UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGIONS III, IV, and V

Technical Support Document 

EPA’s Notice of Proposed Rulemaking 

For 

Approval and Promulgation of Air Quality Plans; Determination of Attainment of the 

1997 Fine Particulate Standard

January 2011

 
2

Technical Support Document

I. INTRODUCTION............................................................................................3

II. CLEAN AIR ACT REQUIREMENTS FOR FINE PARTICULATE (PM2.5) ATTAINMENT.3

A. PM2.5 Attainment Requirements ......................................................................3

B. Determination of Attainment ............................................................................4

III. MONITORING NETWORK ..............................................................................5

IV. LAWRENCE COUNTY HOSPITAL MONITORING SITE .........................................6

V. EPA’S ANALYSIS .........................................................................................6

A. Analysis of Air Quality Data..........................................................................6

B. Addressing Missing Data...............................................................................6

C. Additional Analysis....................................................................................14

D. Air Quality in 2010.....................................................................................14

VI. CONCLUSION.............................................................................................14

APPENDIX A Annual Means for the Huntington-Ashland Area PM2.5 FRM monitors....................16
3

I. INTRODUCTION

On April 1, 2010, Ohio requested that EPA determine that multiple areas, including the 

Huntington-Ashland Area, are attaining the 1997 annual fine particulate (PM2.5) National Ambient Air 

Quality Standard (NAAQS). In addition, pursuant to 179(c)(1) of the Clean Air Act, EPA is required to 

make a determination about the status of this area as of its attainment date. This technical support 

document specifically addresses the Huntington-Ashland PM2.5 nonattainment area, including portions 

in West Virginia, Kentucky, and Ohio (hereafter referred to as “the Huntington-Ashland Area” or “the 

Area”). In this technical support document, EPA provides information supporting: the proposed 

determination that the Huntington-Ashland Area has attained the 1997 annual PM2.5 NAAQS (hereafter 

referred to as “the annual PM2.5 NAAQS” or “the standard”) and that the area has attained the 1997 

annual PM2.5 NAAQS by its applicable attainment date of April 5, 2010. 

In this technical support document, EPA:

- summarizes the statutory and policy requirements for PM2.5 nonattainment area SIPs and 

EPA’s policy concerning attainment.

- provides a description of the air quality monitoring network for the Huntington-Ashland Area

PM2.5 nonattainment area

- provides a description of the air quality monitoring network for the Huntington-Ashland Area

- describes the Lawrence County Hospital (LCH) monitoring site, and provides an explanation 

for monitor shutdown;

- describes our detailed analysis of our proposed determination of attainment, including our 

analysis of the air quality data, and the methodology used for substituting for missing data;

- describes air quality trends in the Huntington-Ashland Area

- summarizes our conclusions on the proposed determination of attainment with respect to 

EPA requirements. 

II. CLEAN AIR ACT REQUIREMENTS FOR FINE PARTICLE (PM 2.5) ATTAINMENT 

A. PM2.5 Attainment Requirements 

In 1997, EPA established the health-based NAAQS for PM2.5, setting an annual standard at 15.0 

micrograms per cubic meter (ug/m3) based on a 3-year average of annual mean PM2.5 concentrations, 

and a 24-hour standard of 65 ug/m3based on a 3-year average of the 98th percentile of 24-hour 

concentrations. EPA established the standards based on significant evidence and numerous health 

studies demonstrating that serious health effects are associated with exposures to particulate matter. 

On January 5, 2005, (70 FR 944) EPA finalized its air quality designations and classifications 

across the country with respect to the 1997 PM2.5 standard. These designations became effective on 

April 5, 2005. The Huntington-Ashland Area was designated nonattainment for the 1997 annual PM2.5

NAAQS (See 40 CFR 81.349 (West Virginia), 40 CFR 81.318 (Kentucky), and 40 CFR 81.336 (Ohio). 

These designations triggered the Clean Air Act’s requirements under section 172(c), which 
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requires the submission of an attainment plan for each designated nonattainment area. EPA’s PM2.5

implementation rule, published on April 25, 2007 (72 Fed. Reg. 20586) specifies that states must submit 

attainment plans for their nonattainment areas to the EPA by no later than three years from the effective 

date of designation, that is, by April 5, 2008. EPA’s PM2.5 implementation rule outlines the SIP 

requirements for the attainment plan, which includes among other things, the submission of an 

attainment demonstration showing the air-quality improvements expected to result from national and 

local control measures, an analysis of reasonably available control measures (RACM), including all 

reasonably available control technology (RACT), reasonable further progress plan, and contingency 

measures. EPA’s implementation rule also sets the attainment date in these areas as April 5, 2010, and

the determination would be based on data from 2007-2009 (72 FR 20600).

The states of West Virginia, Kentucky, and Ohio, are subject to these requirements since several 

counties in the states are located in a PM2.5 nonattainment area. The Huntington-Ashland Area is 

composed of some or all of the following counties in West Virginia, Kentucky, and Ohio: Cabell, 

Mason (part) and Wayne Counties in West Virginia; Boyd and Lawrence (part) Counties in Kentucky; 

and Adams (part), Gallia (part), Lawrence, and Scioto Counties in Ohio. 

B. Determination of Attainment

Under EPA regulations at 40 CFR 50.7, the annual primary and secondary PM2.5 standards are 

met when the annual arithmetic mean concentration, as determined in accordance with 40 CFR part 50, 

Appendix N, is less than or equal to 15.0 ug/m3.

Data handling conventions and computations necessary for determining whether areas have met 

the PM2.5 NAAQS, including requirements for data completeness, are listed in Appendix N of 40 CFR 

Part 50. A year meets data completeness requirements when at least 75 percent of the scheduled 

sampling days for each quarter have valid data. The use of less than complete data is subject to the 

approval of EPA, which may consider factors such as monitoring site closures/moves, monitoring 

diligence, and nearby concentrations in determining whether to use such data. 

If this proposed determination of attainment is made final, EPA will have met its statutory 

obligation pursuant to section 179(c)(1) of the Clean Air Act (CAA) to make a determination based on 

the Area’s air quality data as of the attainment date whether the area attained the standard by that date. 

Additionally, as a result of such determination, the requirements for Kentucky, Ohio or West Virginia to 

submit an attainment demonstration and associated RACM, a RFP plan, contingency measures, and any 

other planning SIPs related to attainment of the 1997 annual PM2.5 NAAQS within the HuntingtonAshland Area would be suspended until such time as: a) the area is redesignated to attainment, at which 

time the requirements would no longer apply; or, b) EPA determines that the area has violated the 

annual PM2.5 NAAQS, at which time, the area would be required to submit such plans. See 40 CFR 

51.1004(c).

A determination of attainment does not shield an area from other required actions such as New 

Source Review (NSR), conformity and emission inventory requirements, and provisions to address 

pollution transport, which would require emission reductions at sources or other types of emission 
5

activities contributing significantly to nonattainment in other areas or states, or interfering with 

maintenance in those areas.

Determinations as to whether individual areas have attained the PM2.5 standards and thus qualify 

for the application of a determination of attainment are being made in the context of rulemakings for 

individual areas. This Technical Support Document (TSD) provides an explanation of EPA’s analysis 

used to determine whether the Huntington-Ashland Area has attained the annual PM2.5 standard by the 

applicable attainment date. 

III. MONITORING NETWORK

The Huntington-Ashland Area currently has three air monitoring locations; one each in West 

Virginia, Kentucky, and Ohio. West Virginia also has a collocated monitor in place at the site for 

quality assurance purposes. The primary monitor, and not the collocated monitor, is used to determine 

compliance with the PM2.5 NAAQS. Since the collocated quality assurance monitor takes many fewer 

readings than the primary monitor, its average annual values may be unrepresentatively high even if 

only a few high values are recorded. (See 40 CFR Part 50, Appendix N, 3(d)(1). Two monitoring 

locations for Ohio are listed in Table 1 due to the LCH monitor shut-down and Ironton DOT start-up 

during the 2007-2009 time period. Table 1 shows the monitor design values (DVs) (i.e., the 3-year 

average of annual mean PM2.5 concentrations) for the years 2007-2009. The area DV is the highest 

annual mean measured for a federal reference method (FRM) monitor that had complete data in a 

county. 

Table 1.— 2007-2009 Design Values for the 1997 Annual PM2.5 NAAQS for the Huntington-Ashland Area Monitors in 

Micrograms per Cubic Meter (ug/m3).

Site Name County Site Number Annual Average 

Concentration 

(μg/m3)

Huntington Cabell 54-011-0006 14.31

Ashland Primary (FIVCO) Boyd 21-019-0017 12.4

Lawrence County Hospital Lawrence 39-087-0010 13.32

 

1 West Virginia has a collocated monitor in place at the same site for quality assurance purposes. The primary monitor, and 

not the collocated monitor, is used to determine compliance with the PM2.5 NAAQS. Since the collocated monitor takes 

fewer readings than the primary monitor, its average annual values may be unrepresentatively high. See 40 CFR Part 50, 

Appendix N, 3(d)(1).

2 Data from the Lawrence County Hospital and Ironton DOT sites were incomplete due to shut-down of the Lawrence County 

Hospital site and startup of the Ironton DOT site in February 2008.
6

Ironton DOT Lawrence 39-087-0012 12.23

EPA meets annually with each state to discuss any problems or issues concerning states’ air 

monitoring data and/or network. In addition, EPA and the states communicate many times during the year so 

that issues can be addressed as they show up. EPA regulations require states to submit annual network plans 

to their respective Regions. These plans outline the current networks and any proposed changes in the 

upcoming 18 months. Regions 3, 4, and 5 have been able to approve these plans due to the quality of the 

West Virginia, Kentucky, and Ohio monitoring networks. 

IV. LAWRENCE COUNTY HOSPITAL MONITORING SITE 

The LCH monitor operated until February 11, 2008, when monitoring was discontinued 

permanently at the site due to the building demolition. Because the monitor at this location could not be 

replaced, a new site in this county was established at the Ironton DOT starting when monitoring at the 

LCH ended. As a result, the Ironton DOT monitor did not obtain any data for 2007 and did not obtain 

complete data for the first quarter of 2008. Nevertheless, the available data for the remainder of 2008 

and all of 2009 indicate attainment at this monitor. 

As discussed in greater detail below, the monitors in Lawrence County were the only monitors in 

the Huntington-Ashland Area without valid attaining DVs for 2007-2009 due to incomplete data. This 

monitor historically measured lower concentrations than other monitors in the Area, including, for 

example, the monitor in Cabell County, West Virginia. 

V. EPA’S ANALYSIS 

A. Analysis of Air Quality Data 

EPA has reviewed the ambient air monitoring data for PM2.5, consistent with the requirements 

contained in 40 CFR part 50 and recorded in the EPA Air Quality System database for the HuntingtonAshland Area from 2007 through the present time. Currently all monitors are measuring concentrations 

averaging well below the annual standard of 15.0 ug/m3. The highest DV for the most recent 3 years, 

2007-2009, for the Huntington-Ashland Area is 14.3 ug/m3, based on monitoring data collected in West 

Virginia at the Huntington monitor. All 3-year averages of the annual mean PM2.5 concentrations are

below the NAAQS from 2007-2009. 

In order to determine whether the NAAQS has been attained for the LCH monitor, EPA has 

applied a recently developed procedure to address the missing data, and determine valid DVs for the 

monitor for the annual standard for 2007-2009. EPA’s procedure is described in the following section.

 

3 The Lawrence County Hospital Site was shut-down in February 2008. The Ironton DOT site began operation in 2008 after 

the Lawrence County Hospital Site ceased monitoring.
7

B. Addressing Missing Data

Additional analysis was necessary for the LCH monitor (site number 39-087-0010) because this 

monitor is no longer operating (due to building demolition) but recorded a violation in the most recent 

three year period in which it collected complete data. An objective statistical method was used to 

determine if this monitor would likely have met the NAAQS in subsequent time periods. 

The general concept behind the statistical method is to establish a linear regression relationship 

between the monitor of interest and another “comparison monitor” in the nonattainment area based on 

data obtained when the monitor of interest was still operating. The method then estimates 

concentrations at the monitor of interest for the period after monitor shutdown by applying a linear 

regression to the more recently observed concentrations at the other monitor. The results are checked 

with an additional statistical technique, known as bootstrapping, to verify if the conclusion of attainment 

is correct. 

The monitor of interest in this analysis is the LCH monitor. This site ceased monitoring in 

February 2008 and had an incomplete DV of 12.9 μg/m3for 2007-2008. The goal of this methodology 

is to appropriately fill in the missing data from the quarters 1-4 of 2008, and quarters 1-4 of 2009 to 

judge whether this location would likely have monitored attainment of the NAAQS had the monitor

continued to operate. The Huntington-Ashland Area has two monitoring locations with complete data

for 2007-2009, listed in Table 1 above, both of which are similar enough to warrant comparison to the 

LCH monitor.

Criteria to be met

EPA established criteria to assure that the DV for the LCH monitor in the Huntington-Ashland 

Area, as estimated by the method, was robust enough to allow consideration of the results in a weight of 

evidence decision. EPA established criteria both for the operating period of the comparison monitor and 

for the number of days of samples that the comparison monitor and the LCH monitor have in common. 

EPA has not established bright lines or specific requirements for determining DVs for monitors with less 

than complete data. 

Operating period

In order to provide satisfactory concentration estimates for the LCH monitor for the period after 

the monitor shut down, comparison monitors in the Huntington-Ashland Area would need to have 

operated from well before from February 2008 to the end of 2009. Operation for a substantial period 

before February 2008 is necessary to support a robust regression relationship with concentrations at the 

LCH monitor, and operation from February 2008 to the end of 2009 is necessary to support 

concentration estimates for this period. 

Paired samples

Pairs of sample data for the LCH monitor and comparison monitors from the most recent 20-

quarter period of operation of the LCH monitor were used. Comparison monitors were required to have
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at least 100 historical sample pairs in common with the target monitor during this period. When there 

were more than 100 pairs in the 20-quarter period, all available pairs were used. In addition to the 100 

pairs over the 20-quarters, comparison monitors were required to have at least 20 paired days of data in 

common with the LCH monitor for each quarter (adding together the number of days in a given calendar 

quarter [Q1, Q2, Q3, or Q4] across the various years in the 20-quarter period).

Both comparison monitors, Ashland Primary and Huntington, met the eligibility criteria of 100 

pairs over the 20-quarters, and at least 20 paired days of data in common with the LCH monitor for each 

calendar quarter. 

Method for determining DVs

Step 1 – Organize data and perform linear regression(s) between the LCH monitor and the comparison

monitors.

For both the Ashland Primary and the Huntington monitors, all the available paired data within 

the 5-year period described above were used to develop a linear regression expressing concentrations at 

the LCH monitor in relation to concentrations at the comparison monitor. 

Step 2 – Select candidate monitor

The Huntington-Ashland Area has 2 monitors which could have been used as comparison

monitors, Ashland Primary and the Huntington. The following steps were used to select the comparison

monitor. 

1) Comparison monitors were placed into order of highest correlation (highest r-squared in the linear 

regression) of concentrations with concentrations at the LCH monitor. The comparison monitor 

showing the highest correlation of concentrations with concentrations at the LCH monitor was used first.

2) Using the regression equation relating concentrations at the LCH monitor and the comparison 

monitor, estimates of the 24-hour average concentrations at the LCH monitor were made for each day 

after this monitor was shut down that the monitor otherwise would have been scheduled to measure 

concentrations, except that no estimate was made if the comparison monitor had no valid measurement. 

The estimates were combined with any reported data at the LCH monitor in the recent 3-year period and 

the data capture rates were computed for each originally incomplete quarter. 

3) If performing the process in #2 results in all 12 quarters at the LCH monitor having at least 75 percent 

of scheduled values, the comparison monitor was selected for use in the remaining steps. If 75 percent of 

the scheduled values for the LCH monitor were not obtained, the steps in #2 were repeated for the next 

best correlated comparison monitor. This process was repeated until the LCH monitor had at least 75 

percent of the number of values expected under its original operating schedule.

Step 3 – DV Computed
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The 3-year DV was calculated using the actual observations at the LCH monitor and the 

regression-based estimates of daily concentrations. The resulting DV for the LCH monitor was 13.3

μg/m3, which is below the annual PM2.5 NAAQS.

Step 4 –Statistical confidence of a DV below the NAAQS checked

In order to show that there is a minimal probability that the actual DV (had the LCH monitor 

operated more days) was above the annual PM2.5 NAAQS, further analysis was performed as follows:

(a) Residuals were calculated from the regression.

(b) A bootstrap analysis was performed, repeating the regression-based substitution in Step 2 

but adding to each estimated 24-hour value that substitutes for a missing scheduled 

monitored value a plus or minus residual that has been randomly drawn (with 

replacement) from the pool of regression residuals. This step randomly applies real 

residuals from the linear regression to the imputed current-period target values.

(c) Repeat (b) for a total of 1000 runs. 

(d) For each of the 1000 bootstrap trials, the 3-year DV was calculated. This provides a 

pseudo confidence interval for the partially imputed current-period DV for the target.

(e) Since none of the 1000 runs resulted in a DV above the annual PM2.5 NAAQS, the LCH

monitor was considered to have met the annual PM2.5 NAAQS. 

Determining the DV for Lawrence County Hospital (AQS ID: 39-087-0010)

The analysis described above was performed to estimate concentrations at the LCH monitor. 

The results of the regressions can be found in Table 2. The LCH monitor is identified in this table as 

Site A. The comparison monitors in this table are all identified in this table as Site B. The Ashland 

Primary monitor (AQS ID: 21-019-0017) had the highest correlation with the LCH monitor and met the 

operating period and paired data eligibility criteria for being the comparison monitor. The results of the 

regression between the LCH monitor and the Ashland Primary monitor are shown in Figure 1. 

Estimates for the missing data for quarters 1 thru 4 of 2008 and for quarters 1 thru 4 of 2009 for the 

LCH monitor were made. These quarters were the quarters with less than 75 percent data capture. As a 

result of filling in the missing data, the LCH monitor now had 32, 30, 31, 30 values for quarters 1 thru 4

for 2008, respectively, and 30, 30, 27, 31 values for quarters 1 thru 4 of 2009, respectively. A DV of 

13.3 g/m3 was calculated for the LCH monitor when the missing data was filled in, as shown in Figure 

2.

The statistical confidence of the DV was checked using the method outlined in Step 4 above. 

The results of the 1000 bootstrap trials provided the following results: 243 DVs) of 13.2 μg/m3, 223

DVs of 13.3 μg/m3, 177 DVs of 13.1 μg/m3, 157 DVs of 13.4 μg/m3, 81 DVs of 13.0 μg/m3, 61 DVs of 

13.5 μg/m3, 21 DVs of 13.6 μg/m3, 19 DVs of 12.9 μg/m3, 8 DVs of 13.7 μg/m3, 6 DVs of 12.8 μg/m3, 2

DVs of 12.7 μg/m3, and 2 DVs of 13.8 μg/m3. None of the 1000 bootstrapping trials resulted in a 

violating DV, which provides statistical confidence that the air quality at the LCH monitor is below the 

annual PM2.5 NAAQS.
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2007 Q1 2007 Q2 2007 Q3 2007 Q4 2008 Q1 2008 Q2 2008 Q3 2008 Q4 2009 Q1 2009 Q2 2009 Q3 2009 Q4

390870010 93% 100% 100% 97% 35%

210190017 93% 97% 97% 100% 94% 100% 100% 100% 97% 97% 90% 97%

540110006 100% 97% 100% 100% 87% 93% 94% 100% 97% 84% 90% 94%

391450013 100% 100% 97% 100% 100% 97% 87% 97% 97% 94% 97% 97%

Site B

Quarterly Data Capture, 2007-2009

npairsQ1 npairsQ2 npairsQ3 npairsQ4 corr

Huntington-Ashland, WV-KY-OH 390870010 390870010 12.9 inc-a 12.9 inc-a 128 146 151 146 1

Huntington-Ashland, WV-KY-OH 390870010 210190017 12.4 A 12.4 A 119 131 145 141 0.86384

Huntington-Ashland, WV-KY-OH 390870010 540110006 14.3 A 14.3 A 124 145 148 137 0.855279

Huntington-Ashland, WV-KY-OH 390870010 391450013 12.3 A 12.3 A 128 143 149 144 0.833266

DV status 

Site A

DV Site 

B

DV status 

Site B

20-quarter look (2003-Q2 - 2008-Q1)

Area Site A Site B DV Site 

A

Table 2. Correlation and data capture for monitors used to determine a DV for Lawrence County Hospital site.
v_a

0

10

20

30

40

50

v_b

0 10 20 30 40 50

Figure 1 Concentrations at Lawrence County Hospital (site 390870010, labeled “v_a”) compared to concentrations at Ashland 

(site 210190017, labeled “v_b”).

The linear relationship between the two monitors is: Concentration at Lawrence County Hospital = 2.293135 + 0.882184 * 

concentration at Ashland. The correlation coefficient was 0.86384.
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Figure 2. Results for Lawrence County Hospital site after filling in missing data 

for all quarters of 2008, and all quarters of 2009
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C. Additional Analysis

Additional statistical analysis was performed for the LCH monitor using a different 

comparison monitor. EPA re-ran the analysis using data from the Huntington monitor (site number 54-

011-0006), a monitor that is similarly correlated with the LCH monitor as the Ashland Primary monitor. 

The results of the analysis using the Huntington monitor as the comparison monitor produced an 

estimated 2007-2009 DV at the LCH of 13.1 μg/m3, which is also below the NAAQS of 15.0 ug/m3. 

That is, the concentration estimates provided by the method described herein indicate a DV at LCH that 

is below the annual PM2.5 NAAQS, regardless of which area monitor is used as the basis for the 

estimates.

D. Air Quality in 2010

The states have submitted monitoring data for 2010. EPA examined 2008 to 2010 data as 

an indication of whether the area continues to attain the standard. Table 3 shows the average 

concentration at each of the sites in the Huntington-Ashland Area. All sites have average concentrations 

well below the standard, with average values ranging from 12.2 to 13.1 μg/m3. Therefore, EPA believes 

that 2008 to 2010 data, interpreted in conjunction with data from 2007 to 2009, supports a determination 

that the Huntington-Ashland Area is attaining the annual PM2.5 NAAQS.

Table 3.— 20008- 2010 annual average PM2.5 concentrations for the Huntington-Ashland Area monitors in micrograms per 

cubic meter (ug/m3).

Site Name County Site Number Annual Average 

Concentration 

(μg/m3)

Huntington4 Cabell 54-011-0006 13.1

Ashland Primary (FIVCO) Boyd 21-019-0017 11.4

Ironton DOT Lawrence 39-087-0012 12.2

VI. CONCLUSION

EPA is proposing to determine that the Huntington-Ashland Area has attained the annual 

1997 PM2.5 NAAQS by its attainment date of April 5, 2010.

 

4 West Virginia has a collocated monitor in place at the same site for quality assurance purposes. The primary monitor, and 

not the collocated monitor, is used to determine compliance with the PM2.5 NAAQS. Since the collocated monitor takes 

fewer readings than the primary monitor, its average annual values may be unrepresentatively high. See 40 CFR Part 50, 

Appendix N, 3(d)(1).
15

EPA has reviewed the ambient air monitoring data for PM2.5, consistent with the 

requirements contained in 40 CFR part 50 and recorded in the EPA Air Quality System database for the 

Huntington-Ashland Area. The 3-year averages of the annual mean PM2.5 concentrations continue to be 

below the NAAQS of 15.0 ug/m3. 

EPA has concluded that use of less than complete data from the LCH monitoring site is 

warranted for determining attainment of the NAAQS. The States of West Virginia, Kentucky, and Ohio

have been diligent in the number and placement of PM2.5 monitors in the nonattainment area. The 

monitor at LCH was shut down due to a planned building demolition and could not be replaced. In light 

of such facts, EPA employed a procedure using a statistical method to estimate concentrations at the 

LCH monitor for the remainder of the time period at issue; and, the resulting analysis supports a finding 

of attainment of the annual PM2.5 NAAQS at this location.

As provided in 40 CFR 51.1004(c), if EPA finalizes this determination, it would suspend the 

requirements for this area to submit attainment demonstrations, reasonably available control measures, 

reasonable further progress plans, and contingency measures related to attainment of the 1997 annual 

PM2.5 NAAQS so long as the Area continues to attain the 1997 annual PM2.5 NAAQS.
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Appendix A

Annual Means for the Huntington-Ashland Area PM2.5 FRM monitors
Kentucky Boyd 210190017 15.1 NA 15.5 NA 14.9 A 14.3 A 14.4 A 14.4 A 14.7 A 13.4 A 12.4 A

Ohio Lawrence 390870010 17.6 NA 16.8 NA 15.8 NA 14.5 A 15.0 A 15.0 A 15.4 NA 13.4 inc-a 12.9 inc-a

Ohio Lawrence 390870012 13.1 inc-a 12.2 inc-a

Ohio Scioto 391450013 22.0 NA 19.4 NA 17.2 NA 14.8 A 14.6 A 14.5 A 14.8 A 13.5 A 12.3 A

West Virginia Cabell 540110006 17.8 NA 17.3 NA 16.6 NA 15.8 NA 16.3 NA 16.1 NA 16.6 NA 15.2 NA 14.3 A

2003-2005 2004-2006 2005-2007 2006-2008

Annual Design Values

2007-2009 state_name county_name 2000-2002 2001-2003 2002-2004 site 1999-2001