PM 2.5 Design Values. Data inputs Completeness requirements Calculations Current levels. Mark Schmidt EPA-OAQPS

Transcription

1 Design Values Data inputs Cmpleteness requirements Calculatins Current levels Mark Schmidt EPA-OAQPS (919)

2 Design Values - Data Inputs Only data present in EPA's Air Quality System (AQS) are used in DV calculatins. Only Federal Reference Methd (FRM), Federal Equivalent Methd (FEM), and Apprved Reginal Methd (ARM) data are used. Duratin 7 fr filter (FRM/FEM) samplers. Duratin X fr cntinuus (FEM/ARM) samplers. Frm NAAQS averages AQS table. Valid if 18+ hurs r pass data substitutin test (using zers fr missing hurs). DVs are calculated fr all mnitrs / all mnitr types. Hwever, Only DVs fr ppulatin-riented mnitrs are cmpared t the NAAQS. [All mnitrs are presumed t be ppulatin-riented unless therwise specified / ntified.] SPMs with less than tw years f data are weeded ut with cmpleteness requirements Mnitrs that are micr/middle scale and represent a unique area can be exempted frm cmparisns t the annual standard. Must be dcumented in mnitring netwrk plan

3 Design Values - Data Inputs cntinued DVs are calculated n a site basis. Site data area aggregated as fllws: The default dataset fr a site cnsists f the measured cncentratins recrded frm the designated primary FRM/FEM/ARM mnitr. The primary mnitr shuld be designated in the apprpriate mnitring netwrk plan. [Until a primary designatin is made, the lwest POC # with data is the presumed primary mnitr.] All daily values prduced by the primary sampler are cnsidered part f the site recrd (i.e., that site's daily value). Data fr the primary mnitr are augmented as much as pssible with data frm cllcated FRM/FEM/ARM mnitrs. If a valid 24-hur measurement is nt prduced frm the primary mnitr fr a particular day (scheduled r therwise), but a valid sample is generated by a cllcated FRM/FEM/ARM instrument (and recrded in AQS), then that cllcated value shall be cnsidered part f the site data recrd (i.e., that site's daily value). If a valid 24-hur measurement is nt prduced frm the primary mnitr fr a particular day and mre than ne valid cllcated FRM/FEM/ARM value is available, the average f thse valid cllcated values shall be used as the daily value.

4 Design Values - Data Inputs cntinued In this example, there are 3 FRM/FEM mnitrs cllcated at ne site. On days where there is a measurement frm the designated primary mnitr (Jan. 1, Jan. 2, Jan. 4, Jan. 7, Jan. 13, Jan. 16), that measurement alne is cnsidered the daily site value (i.e., part f the cmpsite site recrd). On days in which there is nt a primary measurement, but there is ne cllcated measurement (Jan. 11, Jan. 12), that cllcated value is cnsidered part f the site recrd. On days in which there is nt a primary measurement, but there are tw cllcated measurements (Jan. 10), the runded average f the cllcated values is cnsidered the site's daily value. Creatin f cmpsite site recrd - Example Example (Q3): Creatin f cmpsite site data recrd invlving cllcated data Daily value fr the designated primary mnitr Daily value fr a cllcated FRM/FEM Daily value fr a 2nd cllcated FRM/FEM Date Required sampling frequency (µg/m3) mnitr (µg/m3) mnitr (µg/m3) Site daily value (µg/m3) Data surce 1-Jan primary 2-Jan primary 3-Jan 3 4-Jan primary 5-Jan 3 6-Jan 3 7-Jan primary 8-Jan 3 9-Jan 3 10-Jan avg. f 2 cllcated 11-Jan cllcated 12-Jan cllcated 13-Jan primary 14-Jan 3 15-Jan 3 16-Jan primary 17-Jan 3 Nte: Scheduled sampling days are blded. Hwever, when cnstructing the site recrd, sampling frequency and scheduled sampling days are irrelevant.

5 Design Values - Data Inputs cntinued Creatin f cmpsite site recrd Prcedure specified in (10/2006) CFR. AQS is being enhanced t generate cmpsite site recrd data (24-hur and summary)

6 DVs Cmpleteness Requirements Data cmpleteness is determined n a site basis using the cmpsite site recrd Data capture rates are cmputed n a site-year-quarter. "Quarter" is a calendar quarter. Quarterly data capture rates (expressed as a percentage) are calculated as: ((creditable number f samples fr the quarter) (scheduled number f samples fr the quarter))* 100, and runded t the nearest integer. "Creditable samples" are summed by site-year-quarter. Creditable samples are samples that are given credit fr data cmpleteness. They include samples cllected n required sampling days and valid "make-up" samples taken fr missed r invalidated scheduled samples. Makeups can be made by either the primary r the cllcated instruments. The cmpsite site recrd is develped befre ptential make-ups are validated (as creditable samples). Ttal samples are summed by site-year-quarter and als by site-year. Ttal samples include creditable samples plus extra samples. Extra samples are reprted samples in the cmpsite site recrd that are nt deemed creditable. Fr sites that sample every day, the creditable number f samples will always be the same as the ttal number f samples. Als, sites that sample every day can nt have make-ups since every day is a scheduled day.

7 DVs Cmpleteness Requirements The data cmpleteness requirements fr the annual PM2.5 NAAQS are: Fr single site cmparisns t the NAAQS, three valid annual means are required. Fr spatial averaging, three valid spatially averaged annual means are required. A spatially averaged annual mean encmpasses all sites (f thse t be averaged) with a valid annual (site) mean. Thus, fr each f the three years, at least ne site must have a valid annual (site) mean. A site s annual mean is deemed valid ( cmplete ) if it meets ne f the fllwing: (CFR) 75% r greater data capture fr each quarter, r (CFR) 11 r mre samples (ttal number) per quarter and the annual mean (r crrespnding spatially averaged annual mean) is > 15.0 µg/m3, r (CFR) 11 r mre samples (ttal number) per quarter and the annual design value is > 15.0 µg/m3, r (CFR) less than 11 (ttal number) per quarter and pass the "ver NAAQS" data substitutin test, r (guidance) 50% r greater data capture each quarter and pass ne f tw "under NAAQS" data substitutin tests. The data cmpleteness requirements fr the 24-hur PM2.5 NAAQS are: A site must have three valid annual 98th percentile values. A site s annual 98th percentile value is deemed valid ( cmplete ) if it meets ne f the fllwing: (CFR) 75% r greater data capture fr each quarter, r (CFR) 1 r mre samples fr the year and the annual 98th percentile is > 35 µg/m3, r (CFR) 1 r mre samples fr the year and the 24-hur design value is > 35 µg/m3, r cntinued *(guidance) 50% r greater data capture each quarter and pass ne f tw "under NAAQS" data substitutin tests.

8 DVs Annual DV Calculatins Prcedure fr calculating single-site annual DVs (nt spatially averaged) 1. Calculate the quarterly means fr the site. Add all f the 24-hur sample cncentratins; then, divide by the number f samples (ttal number, nt creditable number). D nt rund quarterly means! 2. Calculate the annual means frm the quarterly means. Fr each year, add the fur (r less) quarterly means; then, divide by 4 (r the number f quarters with data). D nt rund annual means! 3. Calculate the (unrunded) 3-year average annual mean. Add the three (r less) annual averages and then divide by 3 (r the numbers f years with data) 4. Rund t 1 decimal place. 5. Determine validity f design value and cmpare t the standard. The design value is valid if all three years (annual means) meet cmpleteness criteria

9 DVs 24-hur DV Calculatins The 24-hur standard DV is simply a runded average f three annual 98th percentile values. Annual 98th percentile values are actual, discreet, reprted values; they are nt statistically interplated estimates. There are tw prescribed prcedures in Appendix N fr calculating annual 98th percentile values: 1) the regular prcedure, which will be used by mst sites, and 2) a special frmula fr sites that perate n an apprved seasnal sampling frequency. Once yu have identified yur three annual 98th percentile values (using the apprpriate technique(s)), fllw the steps belw: 1. Calculate the (unrunded) 3-year average f the (three) annual 98th percentile values. Add the 3 annual 98 th percentile values and divide the sum by Rund t the nearest integer. The result is the 24-hur standard design value. 3. Determine validity f the 24-hur standard design value and cmpare t the standard. A 24-hur standard design value is valid if the three cnstituent annual 98th percentile values are valid.

10 DVs 24-hur DV Calculatins cntinued Prcedure fr identifying regular (nn-seasnal) annual 98 th percentile values Appendix N (10/2006 versin ) prescribes a particular prcedure and frmula (i.e., Equatin 5) fr identifying regular annual 98th percentile values. Hwever, there is an inadvertent missin in the prcedure/frmula which wuld cause the results (the annual 98 th percentiles) t be calculated errneusly lw whenever the annual creditable number f samples is nt equal t the annual ttal number f samples (i.e., when there are extra samples in the year). OAQPS is in the prcess f crrecting this rule errr. The crrectin will invlve the replacement f the currently-stated statistical frmula and instructins with a simpler lk-up table apprach. The table lk-up methd is nt new; it was described in the previus PM data handling guidance as an acceptable alternative t the previus CFR annual 98 th percentile frmula (1997 versin). Identificatin f annual 98 th percentile values using the regular prcedure will be based n the creditable number f samples (as described belw), rather than n the actual (ttal) number f samples. Extra samples, hwever, are candidates fr selectin as the annual 98th percentile. [The creditable number f samples will determine hw deep t g int the data distributin, but all samples (creditable and extra) will be cnsidered when making the percentile assignment.] The annual creditable number f samples is the sum f the fur quarterly creditable number f samples.

11 DVs 24-hur DV Calculatins cntinued Prcedure fr identifying regular (nn-seasnal) annual 98 th percentile values 1. Srt/array all the daily values frm a particular site and year by descending value. (Fr example: (x[1], x[2], x[3],, x[n]). In this case, x[1] is the largest number and x[n] is the smallest value.) The 98th percentile is determined frm this srted series f daily values which is rdered frm the highest t the lwest number. [Since an annual 98 th percentile will never be further than 8th n such a list (i.e., n lwer in cncentratin than the 8th highest value), a shrtened list (e.g., tp 8) is sufficient.] 2. The 98th percentile value fr year y, P 0.98, y, is identified via the table belw. Using the left clumn f the table, determine the apprpriate range (i.e., rw) fr the annual creditable number f samples fr year y (cn y ). The crrespnding n value in the right clumn identifies the rank f the annual 98th percentile value in the descending srted list f daily site values fr year y. Thus, P 0.98, y = the n th largest value. 98th percentile lk-up table Creditable number f samples fr year "y" (cn y ) P 0.98,y is the n th maximum value fr the year, where n is the listed number

12 DV Levels Annual Std Current nnattainment area (NAA) vilates annual NAAQS [32 areas] Current NAA meets annual NAAQS [7 areas] Sites in current NAA vilate the annual NAAQS (94 sites) Sites nt in a current NAA vilate the annual NAAQS (8 sites) 7 NAA clean fr annual NAAQS: Libby, Clumbus (OH), Evansville, Harrisburg, Philadelphia, Washingtn, Wheeling, but Philadelphia has designated NA sites that are incmplete. Only Evansville and Wheeling are als clean fr the 24-hr NAAQS 8 additinal vilating sites (nt in NAA) are lcated in 7 areas: Greenville, SC (Unclassifiable area); Augusta, GA Clumbia, SC Clumbus, GA Hustn, TX Washingtn Cunty, GA Wilkinsn Cunty, GA

13 DV Levels Annual Std Current nnattainment area (NAA) vilates annual NAAQS [32 areas] Current NAA meets annual NAAQS [7 areas] Sites in current NAA vilate the annual NAAQS (94 sites) Sites nt in a current NAA vilate the annual NAAQS (8 sites) 7 NAA clean fr annual NAAQS: Libby, Clumbus (OH), Evansville, Harrisburg, Philadelphia, Washingtn, Wheeling, but Philadelphia has designated NA sites that are incmplete. Only Evansville and Wheeling are als clean fr the 24-hr NAAQS 8 additinal vilating sites (nt in NAA) are lcated in 7 areas: Greenville, SC (Unclassifiable area); Augusta, GA Clumbia, SC Clumbus, GA Hustn, TX Washingtn Cunty, GA Wilkinsn Cunty, GA

14 DV Levels hur Std Current nnattainment area (NAA) vilates 24-hr NAAQS [29 areas] Current NAA meets 24-hr NAAQS [10 areas] Sites in current NAA vilate the 24- hr NAAQS (131 sites) Sites nt in a current NAA vilate the 24-hr NAAQS (48 sites) 48 vilating sites utside f current NAAA are lcated in 27 areas: 25 CBSAs: Largest are Seattle, Sacrament, San Jse, Milwaukee, Salt Lake City. Tw in MARAMA regin are State Cllege, PA and Allentwn, PA. 2 State-Cunties (nt part f a CBSA): Shshne ID; Ravalli MT

15 DV Levels hur Std Current nnattainment area (NAA) vilates 24-hr NAAQS [29 areas] Current NAA meets 24-hr NAAQS [10 areas] Sites in current NAA vilate the 24- hr NAAQS (131 sites) Sites nt in a current NAA vilate the 24-hr NAAQS (48 sites) 48 vilating sites utside f current NAAA are lcated in 27 areas: 25 CBSAs: Largest are Seattle, Sacrament, San Jse, Milwaukee, Salt Lake City. Tw in MARAMA regin are State Cllege, PA and Allentwn, PA. 2 State-Cunties (nt part f a CBSA): Shshne ID; Ravalli MT

16 Preliminary 24-Hur vs MSA Exceedance Day Cunts USA Tday Cities All year 2006, Jan.-Oct , & Jan. Oct AirNw data (nn-frm/fem)