Conservation Law Foundation 

June 30, 2004 

BY HAND 

Mass. Department of Environmental Protection 

1 Winter Street 

Boston, MA 02108 

Attn: Robert Donaldson, 8th floor 

Re: Proposed Revisions to Emissions Standards for Stationary Engines and Combustion 

Turbines in 310 CMR 7.26(40)-(44) 

Dear Mr. Donaldson: 

I am writing on behalf of the Conservation Law Foundation (CLF) and its membership to submit 

the following comments on the proposed amendments to the emissions standards for engines and 

combustion turbines. CLF, a member-supported nonprofit organization, was founded in 1966. CLF's 

mission is to work to solve the environmental problems that threaten the people, natural resources and 

communities of New England. 

CLF appreciates this chance to comment on the proposed emissions standards for distributed 

generation (DG) technologies. The use of DG for on-site generation of electricity is a growing trend in 

the energy sector. Policy makers and advocates alike have heralded this trend, as many DG technologies 

offer cleaner, more efficient generation of electricity. The amendments proposed by the Department of 

Environmental Protection (Department) supply a critical means of ensuring that DG technologies develop 

in an environmentally sound manner. By creating aggressive clean air standards for engines and turbines, 

the Department can guide industry development to ensure a cleaner, healthier future for Massachusetts. 

Upon reviewing the most recent draft of the emissions standards, CLF remains supportive of the 

scheme developed by the Department. The standards for nitrogen oxides are aggressive throughout the 

regulation and the inclusion of a CO2 standard for non-emergency engines is commendable. Additionally, 

we applaud the Department's decision to expand the applicability of the US EPA's emissions standards 

for non-road engines to all emergency engines. However, CLF is disappointed to see that the Rule does 

not include any credit scheme for concurrent emissions reductions from combined heat and power (CHP) 

and reduced flaring for emergency or non-emergency engines or turbines. We are also discouraged that 

the mandatory review provision and the CO2 standard that apply to non-emergency generators do not 

apply to emergency generators. Additionally, an ammonia standard should have been included for nonemergency engines and a CO standard for emergency turbines. 

62 Summer Street, Boston, Massachusetts 02110-1016 • Phone: 617-350-0990 • Fax: 617-350-4030 • www.clf.org 

MAINE: 14 Maine Street, Suite 200, Brunswick, Maine 04011-2026 • 207-729-7733 • Fax: 207-729-7373 

NEW HAMPSHIRE: 27 North Main Street, Concord, New Hampshire 03301-4930 • 603-225-3060 • Fax: 603-225-3059 

RHODE ISLAND: 55 Dorrance Street, Providence, Rhode Island 02903 • 401-351-1102 • Fax: 401-351-1130 

VERMONT: 15 East State Street, Suite 4, Montpelier, Vermont 05602-3010 • 802-223-5992 • Fax: 802-223-0060 
Conservation Law Foundation 

I. CLF generally supports the Department's proposed DG regulation. 

CLF supports the proposed emissions limitations established for emergency and non-emergency 

generators. 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. As noted in previous comments, the 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. Lean-burn 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. Richburn engines fueled by natural gas can also meet the proposed 2004 NOx

 standard by using a three-way 

catalyst; these units too should be able to meet the 2008 and 2012 standards. 

In addition to the NOx standards, CLF applauds the Department's decision to establish a CO2 

standard for non-emergency engines. A CO2 standard is the first step to effective implementation of the 

environmental and public health mandates in the Department's enabling legislation and the Massachusetts 

Climate Protection Plan. 

Changes made to the proposed standards for emergency generators in the May 2004 Draft 

Regulation are also commendable. In particular, CLF supports the Department's decision to extend the 

applicability of the EPA non-road emission standards in 40 CFR 89.112 to all emergency engines, rather 

than only to those with output under 1MW. The EPA standards sufficiently regulate nitrogen oxides 

(NOx), carbon monoxide (CO), hydrocarbon and particulate matter (PM). 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. 

II. The regulations should include credits for concurrent emissions 

reductions from CHP and reduced flaring. 

The Department's May 2004 Draft DG Regulations do not include credits for concurrent 

emissions reductions from use of combined heat and power (CHP) or reduced flaring for either emergency 

or non-emergency generators. CLF opposes this omission from the Draft Regulations. Such a provision 

is a crucial component of a comprehensive engine and turbine emissions scheme aimed at overall 

emissions reductions and efficient fuel use. 

We understand that the Department is concerned about projects "netting out" of Best Available 

Control Technology (BACT) if credits for concurrent emission reductions are implemented.1 However, 

CLF believes that the overall benefits of a credit scheme would outweigh this concern. As the 

Department knows, CHP systems use byproduct heat for non-electric processes, such as space and water 

1

 See Dept. of Envt'l Protection, Commonwealth of Mass., Proposed Amendments to 310 CMR 7.00 et sea,, at 3 (May 2004) 

(responding to comments received on an earlier draft). 

CLF: "Defending the Law of the Land" 2 
Conservation Law Foundation 

heating. Because of this dual capacity, even less efficient CHP units are cleaner than BACT alternatives 

if separate electric and thermal generators are used. Additionally, if the Department were to adopt the 

scheme proposed by the Regulatory Assistance Project (RAP) Model Rule2, the amount of the credit 

would not be significant enough to result in the removal of pollution control technologies or the 

installation of "dirty" units. Instead of "the consequence being a 'dirtier', non state-of-the-art 

[generator],"3 the credit simply provides incentives for CHP that recognize the unique advantages of this 

technology. CHP reduces overall levels of harmful emissions when taken in context of all available 

technologies. If the Department wishes to ensure that only truly efficient CHP units are utilized, other 

alternatives are available. For example, the credit could be restricted to "Qualifying Facilities," as defined 

by PURPA.4 Regardless of the means, some method of rewarding CHP for displacing emissions from 

other sources is essential. Incentives for CHP will enable the effective development and penetration of 

these technologies, a critical component of meeting rising energy demands. 

The Commonwealth of Massachusetts explicitly recognized the importance of CHP in the recently 

released Massachusetts Climate Protection Plan. The Plan calls upon the Department of Environmental 

Protection "to review [Massachusetts's] existing laws and regulatory policies, and make recommendations 

that facilitate the introduction of distributed energy sources, giving special attention to ... combined heat 

and power ...." (emphasis added).5 The Department also acknowledged the importance of CHP in its 

own comments to the proposed amendments, stating that "[the Department] favors and encourages the 

installation of CHP systems."6 The prudence of a credit scheme to address the importance of CHP, despite 

concerns regarding BACT, is highlighted by the fact that the California rule, the RAP Model Rule, the 

East Texas DG permit and the draft Connecticut permit all include credits for emissions reductions from 

CHP. 

CLF strongly encourages the Department to consider the combined, positive impact of CHP and 

adopt a provision similar to one proposed by the RAP Model Rule. The RAP Model Rule represents a 

collaborative effort between a wide array of interest groups and the contribution of independent 

consultants. We believe the approach advanced in it is sound and commend it to the Department. 

We also recommend that the Department include provisions for crediting concurrent emission 

reductions achieved by reduced flaring of waste gases. Given that flaring is required in Massachusetts for 

many facilities, owners of engines and turbines at such facilities should be allowed to net avoided 

emissions from flaring against their emissions for compliance purposes. Adopting policies that promote 

energy efficient practices effectuates a clear goal of the Commonwealth. The RAP Model Rule allows 

operators either to calculate avoided emissions from a displaced flare or to use default emission rates 

defined in the rule. We believe this is an effective means to calculate emissions avoided by reduced 

flaring. 

2

 The Regulatory Assistance Project, Model Regulations for the Output of Specified Air Emissions From Smaller-Scale Electric 

Generation Resources (Review Draft, October 2002). 

3

 Proposed Amendments to 310 CMR 7.00 et sea., at 3. 

4

 220 CMR 8.02 (indicating that "Qualifying Facility means small power producers and cogenerators that meet the criteria 

specified by FERC in 18 C.F.R. §§ 292.203(a) and (b)"). 

5

 The Commonwealth of Massachusetts, Massachusetts Climate Protection Plan, at 31 (Spring 2004). 

6

 Proposed Amendments to 310 CMR 7.00 et sea., at 4. 

CLF: "Defending the Law of the Land" 3 
Conservation Law Foundation 

III. The mandatory review provision and CO2 standard applicable to non-emergency 

generators should also apply to emergency generators. 

CLF is disappointed in the Department's failure to include mandatory reviews of the emissions 

limitations for emergency generators. The Department's hesitancy to include such a provision is 

surprising since a review requirement for emergency generators would impose little additional burden on 

the Department. The Department has already provided for a mandatory review in 2010, 2017 and every 

five years thereafter "of the state of, and expected changes in, technology and emission rates" of nonemergency generators. 310 CMR 7.26(43)(b)(2)-(3). The scope of these reviews should be altered to 

encompass emergency generators in addition to non-emergency ones. At a minimum, the proposed 

regulation should include a provision clarifying that the Department is authorized to review the standards 

for emergency generators from time to time.7 A review of the state of technology and emission rates of 

emergency generators is critical to ensuring that Massachusetts's citizens receive the full benefit of 

relevant advances in technology. 

CLF encourages the Department to replicate the CO2 standard proposed for non-emergency 

engines for emergency generators. As the primary greenhouse gas (GHG) responsible for rising global 

temperatures, regulation of CO2 will be critical as Massachusetts works toward its "tough but realistic" 

Q 

goal of reducing its GHG emissions to 1990 levels by 2010. Recognizing that this reduction will take 

time, the Climate Plan expressly states that "Massachusetts is calling on the public and private sectors ... 

to take action now." (emphasis added). Any revision of emissions regulations should, therefore, 

incorporate limits on greenhouse gas emissions. The RAP Model Rule suggests the same CO2 limitations 

now proposed for non-emergency engines for all generators: 

Carbon Dioxide 

Phase One (installed on or after 1/1/04) 1,900 lbs./MWh 

Phase Two (installed on or after 1/1/08) 1,900 lbs./MWh 

Phase Three (installed on or after 1/1/12) 1,650 lbs./MWh 

CLF recommends that the Department adopt standards at least as aggressive as these. The CO2 limits 

listed here are not exceptionally rigorous, but they recognize the increasingly urgent need to control the 

release of greenhouse gases. 

7

 The regulation could include a provision similar to 310 CMR 7.26(43)(b)(4), which states that the "Department may at other 

times review the state of technology and emission rates to determine whether the emission limits defined in Table 3 should be 

amended." 

8

 Massachusetts Climate Protection Plan at 13 (2004). 

CLF.- "Defending the Law of the Land" 4 
Conservation Law Foundation 

IV. The proposed emissions limitations for non-emergency engines should 

include an ammonia standard. 

CLF's enthusiasm for the standards is dampened by disappointment over the Department's 

disregard of the need for ammonia standards for non-emergency engines. As noted previously, many 

engine owners will comply with these regulations by using selective catalytic reduction (SCR) systems, 

which create a risk of ammonia slip. We urge the Department to address this issue and apply the 

proposed ammonia standard for non-emergency turbines to non-emergency engines 

CLF is discouraged by the Department's omission of a carbon monoxide (CO) standard for 

emergency turbines. As noted in our previous comments, emissions of CO often rise as combustion 

processes are managed to minimize NOx emissions. Failure to regulate both of these pollutants is likely to 

result in unintended increases in CO emissions. The Department's hesitancy to regulate in this area is 

baffling when a CO standard of 0.5 lb/MWh would ensure an appropriate limit of CO emissions and still 

allow small turbine owners to comfortably meet the NOx standard. Furthermore, including a CO standard 

directly furthers the purpose of the Department's enabling legislation, 310 C.M.R. 7.00, which is "to 

prevent the occurrence of conditions of air pollution where such do not exist [and] ... to attain, preserve, 

and conserve the highest possible quality of the ambient air compatible with needs of society." CLF 

encourages the Department to prevent unintended increases in CO by including a limit for emergency 

turbines, as it has already done for emergency engines and non-emergency generators. 

Despite the omissions mentioned above, CLF supports the promulgation of these emissions 

standards. They ensure adequate attainment of Massachusetts's goals under the Clean Air Act and 

address the potential for environmental degradation with unguided development of DG technologies. We 

applaud the Department's responsiveness to previous comments and extension of the EPA's emissions 

standards for non-road engines to all emergency engines. We urge the Department to consider and 

implement further improvements to the proposed amendments. The goal of the regulation will be 

furthered by including a credit scheme for concurrent emissions reductions for CFfP and reduced flaring; 

including a mandatory review provision and CO2 standards for emergency generators; creating an 

ammonia standard for non-emergency engines; and regulating CO from emergency turbines. 

V. The proposed standards for emergency turbines should include 

an emissions limit for CO. 

Conclusion 

Very truly yours, 

Toni P. Hicks 

Staff Attorney 

CLF.- "Defending the Law of the Land" 5