OZONE 

TRANSPORT 

COMMISSION 

Connecticut 

Delaware 

District of Columbia 

Maine 

Maryland 

Massachusetts 

New Hampshire 

New Jersey 

New York 

Pennsylvania 

Rhode Island 

Vermont 

Virginia 

Anna Garcia 

Executive Director 

444 N. Capitol St. NW 

Suite 638 

Washington, DC 20001 

(202) 508-3840 

FAX (202) 508-3841 

e-mail: ozone@otcair.org 

September 8, 2010 

Lisa P. Jackson, Administrator 

U.S. Environmental Protection Agency 

Air and Radiation Docket 

Mail Code 6102T 

1200 Pennsylvania Avenue, N.W. 

Washington, DC 20460 

RE: Proposed Rule - Docket No. EPA-HQ-OAR-2010-0295 

Dear Administrator Jackson: 

The Ozone Transport Commission (OTC) appreciates the opportunity to 

comment on EPA's proposed rule, "Standards of Performance for Stationary 

Compression Ignition and Spark Ignition Internal Combustion Engines (40 CFR Parts 

60, 1039, 1042, et al.)." The comments herein focus on three issues: (1) emission 

rates for stationary combustion engines; (2) fuel sulfur content limits; and (3) EPA's 

revised definition for emergency demand response. 

Emission Rates 

OTC supports EPA's proposal to align Federal restrictions on emissions of 

particulate matter (PM), oxides of nitrogen (NOX), non-methane hydrocarbons 

(NMHC) and carbon monoxide (CO) from new stationary compression ignition (CI) 

engines with displacement greater than 10 I/cylinder with corresponding non-road 

engine emissions standards for these marine-propulsion and locomotive-type 

engines. (Smaller displacement new stationary engines, typically used for emergency 

generator sets, are already subject to New Source Performance Standards (NSPS) 

emissions limitations that took effect in 2006. They have been aligned with 

corresponding non-road emissions standards.) 

The proposed NSPS amendments also restricts the level of sulfur permitted 

in diesel fuel used in new stationary CI engines greater than 10 I/cylinder. 

OTC is currently developing a draft model rule proposing to set emission 

limits on new, stationary internal combustion engines. The emission limit in the OTC 

draft model rule for new, non-emergency stationary internal combustion engines is 

0.88 IbjMWh NOx (0.4 gjkWh). This is consistent with the Tier 4 non-road engine 

limits that EPA already promulgated (40 CFR 1039). 

The standards EPA is proposing for stationary engines should be consistent 

with the emission limits already promulgated for non-road stationary combustion 

engines. OTC also recommends that these limits should be applied to any portable 

engine that is on site for more than 30 days. These units should not be considered 

portable. 
EPA may also want to consider other provisions that may be included in the OTC model rule, 

which would potentially limit emissions or ensure compliance with the limits in the OTC model rule. 

These provisions include: 

o Monitoring and data reporting on generator usage; 

o Incentives for combined heat and power; 

o Incentives for innovative technologies; and 

o Emission standards for demand response programs. 

Fuel Sulfur Content 

OTC recommends that EPA reduce the maximum fuel sulfur content for stationary engines as 

soon as possible to 15 ppm, as already required for on-road and off-road mobile engines. This is 

consistent with the Northeast and Mid-Atlantic States' commitment to pursue low sulfur in fuel limits to 

help meet the reasonable progress goals set in their state implementation plans for regional haze. 

Emergency Demand Response 

The OTC urges EPA to eliminate its definition of emergency demand response in the proposed 

rule as referenced in the preamble. The OTC also urges EPA to clarify the distinction between 

emergency response units and price response units in its definition of "Emergency stationary internal 

combustion engine" in the proposed rule. Because there are differences between the Independent 

System Operators (ISOs) in the treatment of emergency generator operations, it is critical to have a clear 

distinction between true emergency operations and operation of uncontrolled engines in price response 

mode. We further recommend that EPA evaluate the definition of "real-time emergency generation 

resource" as specified in the current Independent System Operator (ISO) New England, Inc. 

Transmission, Markets and Services Tariff, FERC Electric Tariff No.3, issued December 22, 2004, which 

states: 

"Real-Time Emergency Generation Resource is Distributed Generation whose Federal, State 

and/or local air quality permits limit operation in response to requests from the ISO to the t imes 

when the ISO implements voltage reductions of five percent of normal operating voltage that 

require more than 10 minutes to implement. A Real-Time Emergency Generation Resource must 

be capable of: (i) curtailing its end-use electric consumption from the New England grid within 

30 minutes of receiving a Dispatch Instruction; and (ii) continuing that curtailment until 

receiving a Dispatch Instruction to restore consumption." 

The OTC understands the need for emergency generation and on-peak demand response to 

ensure the reliable delivery of electricity by the various ISOs in our region. As we saw in 2003, there are 

significant public health and economic impacts in addition to air quality considerations that are 

associated with wide-scale grid failure. However, the use of emergency engines to generate electricity 

to satisfy on-peak demand has significant public health impacts on high electric demand days (HEDDs). 

These impacts include high emission rates of ozone precursors and air toxics, which greatly exacerbate 

already impaired air quality on these HEDDs. As a result, OTC believes that EPA should discourage the 

operation of emergency generators to satisfy on-peak demand unless emergency generation is 

necessary to address a true power emergency. 

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With respect to the need for emergency generation in true emergencies (blackouts and 

brownouts, including periods of five percent voltage reduction), OTC believes that restricting the hours 

of operation is not necessary if the definition of "emergency" is specific enough and stringent enough to 

preclude the operation of emergency engines in price-response mode. As such, OTC recommends EPA: 

• Develop a definition of "emergency" that provides precise conditions, including periods of five 

percent voltage reduction, as exemplified by ISO-NE in the implementation of their current 

"real-time emergency generation resource" definition in Tariff No. 3 dated December 22,2004; 

• To the extent possible, set environmental standards that will incentivize the dispatch of nongenerating demand response resources prior to the dispatch of polluting demand response 

resources; and 

• To the extent that emergency engines are called upon to meet on-peak demand, EPA's rules 

should ensure that control technology complements the intended use of these engines for quick 

start capacity and require that emission controls are operating at full effectiveness as soon as 

possible, but not later than 10 minutes following engine start up or the amount of time 

recommended by the engine manufacturer if add-on controls like selective catalytic reduction 

(SCR) are applied. 

In addition to these specific recommendations on the proposed rule, OTC also requests that EPA 

consider with the Federal Energy Regulatory Commission (FERC) the potential energy and environmental 

benefits achievable from the national adoption by all of the ISOs of a definition of emergency consistent 

with the first of the above three bullets. 

OTC respectfully submits these comments for EPA's consideration in developing a final rule for 

new source performance standards on stationary combustion engines. We welcome further discussion 

on this issue and offer our assistance to EPA as work proceeds on development of a final rule. Please 

contact me with any questions at (202) 508-3840. 

Sincerely, 

Anna Garcia 

Executive Director 

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