UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION 10 1200 Sixth Avenue Seattle, WA 98101

May 17, 2010 Replyto Attn Of: OEA-095
MEMORANDUM SUBJECT: Mendenhall Valley PM10 Attainment Detennination FROM: Chris Hall/s/ ECU AirDataAnalyst, OEA TO: SteveBody STAPU Air PlanningTeam, OA WT Atthe request ofthe Office ofAir, Waste and Toxics, Ihave conducted an Expected number ofExceedances (EE) analysis ofall PM10 data submitted to the EPA AQS databasebythe State ofAlaska (ADEC) for theirmonitors located in the Juneau borough airshed. Theintent ofthis analysis is to detennine the attainment status ofthe Federal Reference Method (FRM) and Federal Equivalent Method (FEM) PM10monitors at these sites from January 1, 1992 through December 31, 2009, perthe criteria established in Appendix K to 40 CFR Part 50. Part 50 Appendix K requires three consecutive years ofcomplete data to make an affinnative attainment detennination. A year is deemed complete ifeach ofthe four quarters has at least 75% data completeness. Foryears 1992 to 2009, there were/are a total offive PM10 sites/samplers with datarecords in AQS, but onlytwo ofthese sites have the minimum three years ofcomplete 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, butthe Trio Street site was shut down in June 1997. Floyd Dryden Middle School Site - 24 Hour Standard TheFloyd Dryden site (AQS #02-110-0004) recorded two exceedances in February 1992. These values were flagged byADEC as exceptional events due to high winds, butAQS does not show that RIO concurred onthese flags. As such Ihave included these two daily values in myexceedance calculations as described below and in Table 1. Outside ofthese two exceedances therehavebeen no other exceedances ofthe daily PM10 standard after February 1992 and up to December 31, 2009. Butthere were a number ofyears that did not meet the 75% data completeness criteriaperAQS (1998, 2000, 2003, 2008, and 2009; see rows 11-15 in Table 1) and therefore an affirmative attainment determination can onlybemade for a subset ofthese years; 1992-94, 1993-95, 1994-96, 1995-97,2004-06, and 2005-07. Based onthe 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 criteriathere 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 yearmeans containing one ormore ofthese years are not valid for comparingto the NAAQS. Tabulatedresults providing these data are provided inrows 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 TheTrio Street site (AQS #02-110-0019) recorded five PM10 exceedances in 1992 and three in 1993. Ofthese eight total exceedances onlythe four recorded in the first quarter 1992 were flagged byADEC as high wind exceptional events. As with the Floyd Dryden site AQS does not show that Region 10 concurred onthese high wind events and therefore the data cannot be excluded from EE calculations. Forthe time period of January 1, 1992 to June 30, 1997, the Trio Street site met the 75% quarterly data completeness requirement, therefore it is onlythe 1995-97 timeframe that an affirmative attainment determination cannotbemade (see rows 11-15 in Table 2). As provided in cell f7 ofTable 2the Trio Street site did not attain the PM10 dailyNAAQS 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 yearperiod 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 ofJune 1997. Tabulated results are provided inrows 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) andAppendix K (pre-2007).Table 1 - 24 hour Standard Data for Floyd Dryden MS '0' 1 2 131 

### 4 

## "e r"'1 6 '7 8 '" 9"" 1 10 

### 1 11

### T 12113

### T 

### 1 4"'1e'''' 15'' a Juneau - Floyd DrYden Middle School Site(02-110-0004) 

### , b Expected # ofEXceedances Mean - Annual std Data Completeness

.. = 04 c Year/Otr 01 Q2 03 04 EE/yr EE/3-yr Year 3 Year> Year/Otr 01
. 02 03 . 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 StandardDatafor 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 hrstd 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