CITY OF BOSTON 

THE ENVIRONMENT DEPARTMENT 

Boston City Hall, Room 805 • Boston, MA 02201 • 617/635-3850 • FAX: 617/635-3435 

June 30, 2004 

Department of Environmental Protection 

Bureau of Waste Prevention 

One Winter Street 8t h Floor 

Boston, MA 02108 

Attn: Robert Donaldson 

Dear Mr. Donaldson: 

The City of Boston Air Pollution Control Commission (APCC) has reviewed the proposed 

additions and revisions to the Commonwealth's Air Pollution Control Regulations - 310 CMR 

7.02(40) through (44), which regulate emissions from new stationary engines and combustion 

turbines; 310 CMR 7.02(8)(i) and 310 CMR 7.03(10) for existing engines; 310 CMR 7.02 Plan 

Approval Emission Limitations; 310 CMR 7.05 Fuels, and 310 CMR 70.00 Environmental Results 

Program Certification Regulations. 

The proposed revisions will affect stationary engines and turbines used as emergency and nonemergency power sources. The Department has indicated that the new rules are necessary to 

better regulate the increasing number of diesel stationary engines in the state, many of which are 

smaller than the current permitting threshold. The Department also wishes to streamline 

permitting by expanding the use of Environmental Results Program (ERP) tools in the oversight 

of such engines. 

The general requirements for new stationary engines and turbines include: 

• Rather than existing case-by-case permit review for units, owners of new units will be 

required to certify compliance with all new standards and requirements, which will include 

a manufacturers certificate of emissions performance. 

• Exceptions to certification for unit operations that have specific technical or economic 

considerations, such as turbines that operate as peaking power production units. These 

units may be filed under the traditional case-by-case review process, and DEP will 

require Best Available Control Technologies (BACT). 

• All new liquid fueled engines will be required to burn ULSD when it is required and 

becomes available for on road vehicles in 2006. 

• New emergency and non-emergency turbines will be required to comply with emission 

standards based on DEP's evaluation of vendor information and agency determinations 

of BACT. 

• Requirements for stack height/emission dispersion, noise, operation and maintenance 

record keeping, monitoring and visible emissions are proposed for all new engine and 

turbine installations. 

• New emergency engines rated at 37 kw and greater and emergency turbines rated at 

less than 1 MW will be required to comply with emission standards based on EPA's nonroad engine program and the threshold for regulation is being lowered from 300 kw to 37 

kw. 

• New non-emergency engines rated greater than 50 kw and less than or equal to 10MW 

units will require manufacturer certification based on standards set for in the Regulatory 

Assistance Project (RAP) Model Rule for the Output Specified Air Emissions from 

Antonia M. Pollak, Director Printed on recycled paper Thomas M. Menino, Mayor 
Proposed Amendments to 310 CMR 7.00 and 310 CMR 70.00 - APCC comments 2 

Smaller-Scale Electric Generation Resources, which phases in increasingly stringent 

standards between 2004 and 2012. 

The APCC supports the proposed amendments as they will more comprehensively regulate 

stationary emission sources. The City of Boston has many facilities within the city that employ 

emergency generators and it is anticipated that distributed generation and Combined Heat and 

Power (CHP) systems will grow in number in the city, as these facilities provide for energy 

savings, reduced emissions and the expansion of cleaner burning fuels. Given the concentration 

of these units in the city, along with other stationary and mobile sources of air pollution, it is 

important to have these units adequately regulated by DEP. 

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

as they apply to these generators, to ensure that emissions standards are adhered to and ULSD 

is in use. Furthermore, DEP must ensure that non-emergency engines and turbines systems not 

subject to ERP that undergo traditional review, be required to implement Best Available Control 

Technologies to limit pollutant levels. These units will be utilized during peak periods and will be 

employed, on hot summer days when fossil fuel combustion emissions levels and weather 

conditions create poor air quality. These generators should meet the most stringent standards. 

The APCC supports DEP's position of not allowing emission credits against emission limitations 

for CHP units as suggested in RAP Model Rule. As noted in the Background Information 

Document, this methodology will allow for the installation of units that may exceed limitations, 

hindering the implementation of BACT state of the art engines and turbines. Incentives for CHP 

should not compromise existing air quality standards and regulations. 

The proposed amendments to 310 CMR 7.02(8)(i), 310 CMR 7.03(10), and 310 CMR 7.26(41), 

outline limits upon engine operations, specifying the conditions under which engines may operate 

within the 300 hours, per rolling 12 month period. The DEP should better define "imminent" in 

reference to threats of power outages. The APCC has concern that generators may 

unnecessarily be brought on line to supplement energy use on heavy load days during summer 

months when air quality is already compromised. 

The APCC supports further measures to control air pollutant levels from all new and existing 

stationary engines and combustion turbines through the installation of emission control 

technologies such Diesel Oxidation Catalysts. The DEP should consider requirements for these 

technologies for older, dirtier generators to supplement the improvements brought by use of 

ULSD. Additionally, the amendments should not preclude the use of cleaner, alternative fuels 

such as biodiesel. The ERP tools should also account for units that have additional control 

technologies and utilize alternative fuels. 

We thank you for the opportunity to comment. 

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