Mr. Tim Allen:

I sent you a copy of Delaware’s draft Visibility SIP on April 29, 2008. Thank you for your

comments and suggestions — I think they helped us create a better and clearer proposal.Attached for your information is Delaware’s proposed Visibility SIP. The main change from

the prior draft is in the BART Section, Section 8. In our last draft you may recall thatDelaware relied upon the EPA demonstration that “CAIR is better than BART” for SO2 and

NOx. As you know, CAIR was vacated. Because of this we have revised the BART portion

of our SIP relative to S02 and NOX.CAIR was projected to get no reductions in Delaware (actually, DE EGU emissions were

projected to increase under CAIR). This was one of the reasons Delaware adopted

Regulation No. 1146. Regulation No. 1146 imposes stringent NOX and S02 (and mercury)

requirements on Delaware’s coal and residual oil fired EGUs. It requires actual reductions

from Delaware’s EGUs, while CAIR did not. Given that we had adopted Regulation No.

1146 the revised demonstration in Section 8 is relatively straight forward, and unlike the

version you reviewed that was based on CAIR our SIP now shows that Delaware will achieve

significant reductions at all our BART eligible sources. The demonstration shows that “Reg.

1146 is better than BART” using a variety of demonstrations, including one based on the

methodology in 40 CFR Part 51 3 05(e) — “alternative measures.”40 CFR Part 51.308(e) provides that a state may “demonstrates that an emissions trading

program or other alternative will achieve greater reasonable progress toward natural visibility

conditions.” Under this provision we have done a similar analysis as the EPA did for CAIR;an analysis that shows that our alternative program (i.e., Delaware Regulation No. 1146) is

better than BART. A significant difference between our demonstration and the EPA CAIR

demonstration is that CAIR was a trading program, while Reg. 1146 is not. Reg. 1146 coversall BART-eligible sources in Delaware, and requires each of those units to meet stringent

NOX and S02 emission requirements. It is clearly more stringent than a unit-by-unit BART

analysis (and obviously CAW that was used in our original draft). Even with the absurd

assumption that all Delaware BART-eligible units would emit zero emissions under a unitby-unit BART analysis, Reg. 1146 gets more reductions. In addition, since Reg. 1146 does

not allow trading, unlike CAIR, the distribution of the reductions is no different under our

alternative program (i.e., Reg. 1146) then it would be under a unit-by-unit BART analysis.

We believe that you will agree that this is a very positive change, since this change

demonstrates that Delaware’s units will reduce emissions under our “Reg. 1146 is better than

BART analysis,” rather than increase as was the case under the prior “CAIR is better than

BART analysis.” We believe that unlike many states Delaware’s plan was not reliant on

CAIR and Delaware has done what is needed to reduce emissions from EGUs. Because of

this Delaware EGUs, to include all of the EGUs that were BART-eligible, will not continueto cause visibility problems at Class I areas even in light of EPA’s failure with CAIR. We
Planning Branch Manager

State of Delaware

DNREC Air Quality Management

(302) 739-9402