1 TSRIA Document 4: Removing Data with QA Failures and Li miting PPL Emissions to Regional Haze Levels Results in Almost No Coburn Road Exceedances (Supplements Chart 5 from Februa ry 27, 2014, TSRIA Presentation)

As a result of the February 27, 2014, m eeting with the EPA, TSRIA has conducted additional analysis of Coburn Road SO 2 concentration and PPL emissions data from 2009 – 2013. The additional analysis show s that when (1) t he data with quality assurance (QA) failures from Chart 5 (re vised 2/24/14) in the February 27 TSRIA presentation are removed and (2) emissions from PPL are limited to the new Regional Haze level, almost no high readings occur at Coburn Road. This additional analysis is summarized in the following charts, 5b through 5i, which are meant to supplement Chart
5.

The first chart (5b) shows the relationship t hat exists if all Coburn Road data are taken at face value, and shows a total of 20 hourly SO 2 concentrations exceeding 75 ppb. However, TSRIA has demonstrated that most of the high SO 2 points must be excluded due to quality assurance (QA) failures ( see TSRIA, New Standards Application document). Therefore, Char ts 5c through 5i were devel oped to show the effects of progressively removing invalid data based on objective criteria. As demonstrated by Charts 5g and 5i, only one Coburn Road value above 75 ppb remains valid when 1) all values from Chart 5 with QA failures are elim inated and 2) PPL emissions are restricted
to the levels now allowable under the F ederally enforceable Regional Haze Limit (approximately 840 lb/hr).2 

## Chart 5b:

Chart 5b shows Coburn Road SO 2 levels (ppb) as a function of hourly PPL emissions, for all hours from 2009 – 2013. This displa y includes all Coburn Road data when PPL is operating and emitting greater than 100 lbs SO 2 /hr – including points from Chart 5 with QA failures – resulting in a total of 20 values greater than 75 ppb. 2010 data points from Chart 5 with QA failures are depicted by a triangle, wh ile those from other years are shown by a square. The fo llowing observations can be made:

Every one of the 2010 values above 75 ppb was associated with a QA failure and occurred when PPL emissions were below 840 lb/hr. None occurred when PPL emissions were greater than 840 lb/hr. This is very inconsistent behavior.3 

## Chart 5c:

Chart 5c shows the relationship between Coburn Road SO 2 levels and PPL emissions from 2009 through 2013 after all data points with QA failures from Chart 5 are excluded. This analysis results in only two SO 2 data points exceeding 75 ppb. In other words, if all high SO 2 values with QA failures are excluded, 18 of the 20 high values disappear.4 

## Chart 5d:

Chart 5d is identical to Chart 5b, with the addition of a s haded area depicting periods with PPL emissions below the approximat e 840 lb/hr Regional Haze limit and SO 2 concentrations below 75 ppb.5 

## Chart 5e:

Chart 5e is identical to Chart 5c, with the addi tion of a shaded area depicting periods with PPL emissions below 840 lb/hr and SO 2 levels below 75 ppb. In both 5e and 5c, QA failures from Chart 5 for 2009 through 2013 were removed. The shading demonstrates that only one valid SO 2 value above 75 ppb occurred when PPL emissions were below the approximate 840 lb/h r Regional Haze limit that has been in effect since the spring of 2013.6 

## Chart 5f:

Chart 5f shows SO 2 levels at Coburn versus PPL emissions for 2009, 2011, 2012 and 2013 (i.e. excluding 2010), with all Coburn data included. In t he four years, there are a total of ten SO 2 values above 75 ppb, of which eight have QA failures identified in Chart
5.7 

## Chart 5g:

Chart 5g is identical to Chart 5f, ex cept that the eight high SO 2 values with QA failures have been removed. This results in only two SO 2 values above 75 ppb, and only one such value during periods w hen PPL emissions were below the approximate 840 lb/hr Regional Haze limit that is currently in effect at PPL.8 

## Chart 5h:

Chart 5h depicts the 2011 through 2013 period and includes periods of known QA
failures. Even with these inva lid data included, it is impo rtant to note that the design
value still meet s the standard.9 

## Chart 5i:

Chart 5i is identical to Chart 5h, except that the eight high SO 2 values with QA failures have been removed. This results in only two SO 2 values above 75 ppb, and only one such value during periods w hen PPL emissions were below the approximate 840 lb/hr Regional Haze limit that is cu rrently in effect at PPL.