1 

SUMMARY OF COMMENTS AND RESPONSES TO COMMENTS, 

FROM PUBLIC HEARINGS ON PROPOSED AMENDMENTS TO 

310 CMR 7.00 et seq. And 310 CMR 70.00 

This regulation revision affects the requirements for engines and combustion turbines 

under the Commonwealth's Air Pollution Control Regulations. Public Hearings were 

held on the proposed amendments on June 22, 2004 in Boston and June 23, 2004 in 

Springfield. The hearing record was held open until 5:00 PM on June 30,2004. 

This document responds to comments that were received from the following parties: 

Associated Industries of Massachusetts (Assoc. Industries of Mass.) 

Biomass Energy Resource Center (Biomass Energy Resource Center) 

Blue Sky Environmental LLC (Blue Sky) 

Bob Machaver (Machaver) 

City of Boston Environmental Department (BOSTON) 

Conservation Law Foundation (Conservation Law) 

Division of Energy Resources (Div. of Energy Resources) 

Earth Tech (Earth Tech) 

Energy and Environmental Analysis, Inc (Energy & Env. Analysis) 

EnerNoc, Inc (EnerNoc) 

Engine Manufacturers Association (Engine Mfg.) 

ExxonMobile (Exxon) 

GE Aircraft Engines (General Electric) 

Harvard University (Harvard) 

Homestead Inc. (Homestead) 

ISO-New England (ISO New England) 

Massachusetts Institute of Technology (MIT) 

Massachusetts Petroleum Council (Mass Petroleum) 

Massachusetts Water Resources Authority (MWRA) 

MASSPIRG (MASSPIRG) 

New England Combined Heat and Power Initiative (NECHPI) 

Northeast Energy and Commerce Association (NECA) 

Northeast Utilities System (Northeast) 

Pentti Aalto (Aalto) 

Pinpoint Power (Pinpoint) 

Polaroid Corporation (Polaroid) 

Regulatory Assistance Project (RAP) 

Solar Turbines (Solar Turbines) 

Southworth-Milton (Southworth-Milton) 

Tennessee Gas Pipeline (Tennessee Gas) 

United States Environmental Protection Agency (EPA) 
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TABLE OF CONTENTS 

GENERAL ISSUES 3 

RAP MODEL RULE 10 

EXISTING REGULATION REVISIONS 11 

NEW REGULATIONS 15 

COMBINED HEAT AND POWER 37 
3 

GENERAL ISSUES 

Comment 1. 

Supports the proposal in concept, including requiring emergency engines to meet federal 

standards and the diesel fuel requirements. (Polaroid) 

Response: 

Comment noted. 

Comment 2. 

Supports the proposal in the following areas: use of "national model with regard to 

emission standards"; process and paperwork reduction aspects; and clearer direction of 

what is required. (Assoc. Industries of Mass.) 

Response: 

Comment noted. 

Comment 3. 

The DEP must provide sufficient staff and oversight of the Environmental Results 

Program (ERP) tools as they apply to these generators. (BOSTON) 

Response: 

The Department of Environmental Protection (DEP) has proposed the use of ERP tools to 

implement regulations for engines and turbines. The ERP methods such as certification, 

piggybacking on federal standards for emissions and fuel, along with specifying 

operational and dispersion requirements in the rule, are much less resource intensive than 

case-by-case review of individual projects. 

Comment 4. 

DEP should consider requiring Diesel Oxidation Catalysts on "older, dirtier generators to 

supplement the improvements by use of ULSD." (BOSTON) 

Response: 

The DEP's strategy for older engines is to gain emission improvements by requiring the 

burning of cleaner fuel. In the long run, these older engines will be replaced with cleaner 

engines meeting the up-to-date standards. 
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Comment 5. 

"There are compelling health reasons limiting the operation of older diesel fired 

distributed generators." An attached paper titled "Health Risks of Exhaust from DieselFueled Electric Generators", Geoff Keith, Synapse Energy Economics, June 21, 2004 

examines and puts forth information on the health effects from diesel emissions. 

(MASSPIRG) 

Response: 

The DEP agrees that emissions from liquid fueled diesel engines can potentially pose 

health risks. To minimize these risks, it is not only important that the emission limitations 

reflect the state-of-the-art and burn clean fuel, but also that the units are sited and built 

with suitable emission dispersion characteristics to minimize ambient impacts. DEP 

believes the changes to these regulations will improve air quality from liquid fueled 

engines. 

Comment 6. 

"The DEP has provided only minimal background information on the Proposed Rule. 

More detailed background should be made available to discuss the basis and achievability 

of the standards, and the environmental benefits from implementing the Proposed Rule." 

(Tennessee Gas) 

Response: 

The regulatory strategy for emission limitations was based upon the Regulatory 

Assistance Project (RAP) Model Rule and recent Best Available Control Technology 

(BACT) determinations of DEP. This was stated in the "Background Information 

Document." Reference to the web site where the RAP Rule is located was given. The 

formal title of the RAP Rule is "Model Regulation for the Output of Specified Air 

Emissions from smaller Scale Electric Generation Resources," "Model Rule and 

Supporting Documentation," dated 15 October 2002. This 55-page document includes 

lists of individuals and organizations that participated in the project, as well as those who 

commented. 

Comment 7. 

"The Proposed Rule does not include many necessary implementation details. For 

example, compliance-monitoring requirements are not defined. Monitoring provisions 

should be included that are based on the measurement or monitoring of operating 

parameters. In addition, other implementation issues, such as allowances during start-up 

and shutdown, should be addressed. (Tennessee Gas) 

Response: 

Implementation details, in the form of guidance documents, will be developed based 

upon the regulation's requirements as adopted. DEP will consult with regulated 

community as necessary on implementation details and intends to provide training as 

necessary for affected parties. 
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Comment 8. 

"The DEP has not provided any market-based options for compliance. TGP urges the 

DEP to consider such options, as it will enable companies to derive the most costeffective solution for compliance." (Tennessee Gas) 

Response: 

DEP did not propose any market-based options. No comments were received that provide 

information about any market-based options for consideration. The basis for DEP's 

regulatory strategy is explained in the response to Comment 6. 

Comment 9. 

"The proposed regulations should have a provision that allows for variances, when 

warranted, due to the provision of significant other public benefits." (Biomass 

Energy Resource Center) 

Response: 

Regulations adopted by DEP that affect non-attainment pollutants, which these 

regulations do, must be submitted to EPA for approval into the Massachusetts State 

Implementation Plan (SIP). Emission limits in the SIP are either stated in a regulation or 

are determined by a state new source review (NSR) program. The Massachusetts' NSR 

program requires case-by-case review and approval; the emission limits approved must 

represent BACT. 

Variances to BACT or regulatory emission limitations are possible, but would require 

that the varied emission limits be formally transmitted to EPA after public hearing as a 

single source SIP revision. This process is very time consuming, with the costs being 

borne by the applicant and DEP, and as a practical matter is a very limited option. 

Comment 10. 

"The regulations need to recognize the environmental differences between systems that 

operate frequently and those that only run occasionally. Expensive after treatments 

provide little environmental benefit in peaking systems when peaking do not run. 

(NECA) 

Response: 

The proposal at 310 CMR 7.26(43)(a)2. allows individual case-by-case review and 

approval to set specific BACT limits for specific circumstances such as peaking power 

units. 
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Comment 11. 

"The economic impact of the proposed regulation as stated in Section V of the 

Background Document does not adequately reflect the real costs of the proposed 

regulation and should be revised." (Engine Mfg Assoc) 

Response: 

A major part of this regulatory action is the shifting from a case-by-case review process 

to the DEP's Environmental Results Program (ERP) certification process. In either 

process, emission limits would be set based on state-of-the-art or BACT, resulting in no 

differences in air pollution control or operating costs. This shift to an ERP process should 

save the industry and DEP "permit" processing costs. 

The comment does not specify any examples of costs "not adequately reflected." 

Comment 12. 

"Adoption and implementation of the regulation as proposed will discourage, and perhaps 

halt, the expansion of DG and CHP in the Commonwealth of Massachusetts.' 

(Engine Mfg Assoc) 

Response: 

The Department disagrees. The regulations provide stringent and consistent emission 

requirements, but no more stringent than what would be considered BACT in the near 

term and anticipated BACT in the long run. As Massachusetts requires BACT at 

thresholds lower than Federal New Source Review requirements, the regulation are 

consistent with other Massachusetts' BACT requirements. As such, the regulations are 

neutral regarding DG and CHP. The regulations also provide a streamlined process for 

projects and provide manufacturers and developers with certainty of emission 

requirements for future DG and CHP project development. 

Comment 13. 

The DEP needs to have an effective outreach program to inform all parties of the 

requirements once the regulations are put in place. This includes publicizing the rules to 

building owners, contractors, engineers, etc. (Southworth-Milton) 

Response: 

The DEP agrees with the comment and intends to conduct an outreach program. 
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Fee System 

Comment 14. 

An emission fee system similar to the market based New Hampshire system should be 

implemented as soon as possible. DEP should initiate a committee with the task of 

developing an emissions fee-based system in lieu of the proposed emission standards. A 

proposed system could be developed in a few months. (Blue Sky), (NECA), (Aalto) 

Response: 

The DEP choose to control emissions from these sources based upon technology 

advances, not on a market based fees system. 

Fuel Requirements 

Comment 15. The ultra low sulfur diesel requirement should not preclude the use of biodiesel, bio-diesel blends, bio-oil, vegetable oils or other bio-fuels that can be used in 

diesel engines as long as they meet the EPA sulfur standards. (Homestead Inc.), 

(Biomass Energy Resource Center), (Div. of Energy Resources), & (BOSTON) 

Response: DEP agrees and the fuel requirement will be rewritten such that any liquid 

fuels that do not exceed the sulfur content of Ultra Low Sulfur Distillate (ULSD) are 

allowed. 

Comment 16. 

The citation of 40 CFR 80.500 in 310 CMR 7.05(l)(a)3. is correct. Proposed 310 CMR 

7.02(8)(i)5., 7.03(10)(b), 7.26(42)(c), and 7.26(43)(c) incorrectly cite 40 CFR 80.500(a). 

(Earth Tech) 

Response: 

40 CFR 80.500 is the correct citation. 

Comment 17. 

"We strongly believe the Department should require the use of non-road instead of 

highway diesel fuel for the applications regulated under 310 CMR 7.00." The federal 

non-road fuel track will require ULSD in 2012. 

Because of storage issues in different areas of the state and differences in the methods of 

deliveries, "it may be difficult for users to secure an available and affordable supply of 

ULSD highway fuel for use in small, sometimes remotely located engines.... We believe 

the requirement currently proposed in 310 CMR 7.00 could tax the ability of refiners, 
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suppliers and end users to supply and obtain adequate volumes of compliant ULSD, 

particularly in remote areas of the state." (Mass Petroleum), (Exxon), (Engine 

Manufacturers Assoc.) 

Response: 

The state of Connecticut has recently adopted regulations that require ULSD for 

stationary engines according to the same schedule as on-road vehicles. Connecticut's 

action should facilitate increased supplies and availability for remote locations in 

Massachusetts in addition to ULSD being required for mobile sources in these areas. The 

increased demand should provide an incentive for refiners and marketers. Since ULSD 

will be required for on-road engines across the country beginning in 2006, we do not 

believe that the stationary engine requirement in Massachusetts will present a large 

supply burden to industry. 

Comment 18. 

Highway use fuel is taxed by the state and federal governments. The same fuel used for 

non-road applications is dyed red and is not taxed. Because the highway use fuel may be 

the only fuel available in 2006, stationary source users will most likely have to pay the 

taxes (47.9 cents per gallon) and then seek reimbursement. (Mass Petroleum), (Exxon), 

(Engine Manufacturers Assoc.) 

Response: The Department is delaying the ULSD implementation date until July 1, 

2007 to allow ample time for the fuel distribution markets to stabilize. See response to 

Comment 17. 

Comment 19. 

"According to the suppliers of ultra-low sulfur diesel fuel, due to testing limitations, they 

cannot guarantee the sulfur content of the fuel to 0.015% or 15 ppm. A more realistic 

limit is 0.003% [sic] or 30 ppm sulfur content which is what the Connecticut DEP has 

proposed in its regulations." (Pinpoint Power) 

Response: 

Connecticut has recently adopted the same sulfur-in-fuel requirement that DEP has 

proposed i.e. 15 ppm. This is consistent with the sulfur-in-fuel requirements set by EPA 

for mobile sources beginning in 2006. In any case the regulation will allow purchase of 

15 ppm fuel until July of 2007. 

Comment 20. 

Engine manufacturers are reluctant to certify performance on any non-standard fuel and 

many void warranties for non-standard fuel use. Potential users of non-standard 

(alternative) fuels test performance on used engines rated from 50kW to 300kW. 
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"BERC encourages the development of a provision that provides for trial periods for the 

use of renewable fuels and a variance process that allows for flexibility." (Biomass 

Energy Resource Center) 

Response: 

310 CMR 7.26(43)(a)2. allows a unit fueled by non-traditional fuels to establish emission 

limits on a case-by-case basis by filing a Comprehensive Plan Application (CPA). The 

CPA process can be used to establish trial periods and allow flexibility for worthwhile, 

promising projects. See also response to Comment 9. 

Fuel Tankage Issues 

Comment 21. 

Many MWRA facilities use one fuel storage tank to supply fuel oil to both emergency 

generators and boilers. The proposal would require the installation of additional storage 

tanks or the purchase of ULSD for use in both emergency generators and boilers. "DEP 

should consider deferring the requirement of ULSD in these situations until market forces 

have stabilized the availability and cost of ULSD when this fuel is more readily available, 

at the inception of the non-road diesel program in 2010." (MWRA) 

Response: 

Emergency generators are limited to 300 hours per year operation. Most operate less than 

100 hours per year. Separate small tanks are not unreasonable. ULSD has been available 

in the Greater Boston area and the requirement that it be used in mobile sources will only 

increase its availability for stationary engines. 

Comment 22. 

"At MIT's power plant, the same liquid fuel tanks supply an emergency generator, the 

combustion turbine, and a boiler." ".. .it will be required to either(l) install, at a 

significant cost, a new fuel storage tank dedicated to fuel the emergency generator, or (2) 

use ULSD to fuel the power plant's combustion turbine and the boiler, at an estimated 

increased cost of several hundred thousand dollars annually." (MIT) 

Response: 

See response to Comment 21. 

Comment 23. 

Similar to Comments 21 and 22. Suggests that for small sources using a single tank to 

fuel different combustion processes, such as hospitals and schools, "it may be appropriate 

to provide either a compliance extension or an exemption to avoid their being 

inadvertently saddled with a significant new expense as a result of having to use ultra low 

sulfur oil for all combustion sources." (Machaver) 
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Response: 

See response to Comment 21. 

RAP MODEL RULE 

Comment 24. 

The development of the Model Rule was an open, two year, national stakeholder process. 

Consensus was reached except for carbon dioxide. (RAP) 

Response: 

Comment noted. 

Comment 25. 

The RAP Model Rule provides a strong and appropriate foundation for state emission 

standards. (MASSPIRG) 

Response: 

Comment noted. 

Comment 26. 

"While the Model Rule professes to be fuel neutral, the only way to currently meet the 

proposed emission standards is by using natural gas in new engines and /or after-market 

treatment devices. The emission limitations proposed for 2008 and beyond exceed 

currently demonstrated technology. BERC is particularly concerned about the unintended 

consequences these standards could have on the development and deployment of new 

fuels and cleaner technologies." (Biomass Energy Resource Center) 

Response: 

As stated in the Model Rule, the emission limits are "based on the levels of emissions 

that current technologies can achieve or are expected to achieve over the next decade." 

The three phases of increasingly tighter standards are intended to spur research and 

development to promote new fuels and cleaner technologies. The Department is 

committed to review the third phase standards prior to their effective date. This is to 

assure that the standards remain appropriate or alternatively, be amended as necessary. 

DEP may also review the second phase standards if it deems it appropriate to do so. 

Comment. 27. 

The model regulations are flawed and their development was not open nor a valid 

stakeholder process. Only Connecticut has proposed to follow the model. "A detailed 

technical document must be prepared by the Massachusetts DEP before proceeding 

further with this rule." (NECA) 
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Response: 

The DEP has used the RAP Model Rule, its supporting documentation and recent BACT 

determinations as its technical support for this proposal. DEP disagrees with the 

comment and believes the process was open and valid. In addition, DEP has provided 

another opportunity for public comment on all issues during this rulemaking process 

Also see responses to Comments 6, 24, 25, 26, and 74. 

Comment 28. 

The Model Rule was flawed. Does not believe consensus was reached. (Aalto) 

Response: 

See responses to Comment 6, 24, 25, 26, and 74. 

EXISTING REGULATION REVISIONS 

310CMR7.02(5)(a)3. Comprehensive Plan Application - Applicability 

Comment 29. 

"The proposed amendment to 310 CMR 7.02(5)(a)3 should reference 42 U.S.C. § 7547 

not §7457." (Biomass Energy Resource Center) 

Response: 

The reference will be changed to be consistent with 310 CMR 7.26(40)(b). Also see 

comment 40. 

310 CMR 7.02(8)(i) Emergency or Standby Engines 

Comment 30. 

DEP's background document states that "currently regulated existing liquid fueled 

emergency engines and turbines will be required to receive for use ULSD when available 

in 2006." 310 CMR 7.02(8)(i)l.b. voluntarily applies to existing emergency units 

smaller than 3,000,000 BTU/hr for those facilities electing to establish limits on the hours 
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of operation. It is not entirely clear whether the requirements for ULSD would apply in 

this situation. (Earth Tech) 

Response: 

Yes, engine operation being restricted by complying with 310 CMR 7.02(8)(i)2. through 

5. will be required to use ULSD as required by 310 CMR 7.02(8)(i)5. 

Comment 31. 

310 CMR 7.02(8)(i), 310 CMR 7.03(10), and 310 CMR 7.26(41) specify conditions 

when emergency units may operate. "The DEP should better define "imminent" in 

reference to threats to power outages." (BOSTON) 

Response: The DEP is adopting language as suggested by ISO-New England, the 

regional electrical transmission organization. See response to Comment 42. 

310 CMR 7.02(8)(i)3.b. and c. Emergency or Standby Engines 

Comment 32. 

"These sections of the regulations (and as they exist today) are inconsistent with the 

nature of the devices being addressed" Requests that 310 CMR 7.02(8)(i)3.b. be 

amended to read "A log of hours of operation" and also that 310 CMR 7.02(8)(i)3.c. be 

deleted. (Polaroid), (Harvard), supported by (Assoc. Industries of Mass.) 

Response: 

The existing regulatory language will be retained as it provides the requirements that 

DEP deems necessary for the regulation to be workable and enforceable by DEP and 

EPA. 

310 CMR 7.02(8)(i)5. and 310 CMR 7.03(10)(b) Fuel Requirements 

Comment 33. 

These sections are duplicative of 310 CMR 7.05(l)(a)3. and are opposed as unnecessary 

language. Concerned that these sections will create applicable requirements. These 

sections should be deleted. (Polaroid), supported by (Assoc. Industries of Mass.) 

Response: 

The fuel requirements are repeated in sections to assist small entities subject to the 

regulation by providing applicable requirements in one place. 
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310 CMR 7.02(2)(b)29. Exemptions from Plan Approval - Turbines and 

Reciprocating Engines 

Comment 34. 

Include the following language: "and an individual internal combustion engine such as a 

combustion turbine or reciprocating engine having an energy input capacity of less than 

3,000,000 BTU/Hr installed prior to [six months from the effective date]..." " As 

currently proposed, the new language will no longer specifically exempt these existing 

small units from plan approval, making their regulatory status in the MADEP regulations 

unclear." (General Electric) 

Response: 

The DEP agrees with the intent of the comment and language changes have been made in 

this section to assure greater clarity about past and future exemption requirements. 

310 CMR 7.03(10)(c) Reporting and Record Keeping 

Comment 35. 

This section requires records consistent with 310 CMR 7.02(8)(i)3. through 5., although 

310 CMR 7.02(8)(i)5. is not a recordkeeping requirement. The section should read 310 

CMR 7.02(8)(i)3. and 4. (Polaroid), supported by (Assoc. Industries of Mass.) 

Response: DEP agrees, and the language has been changed. 

310 CMR 7.05(l)(a)3. Stationary Engines and Turbines - Diesel Fuel 

Comment 36. 

Polaroid is concerned that Ultra Low Sulfur Distillate (ULSD) as specified in 310 CMR 

7.05(l)(a)3. may not be available for use as required by the regulations. (Polaroid), 

(General Electric), supported by (Assoc. Industries of Mass.) 

Response: 

The state of Connecticut has recently adopted regulations requiring the use of ULSD fuel 

by stationary engines and turbines during the same time frame as required by the 

proposed regulations. 
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ULSD is currently available for specific users in the Greater Boston area. The 

requirements that ULSD be used in on-road mobile sources in 2006 should promote 

widespread availability. 

See also Comments 17 and 18. 

Comment 37. 

In proposed 310 CMR 7.05(l)(a)3. language is suggested to replace the regulatory 

citations with descriptions of the size units that must burn ULSD. Also another language 

change suggests that "no supplier shall offer for sale" ULSD replace the proposed 

language of "no person ... shall accept delivery..." of ULSD. (Polaroid), (General 

Electric), supported by (Assoc. Industries of Mass.) 

Response: 

The first suggestion would extend coverage of the regulations to engines that received 

plan approvals under 310 CMR 7.02. This was not a part of the Department's proposal 

and as such the Department cannot make the change as suggested. 

With regard to fuel procurement, the Department's position is that it is incumbent on the 

owner/operator procuring the fuel to know what is required. 

Comment 38. 

The background document states that ULSD will be required in 2006 whereas the 

proposed regulation requires 500 ppm sulfur distillate in 2005 and 15 ppm sulfur 

distillate (ULSD) in 2006. (Earth Tech) 

Response: 

Yes. DEP's requirements parallel the federal implementation of lower sulfur content 

diesel fuel for motor vehicles. 

310 CMR 7.02(8)(i)5., 7.03(10)(b), and 7.05(l)(a)3. Fuel Requirements 

Comment 39. 

These sections should be changed to read "... diesel fuel that does not meet the 

applicable U.S. Environmental Protection Agency sulfur limits for fuel pursuant to 40 

CFR 80.29 as promulgated January 18,2001. On or after June 2006, no person shall 

accept for delivery for burning in any engines subject to the appropriate sections listed 

above, diesel fuel that does not meet the applicable U.S. Environmental Protection 

Agency sulfur limits for fuel pursuant to 40 CFR 80.500(a), and 80.520(a) and (b) as 

promulgated January 18, 2001." (EPA) 

Response: 
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Agree, changes have been made to the appropriate sections. The term "or any other" will 

be added following the word "diesel" to allow other fuels such as bio-derivatives to be 

burned so long as the sulfur content is the same or lower than ULSD. 

NEW REGULATIONS 

310 CMR 7.26(40)(b) Engines and Combustion Turbines - Applicability 

Comment 40. 

Change language to read "Engines regulated under 40 CFR 89,90, 91, and 92 are exempt 

from the requirements of 310 CMR 7.26(40) through (44) in its entirety." (EPA) 

Response: The language will be changed. 

310 CMR 7.26(41) Definitions - Emergency 

Comment 41. 

Suggests language to better define imminent threat of a power outage as follows: 

"Emergency shall also mean when the imminent threat of a power outage is likely due to 

failure of the electrical supply, such as when the operation of the emergency engine is 

required during the period of time in which the New England Regional System Operator 

begins voltage reductions or involuntary load interruptions within the Massachusetts load 

zone(s)." (Earth Tech) 

Response: 

The DEP is adopting language as suggested by ISO-New England, the regional electrical 

transmission organization. See response to Comment 42. 

Comment 42. 

Recommends modification of the definition to read as follows: 

"Emergency means an electric power outage due to failure of the grid, 'in whole or in 

part,' on-site disaster, local equipment failure, flood, fire, or natural disaster. Emergency 

shall also mean when the imminent threat of a power outage is likely due to failure of the 

electrical supply or when capacity deficiencies result in a deviation of voltage from the 

electrical supplier to the premises of three percent (3%) above or five percent (5%) below 
16 

standard voltage, 'or periods during which ISO New England, or any successor regional 

transmission organization, directs the implementation of voltage reductions, voluntary 

load curtailments by customers, or automatic or manual load shedding within 

Massachusetts in response to unusually low frequency, equipment overload, capacity or 

energy deficiency, unacceptable voltage levels, or other such emergency conditions." 

(ISO New England) 

Response: The DEP will adopt language as suggested, however without specific 

reference to ISO-New England. 

Comment 43. 

"EnerNOC strongly supports the DEP's Proposed amendment of the definition of 

"Emergency" as it pertains to the operation of new and existing emergency engines." 

(EnerNoc) 

Response: 

Comment noted. 

Comment 44. 

"The DEP's recommendation to amend the definition of "emergency" needs to explicitly 

include situations when ISO New England declares Action 12 under the New England 

Power Pool ("NEPOOL") Operating Procedure 4 ("OP 4") "Action During A Capacity 

Deficiency" or higher for a specified area. OP4, Action 12, as it is referred to, is the start 

of brownouts with the next step being involuntary interruptions of load." 

"It is recommended that the DEP use language similar to the language that the 

Connecticut DEP has used in its proposed amendment to the definition of emergency." 

(Pinpoint Power), (Blue Sky), (EnerNoc), (NECA) 

Response: 

The DEP is adopting language as suggested by ISO-New England, the regional electrical 

transmission organization. See response to Comment 42. 

310 CMR 7.26(42) Emergency Engines and Turbines 

Comment 45. 

Concerned that when existing emergency engines are replaced, their replacements, being 

subject to the proposed requirements, would become emission units under Appendix C, 

the Operating Permit Program. This would affect annual cost in fees and paperwork 

without environmental benefit. (Polaroid), (Harvard), (General Electric), supported by 

(Assoc. Industries of Mass.) 
17 

Response: 

Fees for operating permit sources are based on total emissions from a facility. Emergency 

engines emissions are required to be part of the operating permit fee determination for a 

facility subject to the operating permit program. "Emission units" are no longer part of 

the determination. 

Requirements for emergency engines will be the applicable requirements that must be 

included in a facility's operating permit in accordance with 310 CMR 7.00: Appendix 

C(5). 

Comment 46. 

A supplier-regulated scheme should be adopted where 310 CMR 7.26(42) for emergency 

engines would be comprised of sections (a) and (b) only, and 7.26(42)(d) would be 

addressed elsewhere in the regulations so as to not create applicable requirements in the 

Operating Permit sense. (Polaroid), supported by (Assoc. Industries of Mass.) 

Response: 

The requirements are located together to assist subject entities to find their requirements. 

This approach is designed to be user friendly, especially to those entities that may have 

few or even no other environmental regulatory requirements or may be small businesses 

with limited resources. The regulatory approach will remain as proposed. 

Comment 47. 

It is recommended that the new standards for non-road engines published in the June 29, 

2004 Federal Register be referenced. (EPA) 

Response: EPA's Tier IV standards were not part of the Department's proposal 

because they were adopted by EPA after DEP proposed these regulations. The DEP 

cannot adopt or reference the Tier IV standards without an additional rulemaking process. 

The Department intends to address this issue within the next year. 

Comment 48. 

Temporary emergency engines should exempted similar to 310 CMR 7.03(23) 

Temporary Boilers. (Harvard) 

Response: 

Under EPA's regulatory scheme for non-road engines, temporary emergency engines are 

regulated as non-road engines and would not be subject to the DEP's regulations. 

Comment 49. 
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"This section should be applicable to both emergency and standby engines , in 

conformity with existing subparts 310 CMR 7.02(8)(i) and 7.03(10), which historically 

regulated these engine classifications together." (General Electric) 

Response: DEP intends to continue regulation of standby units consistent with past 

practice. The DEP will adopt language to make clear that standby engines will be subject 

to 310 CMR 7.26(42). 

Comment 50. 

CLF supports the requirement that emergency engines be required to meet EPA non-road 

engine standards. "By bringing all emergency engines under one standard, the 

Department simplifies the regulation, more adequately protects Massachusetts's air 

quality, and avoids undue regulatory burden on the Department. Furthermore, because 

engine manufacturers are already preparing for the EPA standards, incorporating them 

into the proposed emissions limitations should not lead to additional costs for small 

engine manufacturers." (Conservation Law) 

Response: 

Comment noted. 

Comment 51. 

The proposed language is silent on previously approved emergency engines being 

allowed to operate in a manner consistent with the proposed change in the definition of 

"Emergency." Previously approved emergency engines should be allowed to operate 

under the criteria of a modified definition of emergency. (EnerNoc), (Pinpoint Power), 

(Blue Sky), (NECA) 

Response: Agreed, the appropriate sections have been changed to allow existing 

emergency units to operate consistent with the requirements for new units. 

Comment 52. 

"EMA supports the adoption of emission standards for emergency engines based on the 

US EPA Non-road Mobile Source Regulations." (Engine Mfg Assoc) 

Response: 

Comment noted. 

310 CMR 7.26(42)(b)l. Emergency Engines and Turbines - Emission Limitations 

Comment 53. 
19 

"Polaroid believes that the proper implementation of this program is through the 

suppliers." The following language is offered: " at the time of installation. No emergency 

engine ... shall be offered for sale that has not obtained a certificate of conformity..." 

(Polaroid), supported by (Assoc. Industries of Mass.) 

Response: 

Ultimately it is the responsibility of the owner/operator to certify compliance with air 

quality requirements. To protect the owner/operator interests, it is recommended that 

owner/operators obtain from the supplier a certificate of conformity. 

Comment 54. 

Supports the requirement that emergency engines meet EPA's non-road engine standards 

and the requirement for ULSD. (Harvard) 

Response: 

Comment noted. 

Comment 55. 

"Emergency turbines should be afforded the opportunity to meet equivalent USEPA nonroad engine standards, rather than the much stricter limits for turbines now proposed in 

Table 1. (Earth Tech) 

Response: 

The emission limits for emergency engines are much less stringent than the level of 

emission performance that can be achieved by combustion turbines and therefore the 

proposed limits will not be changed. DEP believes the standards for turbines in this 

regulation are appropriate. 

Comment 56. 

The Department should adopt carbon monoxide emission limitations for emergency 

turbines. (MASSPIRG), (Conservation Law) 

Response: 

Carbon monoxide levels are low from combustion turbines and very few installations use 

turbines for emergency power. The DEP does not feel that it is necessary at this time to 

set carbon monoxide emission limits for emergency turbines. 

Comment 57. 

"Large engines (output of over 1 MW) used as emergency generators should either meet 

a more rigorous NOx standard than smaller engines or be held to the same standard as 

small engines." "Absent a compelling rationale, MASSPIRG urges the Department to 

apply the EPA non-road standards to all emergency engines." (MASSPIRG) 
20 

Response: The regulation as proposed and as adopted requires all emergency engines 

to meet EPA's non-road engine standards. This was a change from the September 2003 

pre-draft document. 

Comment 58. 

The Department should include provisions for mandatory review of the standards 

applicable to emergency engines. (MASSPIRG), (Conservation Law) 

Response: 

The emission limits for emergency engines are the same as EPA's non-road engine 

standards. These standards become more stringent over time. Also, at the time of DEP's 

proposal, EPA had not promulgated its Tier IV non-road standards. DEP plans in the 

future to propose the requirement that future emergency engines meet the Tier IV 

standards. 

Comment 59. 

"The Proposed Rule should clearly indicate that the emission limits only apply at full 

load." (Comment made for both emergency and non-emergency units.) (Tennessee 

Gas) 

Response: 

The regulations at 310 CMR 7.26(42)(e)3.c. and 310 CMR 7.26(43)(e)3.c. require that 

"testing shall be conducted at full design load of the engine or turbine." 

Comment 60. 

"The emission limit sections should add a provision that exempts operations from 

complying with the emission limits when unforeseen circumstances arise that are beyond 

the control of the operator." (Tennessee Gas) 

Response: 

The Department disagrees with adopting such an open ended exemption to the proposed 

emission limits. 

310 CMR 7.26(42)(c). Fuel Requirements 

Comment 61. 

This section is redundant and should be removed. See comment 33. (Polaroid), supported 

by (Assoc. Industries of Mass.) 
21 

Response: 

Having all applicable requirements in one place aids sources, especially small businesses, 

in finding what requirements apply to them and facilitates compliance. 

310 CMR 7.26(42)(d)l. Emergency Engines and Turbines - Operational 

Requirements - Hours of Operation. 

Comment 62. 

"For emergency turbines and IC engines, the maximum annual hours of operation 

allowed under the Proposed Rule should be changed from 300 hours to 500 hours. A 500 

hour operating limit is consistent with emergency generator definitions under EPA Title 

V guidance and regulations in many other States." (Tennessee Gas) 

Response: 

The Department disagrees that emergency operation should be allowed for 500 hours per 

year. The current allowed 300 hours per year of operation will be retained. DEP notes 

that Connecticut has recently lowered its hours of operation allowed for emergency units 

from 500 to 300 hours per year. Also, typical emergency units operate approximately 50 

hours per year. 

310 CMR 7.26(42)(d)4. Emergency Engines and Turbines - Operational 

Requirements - Sound -Stack Height and Emission Dispersion 

Comment 63. 

This proposed section is inappropriately onerous for large facilities while providing no 

environmental benefit. Request that section is changed to read: " All emergency engines 

and turbines shall utilize an exhaust stack that discharges so as not to cause a condition of 

air pollution (310 CMR 7.01(1))." (Polaroid), (Harvard), (General Electric), supported 

by (Assoc. Industries of Mass.) 

Response: 

Regardless of the size of the facility, installations must meet minimum design standards 

for stack height and emission dispersion. 

Comment 64. 

Requirement for sound and stack height should be eliminated or clarified with a clear 

indication of need and benefit. (Tennessee Gas) 

Response: 
22 

See response to Comments 63. For sound, 310 CMR 7.10 is an existing universally 

applicable requirement for sound that all operations must comply with. The stack height/ 

emission dispersion requirements are necessary to assure good modern air pollution 

control practices are employed to prevent negative air quality impacts. 

310CMR7.26(42)(d)5. Visible Emissions 

Comment 65. 

This is redundant, unnecessary as all sources must comply. As these are combustion 

emission units and sources of smoke, 7.06(l)(b) does not apply. (Polaroid), supported 

by (Assoc. Industries of Mass.) 

Response: 

See response to Comment 61. 

Also, as combustion emission units, engines and turbines are subject to 7.06(l)(b) as 

potential sources of opacity. 

310CMR7.26(42)(e)l. Certification 

Comment 66. 

It is recommended that this section be deleted as certification should be primarily the 

responsibility of the supplier. Alternately, the second sentence of the section should be 

removed. (Polaroid), supported by AIM 

Response: The section requires certification of "compliance with the requirements of 

310 CMR 7.26(42) in its entirety." It includes the provision that the owner/operator 

obtain from the supplier a statement that it has obtained certificate of conformity from 

EPA pursuant to 40 CFR 89.105 and, second, the owner/operator must certify compliance 

with other requirements such as sound, stack height/emission dispersion, visible 

emissions, fuels. In lieu of case-by-case permitting, this certification of compliance with 

all applicable regulatory requirements, serves to increase the accountability of the 

owner/operator for compliance. 

Comment 67. 

This section is unnecessary as 310 CMR 7.26(42)(b)l. states that engines meeting the 

requirements of 40 CFR 89.105 are automatically certified. "Verification of the engine's 

manufacture date should suffice. (Northeast Utilities) 

Response: See response to Comment 66. 
23 

310 CMR 7.26(42)(e)2. and 3. Monitoring and Testing 

Comment 68. 

"These provisions appear pointless and... exceptionally unfair." "Polaroid urges the 

Department to remove these sections." (Polaroid), supported by (Assoc. Industries of 

Mass.) 

Response: For the regulations to be approvable by EPA for inclusion into the 

Massachusetts State Implementation Plan, they must be enforceable as a practical matter. 

EPA requires that the regulations include monitoring and testing procedures. The DEP 

envisions that such provisions will rarely be for installed certified emergency units; 

nevertheless they must remain in the regulation. 

Comment 69. 

For SIP enforceable emission reductions, all test methods must be EPA approved. The 

language in both sections should read "tests to certify compliance with emission 

limitations must be performed in accordance with EPA reference methods, California Air 

Resources Board Methods approved by EPA, or equivalent methods as approved by the 

Department and EPA. (emphasis added). (EPA) 

Response: DEP agrees. The change has been made. 

Comment 70. 

EPA recommends ISO Method 8178 D2 be cited as it is claimed that D2 is best for 

reciprocating engines as it is a constant speed test. (EPA) 

Response: DEP agrees. The change has been made. 

310 CMR 7.26(42)(f) Record Keeping and Reporting 

Comment 71. 

Emergency engines and turbines are required to certify only at installation and there is no 

annual ERP certification requirement. The required records that are to be maintained on 
24 

site and presented to the Department upon request, should be certified as true and 

accurate under the provisions of 7.01 (2) and not 310 CMR 70.00. (Polaroid), supported 

by (Assoc. Industries of Mass.) 

Response: DEP agrees. The change has been made. 

310 CMR 7.26(42)(f)2. and 3. Record Keeping and Reporting 

Comment 72. 

Same issues as discussed in Comment 32. (Polaroid), (Harvard), supported by (Assoc. 

Industries of Mass.) 

Response: 

See response to Comment 32. 

Comment 73. 

Many facilities have emergency engines at unmanned or remote locations where records 

cannot be stored. The language should be modified from requiring that record be 

maintained on-site to allow records to be kept at the closest facility that can accommodate 

the record keeping requirements. (Northeast Utilities) 

Response: 

DEP has modified the record keeping requirement to address the comment. 

310 CMR 7.26(43) Engines and Turbines 

Comment 74. 

Has "heard" that the emission limitations as proposed are only achievable through the use 

of natural gas. The emission limits should be attainable through a diverse fuel mix as a 

"de facto natural gas only" policy "does not make for sound economic policy, and is not 

required to provide for clean ambient air." (Polaroid), supported by (Assoc. Industries 

of Mass.) 

Response: 

As described in the RAP Model Rule, the emission limitations are fuel neutral. The 

ULSD requirement allows the use of catalyst based emission control technologies for 

liquid fueled units. As Massachusetts is in non-attainment for ozone, the RAP Model 

Rule non-attainment emission limits were proposed. The 2005 emission limits require the 

use of technologies that currently exist. The 2008 limits require technology 

improvements that are within the range of current expectations, and the 2012 limits 
25 

"stretch" the technology but are within reasonable expectations for technology 

expectations. See also responses to Comments 6, 24, 25, and 26. 

310 CMR 7.26(43)(a). Engines and Turbines - Applicability 

Comment 75. 

The regulatory thresholds are proposed to be lowered from approximately 300 kW to 37 

kW for emergency engines and to 50 kW for non-emergency engines. 

The proposed regulation allows a number of engine applications to file a CPA as an 

alternative to complying with the ERP standards. However, both compliance and the 

CPA "process will create a significant economic impact on all operators who were 

previously exempt from the regulations. This includes agriculture, forestry and industrial 

concerns operating pumps, compressors or other stationary mechanical engines as well as 

all users of biogas." (Biomass Energy Resource Center) 

Response: Many of the operations described in the comment are examples of typical 

uses that will fall directly under the EPA non-road engine rules and not these rules. 

Emission limitations for the vast majority of new small installations below 300kw will be 

the EPA non-road emission standards. This is because they are EPA regulated as nonroad engines (portable in practice) or because they are stationary emergency engines 

subject to these DEP regulations. 

The emission standards for traditional fueled non-emergency units are based upon current 

technology for engines of 50 kw and greater output according to the RAP Model Rule. 

For small non-emergency units that are proposed to use non-traditional fuels such as 

biogas, the CPA process will allow a case-by-case analysis determination of appropriate 

emission limits. 

Finally, it should be noted that the operational requirements, including stack height and 

emission dispersion, are less stringent for units less than 300 kw. 

Comment 76. 

"Increase the lower size threshold to 300 kW." (NECA) 

Response: See response to Comment 75. 
26 

Comment 77. 

Non-emergency engines and turbines not subject to ERP and allowed to submit 

traditional applications must be required to implement Best Available Control 

Technology. (BOSTON) 

Response: 

"Traditional" applications are required to propose Best Available Control Technology as 

per 310 CMR 7.02. 

Comment 78. 

Greater flexibility should be provided for submission of individual Plan Applications for 

potentially worthwhile projects. Add language "or other units that the Department 

determines are appropriate to consider." 

"The DEP should not limit the option of obtaining an air plan approval to a limited 

number of facility types. This option should be available to all source types." (Earth 

Tech), (Pinpoint Power), (Blue Sky), (NECA) 

Response: The DEP believes that the benefits of the certification approach would be 

diminished by allowing additional types of projects to file individual applications in lieu 

of the certification program. See also responses to Comments 6,24,25, and 26. 

Comment 79. 

"While units in gas transmission service can follow the CPA process in lieu of complying 

with the Proposed Rule, it is implied that the emission limits in the Proposed Rule are 

feasible. Thus, it is necessary to present a case against the proposed presumptive limits. 

Based on TGP experience, the NOx limits proposed are not achievable for IC engines and 

gas turbines in gas transmission service. The DEP should clarify this fact in support 

documentation, or provide evidence to the contrary." (Tennessee Gas) 

Response: 

Based upon review of prior applications of units in gas transmission service, the DEP 

recognizes that emission limits should be set on a case-by-case basis for these 

installations. If at a future time, technology has advanced such that a proponent is 

confident that emission limits set in the regulations can be achieved, then the proponent 

can take advantage of the time saving features of the regulation. 

Comment 80. 

Users of biogas may file a CPA in lieu of complying with the ERP standards. This 

alternative should be extended to all types of biofuels. (Biomass Energy Resource 

Center) 
27 

Response: 

The DEP has allowed the option of submitting a CPA for case-by-case review for all 

biofuel applications. 

Comment 81. 

Operators may keep older heavily polluting engines in service if engine overhaul, 

rebuilding, replacement or upgrade is determined to be "construction, substantial 

reconstruction or alteration" and therefore be required to meet standards for new engines. 

"BERC recommends the addition of language clarifying your intent in regards to regular 

engine overhauls." (Biomass Energy Resource Center) 

Response: Work that is repair by nature, does not increase capacity, or is not a 

permanent relocation, will not trigger certification to new emission and other standards. 

Comment 82. 

Certain types of projects have the option to file a CPA. "However, the mere promulgation 

of a regulation listing these stringent standards may pre-determine the Best Available 

Control Technology ("BACT") process required for such an individual permit." 

(NECA) 

Response: 

See response to Comment 79. 

310 CMR 7.26(43)(b) Emission Limitations 

Comment 83. 

A new subsection should be added to read "5. Any revisions to the emission limits in 

Tables 2 and 3 shall be submitted to EPA for approval." Also change "will" to "shall" in 

subsections 2. and 3. 

(EPA) 

Response: Massachusetts is aware that for changes in emission limits to be federally 

enforceable, they must be approved by EPA as part of the Massachusetts State 

Implementation Plan. The suggested language is not contained in any of DEP's 

regulations and is not necessary. 

The DEP has changed "will" to "shall." 

Comment 84. 
28 

"We would appreciate if DEP would articulate its larger plan" with respect to carbon 

dioxide controls and climate change strategy. (Northeast Utilities) 

Response: 

The commenter should review the Commonwealth's "Climate Protection Plan" which 

can be found at www.mass.gov/envir under key resources. 

Comment 85. 

"The emission limitations in Table 2 of 310 CMR 7.26(43)(b) that differ from those in 40 

CFR 89 is [sic] confusing and might require the manufacturers to design different engines 

specific to Massachusetts requirements." (General Electric) 

Response: 

Please note that the emission limits in 40 CFR 89 apply to emergency engines whereas 

the emission limits in Table 2 apply to engines in non-emergency service. 

Comment 86. 

"(T)he proposed emission limits in Table 2 seems to pretty much preclude any new liquid 

fuel (diesel) engines, unless they can otherwise qualify for an individual Plan 

Application." (Earth Tech) 

Response: 

See response to Comment 74. 

Comment 87. 

It is proposed to regulate ammonia emissions from turbines but not for engines and to 

regulate CO2 from engines but not turbines. Regulated pollutants from engines and 

turbines should match. The 2ppm ammonia limit is "unnecessarily strict for a small 

turbine SCR unit." Also, "any reference to ppm limits should be referenced to standard 

conditions, such as dry basis at 15% O2." (Earth Tech) 

Response: Ammonia emissions for SCR controlled engines are variable depending on 

engine duty cycles and whether the engine is liquid, gas, or dual fueled. DEP does not 

believe it is appropriate to set ammonia emission limits for engines at this time. 

The CO2 limits will apply to turbines also. The ppm limit will be required to be reported 

at standard conditions. 

Comment 88. 
29 

"MASSPIRG supports the emission standards proposed for non-emergency engines and 

turbines (Table 2 and 3 in proposed 310 CMR 7.26(43)),.. .however, given that 

Massachusetts is classified as a non-attainment area for ozone, the Department should 

follow several other states and adopt more stringent NOx standards." (MASSPIRG) 

Response: The DEP chose to propose the RAP Model Rule emission limits for 

several reasons. Although there may be some more stringent in a few states, the proposed 

DEP limits do in the near term represent BACT and push realistic performance 

improvements over time with the outer year stretch goal emission limits having a better 

chance of being attained if a number of states adopt the Model Rule. This approach also 

provides greater certainty to manufacturers about future requirements and enables them 

to direct their efforts to complying with the same standards for a number of states. 

Comment 89. 

There should be an emission limitation for ammonia standard for non-emergency 

engines. (MASSPIRG),(Conservation Law) 

Response: See response to comment 87. 

Comment 90. 

"The standards for non-emergency generators are aggressive without imposing an undue 

burden on DG customers or manufacturers. Specifically, the NOx standards proposed for 

non-emergency engines are both aggressive and reasonable." ".. .(T)he NOx standards 

are more lenient than those adopted in other states, including California, East Texas, and 

Connecticut. Although current diesel fueled engines will have trouble meeting the 

proposed NOx standards, other reciprocating engines will be able to meet them. Leanburn engines fueled by natural gas can already achieve the proposed 2004 NOx standard 

with selective catalytic reduction (SCR) systems. With reasonable research and 

development efforts, these units will be able to meet the proposed 2008 and 2012 

standards. Rich-burn engines fueled by natural gas can also meet the 2004 NOx standard 

using a three-way catalyst; these units too should be able to meet the 2008 and 2012 

standards." (Conservation Law) 

Response: Comment noted. 

Comment 91. 

"MASSPIRG strongly supports the inclusion of an emission standard for CO2." 

"By regulating CO2, the Department is effectively fulfilling the environmental and public 

health mandate of its enabling legislation and responding to the challenge of the Climate 

Action Plan of the New England Governors and the Eastern Canadian Premiers. 

(MASSPIRG) 
30 

"The CO2 limits listed [in the RAP Model Rule] are not rigorous, but they recognize the 

increasingly urgent need to control the release of greenhouse gases." (Conservation Law) 

Response: 

DEP has added the requirement that the carbon dioxide standards will apply to 

combustion turbines. 

Comment 92. 

"The DEP should consider developing appropriate presumptive emission limits for 

subcategories of equipment that include non-EGU industrial applications." 

(Tennessee Gas) 

Response: 

The DEP does not believe this approach would be the best use of its limited resources. 

DEP allows certain categories of activities to apply for a case-by-case BACT review as 

provided by 310 CMR 7.26(43)(a)2. 

Comment 93. 

"TGP discourages prescriptive emission limits in 2008,2012, and beyond, and urges 

DEP to conduct a Technology Review in advance of each phase-in date to ensure that 

progress in emission reduction technology is commensurate with the forecast emission 

target and to allow public/stakeholder participation in the process." (Tennessee 

Gas) 

Response: 

The regulations require DEP to perform a review of the 2012 emission limits prior to 

December 31,2010. The DEP may perform a review of the 2008 emission limits if the 

DEP determines that such a review is prudent. The review would necessarily include 

public/stakeholder input. 

Comment 94. 

Requirements for greenhouse gas emissions should be eliminated or clarified with a clear 

indication for need and benefit. (Tennessee Gas) 

Response: See response to Comment 84. 

Comment 95. 

"The proposed levels are extremely low for the <10MW class of turbine and represent 

LAER levels for NOx and stricter-than-LAER for CO." 

"Solar recommends that the department pace any required emission levels with dry-lowemissions (DLE) technology developments/advancements. Such a policy will encourage 
31 

DLE technology development while supporting the concept of pollution prevention (vs. 

abatement technologies). Any need for add-on controls should be evaluated and applied 

as required via the PSD and Non-attainment permitting programs." 

"The required emission levels should reflect what is achievable by several manufacturers 

across typical operating and ambient temperature ranges." 

Recommends that the emission levels in Table 2 for NOx and CO be applicable to natural 

gas fired turbines and that Table 3 be deleted and emission levels for liquid fuel be set at 

achievable dry-low-emission levels. (Solar Turbines) 

Response: The emission limits in Table 2 are the RAP Model Rule recommendations. 

DEP proposed Table 3 with emission limits for combustion turbines that represent 

technology that is currently available. Also see responses to Comments 26 and 74. 

Comment 96. 

The emission limitation for particulates from liquid fueled gas turbines should be 

removed. This issue was discussed during the RAP Model Rule development process 

and "consensus was reached that regulating particulate matter emissions from gas 

turbines was unnecessary." 

Emission test data shows particulate emission levels that are four to seven times the 

proposed limits for small turbines. (Solar Turbines) 

Response: DEP agrees. The change has been made. 

Comment 97. 

DEP has had a policy for ammonia slip level of 2 ppm for several years which adds 

unnecessary complexity and cost to the SCR system for little or no environmental benefit. 

"A typical Best Available Control Technology (BACT) level for gas turbines is 5-10 ppm 

ammonia slip." (Solar Turbines) 

Response: 

The DEP disagrees and will maintain the requirement for 2 ppm ammonia slip. 

Comment 98. 

Change the term "gas" to "natural gas" in Table 3 "as there are numerous gas fuels that 

can be burned in turbines that can not be used in conjunction with DLE or add-on control 

systems." (Solar Turbines) 

Response: DEP agrees. The change has been made. 
32 

Comment 99. 

"Our newest turbine the Mercury 50 is at 5 ppm NOx warranty and would be unable to 

meet the proposed standard without cogen or SCR which just doesn't seem right. 

Especially since the Mercury 50 is a huge improvement over average MASS grid 

emissions. Not all DG applications have a steam host and an SCR would kill most 

projects economically. Please consider the levels in Table 2 for gas turbines so that 

millions of dollars spent over the last decade in R&D to achieve single digit NOx levels 

(5 ppm on the Mercury 50, 9 ppm target on the other models) creates an opportunity for 

dry-low-NOx gas turbines (without SCR/CO) to play in DG markets." (Solar 

Turbines) 

Response: 

The emission limitations in Table 2 are for engines only and are the RAP recommended 

levels. Table 3, which is applicable to turbines, is based upon recent Massachusetts 

BACT determinations representing currently available technology. 

Except for emergency only and specialized units, typical Massachusetts' projects of less 

than 10 MW include recovery of waste heat and are intended to operate year-round in 

combined cycle mode. Given that Massachusetts is at the end of the natural gas pipelines, 

these combined heat and power projects have been universally permitted by DEP with 

back-up oil firing capability. It is noted that the Mercury 50 is "available in gas-only 

configuration". 

Comment 100. 

" The emission targets for CO, NOx, and CO2 in the draft regulation are based on 

optimum conditions with the cleanest of fossil fuels." 

"While we recognize that users of biogas may file a Comprehensive Plan Application, we 

are concerned that the targets will preclude any use of biogas in an engine." There is little 

emissions data on biogas emissions, however there is data that suggests that NOx 

emissions compares favorably to natural gas and diesel fueled units. Other emissions 

however do not. (Biomass Energy Resource Center) 

Response: 

The DEP will evaluate each application for use of non-traditional fuels on its own merits. 

Comment 101. 

310CMR7.26(43)(b) Engines and Turbines - Emission Limitations 

"BERC would recommend that any engine operating on at least 20% biogas or other 

biofuels, as measured annually based on output, be exempt from meeting the proposed 

CO2 emission rates." (Biomass Energy Resource Center) 
33 

Response: The regulations will allow units burning non-traditional fuels to have specific 

emission limits established in preconstruction approvals as allowed by 310 CMR 

7.26(43)(a)2. 

Comment 102. 

310 CMR 7.26(43)(b) Engines and Turbines - Emission Limitations 

"(T)he distributed generation ("DG") limits, as proposed, are too low. Although I agree 

that with the use of fuel-neutral, output-based standards for large base-load power 

generating facilities, I do not agree that fuel-neutral standards should be used for small 

DG engines. Diesel-fueled DG engines will not be able to meet the proposed standards, 

even with add-on controls." (Blue Sky) 

Response: DEP disagrees. See response to Comment 26. 

Comment 103. 

"Include more achievable emissions standards for fuels for the first category of limits 

(installation after January 1,2005) by providing for a Best Available Control Technology 

("BACT") analysis." 

"Eliminate the second and third categories of limits (installation on or after May 1, 

2008)." Develop a market-based system to determine emission requirements over the 

long term for various projects based upon engine size, fuel availability and proposed use. 

(NECA) 

Response: The thrust of these comments is to maintain the status quo. The DEP has 

decided that control of emissions from these categories is best accomplished by a 

certification process. The emission standards and implementation procedures set forth in 

the RAP Model Rule reflect current BACT and anticipated future BACT. The regulations 

also provide for review of standards. 

Comment 104. 

"Raise the ammonia limit from 2 ppm to 10 ppm." (NECA) 

Response. The DEP has required 2 ppm ammonia slip as a BACT requirement for 

several years and will maintain this requirement. 

Comment 105. 

With respect to "CO2 neutrality" from biomass applications, DOER believes that detailed 

policy discussions need to occur on this issue. "Therefore, DOER recommends that DEP 
34 

defer the decision regarding CO2 emissions from biomass fuels in the final rule until such 

policy discussions are completed and methodologies adopted.' (Div. of Energy 

Resources) 

Response: Since the engine and turbine regulation is designed to be fuel neutral, no 

fuel is given specific standards in the regulation. Therefore, the CO2 standard in the 

regulation will apply to all fuels at this time. However, DEP is willing to hold discussions 

with DOER about whether a distinction should be made for biomass and if agreement is 

reached, the regulation can be revised at some point in the future. 

Comment 106. 

"The proposed emission standards for new, non-emergency engines are unnecessarily 

stringent and will have a severe negative impact on the use of DG and CHP on the 

Commonwealth. Massachusetts DEP should adopt alternate emission standards that are 

technically feasible and cost effective. This will allow Massachusetts' Businesses and 

industry to continue to deploy clean DG resources, thereby taking advantage of the 

resultant enhanced reliability, economic savings, and air quality benefits of DG and 

CHP." (Engine Mfg Assoc) 

Response: DEP disagrees. See response to Comment 26. 

Comment 107. 

"EMA recommends that DEP propose reasonable and effective NOx standards that are in 

line with the state of technology as it continues to evolve over the near future." 

EMA recommends the following NOx standards: 

- 2005 2.21bs/MWh - lower than current central utility emissions 

- 2008 1.0 lbs/MWh - allows best engines without SCR through 2007 

- 2012 0.3 lbs/MWh - consistent with industry and DOE research objectives 

(Engine Mfg Assoc) 

Response: Consistent with other states and in agreement with the RAP Model Rule 

process, the DEP will adopt the RAP standards and the RAP time schedule for 

implementation. DEP believes the standards are reasonable and DEP has provided itself 

an opportunity to review the standards if necessary. Also see responses to Comments 6, 

24, 25, 26, and 74. 

Comment 108. 

"EMA also recommends that the DEP maintain the initial 10 lb/MWh standard for CO 

throughout the time period and that DEP delete the CO2 standard from the regulation. 

Given the need to meet the other strict emission standards of the proposed regulation, 

there is no way for engine or generator manufacturers to effectively control or alter the 

inherent CO2 emissions from a specific generator set. Considering that the priority to 
35 

control emissions is properly placed on minimizing emissions of criteria pollutants, such 

as NOx, CO, and PM, and that CO2 emissions from stationary engines are minimal, there 

is little to be gained by adding additional constraints that only make compliance with the 

primary emissions standards more difficult." (Engine Mfg Assoc) 

Response: With regard to CO, the DEP will adopt the RAP recommended emission 

limits. See response to Comment 107. 

As stated, CO2 emissions from stationary engines are minimal. However according to the 

RAP model Rule, the Phase I and IICO2 standards are achievable now and the Phase III 

standards are within the range of reasonable expected improvements. 

Comment 109. 

"Revised emissions standards for engines that utilize alternate gaseous fuels, such as 

landfill gas and biogas, are needed so that the environmentally beneficial use of those 

fuels can continue" (Engine Mfg Assoc) 

Response: See 310 CMR 7.26(43)(a) Applicability. The above operations can have 

case-by-case emission limits set through submittal of a CPA. 

Comment 110. 

Technology forcing works when there are no alternatives. If the limits are too strict 

research and development will not happen, costs will be too great, and the option of 

buying electricity from the grid will prevail. (Aalto) 

Response: See responses to Comments 6, 24, 25, 26, and 74. 

310 CMR 7.26(43)(d) Operational Requirements-Sound-Stack Height and Emission 

Dispersion 

Comment 111. 

Requirement for sound and stack height should be eliminated or clarified with a clear 

indication of need and benefit. (Tennessee Gas) 

Response: See response to Comment 64. 

310 CMR 7.26(43)fe)l. Engines and Turbines Certification 

Comment 112. It would be more efficient for manufacturers to certify their 

products than requiring stack testing of engines. (Northeast Utilities) 
36 

Response: 

The regulations require manufacturers (suppliers) to certify their engines. The regulations 

state the test methods and procedures that would constitute a valid manufacturers 

certification. 

Comment 113. 

The certification requirement does not take into account instances where pollution control 

equipment is used to control emissions. Suggests that 310 CMR 7.26(43)(e)l. should 

read: "Certification shall include statement(s) as appropriate from manufacturers and 

other equipment or emission control system providers that the installed engine or 

turbine..." (Earth Tech) 

Response: 

The requirements have been changed substituting "supplier" (a defined term) for 

manufacturer. The supplier typically sells the package that includes the engine or turbine, 

the air pollution control equipment, and other associated equipment. 

Comment 114. 

To comply with the emission limitations, these systems will require some combination of 

add-on controls, and for heat recovery systems additional equipment will be part of the 

installation. This equipment will be provided by several manufacturers. The engine or 

turbine alone is not capable of complying with the emission limits. Can certification of 

compliance be based upon design parameters of the system? (Solar Turbines) 

Response: 

Yes. The DEP will provide guidance on this and related issues as it develops the 

certification documents. Ultimately it is the responsibility of the owner/operator to 

comply. See also response to Comment 113. 

Comment 115. 

"The DEP needs to clarify and prescribe the certification requirements for stationary 

engines." (Engine Mfg Assoc) 

Response: The certification process will be described in detail in implementation 

documents. See also response to Comment 7. 
37 

Comment 116. 

"The proposal to require manufacturers to certify that a generator will meet the proposed 

emission standards for 15,000 hours of operation or 3 years is beyond the current industry 

standard and technical capability of emission control equipment." (Engine Mfg Assoc) 

Response: The requirement is a recommendation contained in the RAP Model Rule. 

Connecticut recently has adopted these requirements and the California Air Resources 

Board (CARB) adopted the 15,000 hour requirement effective January 1, 2003. It should 

be noted that the CARB rules provide for review of the 15,000 hour certification 

provision by July 1,2005. The Department will monitor CARBS review and will respond 

as appropriate. 

Comment 117. "(T)he manufacturers certification process should be eliminated or 

revised to provide a meaningful guarantee of performance, and the DEP should ensure 

that the certification would not introduce unnecessary market constraints." 

(Tennessee Gas) 

Response: See responses to Comments 113,114,115, and 116. 

COMBINED HEAT AND POWER - CHP 

DEP did not propose regulatory provisions for emission or other credits for CHP systems. 

DEP did request comments on the RAP Model Rule credit scheme or suggestions for 

other alternative incentives. The following information was received. 

Comment 

If DEP decides to give credit for combined heat and power systems, the Regulatory 

Assistance Project (RAP) Model Rule language is recommended. (EPA) 

Comment 

Given that many facilities employ emergency engines within the City of Boston and that 

the use of Combined Heat and Power (CHP) systems/distributed generation is expected to 

grow, it is important that these units be adequately regulated by DEP. The Air Pollution 

Control Commission supports the proposed regulations. (BOSTON) 

Comment 

Supports DEP's position of not allowing emission credits against emission limitations 

for CHP as suggested by the RAP Model Rule. "Incentives for CHP should not 

compromise existing air quality standards and regulations." (BOSTON) 
38 

Comment 

The regulations should provide credits for CHP applications. (MASSPIRG), 

(Conservation Law) 

Comment 

The regulations should provide credits for concurrent emission reductions achieved by 

reduced flaring of waste gases. (MASSPIRG), (Conservation Law) 

Comment 

DEP should adopt a steam credit method similar to the simplified method Texas adopted. 

(Solar Turbines) 

Comment 

The goal of recognizing the thermal output from CHP is not to avoid regulation, but to 

promote highly efficient technology, a form of pollution prevention. Pollution prevention 

is preferable to add-on controls as it reduces all emissions, avoids generation of 

secondary pollutants, and reduces fossil fuel consumption. 

"Federal guidance on BACT instructs states to include inherently low-emitting processes 

as part of the BACT analysis. This would include the emission reduction benefits of a 

higher efficiency process such as CHP. A complete assessment of BACT should 

therefore include the cost-effectiveness of CHP as an alternative emission control 

technology. Since the goal of the proposed rule is streamlined permitting, a simpler 

alternative is called for." 

The RAP Model Rule incorporates the effect of BACT on the thermal component of the 

CHP facility by considering the effect of efficiency in a BACT analysis. (Energy & 

Env. Analysis) 

Comment 

The RAP Model Rule recognizes the environmental benefits of CHP and "provides a 

well-thought out credit for CHP facilities. Massachusetts should do likewise." 

(Biomass Energy Resource Center) 

Comment 

"It is recommended that the regulations provide for an emission credit in Combined Heat 

and Power (CHP) applications, provided that the proposed efficiency standard does not 

penalize some efficient systems while allowing other inefficient systems." Recommends 

a formula." 

Also, "NECA believes that a market based system could best address .. .the combined 

heat and power credit." (NECA) 

Comment 

Supports the RAP Model Rule approach to crediting CHP applications. Alternatively, 

DEP should investigate alternative methodologies put forth by other states and federal 

government to treat energy producing projects equitably. (Div. of Energy Resources) 

Comment 
39 

Strongly disagree that the RAP Model Rule provisions for CHP credits would allow 

projects to net out of BACT. The emission limits in Phase II and III "are not BACT, they 

are more stringent than BACT as acknowledged in the RAP Model Rule Background 

Document. In fact, the RAP document suggested that the CHP incentive would be 

required to meet Phase III. " 

"It is currently impossible to meet these limits without add-on controls." (NECHPI), 

supported by (Div. of Energy Resources) 

Comment 

By failing to include all useful energy produced, the proposal regulations do not contain 

true output based standards. (NECHPI), supported by (Div. of Energy Resources) 

Comment 

Without CHP credits, the proposed regulations "actually creates a disincentive to 

increased efficiency." (NECHPI), supported by (Div. of Energy Resources) 

Comment 

"EMA strongly supports the inclusion of adjusted emission standards or emission credit 

or offsets for DG facilities using Combined Heat and Power (CHP) technology in the 

final regulation." (Engine Mfg Assoc) 

Comment 

The positive benefits of CHP as set forth in the RAP Model Rule outweigh the DEP's 

concerns about BACT. (Conservation Law) 

Response 

Based upon the above information and further DEP investigation into this issue, DEP 

intends to consult further with interested parties on CHP issues. The goal of this effort 

will be to propose regulation revisions within the next year providing incentives for CHP 

installations.