TABLE 4-3 Statistical Summary of RECi,j(t) Values

t =

CO

 

PM

PM10

SO2

 

NOx

 

1989

1998

1989

1998

1989

1998

1989

1998

N (number of plants)

5,628

17,286

6,360

20,223

4,957

13,220

6,100

18,635

Mean

0.304

0.07

–0.0576

–0.088

1.934

0.778

0.895

–0.118

Std. Dev.

5.431

1.819

6.589

6.21

87

31.68

15.4

13.85

Fraction > 0

0.492

0.309

0.517

0.477

0.489

0.258

0.48

0.316

Fraction > 1

0.046

0.0104

0.061

0.01

0.162

0.0362

0.113

0.0246

Prob (>1)/Prob(>0)

0.094

0.0337

0.118

0.021

0.331

0.14

0.235

0.0778

Ratio (1989:1998) of Prob (>1)/Prob (>0)

2.79

 

5.62

 

2.36

 

3.02

 

in relative emission increases from 1989 to 1998. Inferences regarding possible implications for NSR enforcement would require information on those facilities undertaking modifications potentially subject to the NSR rules during these periods. Before such an inference could be made, however, other factors that changed during this period (e.g., economic conditions or the stringency of other regulations) would need to be considered. Furthermore, as discussed in Chapter 5, a more complete evaluation would consider more-recent time periods and differences between states.



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