### March 31, 2006

SUMMARY OF COMMENTS AND.RESPONSE TOCOMMENTS FROM PUBLIC HEARINGS ON PROPOSED AMENDMENTS TO

310 CMR7.00 et sea.

This regulation revision affects the requirements for : 1) 310 CMR 7.00 - Definitions. The definition of Volatile Organic Compound (VOC) is modified to exempt five additional compounds. The Environmental Protection Agency (EPA) issued final rules on November 29, 2004 exempting these compounds. 2) 310 CMR 7.06 - Visible Emissions. Visible emissions limitations are proposed for certain facilities required to have Operating Permits. 3) 310 CMR 7.24 - Organic Material Storage and Distribution . Expand the time period during which gasoline tank trucks are required to be tested for vapor leak tightness. Hearings were held on the proposed amendments on October 18, 2005 in Boston and October 19, 2005 in Springfield. The hearing record was held open until 5 :00 PM on October 28, 2005. This document summarizes and responds to the comments received fromthe following parties : Associated Industries of Massachusetts (AIM) General Electric Company (GE) Harvard University (Harvard) Bob Machaver (Machaver) United States Environmental Protection Agency (EPA)

## March 31, 2006 

## 310 CMR7.00 Definitions 1 . Comment: The proposed exemption of t-butyl acetate (TBAC) fromthe term "volatile organic compound" (VOC) differs fromEPA requirements . While EPA Exempts TBAC fromcontrol requirements, TBAC is not exempted fromrecord keeping and reporting requirements. Massachusetts should delete TBAC fromthe list of exempt compounds and add the following language that is consistent with EPA requirements : "In addition, the following compound(s) are VOCfor the purpose of all recordkeeping, emission reporting= photochemical modeling, and inventory requirements which apply to VOCand shall be uniquely identified in emission reports but are not VOCfor the purposes of VOC emissions limitations or VOC content requirements : t-butyl acetate." EPA Response: Agree, the language will be included. 2 . Comment : The CAS Number of two of the chemicals within the list of exempt VOC compounds should be revised to read as follows: 124389 carbon dioxide 420462 HFC-143a(1,1,1,-trifluoroethane) EPA Response: Agree, the change will be made to include the correct CAS numbers.

## March 31, 2006 

## 310 CMR7.06 Visible Emissions

General l . Comment : "Massachusetts' proposed revision to section La, l .b, and l .c under 310 CMR7 .06(l)(c) (exemption to visible emission limits) is in accordance with revisions suggested by EPA in January 2005. We support the proposed language in 310 CMR 7.06(1)(c)l .b., which allows visible emissions to exceed 27 percent opacity during one hour per quarter calendar year . We agree with the state that specifying a threshold for average opacity during this hour would complicate the type of continuous monitoring equipment required ." EPA Response: The comment is noted. 7.06(1)(c)1 . Visible Emission Limits 2 . Comment : The reference to 7.06(1)(c)l .f . in 7.06(1)(c)l .a. appears to be incorrect and should be 7.06 1)(cll .g. EPA, GE Response: Agree, the reference will be changed. 3. Comment: Several comments expressed concern that it is unclear if the shorttermopacity excursions are allowed on an applicable emission unit basis or facility wide. AIM, Harvard, Machaver, GE Response: Language will be added to make it clear that the requirements apply on a per unit basis.

4 . Comment : Facilities should be entitled to the exemptions allowed by both 7 .06(1)(c)l .b and Lc

. Language should be revised to more clearly indicate that both exemption options are available. AIM, Harvard, GE, Machaver Response: Agree. This will be made clear that both exemptions are allowed. 5 . Comment: Requests that 7.06(1)(c)l .b . be changed to allow the two exceedances of 27% opacity to occur at any time during a quarter instead of both occurring within the same hour . The requirement is sufficiently restrictive, compliance will be easier to track and the intent of the requirement will be maintained. GE, Machaver Response: Agree. The regulation will be revised.

## March 31, 2006 6 . Comment : 7 .06(1)(c)l .c. The one-tenth of one per cent allowance penalizes limited use boilers that, because of their limited use, are more prone to experience problems. It is suggested that a fixed number of excursions be allowed that corresponds to one-half of that allowed (22) for a unit that operates at all time. Limited use boilers should be allowed 11 excursions per quarter . AIM, GE, Machaver Response: Agree that a set number ofexcursions is reasonable. The 11 excursions as proposed by the commenters are too many for limited use units such as back-up units or those that operate primarily during below average cold weather. The regulation will allowall units to have a minimum of six excursions per quarter. Six excursions corresponds to a boiler operating 27% of the time in a quarter . Those units operating less than 27% of the time will be allowed six excursions . Those operating more than 27% would be allowed between 6 and 22 excursions depending upon the total quarterly operating hours. 7. Comment : 7 .06(1)(c)l .c. The one-tenth of one percent (0.1) rule is too restrictive for limited operation boilers and should be changed to 0 .5 percent. Harvard Response: See response to Comment 6 . 8 . Comment: 7.06(1)(c)l .c. It is not technologically feasible to comply with the proposed regulations for our older, load following steam plant . The upper cap of 60 percent is burdensome especially during unforeseen conditions such as boiler trip, burner or equipment upsets, and unanticipated load ramps. It is requested that up to 15 spikes above 60% opacity per quarter be allowed . Harvard Response: Except for unanticipated load ramps, the conditions listed in the comment are malfunctions for which no exception to 310 CMR 7.06(1)(c)l .a. are provided. The request to allow15 excursions above 60% opacity was not supported by documentation . The Plan of Good Operating Procedures, developed in concert with the third party combustion experts, should focus on minimizing the frequency of, and emissions from, unanticipated load ramps. 9 . Comment : 7.06(l)(c)l .c . The first sentence should be revised to read "For a facility equipped with a visible emission monitor with a numeric data reduction systemthat can printout or output to an electronicfile individual block averages . . ." This will provide increased flexibility in obtaining the data. Machaver Response: Agree, the change will be made.

## March 31, 2006 10 . Comment : 7.06(1)(c)l .c. The first sentence states that the Department may approve the opacity exceptions for a facility provided in the section . The language should be changed to state that the Department will or shall approve the opacity exceptions, ifconsistent with an approved Plan of Good Operating Practices. GE, Harvard, Machaver Response: The Department should not be bound to approving opacity exceptions that would in effect relax requirements for a unit that historically has complied with 310 CMR7 .06(1)(a) and 310 CMR7.06(1)(b) . The language will be changed to "the Department will make a determination to approve or deny" to indicate that the Department will take action. 11 . Comment : 7.06(1)(c)l .c. References to one hour should be changed to one hour block to be consistent with EPAaccepted data reduction methodologies. Machaver, GE Response: Agree, the change will be made. 12. Comment : 7 .06(1)(c)l .c. The phrase "during the one-hour period when a 6- minute block average exceeds 27 percent opacity" at the end of the second sentence is redundant and should be deleted. GE Response: This language is to minimize any misunderstanding . 13. Comment: 7.06(1)(c)l .d. The regulation should be modified to clarify that a source is not required to use their visible emission monitor as a direct compliance monitor unless such a requirement is contained in an existing 7.02 Plan Approval or the source requests the opacity monitor serve as a direct compliance monitor . Machaver, GE Response: Agree, the change will be made.

14. Comment: 7.06(1)(c)l .g. Recommends that five-business days notification be required instead of two for scheduled activities that are for the purpose of improving boiler performance. As these activities are scheduled, two days may not be adequate time to determine if exemption to visible emission limits is appropriate. EPA Response: The Department agrees with the comment and will modify the language.

## March 31, 2006

7.06(1)(c)2

. Plan of Good Operating Practices 15. Comment: Believes the provisions for an approved "Plan of Good Operating Practices" (POGOP) is overly complicated and unnecessary. AIM Response: More than a dozen facilities statewide have developed POGOP's that have been approved by the Department . The Department has found that this requirement is valuable in obtaining improvements in facility operation and reductions in visible emissions. 16. Comment : Previously approved POGOP should either immediately terminate upon adoption of new

regulations, be allowed to be modified by a source or at the request of sources remain in effect . Machaver, Harvard, GE Response: The Department will work with the facilities to allow modifications to POGOPas appropriate to reflect requirements as adopted. Facilities may request modifications of their approved POGOP and then a minor modification to their Operating Permit to reflect the specific requirements of the regulations as amended. 17. Comment : 7.06(1)(c)2.d. The requirement that the duration and frequency of startup, shutdown, soot blowing and other specified operating conditions be proposed is not feasible. Sources should be allowed to qualitatively characterize these conditions . Machaver, Harvard, GE Response: The Department needs sufficient information about a facility's boiler operations to be convinced that the relief sought is appropriate and that the corresponding POGOP is feasible and hence approvable. 18. Comment : 7.06(1)(c)2.e. It is requested that only a general description of the need for visible emission limitations greater than 15 % opacity be required in the POGOP . Opacity during these special conditions cannot be predicted and past emissions are not necessarily an indicator of future conditions . Sources should be allowed to take advantage of the full range of the visible emission limitations provided for in 7.06(1)(c)

. GE Response: See response to Comment 17. The extent of documentation will be based upon the Department's knowledge of visible emission history of a facility as supplemented by information submitted by a facility . 19. Comment: 7.06(1)(c)2.f . The citation (7.06(1)(c)b) is incorrect and should be 7.06(1)(c)1 . GE Response: The citation will be corrected.

## March 31, 2006 20 . Comment : 7.06(1)(c)2 .f. This provision should be deleted and the source should be required to state if they will be complyingwith the visible emission limits contained in 7 .06(1)(c)l .b or Lc, or they will be complying with the visible emission limits contained in 7.06(1)(c)l .b. and l .c. GE, Machaver, Harvard Response: It is necessary for the facility to state where relief is necessary. The Department will not approve exceptions to visible emission requirements when it determines relief is not necessary. There may be circumstances where historically visible emissions have not been a problemfor a particular boiler . An example is a boiler that starts-up utilizing natural gas should not have a visible emission problem needing relief as provided by these regulation revisions. 7 .06(1)(c)3. Department Action 21 . Comment : 7.06(1)(c)3 .c. This provision should be deleted and the approval should state if the facility is required to comply with the visible emission limits contained in 7 .06(1)(c)l .b or Lc, or comply with the visible emission limits contained in 7 .06(1)(c)l .b. and l .c. GE Response: An approval of a POGOP must state the specific visible emission requirements and the conditions necessary to assure compliance. See response to Comment 20

. 7.06(l)(c)4

. Notice of Exceedances 22. Comment: 7.06(1)(c)4. "It is requested that a sentence be added at the end of this Section indicating that `opacity excursions > 27°lo that qualify as allowed exceptions under 310 CMR7 .06(1)(c)l .b and 7.06(1)(c)l .c shall not be considered deviations under the Operating Permit ."' Machaver Response: Agree, language will be added.

### March 31, 2006



## 310 CMR 7.24 Organic Material Storage and Distribution

l . Comment: The proposed change is reasonable, however, 310 CMR 7.24(4)(a)4 .b. states that the certification "shall expire July 1 of the year following the test ." This is inconsistent with the stated goal of spreading out the testing and 7.24(4)(a)4 .b . should be revised to read: "shall expire not more than 12 months after the date the tank truck last passed the test ." EPA Response: Agree, the suggested change will be made to make the regulation consistent .