General Provisions. Similarly, individual subparts may include provisions that make certain requirements listed below inapplicable.) The requirements of the General Provisions are as follows:

• Notification must be made to the EPA (or authorized representative) and must include, as appropriate:
  
  • The date of construction of an affected facility, within 30 days of that date
  • The actual date of initial startup of an affected facility, within 15 days of that date
  • A detailed description of any physical or operational change (unless otherwise exempted) to an existing facility that may increase the emission rate of any air pollutant to which a standard applies, within 60 days or as soon as practicable before the change is commenced
  • The date on which demonstration of continuous emissions monitoring system (CEMS) performance commences if CEMS is required--not less than 30 days prior to that date
  • The anticipated date for conducting opacity observations (if required) and a request for a visible-emissions reader--not less than 30 days prior to the date of the performance test
  • A notice of any intent to use a continuous opacity-monitoring system rather than using a visible-emissions reader--not less than 30 days prior to the performance test
• Records must be kept of the occurrence and duration of any startup, shutdown or malfunction in the operation of an affected facility; any malfunction of the air-pollution-control equipment; or any periods during which a CEMS or monitoring device is inoperative.
  
• Excess emissions and monitoring systems performance reports must be submitted by an owner/operator required to install a CEMS device semiannually, postmarked by the 30th day following the end of each six-month period.
  
• Records must be kept of all measurements, including CMS, monitoring-device and performance-testing measurements; all CMS performance evaluations; all CMS or monitoring-device calibration checks, adjustments and maintenance performed on these systems or devices; and all other information required by NSPS recorded in a permanent form suitable for inspection. All such records must be retained for two years (certain exceptions apply).

A CEMS is all the equipment necessary for the determination of a gas, particulate matter concentration or emission rate. A CEMS uses pollutant analyzer measurements and a conversion equation, graph or computer program to produce results in units of the applicable emissions limitation or standard.

Two NSPS sources commonly found in a campus power plant are Small Industrial-Commercial-Institutional Steam Generating Units (e.g., your campus' power plant boilers) (40 CFR 60 Subpart Dc) and Stationary Gas Turbines (40 CFR 60 Subpart GG), both of which are described below.

Small Industrial-Commercial-Institutional Steam Generating Units - If your campus has a boiler that has a maximum design heat input capacity of 29 megawatts (MW) (100 million Btu per hour [Btu/hr]) or less, but greater than or equal to 2.9 MW (10 million Btu/hr), and was constructed, modified or reconstructed after June 9, 1989, then NSPS Subpart Dc is applicable. Subpart Dc includes: emissions standards, compliance and performance test methods and procedures, emissions monitoring, and reporting and recordkeeping requirements for sulfur dioxide and particulate matter. The specific requirements vary according to the type(s) of fuel used.

Stationary Gas Turbines - NSPS Subpart GG applies to stationary gas turbines that have a heat input at peak load equal to or greater than 10.7 gigajoules (10 million Btu) per hour, based on the lower heating value of the fuel fired, and for which construction, modification or reconstruction commenced after October 3, 1977. Subpart GG includes emissions standards, operations monitoring and test methods and procedures required for nitrogen oxides and sulfur dioxide.

Hazardous Air Pollutant (HAP) Program: EPA regulates stationary sources that emit or that have the potential to emit any one or more of the hazardous air pollutants identified in 40 CFR 63. (Note: This is separate from the NESHAPs program in 40 CFR 61.) If the HAP program is applicable to your campus power plant, then you may be subject to requirements in the following areas: operation and maintenance, opacity and visible emissions standards, performance testing, continuous emissions monitoring, notifications to the EPA regarding construction/reconstruction of (new) sources, recordkeeping and reporting. The monitoring requirements of the regulations govern the conduct of monitoring, and requests to use alternative monitoring methods, and specific parameters affecting sources required to use continuous monitoring systems (CMS).

For the complete text of the regulations described above (40 CFR 60, 63, 70, and 72), click here: