# 2001-2012 Evaluation of Colorado PM2.5 Data

The PM2.5 NAAQS was promulgated in 1997. Because t his was a new NAAQS, requiring new

monitoring technology, the monitoring network was n ot deployed until January 1999. OAQPS is

currently preparing a national summary of PM2.5 des ign values from 2001-2003 through 2010-2012

based on certified data through 2012; that is plann ed for public release the week of August 26, 2013. I

have extracted the Colorado portion of the monitor by monitor data from that material and attached it as

an “Table 6”, below. I have color coded the data, using green to indicate valid 3-year design value ( either

annual mean or 24-hour mean of 98 th 

# percentiles) less than or equal to the NAAQS, blue for design value

less than or equal to the NAAQS but not valid per 4 0 CFR Part 50 Appendix N (generally due to

incomplete data) and yellow for a design value grea ter than the NAAQS, but again not a valid violation

per Appendix N, again usually due to incomplete dat a.

The table from the OAQPS data set I used (Table 6) is the raw data underlying summary tables of

regulatory data. The table is not intended to repr esent regulatory design values. Rather, it shows p urely

mathematical 3 year means of data. Other tables re strict reported data to only that which shows desig n

values meeting regulatory data completeness require ments. I chose to use this more extensive nonregulatory dataset as a more comprehensive review o f all available PM2.5 data from Colorado from 2001

through 2012. Since it includes some data which is of no regulatory significance, I will discuss in d etail

in the text below any values above the current leve l of the standard indicated in the table.

There are 3 monitors with Yellow design values (that is, means above the current level of the stan dard,

but for which the calculated means are not valid pe r CFR). I have attached a pdf file with the data e xtract

from AQS to allow me to explain why these incomplet e design values over the NAAQs are no real

concern. First, note that the Yellows occurred pri or to 2005; at that time the levels of the standard s were

15 ug/m3 for the annual standard and 65 ug/m3 for t he 24 hour standard, so the yellow values were not

above the levels of the standard in place at the ti me they occurred.

So, first, for monitor 08-001-0001, Commerce City, 2001-2003 annual mean shown equals 12.6 ug/m3,

24 hr DV equals 57 ug/m3. This monitor operated from Jan. 26, 1999 to April 12, 2001 as a 1 day in 3

sampler. Data from 1 st



# Quarter 1999 was incomplete (36% of scheduled samp les were collected, 75%

required for completeness) as were 2 nd 

# , 3 rd 

# and 4 th 

# quarter 2001 (no samples collected in those quarters,

for 0% completeness). Appendix N would not allow a regulatory annual mean calculation with data this

incomplete, particularly for 2001-2003 when data on ly were collected in the 1 st 

# 4 months of 2001, but

OAQPS calculated a mathematical (not regulatory) me an for this period. The value is only above 12

because the data from 2011 is dominated by high win ter values without compensating lower spring and

summer values not collected due to monitor shut-dow n. Means in 1999 and 2000, with more complete

year-round data, are well below 12 ug/m3. For 24-hour PM2.5, only 3 exceedances were recorded in 26.5

months of operation. The 98 th 

# percentiles in the nearly complete 1999 and 2000 w ere 24.9 and 23.3

ug/m3, respectively, well below the 65 ug/m3 NAAQS at the time and the current 35 ug/m3 NAAQS. In

2001, however, with the monitor only running until mid-April, and with exceedances on Feb. 16 and 17,

the 98 th 

# percentile is the 1 st



# max, 57.3 ug/m3 on Feb. 17. OAQPS uses this 98 th 

# percentile from 2001 as

the non-regulatory DV for the 2001-2003 period (not a valid approach p er Appendix N) to come up with

an invalid design value for 2001-2003 of 57 ug/m3 that really has no validity for NAAQS comparison.

Similarly for the National Jewish Hospital monitor, 08-031-0013, the monitor ran winters only, Nov. 20

, 1999 to March 30, 2000 and Nov. 1, 2000 to March 28 , 2001 as part of a special study, not intended to be

NAAQS compared. The Annual Mean 2001-2003 shown by OAQPS of 13.5 ug/m3 is based solely on

the Jan.-March 2001 data, and is not valid per Appe ndix N, with no data from 2002 or 2003, and only 1

quarter of data from 2001. Ditto for the 24-hour D V of 46 ug/m3. That is the second maximum of 4

exceedances measured that February, but is not a va lid design value for a 3 year period (with no date from

# 2 of the 3 years). A valid design value is availab le for Denver from the CAMP monitor, 08-031-0002 fo r

2001-2003, at 29 ug/m3. It had higher PM2.5 on eac h of the 4 days the National Jewish Monitor

exceeded in Feb. 2001, and has complete data for th e 3 year period, so is a much better indicator of t he

actual Denver PM2.5 air quality over the 2001-2003 time period than is the very incomplete data from t he

National Jewish Hospital monitor.

For 08-031-0023, with yellow annual means over 12 u g/m3 in 2002-2004 and 2003-2005, a special study

monitor operated at Swansea Elementary School as pa rt of an air toxics study, the monitor only ran the

last 3 days of 2004 and then during all of 2005. So that 2002-2004 annual mean of 14.6 ug/m3 is in fact

the average of Dec. 29, 30 and 31, 2004; this would not be a valid annual mean or design value in any

context, and certainly not by Appendix N criteria. Likewise, the 2004-2006 mean lacks any 2006 data,

and is also invalid for NAAQS comparison under CFR. The 2005 mean is only 10.14 ug/m3, so that is

much more indicative of what a complete year of dat a in Denver actually looked like mid-2000s.

Finally, Grand Junction, 08-077-0017 had a legitima te, valid 24-hour design value 2008-2010 of 35

ug/m3. High winter PM2.5 in January 2009 and Decem ber 2009-January 2010 lead to 98 th 

# percentiles for

2008-2010 of 25.2, 41 and 37.3 ug/m3 respectively; the design value of 34.5 ug/m3 rounds up to 35

ug/m3 per 40 CFR Part 50, Appendix N. Since 2010, Grand Junction has not had a PM2.5 exceedance

until January 2013, so the winters of 2009 and 2010 were somewhat unusual over the long term, and

Grand Junction has maintained a design value equal to or below the NAAQS continuously from 2001

through 2012.

Elsewhere in the state, no monitor with complete da ta has come close to a NAAQS violation. Any other

near misses have been statistical anomalies do to m onitor malfunctions or shut-downs, rather than actu al

poor air quality.Colorado Data Extract, Edited by Richard Payton, EPA Region 8, 8/22/2013AQS Data Query: 07/10/2013; Last updated: 08/20/2013Attains the 24-hour or Annual PM2.5 NAAQS with a valid 3-year Design value per 40 CFR Part 50 AppendixNDesign Value equal to or below the level of the NAAQS, but the design value is not valid (generally incomplete) per 40 CFR Part 50 Appendix NDesign Value above the level of the NAAQS, but thedesign value is not valid (generally incomplete) per 40 CFR Part 50 Appendix NTable 6. PM2.5Site Design Value History, 2001-2003 through 2010-2012Colorado Adams Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 001 080010001 12.6NVColorado Adams Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 001 080010006 10.4 10.2 10.1 9.9 10.2 10.0 9.4 8.7 8.1 8.2NVColorado Arapahoe Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 005 080050005 8.9 8.3 8.1 7.8 8.0 7.6 7.2 6.7 6.3 6.4NVColorado Archuleta 8 08 007 080070001 6.0NV6.0 5.5NV5.1NV4.8NV4.6NVColorado Archuleta 8 08 007 080070002 6.8NVColorado Boulder Boulder, CO Denver-Aurora, CO 8 08 013 080130003 9.4 8.9 8.5 8.2 8.3 8.2 8.0 7.4 6.9 6.9NVColorado Boulder Boulder, CO Denver-Aurora, CO 8 08 013 080130012 8.0 7.5 7.1 6.8 7.0 6.9 6.8 6.5 6.3 6.2NVColorado Delta 8 08 029 080290004 8.0 8.2 7.6 7.3 7.0NV7.1NVColorado Denver Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 031 080310002 10.8 10.0 9.7 9.1 9.3 8.8 8.5 7.8 7.6 7.8NVColorado Denver Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 031 080310013 13.5NVColorado Denver Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 031 080310023 14.6NV12.4NV11.2NV9.8 9.1 8.7 7.9 7.5 7.6NVColorado Denver Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 031 0803100259.9NV9.0NV8.4NV7.6 7.2 7.6NVColorado Denver Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 031 0803100266.9NVColorado Douglas Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 035 080350003 6.4NVColorado Douglas Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 035 080350004 5.6NV5.9NV6.2NV6.3 6.1 5.8 5.7 5.8NVColorado Elbert Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 039 080390001 4.4 4.3 4.4 4.3 4.5 4.4 4.4 4.2 4.0NV4.0NVColorado El Paso Colorado Springs, CO 8 08 041 0804100086.9 6.7 6.7 6.7 6.7NV6.7NVColorado El Paso Colorado Springs, CO 8 08 041 0804100117.8 8.1 8.0 8.1 7.7 7.7NV7.5NV7.7NVColorado El Paso Colorado Springs, CO 8 08 041 0804100176.1NV5.8NV6.0 y 6.3NVColorado Gunnison 8 08 051 080510005 6.9 6.7 6.4NV5.8NV6.1NVColorado Gunnison 8 08 051 080510007 5.6NV6.0NV6.0NV6.4NVColorado La Plata Durango, CO 8 08 067 080670008 5.7 6.1NV6.3NVColorado La Plata Durango, CO 8 08 067 0806770014.3NV4.2NV4.2NV4.1NVColorado La Plata Durango, CO 8 08 067 0806770033.8NV4.0NV4.2NV4.2NVColorado Larimer Fort Collins, CO 8 08 069 080690009 7.9 7.6 7.3 7.3 7.4 7.3 7.1 6.6 6.3 6.5NVColorado Mesa Grand Junction, CO 8 08 077 080770003 7.8 7.8NV7.5NVColorado Mesa Grand Junction, CO 8 08 077 080770017 10.4NV10.4NV9.2 9.5 9.2 9.4 9.4 9.3 8.6 7.8NVColorado Montezuma 8 08 083 0808300066.0NV6.4NV6.3NV6.3 5.9Colorado Pueblo Pueblo, CO8 08 101 081010012 8.0 7.4 7.2 7.5 7.7 7.7 7.3NV7.4NV7.4NVColorado Pueblo Pueblo, CO8 08 101 0810100155.0NV5.6NV5.6NV6.2NVColorado Rio Blanco 8 08 103 0810300062.5NV3.2NV9.3NVColorado Routt 8 08 107 081070003 7.5 7.3 6.8NV6.7NV6.0NVColorado San Miguel 8 08 113 081130004 5.6 5.1 4.8 4.5 4.5NV4.1NVColorado Weld Greeley, CO Denver-Aurora, CO 8 08 123 081230006 9.0 8.5 8.1 8.1 8.4 8.4 8.2 7.6 7.3 7.3NVColorado Weld Greeley, CO Denver-Aurora, CO 8 08 123 081230008 9.6 8.8 8.5 8.6 9.3 9.3 8.7 7.8 7.5 7.6NVState County CBSA CSAEPARegionST COU SiteAnnual Standard Design Values1, 22001-2003 2002-2004 2003-2005 2004-2006 2005-2007 2006-2008 2007-2009 2008-2010 2009-2011 2010-2012Colorado Adams Denver-Aurora-Broomfield, CODenver-Aurora-Boulder, CO8 08 001 080010001 57NVColorado Adams Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 001 080010006 27 24 23 24 29 30 29 23 21 22NVColorado Arapahoe Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 005 080050005 24 23 22 21 21 19 18 16 15 18NVColorado Archuleta 8 08 007 080070001 15NV16 12NV10NV8NV7NVColorado Archuleta 8 08 007 080070002 14NVColorado Boulder Boulder, CO Denver-Aurora, CO 8 08 013 080130003 26 24 22 19 22 24 23 22 20 23NVColorado Boulder Boulder, CO Denver-Aurora, CO 8 08 013 080130012 21 21 19 18 20 19 19 18 17 17NVColorado Delta 8 08 029 080290004 20 23 22 19 15NV16NVColorado Denver Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 031 080310002 29 25 26 26 28 25 23 19 19 19NVColorado Denver Denver-Aurora-Broomfield, CODenver-Aurora-Boulder, CO8 08 031 080310013 46NVColorado Denver Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 031 080310023 23NV25NV24NV26 25 24 20 19 20NVColorado Denver Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 031 08031002520NV20NV20NV19 18 17NVColorado Denver Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 031 08031002634NVColorado Douglas Denver-Aurora-Broomfield, CODenver-Aurora-Boulder, CO8 08 035 080350003 15NVColorado Douglas Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 035 080350004 17NV17NV18NV16 17 15 16 16NVColorado Elbert Denver-Aurora-Lakewood, CO Denver-Aurora, CO 8 08 039 080390001 12 11 11 14 15 14 11 10 9NV9NVColorado El Paso Colorado Springs, CO 8 08 041 08041000818 16 17 16 16NV14NVColorado El Paso Colorado Springs, CO 8 08 041 08041001118 18 17 16 16 20NV23NV30NVColorado El Paso Colorado Springs, CO 8 08 041 08041001714NV13NV12 14 16NVColorado Gunnison 8 08 051 080510005 20 20 18NV14NV14NVColorado Gunnison 8 08 051 080510007 15NV15NV15NV15NVColorado La Plata Durango, CO 8 08 067 080670008 15 17NV14NVColorado La Plata Durango, CO 8 08 067 0806770019NV8NV9NV9NVColorado La Plata Durango, CO 8 08 067 08067700312NV11NV12NV11NVColorado Larimer Fort Collins, CO 8 08 069 080690009 20 1817 19 19 19 18 19 18 21NVColorado Mesa Grand Junction, CO 8 08 077 080770003 18 17NV16NVColorado Mesa Grand Junction, CO 8 08 077 080770017 18NV23NV23 25 23 25 31 35 34 28NVColorado Montezuma 8 08 083 08083000625NV20NV18NV14 14Colorado Pueblo Pueblo, CO 8 08 101 081010012 18 17 15 16 15 16 16NV16NV17NVColorado Pueblo Pueblo, CO Pueblo-Cañon City, CO 8 08 10108101001510NV12NV12NV15NVColorado Rio Blanco 8 08 103 0810300066NV9NV18NVColorado Routt 8 08 107 081070003 17 17 15NV15NV13NVColorado San Miguel 8 08 113 081130004 11 9 9 11 12NV16NVColorado Weld Greeley, CO Denver-Aurora, CO 8 08 123 081230006 25 22 22 23 24 24 25 22 23 25NVColorado Weld Greeley, CO Denver-Aurora, CO 8 08 123 081230008 27 21 18 19 24 26 26 21 20 20NV24-hour Design Values1 32001-2003 2002-2004 2003-2005State County CBSA CSAEPARegionST COU Site2010-20122004-2006 2005-2007 2006-2008 2007-2009 2008-2010 2009-2011Notes:1. In this table, all design values are calculatedbased on the rules specified in Appendix N for the 2012PM2.5 NAAQS.The term "NV" denotes design values that are not valid in accordance with the 2012 NAAQS2. Monitoring sites with an annual deesign value status of 'X' hev been determined by EPA to represent uniquemicroscale or middle scale locations are not used for comparison to the annual PM2.5 NAAQS. The 2012 revisions to 40CFR 58 require a formal exclusion justification to be described in the annual State monitoring plan.3. For sites with approved seasonal sampling, thepromulgated methodology may change the annual 98thpercentile and 24-hour design value from the valuesposted on this website in previous years which werecalculated under the 2006 NAAQS methodology. Datafrom 2011 and previous years processed using the2006 rules can be found in the 2011 “PM2.5 DetailedInformation” file posted here:http://www.epa.gov/airtrends/values.html. These changes in design values and corresponding changes inthe trend are due to the new official calculation methodology and may not indicate a change in air qualityobserved for that area or location.3. For sites with approved seasonal sampling, thepromulgated methodology may change the annual 98thpercentile and 24-hour design value from the valuesposted on this website in previous years which werecalculated under the 2006 NAAQS methodology. Datafrom 2011 and previous years processed using the2006 rules can be found in the 2011 “PM2.5 DetailedInformation” file posted here:http://www.epa.gov/airtrends/values.html. These changes in design values and corresponding changes inthe trend are due to the new official calculation methodology and may not indicate a change in air quality