STATE OF DELAWARE DEPARTMENT OF NATURAL RESOURCES & ENVIRONMENTAL CONTROL DIVISION OF AIR QUALITY 655 S. Bay Road, Suite 5N DOVER, DELAWARE 19901

December21, 2012

Molla Sarros Maryland Departmentofthe Environment Airand RadiationManagementAdministration 1800WashingtonBoulevard, Ste. 730 Baltimore, Maryland21230 Telephone: (302) 739 9402 Fax No.: (302) 739 3106

Subject: Delaware's comments on Maryland's § 110(a)(2)(A)-(M) State ImplementationPlan (SIP) Draftforthe 2008 8-hourOzoneNational AmbientAirQuality Standards (NAAQS)

DearMs. Sarros,

Thankyou forthis opportunityto submitcomments on Maryland's proposed SIP revision titled, "Implementation, Maintenance, and Enforcement ofthe 8-hour Ozone National Ambient Air Quality Standard State Implementation Plan," dated December, 2012. The State of Maryland's air pollution control program is to be commended for its tine work and progress in improving air quality over the years. Maryland is truly a leader in addressing regional air pollution eoneerns. Like Maryland, Delaware has endured unhealthy air quality relative to the pollutantozone formore than40-years.

Delaware has eontrolled its emission sources at eonsiderable expense, yet it is still monitoring nonattainment for the most recent 2008 0.075 ppm ozone NAAQS. Much of Delaware's ozone problems are due to emissions from outside ofDelaware. In fact, based on EPA modeling as much as 90% ofDelaware's ozoneproblems are attributableto emissions from outside ofDelaware. EPA Cross State Air Pollution Rule (CSAPR) 2012 base case modeling indicates that emissions from Maryland eontribute more than 23 ppb to ozone concentrations in Delaware

- almost one third ofthe NAAQS. EPA has determined that any impact greater than I% of the standard is significant, so based on CSAPR modeling emissions from Maryland significantly impactDelaware (i.e., 23 ppb is greaterthan 0.75 ppb).MollaSan'os Deeember21, 2012 Page 2

eAA § II0(a)(2)(D) requires Maryland's SIP to eontain adequate provisions prohibiting any souree or othertype ofemissions aetivity within the state from emitting any air pollutant in amounts whieh will eontribute signifkantly to nonattainment in, or interfere with maintenanee by, any other state with respeet to any sueh NAAQS. We have reviewed Maryland's draft SIP, and aeknowledge that Maryland has implemented many measures to reduee the emission of volatile organie eompound (YOC) and nitrogen oxide (NOx) emissions, sueh as Maryland's Clean Car program and Healthy Air Aet. However, the draft SIP does not appear to provide information suffieient for Delaware to determine if Maryland has eompliedwith II0(a)(2)(D).

Relative to 110(a)(2)(D), Maryland's draft SIP doeument appears to be a listing ofthe eontrol measures Maryland has adopted, rather than an evaluation or demonstration as to how these eontrol measures satisfy the requirements of 110(a)(2)(D). For example, there appears to be no substantive evaluation of the effeetiveness ofthe listed eontrol measures in redueing emissions, and no identifieation and evaluation ofthe eost effeetiveness ofadditional measures Maryland eould adopt to reduee its emissions and to further mitigate its impaet on downwind states including Delaware. Without this type ofanalysis Delaware eannot eonclude whether or not Maryland has adequate measures in its SIP that prohibit its emission sourees from eontributing signifieantly to downwind states' non-attainment or maintenanee issues under the 2008 0.075 ppb standard.

Delawarerequests that Marylandeonduetan analysis that I) identifies the emissions from all non-trivial voe and NOx emitting sourees and souree eategories in Maryland, 2) identifies potential additional eontrol measures that Maryland eould adopt to reduee emissions fl'om eaeh ofthose sourees and souree eategories, and 3) evaluates the eost effeetiveness ofthe identified potential additional measures to demonstrate the level of eontrol Maryland's eurrent SIP
measures provide. Delaware believes that in order to demonstrate that Maryland has met its obligations under II0(a)(2)(D) is must demonstrate that additional opportunities for eontrolling emissions are either outside of Maryland's regulatory authority, impraetieal as a "Maryland only" initiative, orearry an additional ineremental eostin exeess ofat least $5,000 perton. Note that Delaware has eondueted this same type ofanalysis and has reeommended that the EPA establishitand a $5,000 perton eostthreshold as eriteriafor evaluating all transport SIPs.

In addition to eondueting the analysis diseussed above, Delaware believes the following speeifie measures in Maryland's SIP may not be suffieientto mitigate the impaets from the State ofMaryland upon the air quality in Delaware, and eneourages Maryland to eonsideI' additional airpollutioneontrol requirements, with state-wide applieability, sueh as:

I. Adopting all ofthe OTe model rules and model rule updates that Maryland has not yet adopted. These modcl rules are regional measures to reduee voe and NOx emissions, and full implementation of these measures in Maryland may reduee Maryland's ozoneimpaetonDelaware.MollaSarros December21,2012 Page 3

2. Revising Maryland's distributive generator regulation to not allow, without exception, uncontrolled diescl generators to peak shave except during poweroutages. Uncontrolled diesel generators used for peak shaving do not operate many hours per year, but are]) very highNOx emitters, 2) often operatc attimes conducive to ozone formation, and 3) are projected to be utilizcd and relied uponmuch more in the future than in the past. Delaware believes Maryland could make their distributive generation regulation better by closing a loop-hole that allows diesel generators to operate as load shaving units, uncontrolled, for up to ]0 hours during the ozone season (i.e., May ] through September). For example, consider the operation of uncontrolled diesel generators in the context of Maryland's excellent Clean Cars Program.

• Maryland has estimated their Clean Cars Program will provide in 2020 about 2.9 tons perday morc NOx reductions when compared to existing federal Tier 2standards.

• An uncontrolled] MW diesel generatoremits about 32.2 Ibs ofNOxperhour ofoperation.

• This means thatitwould take only about ]80 ofthese generators operating for ] hourto fully negate the 2020 benefit ofMaryland's Clean Cars program on the day theyoperate.

In addition, Maryland provides an alternative compliance method that allows load shaving units to, in lieu of installing emission controls, achieve compliance by securing ozone seasonNOx allowances, ata3:] or 5:I discounted rate, to offsetNOx emittcd for load shaving that is beyond the exempted 10 hours. Delaware believes any type of allowance purchase, regardless of the discount rate, may completely negate the effectiveness oftheprogram because allowance costis very lowrelative to control cost and relative to the financial benefit achieved from peak shaving. Buildingonthe example above:

• 2.9 tons of NOx emissions would require about 15 ozone season NOx allowances be securedandretired.

• Based on an allowance cost of $350, this alternative compliance method would costahout $5,250.

• In comparison, the financial benefit for a ] MW generator participating in a PJMpeakshavingprogramis onthe orderof$60,000to $80,000peryear.
Delaware recommends Maryland consider removing the ]0 hour exemption and the alternative compliance method from its regulation, which would reduce Maryland's
ozone impacton Delaware.

3. Revising the requirements of Maryland's Healthy Air Act to include short term average emission limitations. It is Delaware's opinion that NOx control regulations should include a shortterm NOx emissions rate limit protective ofNational AmbientMollaSarros Deeember21, 2012 Page4

Air Quality Standards (NAAQS). For ozone, the NAAQS is based on a 8-hour averaging period. Long term emission limits, such as annual or seasonal NOx mass emissions eaps, do not ensure thatNOx emissions from subject sourees are emitted at rates that do not eompromise eomplianee with short term NAAQS. Without a short term enforceable NOx emissions rate limitation, a subject unit's potential to emit is the onlyemissions limitingfactor overthe shortterm. NOx emissions rate limits with short averaging periods (no greater than rolling 24-hour periods) should be included to ensureprotectionofthe shortterm ozoneNAAQS indownwind states.

For example, Maryland's Healthy Air Act includes annual and ozone season NOx
mass emissions caps for subject units. However, the Healthy Air Act does not include any short term NOx emission rate limits for those units. While the Healthy Air Aet ensures control ofNOx emissions reductions over annual and ozone season periods, the Healthy Air act may not ensure that NOx emission rates over any given shortperiod are representative ofthe annual and seasonal requirements. This can be
seen inthe NOx emissions rate data for some ofMaryland's coal-fired units for 2011 taken from the EPA's AMPD. The data below represents the individual unit's daily average NOx emissionrates only for those days where the data indicates thatthe unit operated for entire 24-hours in the respective calendar day. The value for average of 2011 daily NOx rates was calculated as the average ofall ofthe respective unit's daily NOx emissionrates when the unitoperated for all 24 hours in the calendarday, not simplythe average ofthe lowandhighvalues.

2011 low 2011 High DailyNOx DailyNOx Averageof2011 Days Days Rate Rate DailyNOx Rates Below Above Fadlity Wit (Ib/MVBTU (Ib/MVBTU (Ib/MVBU) Average Average Brandon Shores 1 0.0345 0.4979 0.1558 1ffi 94 Brandon Shores 2 0.0585 0.6268 0.1655 232 00 CPo Crane 1 0.2134 0.7051 0.4344 85 79 CPo Crane 2 0.1817 0.7482 0.3865 lCE 75 HA llltagner 2 0.2776 0.5675 0.3624 172 113 H.A. llltagner 3 0.0486 0.2962 0.1029 153 52 RP. Srrith 11 0.183 0.4389 0.2959 31 22 d1alkPoint 1 o.Oll 0.3705 0.18a3 122 114 d1alkPoint 2 0.1495 0.4541 0.2423 207 98 Didkerson 1 0.2219 0.3548 0.2702 88 59 Didkerson 2 0.21CE 0.3712 0.2735 99 76 Didkerson 3 0.2027 0.3712 0.2689 105 74 IVbrgantown 1 0.014 0.2024 0.0351 175 120 IVbrgantown 2 0.0168 0.1316 0.0322 183 144MollaSarros December21, 2012 Page5

It can be seen in the data that there is a wide range oflow to high daily average NOx emission rates, sometimes on an orderofmagnitude difference. In several cases the low daily NOx emissionrate values are indicative ofwell controlled units, while forthe same unit the high daily NOx emission rate value is more representative ofa unit with few NOx controls. The number ofdays with the respective unit operating above and below average value is an indication that the existing long term mass emissions limitations do not assure unit operation with NOx control as a priority on a full time basis. It is Delaware's opinion that appropriate short term NOx emission rate limits would serve to require operation ofthe respective units more consistently in a manner appropriate to good NOx emissions control. Delaware believes adding short term limits would make Maryland's excellent Healthy Air Act even better, and would reduce Maryland's ozone impactonDelaware.

We appreciate the effective air pollution controls Maryland has in place, the extensive research work Maryland has done relative to transported air pollution, and Maryland's continued efforts to support the development of necessary federal and regional measures to meet and maintain the ozone standard. Thank you for the oppOliunity to comment upon your draft SIP. Should you have any questions, please call me at (302) 739-9402, and I look forward to working with you in the future.

Sincerely, /\ ! i

, !

RonAmirikian Planning BranchManager