UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 


REGION 10 


1200 Sixth Avenue 

Seattle, WA 98101 

May 17, 2010 

Reply to 

Attn Of: OEA-095 

MEMORANDUM 

SUBJECT: Mendenhall Valley PM10 Attainment Detennination 

FROM: Chris Hall/s/ 

ECU Air Data Analyst, OEA 

TO: Steve Body 

STAPU Air Planning Team, OA WT 

At the request ofthe Office ofAir, Waste and Toxics, I have conducted an Expected 

number of Exceedances (EE) analysis of all PM10 data submitted to the EPA AQS 

database by the State of Alaska (ADEC) for their monitors located in the Juneau borough 

airshed. The intent ofthis analysis is to detennine the attainment status ofthe Federal 

Reference Method (FRM) and Federal Equivalent Method (FEM) PM1 0 monitors at 

these sites from January 1, 1992 through December 31, 2009, per the criteria established 

in Appendix K to 40 CFR Part 50. 

Part 50 Appendix K requires three consecutive years of complete data to make an 

affinnative attainment detennination. A year is deemed complete if each of the four 

quarters has at least 75% data completeness. For years 1992 to 2009, there were/are a 

total of five PM1 0 sites/samplers with data records in AQS, but only two of these sites 

have the minimum three years of complete data and therefore meet the Appendix K 

requirements for detennining attainment status. These sites are the Floyd Dryden Middle 

School site and the Trio Street site, both ofwhich are/were in the Mendenhall Valley 

neighborhood. The Floyd Dryden was running in 1992 and is still in operation today, 

but the Trio Street site was shut down in June 1997. 

Floyd Dryden Middle School Site - 24 Hour Standard 

The Floyd Dryden site (AQS #02-110-0004) recorded two exceedances in February 1992. 

These values were flagged by ADEC as exceptional events due to high winds, but AQS 

does not show that RIO concurred on these flags. As such I have included these two 

daily values in my exceedance calculations as described below and in Table 1. Outside 

ofthese two exceedances there have been no other exceedances ofthe daily PM10 

standard after February 1992 and up to December 31, 2009. But there were a number of 
years that did not meet the 75% data completeness criteria per AQS (1998, 2000, 2003, 

2008, and 2009; see rows 11-15 in Table 1) and therefore an affirmative attainment 

determination can only be made for a subset ofthese years; 1992-94, 1993-95, 1994-96, 

1995-97,2004-06, and 2005-07. Based on the 2 exceedances recorded in February 1992, 

the annual EE for 1992 is 2.02. As there were no exceedances in 1993 or 1994, the 1992­

94 EE calculation equates to 0.7, which is less than the attainment upper limit of 1.0 and 

therefore shows attainment. In regard to the multiple years that did not meet data 

completeness criteria there were no recorded exceedances in that dataset (i.e., annual EE 

= 0.0), therefore we can affirm that this site did not fail the attainment testl for years 

1996-98,1997-99, 1998-2000, 1999-2001,2000-02,2001-03,2002-04,2003-05,2006­

08, and 2007-09. 

Floyd Dryden Middle School Site - Annual Standard 

The annual standard for the Floyd Dryden site were met for each three year period that 

data was available and quarterly data completeness was 2: 75%2. These years are 1992­

94, 1993-95, 1994-96, 1995-97,2004-06, and 2005-07. Years 1998,2000,2003,2008, 

and 2009 did not met data completeness criteria and therefore 3 year means containing 

one or more ofthese years are not valid for comparing to the NAAQS. Tabulated results 

providing these data are provided in rows 8-9 in Table 1. As with the 24-hour standard 

we can affirm that this site did not fail the annual attainment testl for years 1996-98, 

1997-99, 1998-2000, 1999-2001,2000-02,2001-03,2002-04,2003-05,2006-08, and 

2007-09. 

Trio Street Site - 24 Hour Standard 

The Trio Street site (AQS #02-110-0019) recorded five PM10 exceedances in 1992 and 

three in 1993. Of these eight total exceedances only the four recorded in the first quarter 

1992 were flagged by ADEC as high wind exceptional events. As with the Floyd Dryden 

site AQS does not show that Region 10 concurred on these high wind events and 

therefore the data cannot be excluded from EE calculations. For the time period of 

January 1, 1992 to June 30, 1997, the Trio Street site met the 75% quarterly data 

completeness requirement, therefore it is only the 1995-97 timeframe that an affirmative 

attainment determination cannot be made (see rows 11-15 in Table 2). As provided in 

cell f7 ofTable 2 the Trio Street site did not attain the PM1 0 daily NAAQS for years 

1992-94. The EE calculation for years 1993-95 was 1.0, which is the upper limit for 

showing attainment. 

Trio Street Site - Annual Standard 

The annual standard for the Trio Street site were met for each three year period that data 

was available and quarterly data completeness was 2: 75%. These are years 1992-94, 

1993-95, and 1994-96. Years 1995-97 did not met data completeness criteria as the site 

was shut down at the end of June 1997. Tabulated results are provided in rows 8-9 in 

Table 2. 

I The showing for non-attainment is less stringent than the showing for attainment. See 40 CFR 50, 


Appendix K, section 2.3(c). 


2 The Annual Standard is 50Ilg/m3 and is determined with 3 consecutive years ofdata. Three year means:'S 


50llg/m3 attain the Annual Standard. See 40 CFR 50.6(b) and Appendix K (pre-2007). 

Table 1 - 24 hour Standard Data for Floyd Dryden MS '0' 1 2 131 4 "er"'1 6 '7 8 '" 9"" 1 10 1 11 T 12113T 14"'1e''''15'' 

a Juneau - Floyd DrYden Middle School Site (02-110-0004) , 

b Expected # of EXceedances Mean - Annual std Data Completeness .. = c Year/Otr 01 Q2 03 04 EE/yr EE/3-yr Year 3 Year> Year/Otr 01 . 02 03 04 . Met rqrmt? 

d 1992 2.02 0 0 0 2.02 - 18.0 - 1992 99 84 98 100 Y 

e 1993 0 0 0 0 0 - 18.5 - 1993 99 94 100 99 Y 

f 1994 0 0 0 0 0 0.7 16.7 18 1994 100 100 98 99 Y 

9 1995 0 0 0 0 0 0.0 15.6 17 1995 100 100 98 98 Y 

h 1996 0 0 0 0 0 0.0 15.3 16 1996 99 100 100 99 Y 

i 1997 0 0 0 0 0 0.0 10.7 14 1997 98 100 87 84 Y 

j 1998 0 na na 0 na na na na 1998 87 57 13 91 N 

k 1999 ' 0 0 0 0 0 na 6.6 na 1999 90 93 90 100 Y 

I 2000 0 0 na 0 na na na na 2000 77 97 48 90 N 

m 2001 0 0 0 0 0 na 6.8 na -2001 100 97 100 97 Y 

n 2002 0 0 0 0 0 na 7.8 na 2002 90 90 93 88 Y 

0 2003 0 0 na 0 na na na na 2003 100 0 0 100 N 

P 2004 0 0 0 0 0 na 9.3 na 2004 100 100 100 100 Y 

q. 2005 0 0 0 0 0 na 10.3 na 2005 100 87 87 100 Y 


r 2006 0 0 0 0 0 0.0 9.1 10 2006 93 93 100 100 Y 


s ?2007 0 0 0 0 0 0.0 6.9 9 2007 100 100 100 90 Y 


f . 2008. 0 na 0 0 na na na na 2008 94 73 100 .100 N 

· u 200~, . 0 0 na 0 na na na na 2009 100 100 7 100 N 

Table 2 - 24 hour Standard Data for Trio Street 

.1 :2 .3 1 4 5 6 7 8 9 1 10 11 I 12 1 13 I 14 15 

a ~ Juneau '- .Trio' Stre~t Site (02-110-0019) 

b Expected'# of Exceedances - 24 hr std Mean - Annual std Completeness 

c Year/Otr 01 02 03 :04 EElyr EEl3-yr Year 3 Year Year/Otr 01 02 03 04 Met rqrmt? 

d 1992 4.04 1.02 0 0 5.06 - 27 - 1992 99 98 99 100 Y 


e 1993 2.02 1.05 0 0 3.07 - 29.2 - 1993 99 96 99 100 Y 


f 1994 0 0 0 0 0 2.7 20.7 26 1994 97 97 97 96 Y 


9 1995 0 0 0 0 0 1.0 19.2 23 1995 100 98 90 99 Y 


h ':199_6, 0 0 0 0 0 0.0 19.7 20 1996 98 99 98 97 Y 


i "1997'1 0 0 nd nd na na na na 1997 98 97 0 0 N