New Source Performance Standards

NSPS originated with the CAA of 1970. The authority for the NSPS regulations is in Section 111 and covered by Title V. NSPS regulations establish stringent emission limitations for new or substantially modified sources in designated industrial categories regardless of the state or ambient air quality region in which the source is located. These source category limits are the maximum allowable emissions for the applicable sources. The emission limits are meant to represent the “best

demonstrated technology,” taking into consideration cost and energy and environmental impacts. The basis for NSPS limits is different than for BACT. NSPS levels are negotiated as industry-wide standards, while BACT is determined on a case-by-case basis. For this reason, BACT standards are usually more stringent than NSPS standards.

The source categories affected by NSPS regulations are those that have been identified by EPA as emitting one or more pollutants in quantities significant enough to endanger the public health or welfare. Under the NSPS regulations these sources must either (1) achieve the degree of emission limitation or percentage reduction or (2) apply a design, equipment, work practice, operational standard, or combination which reflects the best available technological system of continuous emission reductions. Examples of general control methods currently in use under the NSPS regulations include the following:

• Air pollution control systems such as electrostatic precipitators, fabric filters, wet scrubbers, and dry scrubbers

• Precombustion cleaning or treatment of fuels

• Inherently low-polluting or nonpolluting production processes

• Work practices and operational standards

Between 1970 and 1990, the U.S. EPA promulgated NSPS standards for more than 70 source categories. The owner/operator of a new or

modified source subject to one of the NSPS regulations must

demonstrate compliance within 180 days of initial start-up of the facility and at other times as required by EPA. Primary authority for the enforcement of these regulations rests with EPA. However, in most cases, this authority has also been delegated to the states. In such cases, the states and EPA have concurrent enforcement authority.

NOX REGULATORY PROGRAMS 4-19 NSPS standards cover the same facilities regulated by the PSD and NSR programs. However, these programs differ in a few important aspects.

One difference is that NSPS is the responsibility of the federal EPA, while NSR/PSD is the responsibility of one of the 10 EPA regional offices. In addition, NSPS sets an emission limit standard covering all facilities included in a specified source category; while NSR/PSD emission limits are established on a case-by-case basis.

Revised Fossil Fuel-Fired Boilers NSPS

On September 24, 1998, EPA repromulgated the NSPS NOX limits for utility boilers (40 CFR Part 60, Subpart Da) and industrial boilers (40 CFR Part 60, Subpart Db). The reductions were made to reflect the

performance of the most recent best demonstrated technology. After considering available performance data and performing cost analyses, EPA chose Selective Catalytic Reduction (SCR) as the basis for revising the NO_X emission limits for both categories of boilers.

In the revised NSPS, EPA states that, “The revisions being promulgated reflect the Administrator’s determination that the best system of NO_X emission reduction (taking into consideration the cost of achieving such emission reduction and non-air quality health and environmental impact) for these sources is now reflective of flue gas treatment technologies, particularly SCR.”⁴ The new limits are based on coal-firing electric utility boilers and industrial boilers with SCR units installed in combination with combustion controls.

The new revisions regulate NO_X, SO₂, and PM emissions by developing a single limit for an industrial category. The limit is expressed as emissions per unit of output energy. The new emission limits are on a “fuel neutral emission rate,” which is meant to add flexibility and encourage industry to use cleaner fuels such as natural gas.

The NSPS revisions affect those utility and industrial boilers for which construction is commenced after the date of proposal. The EPA

estimates that 17 new utility boilers and 381 new industrial boilers will be constructed in the next five years.

The new limits would reduce NOX emissions by approximately 42% from the existing standards. The reduction of baseline NOX emissions from utility steam generating units is approximately 23,000 Mg/year (25,800 tons/year) and from industrial steam generating units is 18,000 Mg/year (20,000 tons/year) in the fifth year after proposal.⁴

Subpart Da of the NSPS covers electric utility steam generating units that are capable of combusting more than 73 MW (250 MMBtu/hr) heat input of fossil fuel. The NOX emission limit in the final rule for newly

constructed subpart Da units is 200 ng/JO [1.6 lb/megawatt-hour (MWh)]

gross energy output, regardless of fuel type. The NOx emission limit in the final rule for existing sources that become subject to subpart Da

4-20 NOX REGULATORY PROGRAMS

through modification or reconstruction is 65-ng/J_I [0.15 lb/MMBtu] heat input.

Industrial-commercial-institutional steam generating units greater than 29 MW (100 MMBtu/hr) of power are categorized under Subpart Db. For units covered under subpart Db, the NO_X emission limit being

promulgated is 87 ng/J_I (0.20 lb/MMBtu) heat input from the combustion of natural gas, oil, coal or a mixture containing any of the fossil fuels.

However, for low heat release rate units firing natural gas or distillate oil, the current NO_X emission limit of 43 ng/ J_I (0.10 lb/MMBtu) heat input is unchanged.

NOX REGULATORY PROGRAMS 4-21

Review Exercises

1. Which of the following programs are designed to attain the ozone NAAQS through the control of NOX emissions?

(Select all that apply.)

a. Eight-hour ozone NAAQS b. NOX SIP Call

c. Section 126 Petitions d. One-hour ozone NAAQS e. All of the above

2. Which of the following distinguishes pollutants covered by NAAQS from those covered by NESHAPs?

(Hint: Choose the answer associated with those pollutants covered by NAAQS.) a. These pollutants are only emitted by fossil fuel-fired boilers.

b. Causes irreversible or incapacitating illness at low concentrations.

c. Emitted by numerous diverse stationary and mobile sources.

d. All of the above

3. Match the following acronyms with the descriptions given.

a. SIP b. NAAQS

i. Stringent emission limitations for new or substantially modified sources in designated industrial categories regardless of the state or ambient air quality region in which the source is located.

c. NSPS d. PSD

ii. Standards set for the group of six common air pollutants (criteria pollutants) defined by EPA. The standards are to maintain low concentrations of the criteria pollutants in the ambient air in order to protect public health.

iii. Plan developed by state air pollution control agencies to demonstrate attainment of the NAAQS.

iv. Regulation aimed at protecting Class I and other attainment areas.

4-22 NOX REGULATORY PROGRAMS

4. Match the following acronyms with the descriptions given.

a. BACT b. NSR c. SIP

i. Case-by-case emission limits based on the most up-to-date methods, systems, techniques, and production processes available to achieve the greatest feasible reductions taking into consideration energy, environmental, and economic impacts.

d. LAER

ii. A state plan adopted and submitted to EPA that addresses the implementation, maintenance, and enforcement of standards set forth by EPA.

iii. Requires all major new sources and significantly modified sources in both non-attainment areas and attainment areas to obtain permits.

iv. The best and most up-to-date control technology without consideration of economic cost used to determine emission limits for the NSR program.

5. When were the NAAQS first introduced into law?

a. 1963

b. 1967

c. 1970

d. 1990

6. When was acid deposition control under Title IV first promulgated?

a. 1963

b. 1967

c. 1970

d. 1990

7. Title IV requires the reduction of which of the following emissions?

(Select all that apply.) a. Sulfur dioxide

b. Ozone

c. Nitrogen oxides d. None of the above

NOX REGULATORY PROGRAMS 4-23

References

1 Mobley, J. D. July 2, 1999. Memorandum - Implications of the Court Decision on Emission Inventory Guidance.

2 Environmental Protection Agency, Office of Air Quality Planning and Standards. November 18, 1998. Emission Inventory Guidance for

Implementation of Ozone and Particulate Matter National Ambient Air Quality Standards (NAAQS) and Regional Haze Regulations– Draft Guidance.

Research Triangle Park, NC.

3 Environmental Protection Agency. Findings of Significant Contributions and Rulemaking on Section 126 Petitions for Purposes of Reducing Interstate Ozone Transport. 40 CFR Parts 52 and 97.

4 Environmental Protection Agency. Revision of Standards of Performance for Nitrogen Oxide Emissions From New Fossil-Fuel Fired Steam Generating Units; Revisions to Reporting Requirements for Standards of Performance for New Fossil-Fuel Fired Steam Generating Units. RIN-2060-AE56, Final Rule.

40 CFR Part 60.

COMBUSTION SOURCES 5-1