1 

### Appendix **D -**  **16 RESPONSE TO**  **COMMENTS**

**August 201**  **2** In February 20 12 , the Massachusetts Department of Environmental Protection ( MassDEP ) proposed amendments to its December 30, 2011 Regional Haze State Implementation Plan (SIP) to address Best Available Retrofit Technology (BART) requirements and other emission reduction commitment s for electric generating units (EGUs)

. MassDEP held public hearing s and solicited oral and written testimony on the proposed SIP amendments in accor dance with Massachusetts General Laws (M

. G

. L

. ) Chapter 30A. On February 21 , 201 2 , MassDEP published notice of the public hearings and public comment period on the proposed amendments in the Boston Globe and the Springfield Republican, and notified interes ted parties via electronic mail. P ublic hearing s w ere held on March 27, 2012 in Springfield and on March 28, 2012 in Boston. No oral testimony was provided at either hearing. T he public comment period closed on April 9 , 201 2

. MassDEP received several sets of written comments. A summary of written comments received and MassDEP’s responses are provided below. **Commenters:** 1. U.S. Department of the Interior , National Park Service, comments dated April 9 , 201 2 [NPS ] 2. U.S. Department of Agriculture , Forest Service, comments dated April 9 , 201 2 [FS] 3. U.S. E nvironmental P rotection A gency Region 1, comments dated April 4 , 201 2 [EPA] 4. Sierra Club, Massachusetts Sierra Club, and Conservation Law Foundation, comments dated April 9 , 201 2 [ SC/CLF ] 5. Domi nion Energy

New England, comments dated April 9, 2012 [Dominion]
**1. Comment** : MassDEP i s propos ing a Best Available Retrofit Technology ( BART ) Alternative that includes BART and non

- BART EGUs. In a similar case regarding trading among BART and non

- BART boilers, EPA required Wisconsin to follow EPA’s economic incentive program (EIP) guidance. We believe that MassDEP’s BART Alternative should be consistent with EPA’s EIP policy

and demonstrate a 10% “environmental benefit.” [NPS] **Response** : MassDEP ’s Alternative to BART does not involve emissions trading between sources, and therefore EPA’s EIP policy is not applicable. **2. Comment** : From the pe rspective of a Federal Land Manager, who has affirmative responsibility

to protect the air qualit y related values in federal Class I areas, we are encouraged that a number of significant steps are bein g taken to reduce sulfur dioxide emissions. Some of th e steps include the retirement of Somerset Power Unit 8 in 2010, the proposed retirement of Salem Harbor Units 3 and 4 in 2014, and MassDEP’s proposed amendments to its low su l f ur fuel oi l regulation (which would require EGUs that burn residual oil to limi t the sulfur content to 0.5% by we i ght beginning July

1, 2014). We also acknowledge y our proposal to review EGU emission s in 2013, with the intent of a 90% reduction in sulfur dioxide emissions from EGUs from 2002 levels b y 2018. (FS)2

**Response** : MassDEP appreciates the Forest Service’s comments

. **3. Comment** : In Tables 16

- 19, for clarity , EPA suggests that the term “projected” be replaced with the term “estimated.” These emissions are not being projected for a specific future y ear, but are the estimate d reduced emiss i ons resulting from the application of either the BART benchmark or alternative BART. [EPA] **Response** : MassDEP has made this change. **4. Comment** : In Tables 17, 19, and 20, EPA recommends that MassDEP add a column which indicates the enforceable mechanism for the state SO2, NOx and PM10 emission limits, respectivel y. [EPA] **Response** : MassDEP has not added columns to the Tables due to limited space, but the enforceable mechanisms for the emission rates are described in the text surrounding these tables. **5. Comment** : The first sentence of Section 8.11 states, “MassDEP’s proposed Alternative to BART does not cover PM10 emissions.” EPA recommends that this statement be clarified to indicate that for PM10, MassDEP undertook source

- by

- source BART determinations. [EPA] **Response** : MassDEP has made this change. **6. Comment** : MassDEP’s proposal includes several new Appendices, including one rule and severa l emissions control plan approvals. As these items are relied upon by MassDEP to implement BART, these Appendices need to be included in the final SIP revision and incorporated into the SIP. As such, if there are certain provisions of the rule or emission control plans that MassDEP does not want to be incorporated into the SI P, it should make that clear in the SIP revision. Conditions which MassDEP does not want to incorporate into the SI P should be struck out in the final submittal. [EPA] **Response** : Ma ssDEP has included the final emissions control plans (ECPs) and regulations it is relying on in the SIP as Appendices in the SIP, and has struck out those portions of the ECPs and regulations it does not want incorporated into the SIP. **7. Comment** : Since a number of new Tables are being added to Section 8.10 and 8.11 of the SIP, the tables contained in Sections 9 and 10 of the final SIP submitted in December should be revised. This includes the revised “Table 19: Massachusetts Targeted EGUs” in proposed S ection 10.5, which should be renumbered as Table 25. The references to Table 19 on pages 16 and 18 should likewise be changed to Table 25. [EPA] **Response** : MassDEP has made these changes. **8. Comment** : MassDEP’s proposed plan to address BART requirement s for EGUs does not comply with the requirements of the Clean Air Act (CAA) and EPA’s implementing regulations, 40 C.F.R. Pt. 51. MassDEP impermissibly seeks to rely on a handful of state regulations as an alternative to requiring source

- specific BART emi ssion limits for subject

- to
- BART EGUs in3

Massachusetts. However, not only does the plain language of the Clean Air Act preclude the use of such alternatives, but Massachusetts has also failed to meet its specific obligations under EPA’s regional haze regu lations to justify the use of these regulations to replace source

- specific BART limits. [SC/CLF] **Response** : MassDEP believes its SIP complies with the Clean Air Act and EPA’s regional haze regulations. The Clean Air Act does not prohibit a state from de veloping an Alternative to BART program and EPA’s implementing regulations at 40 CFR 51.308 (e)( 2 ) specifically allow a state to adopt an Alternative to BART provided that such alternative achieves greater reasonable progress toward natural visibility conditions than source

- by

- source BART

. 40 CFR 51.308(e)(3) provides that an alternative program can be deemed to achieve greater reasonable progress than source

- specific BART if the alternative program results in greater emission reductions, provided the geographic distribution of emissions is similar under the alternative measure and BART. EPA’s regulations allow ing an Alternative to BART have been upheld by the D.C. Circuit Court of Appeals. CEED v. EPA , 398 F.3d 653, 659

- 660 (D.C.Cir. 2005) Inits SIP , MassDEP demonstrates that its Alternative to BART achieves greater emissions reductions than would source

- specific BART, and that the distribution of emissions is similar. Therefore, MassDEP’s Alternati ve to BART achieve s greater reasonable progress and meets the requirements of EPA’s regional haze regulations. **9. Comment** : MassDEP has not included or referenced in its SI P revision the statutorily required source

- by

- source BART anal ys is for each emission unit subject to BART. Consequently , MassDEP cann ot substantiate whether its proposed BART alternative results in greater reductions of haze

- forming pollutants than would be achieved under source

- by

- source BART, as is required for MassDEP to rely on a BART alternative. EPA has promulgated detailed BART guidelines that lay out the five

- step process that must be followed to determine BART for units at facilities with a capacit y greater than 750 MW. MassDEP must follow that process here for Bray

ton Point, Canal, My stic and Salem Harbor and must include the se anal ys es in its SIP. In addition, for units at smaller facilities, the statute and regulations establish factors that MassDEP must consider in establishing BART. These analy ses are missing from MassDEP’s proposed regional haze SI P, and this deficiency must be remedied before MassDEP can purport to rely

on its proposed BART alternative. [SC/CLF] **Response** : Under EPA’s regional haze regulations, if a state pursues an A lternative to BART program it must submit an anal ys is that includes a determination of BART for each source subject to BART and covered b y the alternative as part of its SIP . However, there is one exception to this requirement where the “... alternative measure has been designed to meet a requirement other than BART (such as the core requ irement to have a long

- term strategy to achieve the reasonable progress goals established by States). In this case, the State may determine the best s ys tem of continuous emission control technology and associated emission reductions for similar ty

pes of s ources within a source category based on both source

- specific and category
- wide information, as appropriate. ” [see 40 CFR 308(e)(2)(i)(C)] MassD EP’s alternative BART measures were designed for purposes other than BART and are part of Massachusetts’ long

- t erm strategy to meet reasonable progress goals. Therefore, EPA’s regulations allow MassDEP to establish a BART benchmark to compare to its Alternative to4

BART using assumptions for categories of sources, rather than determining source

- specific BART for ea ch BART

- eligible source

. **10. Comment** : In seeking to demonstrate that its proposed BART alternative produces emissions benefits relative to source

- specific BART, MassDEP improperl y compared emissions reductions under its proposed BART alternative to those under MANE

- VU’s categoricall y derived presumptive BART. But presumptive BART is not BART, and is not a substitute for anal ys es that compl y with the regional haze rule and BART guidelines for each subject

- to
- BART source. Because source

- specific BART limits are often significantly lower than those identified by EPA as presumptive BART, MassDEP’s comparison of its BART alternative to presumptive BART is impermissibly

skewed in favor of the BART alternative. MassDEP must redo its anal ys is and compare e mission reductions under the proposed alternative to those produced by full source

- specific BART anal ys es. MassDEP must include in this analy sis an evaluation of the impact of source

- specific emission reductions on each affected Class I area. [SC/CLF] **Response** : As noted in the response to Comment 9 , EPA’s regional haze r egulations allow MassDEP to establish a BART benchmark to compare to its Alternative to BART based on an anal ys is that includes simplifying assumptions about BART control levels for sources within a source category , rather than determining source

- specific BART for each BART

- eligible source. At a minimum, MassDEP believes its BART benchmark should be based on EPA’s presumptive limits for EGUs in its BART Guidelines. However, MassDEP has gone bey ond EPA’s presumptive BART Guidelines and based its BART benchmark on MANE

- VU’s more stringent recommended BART emission limits for EGUs. Therefore, MassDEP’s BART benchmark appropriatel y and adequately represents what BART is likely to be for th e category

of EGU sources. **11. Comment** : MassDEP cannot establish that its proposed BART alternative results in greater reasonable progress toward achieving natural baseline visibility conditions in Class Iareas than would properl y conducted source

- by

- so urce BART. MassDEP’s comparison of the sulfur dioxide (SO2) and nitrogen oxide (NOx) emission reductions under its proposed alternative and source - specific BART is fatally flawed because the agency ignores emission reductions already being achieved at sub

ject

- to
- BART units and ignores enforceable emission reductions at units subject to its BART alternative that should be included as well in the source

- specific BART benchmark case. The BART emissions benchmarks for SO2 and NOx included in Tables 16 and 18 of the SIP appear to significantly under predict emission reductions that would be achieved under properl y conducted source

- specific BART. For example, Bray ton Point Units 1 and 2 alread y are achieving SO2 emissions rates that are lower than the presumpti ve BART emission rate of 0.15 lb/MMBtu that MassDEP assumed in its BART Benchmark , so that emissions from these two units should be at most 1,811 tons, not 2,467 tons as MassDEP presumes, an overestimate of 656 tons . Bray ton Point Unit 3 is installing a dry scrubber that could result in emissions of 778 tons, compared to the 2,725 tons of SO2 presumed b y MassDEP, which is an overestimate of 1,947 tons. In addition, MassDEP credits its BART alternative with 9,998 tons of SO2 reductions from Salem Harbor Un its 1, 2 and 3. This is improper since each of these units is subject to an enforceable consent decree between Conservation Law Foundation, Healthlink, and Dominion requiring the complete shutdown of Salem Harbor as a coal

- fired power plant no later than June 1, 2014. Consequently , these emission reductions would have occurred under the5

source - specific BART scenario just as they occur in MassDEP’s BART alternative. MassDEP therefore cannot consider the emissions reductions occurring at Salem Harbor Units 1 through 3 only for its BART alternative, but must include the enforceable emission reductions for these units in its analy sis of source

- specific BART as well. Likewise for NOx, MassDEP underestimates the emission reductions that would be achieved under source

- specific BART and improperl y credits it proposed BART alternative with achieving thousands of tons of NOx reductions from Salem Harbor that would occur under either scenario. In addition, MassDEP has not provided sufficient information in it s regional haze SIP to evaluate or eliminate selective catal yt ic reduction (SCR) or selective non

- catal yt ic reduction (SNCR) as control technologies for NOx at Bray ton Point Unit 2. Correcting these errors reveals that in 2018 source

- specific BART would r esult in SO2 emissions reductions at least 8,600 tons greater than under the BART alternative and NOx emissions at least 3,200 tons greater than under MassDEP’s proposed alternative to BART. Consequently , MassDEP cannot demonstrate that its proposed BART alternative would result in greater reasonable progress toward achieving natural baseline visibility conditions in the areas prote cted by the regional haze rule, and MassDEP’s BART alternative fails to meet the basic requirements of 40 CFR 51.308(e)(2). [ SC/CLF] **Response** : The se comments assert that MassDEP significantl y underestimated emissions reductions for SO2 and NOx in its BART benchmar k , which assume s that the BART benchmark must be based on a source

- specific BART determination for each BART

- eligib le source. However, as noted in the responses to Comments 9 and 10, the BART benchmark does not require a source

- specific BART determination for each BART

- eligible source, but may be based on an anal ys is that includes simplifying assumptions about BART co ntrol levels for sources within the source category being considered (i.e., EGUs). This is the case even if existing controls or future controls (including shutdowns) c ould result in more emissions reductions than estimated by

the BART benchmark. The pre amble to EPA’s 2006 regional haze regulations (71 FR 60612) includes the following language that makes clear that source - specific BART determinations are not required under the Alternative to BART that MassDEP has established in its SIP , and that states may use EPA’s presumptive BART limits in establishing a BART benchmark : “In today 's final rule, the regulations make clear that, with one exception, States must follow the approach for making BART determinations under section 51.308(e)(1) in establishing a BART benchmark. This includes the requirement for States to use the BAR T guidelines in making BART determinations for EGUs at power plants of a certain size. As discussed above, the one exception to this general approach is where the alternative program has been designed to meet requirements other than BART; in this case, **Sta tes are not required to make BART determinations under §**  **51.308(e)(1) and may use simplifying assumptions in establishing a BART benchmark based on an analysis of what BART is likely to be for similar types of**  **sources within a source category.** [emphasis ad ded] Under either approach to establishing a BART benchmark, we believe that the presumptions for EGUs in the BART guidelines should be used for comparison to a trading program or other6

alternative measure, unless the State determines that such presumptio ns are not appropriate for particular EGUs. We note that this limitation on the use of the presumptions is most likely to appl y onl y in a source

- by

- source determination under § 51.308(e)(1). **States establishing a BART benchmark based on simplifying assumpt**  **ions as to the most**

**- stringent BART for EGUs may rely on the**  **presumptions, as EPA did in the CAIR rule.”** [emphasis added] **12. Comment** : T he Massachusetts SIP revision fails to demonstrate that the distribution of emission reductions under its proposed BART alternative will be similar to that under source

specific BART or conduct dispersion modeling showing that the BART alternative results in greater reasonable progress in areas protected b y the regional haze rule. Although MassDEP asserts that the distrib ution of emissions is similar, its rationale is flawed and a further demonstration is required. Under EPA’s haze regulations, it is insufficient to simply compare the total emissions reductions from source

- specific BART and a state’s BART alternative; the state must also take into consideration the location of these emission reductions. Where the distribution of emissions under BART and the alternative are substantially different, the state proposing to rely

on a BART

- alternative must conduct dispersion m odeling to show the difference in visibility

under each program for each impacted Class I area on the worst and best 20 percent of day s. The modeling will demonstrate greater reasonable progress only if: (1) Visibility does not decline in any

Class I area ; and (2) There is an overall improvement in visibility , determined by

comparing the average differences between BART and the alternative over all affected Class I areas. MassDEP does not offer dispersion modeling to compare the visibility improvements re sulting from source

- specific BART and its proposed BART alternative. Instead the agency claims that “the Alternative to BART achieves greater emissions reductions than BART and the geographic distribution of emissions reductions is nearly identical since all of the units subject to BART are included in the Alternative to BART. ” But this reasoning is flawed. The mere fact that the subject

- to
- BART units are a subset of the alternative BART units say s nothing about the similarity of emission reduction distr ibutions under each scheme. Instead, to assess emission distributions MassDEP would have to compare the magnitude of emission reductions at units common to both schemes and evaluate whether the additional units covered by the BART alternative are proximat e to subject to BART sources. MassDEP has not done so, and therefore cannot presume that its BART alternative produces a similar distribution of emission reductions. [SC/CLF] **Response** : MassDEP believes that the geographic distribution of the emissions reductions from the Alternative to BART is not significantly different to the geographic distribution of emissions reductions from source

- specific BART, and therefore comparison of the Alternative to BART and BART benchmark may be made on the basis of emis sions alone in accordance with 40 CFR 51.308(e)(3). The Table below show s the geographic distribution of SO 2 and NO x emission reductions for the BART benchmark and Alternative to BART

. With the exception of emissions reductions at Mt. Tom in Western Massachusetts (which will help reduce visibility impacts at the Lye Brook Class I area in Vermont), all of the emission reductions that result from MassDEP’s Alternative to BART occur in Eastern Massachusetts, which is the same geographic area where emissi ons reductions would occur from source

- specific BART (represented by the BART benchmark). On this basis alone, MassDEP believes that the distribution of emissions reductions is similar between the two approaches given the relatively small size of Massachu setts in the7

context of regional haze, which is visibility impairment produced by a multitude of sources and activities located across a broad geographic area. The Alternative to BART results in a greater portion of overall emissions reductions in Northea st MA versus Southeast MA, compared to the BART benchmark, which could be beneficial since Northeast MA is closer in distance to the MANE

- VU Class I areas. It should be noted that while the BART modeling performed b y MANE

- VU showed that emissions from Southeast MA had the greatest visibility impact at Class I areas in Maine (due to Bray ton Point and Canal), the modeling of emissions from Northeast MA did not include Salem Harbor Units 1

- 3 because they are not BART units. Had emissions from Salem Harbor Un its 1

- 3 been included in the MANE

- VU BART modeling, the impact from Northeast MA would have been greater than reported in the original modeling. **SO 2**  **Emissions Reductions (in tons)**  **Geographic Region BART Benchmark**  **Alternative to**  **BART** North east MA 3,097 12,363 South east MA 47,65 5 38,912 Western MA 0 3 , 710 **Total 50,75**  **2 54,986** 

**NO x**  **Emissions Reductions (in tons) Geographic Region**  **BART Benchmark Alternative**  **to BART**  Northeast MA 526 2,376 Southeast MA 12,294 9,55 7 Western MA 0 1,184 **Total 12,820**  **13,117** Note s : Northeast MA includes Salem Harbor and Mystic

Southeast MA includes Brayton Point, Canal, Somerset, and Cleary Flood Western MA includes Mt. Tom Totals shown may not add precisely due to rounding **13. Comment** : MassDEP has not demonstrated that the state will achieve the reasonable progress goals established by MANE

- VU for 2018. MANE

- VU includes as a reasonable progress goal emission reductions of 90% from each of the 167 power plant stacks in the MANE

- VU region whose SO2 emissions were determined to significantly impair visibility

in one or more MANE

- VU Class Iareas. The Massachusetts regional haze SIP fails to put the state on a path to achieve those reductions, even under the optimistic projections made b y M assDEP, and fails to require enforceable commitments to achieve these reductions. Where a state has participated in a regional planning process, “ the State must ensure it has included all measures needed to achieve its apportionment of emission reduction obligations agreed upon through that process. ” 40 C.F.R. § 51.308(d)(3)(ii). However, under Mass DEP’s proposed SIP, the state is not projected to achieve the 90% SO2 reduction target by 2018 at major EGUs. In stead, MassDEP projects emission reductions of between 67 and 87% from the affected units. This is unacceptable given its regulatory obligation, and particularl y in light of the levels of SO2 emissions cost

- effectively achievable from these units. To remedy this deficiency , the SIP at a minimum shou ld include enforceable requirements that Mount Tom and Brayton Point operate their sulfur dioxide controls continuously and require an enforceable SO2 emission limit of zero for Salem Harbor Units 1 and 2 consistent with the consent decree requiring the shutdown of the8

Salem Harbor facility

as a coal

- fired power plant. When coupled with an enforceable shutdown of all units at Salem Harbor and the shutdown of Somerset Unit 8, the requirement of continuous operation of SO2 controls at Bray ton Point and Mount Tom should enable Massachusetts to meet its obligation of achieving an enforceable 90% reduction in SO2 emissions from the stacks covered b y the MANE

- VU reasonable progress goal. [SC/CLF] **Response** : As a point of clarification, the MANE

- VU commitment to a 90% reduction in SO2 emissions from 167 EGU stacks is not a reasonable progress goal, but is part of the long

- term strategy MANE

- VU states adopted to achieve the reasonable progress goals established by the Class Istates (the reasonable progress goals f or the Class Iareas are described in Section 9 of the SIP). In addition, the MANE

- VU commitment provides flexibility in achieving the emission reductions that were assumed for each state in the modeling that form ed the basis of the reasonable progress go als. MassDEP has demonstrated that its long

- term strategy includes all the measures needed to achieve its apportionment of emission reduction obligations agreed upon through the regional planning process, in accordance with 40 CFR 51.308(d)(3)(ii). R egarding the 167 EGU strategy , as described on page 18 of the proposed SI P revision, MassDEP’s conservative 67% reduction projection for targeted EGUs results in 26,811 tons of SO 2 emissions in 2018, which is well below the 45,941 tons of SO 2 emissions that M assachusetts needs to meet the modeled 2018 reasonable progress goals for the Class Iareas. Therefore, MassDEP has met the requirement of 40 CFR 51.308(d)(3)(ii) with regard to EGU emissions even under its most conservative projection. Fortunatel y, Mass DEP projects that EGU SO 2 emissions reductions in 2018 will be much lower, by 87% or more. **1 4**  **. Comment** : We agree with MassDEP’s proposed revision s to the Massachusetts Regional Haze SIP and urge y ou to finalize them as proposed with regard to the Amended Emission Control Plan Draft Approvals for Salem Harbor and Bray ton Point. In particular, we also support MassDEP’s Alternative to BART approach as part of the prop o sed revisions. Based on the provisions of 40 CFR 51.308(e)(2), we agree that Massachusetts has the authority to implement the proposed Alternative to BART. Furthermore, as shown in section 8.10 of the propo sed SIP revision , MassDEP has demo n strated its alte rnative to BART will achieve greater emission reductions of SO2 and N O x than would be achieved through the installation and operation of BART alone. The Proposed Revision to the SI P also addresses BART for PM10. However, MassDEP has determined that no ad ditional controls are warranted for primary PM10 because controls have been added to all but one of the (non

- Dominion) facilities, and the additional cost of further control is not justified since there would be no significant visibility improvement. [Dom inion] **Response** : MassDEP has finalized the Amended Emission Control Plans for Salem Harbor and Bra yt on Point as proposed in the SI P revision. In addition, MassDEP has adopted its Alternative to BART as proposed

.