### Environmental ProtectionAgency



## PART58-AMBIENT AIRQUALITY SURVEILLANCE
SubpartA--General Provisions

Sec. 

### 58.1 58.2 58.3 Definitions. Purpose. Applicability. 

### Subpart B-Monitoring Network

58.10 Annual monitoring network plan and periodicnetwork assessment. 58.11 Network technical requirements. 58.12 Operating schedules. 58.13 Monitoring networkcompletion. 58.14 System modification. 58.15 Annual air monitoring data certification. 58.16 Data submittal and archiving requirements. 

### Subpart C-Special Purpose Monitors

58.20 Specialpurpose monitors (SPM). 

### Subpart D-Comparability ofAmbient Data toNAAQS

58.30 Special considerations for data comparisons to theNAAQS. 

### Subpart E [Reserved] Subpart F-AirQualityIndexReporting

58.50 Indexreporting. 

### Subpart G-Federal Monitoring

58.60 Federal monitoring. 58.61 Monitoring otherpollutants.

APPENDIX A TO PART 58-QUALITY ASSURANCE REQUIREMENTS FOR STATE AND LOCAL AIR MONITORING STATIONS (SLAMS)
APPENDIX BTO PART58 [RESERVED] APPENDIX C TO PART 58-AMBIENT AIR QUALrrY MONITORING METHODOLOGY APPENDIX D TO PART 58--NETWORK DESIGN CRITERIA FOR AMBIENT AIR 

### QUALITYMONITORING
APPENDIX E TO PART 58-PROBE AND MONITORING PATH SITING CRITERIA FOR AMBIENTAIR QUALITY MONITORING APPENDIX F TO PART58 [RESERVED] APPENDIX G TO PART 58-UNIFORM AIR QUALITY INDEX (AQI) AND DAILY REPORTING

AUTHORITY: 42 U.S.C. 7403, 7405, 7410, 7414, 7601, 7611, 7614, and7619.

SOURCE: 44 FR 27571, May 10, 1979; 59 FR 41628, Aug. 12, 1994, unless otherwise noted. 

## §58.1 

## Subpart A-General Provisions

SOURCE: 71 FR 61296, Oct. 17, 2006, unless otherwise noted. 

### §58.1 Definitions.

As used in this part, all terms not defined herein have the meaning given them in the Act.

AADT means the annual average daily traffic.

Act means the Clean Air Act as amended (42 U.S.C. 7401, etseq.)



### Additive andmultiplicativebiasmeans the linear regression intercept and slope of a linear plot fitted to cor- responding candidate and reference method mean measurement data pairs.

Administrator means the Administrator ofthe Environmental Protection Agency (EPA) or his or her authorized representative.



### Air Quality System (AQS) means EPA's computerized system for storing 

### and reporting of information relating
to ambient air quality data.

Approved regional method (ARM)

means a continuous PM 2.5 method that has been approved specifically within a State or local air monitoring network 

### for purposes of comparison to the NAAQS and to meet other monitoring objectives.

AQCR means air quality control re- gion.

CO meanscarbon monoxide. Combined statisticalarea(CSA) is definedby the U.S. Office ofManagement and Budget as a geographical area con- sisting of two or more adjacent Core Based Statistical Areas (CBSA) with employment interchange of at least 15 percent. Combination is automatic if the employment interchange is 25 percent and determined by local opinion if

more than 15 but less than 25 percent(http://www.census.gov/population/estimates/metro-city/List6.txt).

Community monitoring zone (CMZ)

means an optional averaging area with established, well defined boundaries, such as county or census block, within

an MPA that has relatively uniform concentrations of annual PM 2

### .

5 

### as defined by appendix N of part 50 of this chapter. Two or more community-oriented SLAMS monitors within a CMZ that meet certain requirements as set forth in appendix N of part 50 of this



### 245

### 40CFR Ch. 1(7-1-12 Edition)

chapter may be averaged for making comparisons to the annual PM 2

### .

5 

### NAAQS.

Core-based statistical area (CBSA) is defined by the U.S. Office of Management and Budget, as a statistical geographic entity consisting ofthe county

or counties associated with atleast one urbanized area/urban cluster ofat least 10,000 population, plus adjacent coun- ties having a high degree of social and economic integration. Metropolitan Statistical Areas (MSAs) and micropolitan statistical areas are the two categories of CBSA (metropolitan

areas have populations greater than 50,000; and micropolitan areas have populations between 10,000 and 50,000). In the case of very large cities where two or more CBSAs are combined, these larger areas are referred to as combined statistical areas (CSAs)(http://www.census.gov/population/estimates/rnetro-city/ListL.txt).

Corrected concentration pertains to the result of an accuracy or precision assessment test of an open path ana- lyzer in which a high-concentration test or audit standard gas contained in

a short testcell is inserted into the optical measurement beam of the instrument. When the pollutant concentration measured by the analyzer in such

a test includes both the pollutant con- centration in the test cell and the con- centration in the atmosphere, the atmospheric pollutant concentration must be subtracted from the testmeas- urement to obtain the corrected con- centration test result. The corrected concentration is equal to themeasured concentration minus theaverage ofthe atmospheric pollutant concentrations measured (without the test cell) immediately before and immediately after the test.

Design value means the calculated concentration according to the applicable appendix of part 50 of this chapter forthe highest site in an attainment or nonattainment area.

EDO means environmental data operations.

Effective concentration pertains to testing an open path analyzer with a high-concentration calibration oraudit standard gas contained in a short test cell inserted into the optical measure- ment beam of the instrument. Effective concentration is the equivalent ambient-level concentration that would produce the same spectral absorbance over the actual atmospheric monitoring path length as produced by thehigh-concentration gas in the short
test cell. Quantitatively, effective concentration is equal to the actual concentration of the gas standard in the
test cell multiplied by the ratio ofthe path length of the test cell to the ac- tual atmospheric monitoring path length.

Federal equivalent method (FEM)

meansa method for measuring the concentration of an air pollutant in the ambient air that has been designated

as an equivalent method in accordance withpart 53 ofthis chapter; it does not include a method forwhich an equivalent method designation has been canceled in accordance with 

### §53.11 or 

### §53.16 ofthischapter.

Federalreferencemethod(FRM)means
a method of sampling and analyzing the ambient air for an air pollutant that is specified as a reference method in an appendix to part 50 ofthis chapter, or a method that has been designated as a reference method in accordance with this part; it does not include a method for which a reference method designation has been canceled in accordance with 

### §53.11 or 

### §53.16 of thischapter.

HNO 3 

### means nitric acid. Localagency means any local government agency, other than the State agency, which is charged by a State with theresponsibility for carrying out

aportion oftheplan.

Meteorological measurements means measurements of wind speed, wind direction, barometric pressure, temperature, relative humidity, solar radiation, ultraviolet radiation, and/or precipitation.

Metropolitan Statistical Area (MSA)

means a CBSA associated with at least

one urbanized area of50,000 population

or greater. The central county plus adjacent counties with a high degree of integration comprise the area.

Monitor means an instrument, sam- pler, analyzer, or other device that

measures or assists in the measurement ofatmospheric air pollutants and which is acceptable for use in ambient



## 246 §$58.1

## Environmental ProtectionAgency

air surveillance under the applicable provisions ofappendix Cto this part.

Monitoring agency means a State or local agency responsible for meeting the requirements ofthis part.

Monitoring organization means a State, local, or other monitoring organization responsible for operating a monitoring site for which the quality

assurance regulations apply.

Monitoring pathfor an open path ana- lyzer means the actual path in space between two geographical locations

over which the pollutant concentration ismeasured and averaged.

Monitoring path length of an open path analyzer means the length of the monitoring path in the atmosphere

over which the average pollutant con- centration measurement (path-averaged concentration) is determined. See also, opticalmeasurementpathlength.

Monitoring planning area (MPA)

means a contiguous geographic area with established, well defined boundaries, such as a CBSA, county or State, having a common area that isused for planning monitoring locations for PM2

### . 5

### . An MPA may cross State boundaries, such as the Philadelphia PA-NJ MSA, and be further subdivided into community monitoring zones. MPAs

are generally oriented toward CBSAs

or CSAs with populations greater than 200,000, but for convenience, those portions ofa State that are not associated with CBSAs can be considered as a single MPA.

NATTS means the national air toxics trends stations. This network provides hazardous airpollution ambient data.

NCore means the National Core multipollutant monitoring stations. Monitors at these sites are required to

measure particles (PM2

### .5

### , speciated PM 2

### .

5

### , PM10-2.5), 0, SO2

### , CO, nitrogen oxides (NO/NO 2 

### /NOy), Pb, and basic me- teorology.

Near-road NO2

### Monitormeans anyNO2 

### monitor meeting the specifications in 4.3.2 of appendix D and paragraphs 2, 4(d), 6.1, and 6.4 of appendix E of this part.

Networkmeans all stations ofa given type ortypes.

NH3

### means ammonia. NO2 

### means nitrogen dioxide. NO

means nitrogen oxide. NOx means ox- ides of nitrogen and is defined as the 

## §58.1

sum of the concentrations of NO2 

### and NO.

NOy means the sum of all total reac- tive nitrogen oxides, including NO, NO2

### ,and other nitrogen oxides referred toas NOz.

03means ozone. Open path analyzer means an automated analytical method that meas-
ures theaverage atmospheric pollutant concentration in situ along one or
more monitoring paths having a monitoring path length of 5meters or more and that has been designated as a ref-

erence or equivalent method under the provisions ofpart53 ofthischapter.

Optical measurement path length

means the actual length of the optical beam over which measurement of the pollutant is determined. The path-integrated pollutant concentration meas- ured by the analyzer is divided by the optical measurement path length todetermine the path-averaged concentration. Generally, the optical measure- mentpath length is:

(1) Equal to the monitoring path length for a (bistatic) system having a transmitter and a receiver at opposite ends ofthe monitoring path;

(2) Equal to twice the monitoring path length for a (monostatic) system having a transmitter and receiver at

one end of the monitoring path and a mirror or retroreflector at the other end; or

(3) Equal to some multiple of the monitoring path length for more complex systems having multiple passes of the measurement beam through the monitoring path.

PAMS means photochemical assessmentmonitoring stations.

Pb means lead. Planmeans an implementation plan approved or promulgated pursuant to section 110 oftheAct.

PM means PMo, PM1 1

### oc, PM2

### .5, PM 1

### O-2.5, or particulate matter of unspecified sizerange.

PM 2

### .5means particulate matter with

an aerodynamic diameter less than or equal to a nominal 2.5 micrometers as measured by a reference method based

on appendix L ofpart 50 ofthis chapter and designated in accordance with part 53 of this chapter, by an equivalent method designated in accordance with



## 247

### 40CFR Ch. I(7-1-12 Edition)

part 53 of this chapter, or by an approved regional method designated in accordance with appendix C to this part.

PMIo means particulate matter with

an aerodynamic diameter less than or equal to a nominal 10 micrometers as measured by a reference method based

on appendix J ofpart 50 of thischapter and designated in accordance with part 53 of this chapter or by an equivalent method designated in accordance with part 53 ofthis chapter.

PMIocmeans particulate matter with

an aerodynamic diameter less than or equal to a nominal 10 micrometers as measured by a reference method based

on appendix 0 ofpart 50 ofthischapter and designated in accordance withpart 53 ofthis chapter or by an equivalent method designated in accordance with part 53 ofthis chapter.

PM 10-2.5 

### means particulate matter with an aerodynamic diameter less than or equal to a nominal 10 micrometers and greater than a nominal 2.5 micrometers as measured by a ref-

erence method based on appendix 0 to part 50 of this chapter and designated in accordance with part 53 ofthis chapter or by an equivalent method designated in accordance with part 53 of thischapter.

Point analyzer means an automated analytical method that measures pollutant concentration in an ambient air sample extracted from the atmosphere ata specific inlet probe point and that has been designated as a reference or equivalent method in accordance with part 53 ofthis chapter.

Population-oriented monitoring (or sites)means residential areas, commer- cial areas, recreational areas, industrial areas where workers from more than one company are located, and other areas where a substantial num- ber of people may spend a significant fraction oftheir day.

Primaryqualityassuranceorganization

means a monitoring organization or other organization that is responsible for a set of stations that monitor the

same pollutant and for which data quality assessments can be pooled. Each criteria pollutant sampler/monitor at a monitoring station in the SLAMS and SPMnetworks must be associated with one, and only one, primary quality assurance organization.

Probemeans the actual inlet where

an air sample is extracted from the atmosphere for delivery to a sampler or point analyzer for pollutant analysis.

PSD stationmeans any station operated for the purpose ofestablishing the effect on air quality of the emissions from a proposed source for purposes of prevention of significant deterioration

as required by 

### §51.24(n) ofthis chapter.

RegionalAdministratormeans the Administrator of one ofthe ten EPA Regional Offices or his or her authorized representative.

Reportingorganizationmeans an entity, such as a State, local, or Tribal monitoring agency, that collects and reports air quality data toEPA.

Sitemeans ageographic location. One

or more stations may be at the same site.

SLAMS means State orlocal airmon- itoring stations. The SLAMS make up the ambient air quality monitoring sites that are primarily needed for NAAQS comparisons, but may serve other data purposes. SLAMS exclude special purpose monitor (SPM) stations and include NCore, PAMS, and all other State or locally operated stations that have not been designated as SPM stations.

SO2

### means sulfur dioxide. Specialpurposemonitor (SPM)station

means a monitor included in an agency's monitoring network thattheagency has designated as a special purpose monitor station in its monitoring network plan and in the Air Quality System, and which the agency does not count when showing compliance with the minimum requirements ofthis subpart for the number and siting ofmon- itors ofvarious types.

State agency means the air pollution control agency primarily responsible for development and implementation of

a planunder theAct.

State speciationsite means a supplemental PM2. 5 

### speciation station that is not part of the speciation trends network.

Stationmeans a single monitor, or a group of monitors with a shared objective, located at aparticular site.

STN station means a PM 2.5 

### speciation station designated to be part of the



## 248 §58.1

## Environmental ProtectionAgency

speciation trends network. This network provides chemical species data of fine particulate.

Traceablemeans that a local standard has been compared and certified, either directly or via not more than one intermediate standard, to a National Institute of Standards and Technology (NIST)-certified primary standard such

as a NIST-traceable Reference Material (NTRM) or a NIST-certified Gas Manufacturer'sInternal Standard (GMIS).

TSP (total suspended particulates)

means particulate matter as measured by the method described in appendix B ofpart 50 ofthis chapter.

Urbanizedareameans an area with a minimum residential population of at least 50,000 people and which generally includes core census block groups or blocks that have a population density of at least 1,000 people per square mile and surrounding census blocks that have an overall density of at least 500 people per square mile. The Census Bureau notes that under certain conditions, less densely settled territory may bepart ofeach Urbanized Area.

VOC means volatile organic compounds. [71 FR 61296, Oct. 17, 2006, as amended at 75 FR6534, Feb. 9,20101
§58.2 Purpose.

(a) This part contains requirements for measuring ambient air quality and for reporting ambient air quality data and related information. The monitoring criteria pertain to the following

areas:

(1) Quality assurance procedures for monitor operation and datahandling.

(2) Methodology used in monitoring stations.

(3)Operating schedule. (4)Siting parameters forinstruments

orinstrument probes.

(5) Minimum ambient air quality monitoring network requirements used to provide support to the State implementation plans (SIP), national air quality assessments, and policy decisions. These minimums are described

as part of the network design requirements, including minimum numbers and placement of monitors of each type. 

## §58.10

(6)Air qualitydata reporting, and re- quirements for the daily reporting of

an indexofambient air quality.

(b) The requirements pertaining to provisions for an air quality surveillance system in the SIP are contained inthispart.

(c) This part also acts to establish a national ambient air quality monitoring network for the purpose of providing timely air quality data upon which tobase national assessments and policy decisions.

§58.3 Applicability.

Thispart applies to: (a) State air pollution control agencies.

(b) Any local air pollution control agency to which the State has delegated authority to operate aportion of the State's SLAMS network.

(c) Owners or operators of proposed

sources.



## Subpart B-Monitoring Network

SOURCE: 

### 71 FR 61298, Oct. 17, 2006, unless otherwise noted.

§58.10 Annual monitoring network plan and periodic network assess- ment. (a)(1) Beginning July 1, 2007, the State, or where applicable local, agency shall adopt and submit to the Regional Administrator an annual monitoring network plan which shall provide forthe establishment and mainte-

nance of an air quality surveillance system that consists of a network of SLAMS monitoring stations including FRM, FEM, and ARM monitors that

are part of SLAMS, NCore stations, STN stations, State speciation stations, SPM stations,.and/or, in serious,

severe and extreme ozone nonattainment areas, PAMS stations, and SPM monitoring stations. The plan shall include a statement of purposes for each monitor and evidence that siting and operation of each monitor meets the requirements of appendices A, C, D, and E of this part, where applicable. The annual monitoring network plan
must be made available for public inspection for at least 30 days prior to submission to EPA.



## 249

### 40 CFRCh. I(7-1-12 Edition)

(2) Any annual monitoring network plan that proposes SLAMS network modifications including new monitoring sites is subject to the approval of the EPA Regional Administrator, who shall provide opportunity for public comment and shall approve or disapprove the plan and schedule within 120 days. If the State or local agency has already provided a public comment opportunity on its plan and has made

no changes subsequent to that com- ment opportunity, and has submitted the received comments together with the plan, the Regional Administrator is not required to provide a separate opportunity forcomment.

(3)The plan for establishing required NCore multipollutant stations shall be submitted to the Administrator not later than July 1,2009. The plan shall provide for all required stations to be operational by January 1,2011.

(4)A plan for establishing source-oriented Pb monitoring sites in accord-

ance with therequirements ofappendix D to this part for Pb sources emitting 1.0 tpy orgreater shallbe submitted to the EPA Regional Administrator no later than July 1, 2009, as part of the annual network plan required in paragraph (a)(1) of this section. The plan shall provide for the required source- oriented Pb monitoring sites for Pb

sources emitting 1.0 tpy or greater to be operational by January 1, 2010. A plan for establishing source-oriented Pbmonitoring sitesin accordance with the requirements ofappendix D to this part for Pb sources emitting equal to

or greater than 0.50 tpy but less than 1.0 tpy shall be submitted to the EPA Regional Administrator no later than July 1, 2011. The plan shall provide for the required source-oriented Pb monitoring sites for Pb sources emitting equal to or greater than 0.50 tpy but less than 1.0 tpy to be operational by December 27, 2011.

(5)A plan for establishing NO2

### monitoring sites in accordance with the re- quirements of appendix D to this part shall be submitted to the Administrator by July 1, 2012. The plan shall provide for all required monitoring stations to be operational by January 1, 2013.

(6)A plan for establishing S02 

### monitoring sites in accordance with the requirements of appendix D to this part shall be submitted to the EPA Regional Administrator by July 1, 2011 as part of the annual network plan re- quired in paragraph (a) (1). The plan shallprovide for all required SO2

### monitoring sites to be operational by January 1,2013.

(7) A plan for establishing CO monitoring sites in accordance with the re- quirements of appendix D to this part shall be submitted to the EPA Regional Administrator. Plans for re- quired CO monitors shall be submitted at least six months prior to the date such monitors must be established as required by section58.13.

(b) The annual monitoring network plan must contain the following information for each existing and proposed site:

(1) The AQS site identification num- ber.

(2) The location, including street address and geographical coordinates.

(3) The sampling and analysis method(s)for each measured parameter.

(4) The operating schedules for each monitor.

(5)Any proposals to remove or move
a monitoring station within a period of 18 months following plan submittal.

(6) The monitoring objective and spatial scale of representativeness for each monitor as defined in appendix D to thispart.

(7) The identification of any sites that are suitable and sites that are not suitable for comparison against thean- nual PM 2

### .

5 

### NAAQS as described in 

### §58.30.

(8) The MSA, CBSA, CSA or othei

arearepresented by the monitor.

(9) The designation of any Pb monitors as either source-oriented or non- source-oriented according to Appendix D to40 CFR part 58.

(10) Any source-oriented monitors for which a waiver has been requested or granted by the EPA Regional Administrator as allowed for under paragraph 4.5(a)(ii) ofAppendix D to 40 CFR part 58.

(11) Any source-oriented or non- source-oriented site for which a waiver has been requested or granted by the EPA Regional Administrator for the

use of Pb-PMo monitoring in lieu of Pb-TSP monitoring as allowed for



## 250 §58.10

## Environmental ProtectionAgency

under paragraph 2.10 of Appendix C to 40 CFR part58.

(12) The identification of required NO2 

### monitors as either near-road or area-wide sites in accordance with appendix D, section 4.3 ofthispart.

(c) The annual monitoring network plan must document how States and local agencies provide for the review of changes to a PM 2

### .5

### monitoring network that impact the location of a violating PM2
. 5 

### monitor or the creation/change to a community monitoring zone, including a description of the proposed

use ofspatial averaging for purposes of making comparisons to the annual PM2

### . 5 

### NAAQS as set forth in appendix N-to part 50 of this chapter. The affected State or local agency must document the process for obtaining public
comment and include any comments received through the public notification process within their submitted plan.

(d) The State, or where applicable local, agency shall perform and submit
to the EPA Regional Administrator an assessment of the air quality surveillance system every 5 years to determine, at a minimum, if the network meets the monitoring objectives defined in appendix Dto thispart,whethernew sites are needed, whether existing sites are no longer needed and can be terminated, and whether new technologies are appropriate for incorporation into the ambient air monitoring network. The network assessment must consider the ability of existing and proposed sites to support air quality characterization for areas with relatively high populations ofsusceptible individuals (e.g., children with asthma), and, for any sites that are being proposed for discontinuance, the effect

on data users other than the agency itself, such as nearby States and Tribes

or health effects studies. For PM 2

### . 5

### ,the assessment also must identify needed changes to population-oriented sites. The State, or where applicable local, agency must submit a copy of this 5- year assessment, along with a revised annual network plan, to the Regional Administrator. The first assessment is due July 1,2010.

(e) All proposed additions and discontinuations of SLAMS monitors in annual monitoring network plans 

## §58.11

and periodic network assessments are subject to approval according to 

### §58.14. [71 FR 61298, Oct. 17, 2006, as amended at 72 

### FR32210, June 12, 2007; 73 FR67059, Nov. 12, 2008; 73 FR 77517, Dec. 19, 2008; 75 FR 6534, Feb. 9,2010;75 FR 35601, June 22, 2010; 75FR 81137, Dec. 27, 2010; 76 FR 54341, Aug. 31, 2011]
§58.11 Network technical requirements. (a)(1) State and local governments shall follow the applicable quality as-
surance criteria contained in appendix A to this part when operating the SLAMS networks.

(2) Beginning January 1, 2009, State and local governments shall follow the quality assurance criteria contained in appendix A to this part that apply to SPM sites when operating any SPM site which uses a FRM, FEM, or ARM and meets the requirements of appendix E to this part, unless the Regional Administrator approves an alternative to the requirements ofappendix A with respect to such SPM sites because meeting those requirements would be physically and/or financially impractical due to physical conditions at the monitoring site and the requirements

are not essential to achieving the intended data objectives of the SPM site. Alternatives to therequirements ofappendix A may be approved for an SPM site as part of the approval of the annual monitoringplan, or separately.

(3)The owner or operator ofan existing or a proposed source shall follow thequality assurance criteria in appendix A to this part that apply to PSD monitoring when operating a PSD site.

(b) State and local governments must follow the criteria in appendixC to this part to determine acceptable monitoring methods or instruments for use in SLAMS networks. Appendix C criteria are optional at SPM stations.

(c) State and local governments must follow thenetwork design criteria contained in appendix D to this part in designing and maintaining the SLAMS stations. The final network design and all changes in design are subject to approval ofthe Regional Administrator. NCore, STN, andPAMS network design and changes are also subject to approval of the Administrator. Changes in SPM stations do notrequire approvals, but a change in the designation of



## 251

### 40 CFRCh. 1 (7-1-12 Edition)

a monitoring site from SLAMS to SPM requires approval of the Regional Administrator.

(d) State and local governments must follow the criteria contained in appendixE tothis part for siting monitor inlets, paths or probes at SLAMS stations. Appendix E adherence is optional for SPM stations.

§58.12 Operatingschedules.

State and local governments shall collect ambient air quality data at any SLAMS station on the following operational schedules:

(a) For continuous analyzers, con- secutive hourly averages must be collected except during:

(1)Periods ofroutine maintenance, (2)Periods ofinstrument calibration,

or(3)Periods or monitoring seasons ex- empted by the Regional Administrator.

(b) For Pb manual methods, at least

one 24-hour sample must be collected every 6 days except during periods or
seasons exempted by the Regional Administrator.

(c) For PAMS VOC samplers, samples must be collected as specified in sec- tion 5ofappendix D to this part.Areaspecific PAMS operating schedules must be included as part of the PAMS network description and must be approved by the Regional Administrator.

(d) For manual PM2

### . 5 

### samplers: (1)(i) Manual PM2

### . 5 

### samplers at re- quired SLAMS stations without a collocated continuously operating PM2

### . 5 

### monitor must operate on at least a 1- in-3 day schedule.

(ii) For SLAMS PM2

### . 5 

### sites with both manual and continuous PM2
. 5 

### monitors operating, the monitoring agency may request approval for a reduction to 1- in-6 day PM2

### . 5 

### sampling or for seasonal sampling from the EPA Regional Administrator. The EPA Regional Administrator may grant sampling frequency reductions after consideration of factors, including but not limited to the historical PM 2

### .5 

### data quality assess- ments, the location ofcurrent PM2

### .5

### design value sites, and their regulatory data needs. Required SLAMS stations whose measurements determine the design value for their area and that are within plus or minus 10 percent ofthe NAAQS; and all required sites where one or more 24-hour values have ex- ceeded the NAAQS each year for a con- secutive period of at least 3 years are required to maintain at least a 1-in-3 day sampling frequency. A continuously operating FEM or ARM PM 2

### .

5 

### monitor satisfies thisrequirement.

(iii)Required SLAMS stations whose measurements determine the design value for their area and that arewithin plus or minus 5 percent of the daily PM2

### . 5 

### NAAQS must have an FRM or FEM operate on a daily schedule. A continuously operating FEM or ARM PM 2

### .

5 

### monitor satisfies this requirement.

(2) Manual PM2

### . 5 

### samplers at NCore stations and required regional background and regional transport sites must operate on at least a 1-in-3 day samplingfrequency.

(3) Manual PM 2

### .

5 

### speciation samplers at STN stations must operate on at leasta 1-in-3 day sampling frequency.

(e) For PM1

### osamplers, a 24-hour sam- ple must be taken from midnight to midnight (local standard time) to en-
sure national consistency. The minimum monitoring schedule for the site in the area of expected maximum con- centration shall be based on the relative level ofthat monitoring site con- centration with respect to the 24-hour standard as illustrated in Figure 1. If the operating agency demonstrates by monitoring data that during certain periods of the year conditions preclude violation of the PM 1

### o24-hour standard, the increased sampling frequency for those periods or seasons may be ex- empted by the Regional Administrator andpermitted torevert back toonce in six days. The minimum sampling schedule for all other sites in the area remains once every six days. No less frequently than as part of each 5-year network assessment, the most recent year ofdata mustbe considered to estimate the air quality status at the site

near the area of maximum concentration. Statistical models such as analysis of concentration frequency distributions as described in "Guideline for the Interpretation of Ozone Air Quality Standards," EPA-450/479-003, U.S. Environmental Protection Agency, Research Triangle Park, NC, January 1979, should be used. Adjustments to the monitoring schedule must be



### 252 §58.12

## Environmental ProtectionAgency

made on the basis of the 5-year network assessment. The site having the highest concentration in the most cur- rent year must be given first consideration when selecting the site for the

more frequent sampling schedule. Other factors such as major change in

sources of PM10 

### emissions or in sam- pling site characteristics could influ-

ence the location of the expected max- imum concentration site. Also, the use of the most recent 3 years of data might, in some cases, be justified in order to provide a more representative database from which to estimate cur- rent air quality status and to provide stability to the network. This 

## § 58.13

multiyear consideration reduces the possibility of an anomalous year biasing a site selected for accelerated sampling. If the maximum concentration site based on the most current year is
not selected for the more frequent operating schedule, documentation ofthe justification for selection of an alternative site must be submitted to the Regional Office for approval duringthe 5-year network assessment process. Minimum data completeness criteria, number ofyears of data and sampling frequency for judging attainment of the NAAQS are discussed inappendix K ofpart50 ofthischapter.



## EverySixthDay 

# I Every OtherDay 

# EveryDay

0.8 0.9 1.0 1.1 1.2 1.3 1.4



# Figure 1

- Ratioto Standard

(f) For manual PM, 2

### . 5 

### samplers: (1)Manual PM 1

### o-2.s samplers at NCore stations must operate on at least a 1- in-3 day schedule at sites without a collocated continuously operating federal equivalent PM1

### o-2.5 

### method that has been designated inaccordance with part 53 ofthischapter.

(2) Manual PM 1

### o-

2

### .

5 

### speciation samplers at Nore stations must operate

on at least a 1-in-3 day sampling frequency.

(g) For continuous SO2 

### analyzers, the maximum 5-minute block average concentration of the twelve 5-minute blocks in each hour must be collected except as noted in

## §58.12(a).

[71 FR 61298, Oct. 17, 2006, as amended at 72 

### FR 32210, June 12, 2007; 75FR 35601, June 22, 2010]


### §58.13 Monitoring network comple- tion. (a) The network of NOore multipollutant sites must be physically established no later thanJanuary 1,2011, and at thattime, operating under all of the requirements of this part, including the requirements of appendices A, C, D, E, and G to thispart. NCore sites required to conduct Pb monitoring as required under 40 CFR part 58 appendix


## 253

### 40CFRCh. 1 (7-1-12 Edition)

D paragraph 3(b), or approved alternative non-source-oriented Pb monitoring sites, shall begin Pbmonitoring in accordance with all of the requirements of this part, including the requirements of appendices A, C, D, E, and G to this part no later than December 27, 2011.

(b) Not withstanding specific dates included in this part, beginning January 1,2008, when existing networks are not in conformance with the minimum number of required monitors specified in this part, additional required monitors must be identified in the next applicable annual monitoring network plan, with monitoring operation beginning by January 1 of the following year. To allow sufficient time to prepare and comment on Annual Monitoring Network Plans, only monitoring requirements effective 120 days prior to the required submission date of the plan (i.e., 120 days prior to July 1 of each year) shall be included in that year's annual monitoring network plan.

(c) The network of NO2 

### monitors mustbe physically established no later than January 1,2013, and at that time, must be operating under all of the re- quirements of this part, including the requirements of appendices A, C, D, andEto this part.

(d) The network of S02 

### monitors
mustbe physically established no later than January 1,2013, and at that time, must be operating under all of the requirements of this part, including the requirements of appendices A, C, D, andE to thispart.

(e) The CO monitors required under Appendix D, section 4.2 of this part must be physically established and operating under all of the requirements of this part, including the requirements of appendices A, C, D, and E to thispart,no later than:

(1)January 1,2015 for CO monitors in CBSAs having 2.5 million persons or more; or

(2)January 1,2017 for other CO mon- itors. [71 FR 61298, Oct. 17, 2006, as amended at 73 FR 67059, Nov. 12, 2008; 75 FR 6534, Feb. 9, 2010; 75 FR 35601, June 22, 2010; 75 FR 81137, Dec.27, 2010;76 FR54341, Aug.31, 2011] §58.14 System modification. (a) The State, or where appropriate local, agency shall develop and implement a plan and schedule tomodify the ambient air quality monitoring network that complies with the findings of the network assessments required every 5years by 

### §58.10(e). The State or local agency shall consult with the EPA Regional Administrator during the development of the schedule to modify the monitoring program, and shall make theplan and schedule available to the public for 30 days prior to submission to the EPA Regional Administrator. The final plan and schedule with respect to the SLAMS network are subject to the approval ofthe EPA Regional Administrator. Plans containing modifications toNCore Stations or PAMS Stations shall be submitted to the Administrator. The Regional Administrator shall provide.opportunity forpublic comment and shall approve or disapprove submitted plans and schedules within 120 days.

(b) Nothing in this section shall preclude the State, or where appropriate local, agency from making modifications to the SLAMS network for reasons other than those resulting from the periodic network assessments. These modifications must be reviewed and approved by theRegional Administrator. Each monitoring network may make or be required to make changes between the 5-year assessment periods, including for example, site relocations

or the addition of PAMS networks in bumped-up ozone nonattainment areas. These modifications must address changes invoked by a new census and changes due to changing air quality levels. The State, or where appropriate local, agency shall provide written communication describing the network changes to the Regional Administrator for review and approval as these changes are identified.

(c) State, or where appropriate, local agency requests for SLAMS monitor station discontinuation, subject to the review of the Regional Administrator, will be approved if any of the following criteria are met and if the requirements of appendix D to this part, if any, continue to be met. Other re- quests for discontinuation may also be



### 254 §58.14

## Environmental ProtectionAgency

approved on a case-by-case basis ifdiscontinuance does not compromise data collection needed for implementation of a NAAQS and ifthe requirements of appendix D to this part, if any, continue to be met.

(1) Any PM 2

### .

5

### , 03, CO, PM 10

### , SO2

### ,

## Pb,

or NO2 

### SLAMS monitor which has shown attainment during the previous five years, that has a probability of less than 10 percent ofexceeding 80 percent of the applicable NAAQS during the next three years based on the levels, trends, and variability observed in the past, and which is not specifically required by an attainment plan or maintenance plan. In a nonattainment

or maintenance area, if the most recent attainment or maintenance plan adopted by the State and approved by EPA contains a contingency measure to be triggered by an air quality concentration and the monitor to be discontinued is the only SLAMS monitor operating in the nonattainment or maintenance area, the monitor may not be discontinued.

(2) Any SLAMS monitor for CO, PM 10

### , SO2, 

### or NO2 

### which has consistently measured lower concentrations than another monitor for the same pollutant in the same county (or portion of a county within a distinct attainment area, nonattainment area, or maintenance area, as applicable) during the previous five years, and which is not specifically required by an attainment plan or maintenance plan, if control measures scheduled to be implemented or discontinued during the
next five years would apply to the

areas around both monitors and have similar effects on measured concentrations, such that the retained monitor would remain the higherreading ofthe two monitorsbeing compared.

(3) For any pollutant, any SLAMS monitor in a county (or portion of a county within a distinct attainment, nonattainment, or maintenance area,
as applicable) provided the monitorhas
not measured violations ofthe applicable NAAQS in the previous five years, and the approved SIP provides for a specific, reproducible approach to representing the air qualityofthe affected county in the absence of actual monitoring data. 

## §58.15

(4) A PM2

### .5 

### SLAMS monitor which EPA has determined cannot be com- pared to the relevant NAAQS because of the siting of the monitor, in accordance with §58.30.

(5) A SLAMS monitor that is designed to measure concentrations upwind ofan urban area forpurposes of characterizing transport into the area and that has not recorded violations of the relevant NAAQS in the previous five years, if discontinuation of the monitor is tied to start-up of another station alsocharacterizing transport.

(6)A SLAMS monitor not eligible for removal under any of the criteria in paragraphs (c)(1) through (c)(5) of this sectionmay be moved toa nearby location with the same scale ofrepresentation if logistical problems beyond the State's control make it impossible to continue operation at itscurrent site.

§58.15 Annual airmonitoring data cer- tification. (a) The State, or where appropriate local, agency shall submit to the EPA Regional Administrator an annual air monitoring data certification letter to certify data collected at all SLAMS and at all FRM, FEM, and ARM SPM stations that meet criteria in appendix A to this part from January 1 to December 31 of the previous year. The senior air pollution control officer in each agency, or his or her designee, shall certify that the previous year of ambient concentration and quality assurance data are completely submitted
to AQS and that the ambient con- centration data are accurate to the best of her or his knowledge, taking into consideration the quality assur-
ance findings.

(1)Through 2009, the annual data cer- tification letter is due by July 1 of each year.

(2) Beginning in2010, the annual data certification letter is due by May 1 of each year.

(b) Along with each certification letter, the State shall submit to the Administrator (through the appropriate Regional Office) an annual summary report of all the ambient air quality data collected at all SLAMS and at SPM stations using FRM, FEM, or ARMs. The annual report(s) shall be



## 255

### 40 CFRCh. I(7-1-12 Edition)

submitted for data collected from January 1 to December 31 of the previous year. The annual summary report(s) must contain all information and data required by the State's approved plan and must be submitted on the same schedule as the certification letter, un- less an approved alternative date is included in the plan. The annual summary serves as the record of the specific data that is the object ofthe cer- tification letter.

(c) Along with each certification letter, the State shall submit to the Administrator (through the appropriate Regional Office) a summary ofthe precision and accuracy data for all ambient air quality data collected at all SLAMS and at SPM stations using FRM, FEM, or ARMs. The summary of precision and accuracy shall be submitted for data collected from January 1 to December 31 of the previous year. The summary of precision and accu- racy must be submitted on the same schedule as the certification letter,un- less an approved alternative date is included intheplan.

§58.16 Data submittal and archiving requirements. (a) The State, or where appropriate, local agency, shall report to the Administrator, via AQS all ambient air quality data and associated quality as-
surance data for SO2; CO; 

### 03; NO2

### ;NO; NOv; NOx; Pb-TSP mass concentration; Pb-PMIO mass concentration; PMo

mass concentration; PM 2

### .

5

### mass con- centration; for filter-based PM 2

### .sFRM/ FEM the field blank mass, samplergenerated average daily temperature, and sampler-generated average daily pressure; chemically speciated PM 2

### . 5 

### mass concentration data; PMIO-2.5

### mass concentration; chemically speciated PM 1

### o-2.5 

### mass concentration data; me- teorological data from NCore and PAMS sites; average dailytemperature and average daily pressure for Pb sites if not already reported from sampler generated records; and metadata records and information specified by the AQS Data Coding Manual (http:// www.epa.gov/ttn/airs/airsaqs/manuals/ manuals.htm). The State, or where appropriate, local agency, may report site specific meteorological measure- ments generated by onsite equipment (meteorological instruments, or sampler generated) or measurements from the nearest airport reporting ambient pressure and temperature. Such air quality data and information must be submitted directly to theAQS via electronic transmission on the specified quarterly schedule described in paragraph (b) ofthis section.

(b) The specific quarterly reporting periods are January 1-March 31, April 1-June 30, July 1-September 30, and October 1-December 31. The data and information reported for each reporting period must contain all data and information gathered during the reporting period, and be received in the AQS within 90 days after the end of the quarterly reporting period. For example, the data for the reporting period January 1-March 31 are due on or before June 30 ofthat year.

(c) Air quality data submitted for each reporting period must be edited, validated, and entered into the AQS (within the time limits specified in paragraph (b) ofthis section) pursuant to appropriate AQS procedures. The procedures for editing and validating data are described in the AQS Data Coding Manual and in each monitoring agency's quality assurance project plan.

(d) The State shall report VOC and if collected, carbonyl, NH3

### , and HNO3 

### data, fromPAMS sitesto AQS within6 months following the end ofeach quarterly reporting period listed in paragraph (b) ofthis section.

-(e) The State shall also submit any portion or all of the SLAMS and SPM data to the appropriate Regional Administrator uponrequest.

(f) The State, or where applicable, local agency shall archive all PM 2

### .5

### , PMao, and PMIO-2.5 

### filters 

### from manual low-volume samplers (samplers having flow rates less than 200 liters/minute) from all SLAMS sites for a minimum period of 1 year after collection. These filters shall be made available during the course of that year for supplemental analyses at the request of EPA

or to provide information to State and local agencies on particulate matter composition. Other Federal agencies



### 256 §58.16

## Environmental ProtectionAgency

may request access to filters for purposes ofsupporting airquality management or communityhealth-such asbiological assay-through the applicable EPA Regional Administrator. The filters shall be archived according to procedures approved by the Administrator. The EPA recommends that particulate matter filters be archived for longer periods, especially for key sites in making NAAQS related decisions or for supporting health-related airpollution studies.

(g) Any State or, where applicable, local agency operating a continuous SO
2 

### analyzer shallreport the maximum 5-minute SO2 

### block average of the twelve 5-minute block averages in each hour, inaddition to the hourly SO2 

### average. [71 FR 61298, Oct. 17, 2006, as amended at 73 FR 67059, Nov. 12, 2008; 75 FR 6534, Feb. 9, 2010; 75FR35602,June 22,2010] 

## SubpartC-Special Purpose Monitors

SOURCE: 71 FR 61302, Oct. 17, 2006, unless otherwise noted. 

### §58.20 Special purpose monitors (SPM). (a)An SPMis defined as any monitor included in an agency's monitoring network that the agency has designated as a special purpose monitor in its annual monitoring network plan and in AQS, and which the agency does not count when showing compliance with the minimum requirements of this subpart for the number and siting ofmonitors ofvarious types. Any SPM operated by an air monitoring agency mustbe includedin theperiodic assess- ments and annual monitoring network plan required by 

### § 58.10. The plan shall include a statement of purposes for each SPM monitor and evidence that operation of each monitor meets the requirements of appendix A or an approved alternative as provided by §58.11(a)(2) where applicable. The monitoring agency may designate amonitor

as an SPM after January 1,2007 only if it is a new monitor, i.e., a SLAMS monitor that isnotincluded in the cur- rently applicable monitoring plan or, for a monitor included in the monitoring plan prior to January 1,2007, if 

### §58.20

the Regional Administrator has approved the discontinuation of themonitor asa SLAMS site.

(b) Any SPMdata collected by an air monitoring agency using a Federal reference method (FRM), Federal equivalent method (FEM), or approved regional method (ARM) must meet the requirements of

### §58.11, §58.12, and appendix A tothis partor an approved alternative to appendix A to this part. Compliance with appendix E to this part is optional but encouraged except when the monitoring agency's data objectives are inconsistent with thoserequirements. Data collected at an SPM using a FRM, FEM, or ARM meeting the requirements of appendix A must be submitted to AQS according to the requirements of 

### §58.16. Data collected by other SPMs may be submitted. The monitoring agency must also submit to 

### AQS an indication of whether each SPM reporting data to AQS monitor meets the requirements of appendices A andEtothis part.

(c) All data from an SPM using an FRM, FEM, or ARM which has operated for more than 24 months is eligible for comparison to the relevant NAAQS, subject to the conditions of 

### §58.30, unless the air monitoring agency demonstrates that the data came from a particular period during which the requirements ofappendix A, appendix C, or appendix E to this part were notmet inpractice.

(d) Ifan SPM using an FRM, FEM, or ARM is discontinued within 24 months of start-up, the Administrator will not base a NAAQS violation determination for thePM2

### . 5 

### or ozone NAAQS solely on data fromthe SPM.

(e) Ifan SPM using an FRM, FEM, or ARM is discontinued within 24 months of start-up, the Administrator will not designate an area as nonattainment for the 

### CO, S02, 

### NO2

### , or 24-hour PM 10 

### NAAQS solely onthe basis ofdatafrom the SPM. Such data are eligible for use in determinations of whether a nonattainment area has attained one of these NAAQS.

(f)Priorapproval fromEPA is notrequired for discontinuance ofan SPM.
[71 FR 61298, Oct. 17, 2006, as amended at 72 

### FR 32210, June 12, 2007; 73 FR 67060, Nov. 12, 2008]



### 257

## 40CFRCh. 1 (7-1-12 Edition) SubpartD-National Air Monitoring Stations(NAMS)

SOURCE: 71 FR 61302, Oct. 17, 2006, unless otherwisenoted.



### § 58.30 Special considerations for data comparisons totheNAAQS. (a) Comparability of PM 2

### . 5 

### data. (1) There are two forms of the PM2

### . 5 

### NAAQS described in part 50 of this chapter. The PM2

### . 5 

### monitoring site characteristics (see appendix D to this part, section 4.7.1) impact how the re- sulting PM2

### . 5 

### data can be compared to the annual PM 2

### .5 

### NAAQS form. PM 2

### .

5 

### data that are representative, not of areawide but rather, of relatively unique population-oriented microscale,

or localized hot spot, or unique population-oriented middle-scale impact sites are only eligible for comparison
to the 24-hour PM 2

### .

5 

### NAAQS. Forexam- ple, ifthePM 2

### .

5

### monitoring site is adjacent to a unique dominating local PM2

### .5 

### source or can be shown to have average 24-hour concentrations representative ofa smaller than neighborhood spatial scale, then data from a monitor at the site would onlybe eligible for comparison to the 24-hour PM 2

### .

5 NAAQS.



### (2)There are cases where certain population-oriented microscale or middle scale PM2

### . 5 

### monitoring sites are determined by the Regional Administrator to collectively identify a larger region of localized high ambient PM 2

### .

5 

### con- centrations. In those cases, data from these population-oriented sites would be eligible for comparison to the an- nual PM 2

### .5

### NAAQS. (b) [Reserved] 

## Subpart E[Reserved] Subpart F-AirQuality Index Reporting

§58.50 Index reporting.

(a) The State or where applicable, local agency shall report to the general 

### public on a daily basis through prominent notice an air quality index that complies with the requirements of appendix Gto thispart. (b) Reporting is required for all individual MSA with a population exceeding350,000.

(c) The population ofa MSA for purposes ofindexreporting is the mostre- cent decennial U.S. census population. [71FR 61302,Oct. 17, 2006]



## Subpart G-Federal Monitoring

SOURCE: 44 FR 27571, May 10, 1979, unless otherwise noted. Redesignated at 58 FR 8467, Feb. 12, 1993.


### §58.60 Federal monitoring.

The Administrator may locate and operate an ambient air monitoring site if the State or local agency fails to locate, or schedule to be located, during the initial network design process, or
as a result of the 5-year network as- sessments required in 

### §58.10, a SLAMS station at a site which is necessary in thejudgment ofthe Regional Administratorto meet the objectives defined in appendix D tothis part. [71 FR61303, Oct. 17, 2006]


### §58.61 Monitoring otherpollutants.

The Administrator may promulgate criteria similar to that referenced in subpart B ofthis part.for monitoring a pollutant forwhich an NAAQS does not exist. Such an action would be taken whenever the Administrator determines that a nationwide monitoring program is necessary to monitor such a pollutant.
[71 FR61303, Oct. 17, 2006]

APPENDIX A TO PART 58-QUALITY ASSURANCE REQUIREMENTS FOR 

### SLAMS, SPMS AND PSD AIR MONITORING

1. General Information 2. Quality System Requirements 3. Measurement Quality Check Requirements 4. Calculations for Data Quality Assessments 5. Reporting Requirements 6. References

1.GeneralInformation. This appendix specifies theminimum quality system requirements applicable to SLAMS air monitoring data and PSD data for the pollutants SO2, NO2, 03, CO, Pb, PM2 . 5, PM 10 and PMI 2. 5 submitted to EPA. This appendix also applies to all SPM stations using FRM, FEM, or ARM methods


## 258 

## §

58.30

## Environmental ProtectionAgency

which also meet the requirements ofAppendix E of thispart. Monitoring organizations

are encouraged to develop and maintain quality systems more extensive than the required minimums. The permit-granting authority for PSD may require more frequent

or more stringent requirements. Monitoring organizations may, based on their quality objectives, develop and maintain quality systems beyond the required minimum. Additional guidance for the requirements reflected in this appendix can be found in the "Quality Assurance Handbook for Air Pollution Measurement Systems", volume II,part 1(see reference 10 ofthis appendix) and at a national level in references 1,2,and 3 ofthis appendix.

1.1 Similarities and Differences Between SLAMS and PSD Monitoring. In most cases, the quality assurance requirements for SLAMS, SPMsifapplicable, and PSD arethe

same. Affected SPMs are subject to all the SLAMS requirements, even where not specifically stated in each section. Table A-1 of this appendix summarizes the major similarities and differences ofthe requirements for SLAMS and PSD. Bothprograms require:

(a) The development, documentation, and implementation ofan approved quality system;

(b)The assessment ofdata quality; (c) The use ofreference, equivalent, or approved methods. The requirements of this appendix do not apply to a SPM that does not usea FRM, FEM, orARM;

(d) The use ofcalibration standards traceable toNIST orother primary standard;

(e) Performance evaluations and systems. 1.1.1 The monitoring and quality assurance responsibilities for SLAMS are withthe State or local agency, hereafter called the monitoring organization, whereas for PSD they are with the owner/operator seeking the permit. The monitoring duration for SLAMS is indefinite, whereas for PSD the durationis usually 12 months.Whereas the reportingperiod forprecision and accuracy data is on an annual or calendar quarter basisfor SLAMS, it is on a continuing sampler quarter basis for PSD, since the monitoring may not com-
mence at the beginning of a calendar quarter.

1.1.2 The annual performance evaluations (described in section 3.2.2 of this appendix) for PSD mustbe conducted by personnel different from those who perform routine span checks andcalibrations, whereasfor SLAMS, it isthe preferred butnot the requiredcondition. For PSD, theevaluation rate is 100 percent ofthe sitesper reportingquarter whereas for SLAMS it is 25 percent ofthe sites or instruments quarterly. Monitoring for sulfur dioxide (SO 2) and nitrogen dioxide (NO2) for PSD must be done with automated analyzers--the manual bubbler methods are not permitted. 

## Pt.58, App.A

1.1.3 The requirements for precision as- sessment for the automated methods are the

same forboth SLAMS and PSD. However, for manual methods, only one collocated site is requiredfor PSD.

1.1.4 The precision, accuracy and bias data for PSD are reported separately for each sampler (site), whereas for SLAMS, the report may be by sampler (site), by primary quality assurance organization, or nationally, depending on the pollutant. SLAMS data are required to be reported to theAQS, PSD data are required to be reported to the permit-granting authority. Requirements in this appendix, with the exception of the differences discussed in this section, and in Table A-1 of this appendix will be expected
tobe followed by both SLAMS and PSD networks unless directly specified in a particular section.

1.2 Measurement Uncertainty. Measurement uncertainty is a term used to describe deviations from a true concentration or estimate that are related to the measurement process and not to spatial ortemporal population attributes ofthe air being measured. Monitoring organizations must develop quality assurance project plans (QAPP) which describe how the organization intends to con- trol measurement uncertainty to an appropriate level in order to achieve the objectives for which the data are collected. The process by which one determines the quality ofdata needed tomeet the monitoring objective is sometimes referred to the Data Quality Objectives Process. Data quality indicators associated with measurement uncertainty include:

(a) Precision. A measurement of mutual agreement among individual measurements of the same property usually under prescribed similar conditions, expressed generally interms ofthe standard deviation.

(b) Bias. The systematic or persistent distortion of a measurement process which

causes errorsin one direction.

(c) Accuracy. The degree ofagreement between an observed value and an acceptedreference value. Accuracy includes a combination of random error (imprecision) and systematic error (bias) components which are due to sampling and analytical operations.

(d) Completeness.A measure ofthe amount of valid data obtained from a measurement system compared tothe amount thatwas expected to be obtained under correct, normal conditions.

(e) Detectability. The low critical range value of a characteristic that a method specific procedure can reliably discern.

1.3 Measurement Quality Checks. The SLAMS measurement quality checks described in sections 3.2 and 3.3 of this appendix shall bereported toAQS andare included in the data required for certification. The PSD network is required to implement the
measurement quality checks and submit this



## 259

### Pt.58, App.A

information quarterly along with assessment information to the permit-granting authority.

1.4 Assessments and Reports. Periodic as- sessments and documentation of data quality are required to be reported to EPA or to thepermit granting authority(PSD). Toprovide national uniformity in this assessment and reporting of data quality for all networks, specific assessment and reporting procedures are prescribed in detail in sec- tions 3, 4, and 5 of this appendix. On the other hand, the selection and extent of the quality assurance and quality controlactivities used by a monitoring organization depend on a number of local factors such as field and laboratory conditions, the objectives for monitoring, the level of data quality needed, the expertise of assigned personnel, the cost of control procedures, pollutant concentration levels, etc. Therefore, quality system requirements in section 2 of this appendix are specified in general terms to alloweach monitoring organization to develop a quality system thatis most efficient and effective for itsown circumstances while achieving the data quality objectives re- quired for the SLAMS sites.

2.QUALITY SYSTEMREQUIREMENTS
A quality system is themeans by which an organization manages the quality of the monitoring information it.produces in a systematic, organized manner. It provides a framework for planning, implementing, as- sessing and reporting work performed by an organization and for carrying out required quality assurance andquality control activities.

2.1 Quality Management Plans and Quality Assurance Project Plans. All monitoring organizations must develop a quality system that is described and approved in quality management plans (QMP) and quality assur-
ance project plans (QAPP) to ensure that the monitoring results:

(a) Meet a well-defined need, use, or purpose;

(b) Provide data ofadequate quality forthe intended monitoring objectives;

(c) Satisfy stakeholder expectations; (d) Comply with applicable standards specifications;

(e) Comply with statutory (and other) re- quirements ofsociety; and

(f) Reflect consideration of cost and eco- nomics.

2.1.1 The QMP describes the quality system interms ofthe organizational structure, functional responsibilities of management and staff, lines of authority, and required interfaces for those planning, implementing, assessing and reporting activities involving environmental data operations (EDO). The QMP must be suitably documented in ac- cordance withEPArequirements (reference 2 ofthis appendix), and approved by the appro

### 40 CFRCh. I(7-1-12 Edition)

priate Regional Administrator, orhis orher representative. The quality system will be reviewed during the systems audits described in section 2.5 ofthis appendix. Organizations that implement long-term monitoring programs with EPA funds should have a separate QMP document. Smaller organizations

or organizations that do infrequent work with EPA funds may combine theQMP with the QAPP based on negotiations with the funding agency. Additional guidance on this process can be found in reference 10 of this appendix. Approval oftherecipient's QMPby the appropriate Regional Administrator or his or her representative, may allow delegation ofthe authority to review and approve the QAPP to the recipient, based on adequacy of quality assurance procedures described and documented in the QMP. The QAPP will be reviewed by EPA during systems audits or circumstances related todata quality.

2.1.2 The QAPP is a formal document describing, in sufficient detail, the quality system that must be implemented to ensure that the results ofwork performed will satisfy thestated objectives. The quality assur-
ance policy ofthe EPA requires every environmental data operation (EDO) to have a written and approved QAPP prior to the start of the EDO. It is the responsibility of the monitoring organization to adhere to this policy. The QAPP mustbe suitably documented in accordance with EPA requirements (reference 3ofthis appendix).

2.1.3 The monitoring organization's quality system must have adequate resources both inpersonnel andfunding to plan, implement, assess and report on the achievement ofthe requirements ofthis appendix and its approved QAPP.

2.2 Independence of Quality Assurance. The monitoring organization must provide for a quality assurance management function- that aspect ofthe overall management system ofthe organization that determines and implements thequality policy defined in a monitoring organization's QMP. Quality management includes strategic planning, allocation of resources and other systematic planning activities (e.g., planning, implementation, assessing and reporting) pertaining to the quality system. The quality assurance management function must have sufficient technical expertise and management authority to conduct independent oversight and assure the implementation of the organization's quality system relative to the ambient air quality monitoring program and should be organizationally independent ofenvironmental data generation activities.

2.3. Data Quality Performance Requirements.

2.3.1 Data Quality Objectives. Data quality objectives (DQO) or the results of other systematic planning processes are statements that define the appropriate type of



### 260

## Environmental ProtectionAgency

data to collect and specify the tolerable levels of potential decision errors that will be used as a basis for establishing the quality and quantity of data needed to support the objectives of the SLAMS stations. DQO will be developed byEPA to support the primary SLAMS objectives for each criteria pollutant.As they are developed they will be added to the regulation. DQO or the results of other systematic planning processes for PSD

or other monitoring will be the responsibility of the monitoring organizations. The quality of the conclusions made from data interpretation can be affected by population uncertainty (spatial or temporal uncertainty) and measurement uncertainty (uncertainty associated with collecting, ana- lyzing, reducing and reporting concentration data). This appendix focuses on assessing and controlling measurement uncertainty.

2.3.1.1 Measurement Uncertainty for Automated and Manual PM 2. 5 Methods. The goal for acceptable measurement uncer- tainty is defined as 10 percent coefficient of variation (CV) fortotal precision andplus or minus 10 percent for total bias.

2.3.1.2 Measurement Uncertainty for Automated Ozone Methods. The goal for ac- ceptable measurement uncertainty isdefined for precision as an upper 90 percent confidence limit for the coefficient variation (CV) of7 percent and forbias as anupper 95 percent confidence limit for the absolute bias of7percent.

2.3.1.3 Measurement Uncertainty for PMO 25 Methods. The goal for acceptable measurement uncertainty is defined for precision as an upper 90 percent confidence limit for the coefficient variation (CV) of15 percent and for bias as an upper 95 percent confidence limit for the absolute bias of 15 percent.

2.3.1.4 Measurement Uncertainty for Pb Methods. The goal for acceptable measure- ment uncertainty is defined for precision as
an upper 90 percent confidence limit for the coefficient variation (CV) of 20 percent and for bias as an upper 95 percent confidence limit forthe absolute biasof15percent.

2.3.1.5 Measurement Uncertainty for NO2. The goal for acceptable measurement uncer- tainty is defined forprecision as an upper90 percent confidence limit for the coefficient ofvariation (CV) of 15percent and forbiasas
an upper 95 percent confidence limit for the absolute biasof15percent.

2.3.1.6 Measurement Uncertainty for SO 2 

### . The goal for acceptable measurement uncer- tainty for precision is defined asan upper 90 percent confidence limit for the coefficient ofvariation (CV) of10 percent and forbiasas
an upper 95 percent confidence limit for the absolute biasof10percent.

2.4 National Performance Evaluation Programs. Monitoring plans or the QAPP shall provide for theimplementation ofa program of independent and adequate audits of all 

## Pt.58,App.A

monitors providing data for SLAMS and PSD including theprovision ofadequate resources for such audit programs. A monitoring plan (or QAPP)which provides for monitoring or- ganization participation in EPA's National Performance Audit Program (NPAP) and the PM Performance Evaluation Program (PEP) program and which indicates the consent of the monitoring organization for EPA to apply an appropriate portion of.the grant funds, which EPA would otherwise award to the monitoring organization for monitoring activities, will be deemed by EPA to meet this requirement. For clarification and to participate, monitoring organizations should contact either the appropriate EPARegional Quality Assurance (QA) Coordinator at the appropriate EPARegional Office location, or the NPAP Coordinator atthe Air Quality Assessment Division, Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency in Research Triangle Park, North Carolina.

2.5 Technical Systems Audit Program. Technical systems audits ofeach ambient air monitoring organization shall be conducted
at least every 3 years by the appropriate EPA Regional Office and reported to the AQS. Systems audit programs are described in reference 10 ofthis appendix. For further instructions, monitoring organizations should contact the appropriate EPA Regional QACoordinator.

2.6 Gaseous and Flow Rate Audit Standards.

2.6.1 Gaseous pollutant concentration standards (permeation devices or cylinders ofcompressed gas) used to obtain test con- centrations for carbon monoxide (CO), sulfur dioxide (SO2),nitrogen oxide (NO), and nitrogen dioxide (NO2)mustbe traceable toeither

a National Institute ofStandards and Technology (NIST) Traceable Reference Material (NTRM) ora NIST-certified Gas Manufacturer's Internal Standard (GMIS), certified in accordance with one ofthe procedures given in reference 4 ofthis appendix. Vendors advertising certification with the procedures provided inreference 4 of this appendix and distributing gasses as "EPA Protocol Gas" must participate in the EPA Protocol Gas Verification Program or not use "EPA" in any form ofadvertising.

2.6.2 Test concentrations for ozone (03)
must be obtained in accordance with the ultra violet photometric calibration procedure specified in appendix D topart 50 ofthis chapter, or by means ofa certified 03 transfer standard. Consult references 7 and 8 of this appendix for guidance on primary and transfer standards for03.

2.6.3 Flow rate measurements must be made by a flow measuring instrument that is traceable to an authoritative volume or other applicable standard. Guidance for cer- tifying some types offlowmeters is provided inreference 10ofthisappendix.



## 261

### Pt.58, App.A

2.7 Primary Requirements and Guidance. Requirements and guidance documents for developing the quality system are contained in references 1 through 10 of this appendix, which also contain many suggested procedures, checks, and control specifications. Reference 10 of this appendix describes specific guidance for the development ofa quality system for SLAMS. Many specific quality control checks and specifications for methods are included in the respective reference methods described in part 50 of this chapter

or in the respective equivalent method descriptions available from EPA (reference 6 of this appendix). Similarly, quality control procedures related to specifically designated reference and equivalent method analyzers

are contained in the respective operation or instruction manuals associated with those analyzers.

3. MEASUREMENT QUALITY CHECK REQUIREMENTS
This section provides the requirements for primary quality assurance organizations (PQAOs) to perform the measurement quality checks that can be used to assess data quality. With the exception of the flow rate verifications (sections 3.2.3 and 3.3.2 of this appendix), data from these checks are re- quired to be submitted to the AQS within the same time frame asroutine ambient con- centration data. Section 3.2 ofthis appendix describes checks of automated or continuous instruments while section3.3 describe checks associated with manual sampling instruments. Other quality control samples are identified inthe various references described earlier and canbe used to control certain as- pects ofthe measurement system.

3.1 Primary Quality Assurance Organization. A primary quality assurance organization is defined as a monitoring organization

or a coordinated aggregation ofsuch organizations that is responsible for a set of stations that monitors the same pollutant and forwhich data quality assessments can logicallybe pooled. Each criteria pollutant sam- pler/monitor at a monitoring station in the SLAMS network must be associated with
one, and only one,primary quality assurance organization.

3.1.1 Each primary quality assurance or- ganization shall be defined such that meas- urement uncertainty among all stations in the organization can be expected to be rea- sonablyhomogeneous, as a result ofcommon factors. Common factors that should be con- sideredbymonitoring organizations indefining primary quality assurance organizations include:

(a) Operation by a common team of field operators according to a common set ofprocedures;

(b) Use of a common QAPP or standard operating procedures; 

### 40 CFRCh. 1(7-1-12 Edition)

(c) Common calibration facilities and standards;

(d) Oversight by a common quality assur-
ance organization; and

(e) Support by a common management, laboratory orheadquarters.

3.1.2 Primary quality assurance organizations are not necessarily related tothe organization reporting data to the AQS. Monitoring organizations having difficulty in defining the primary quality assurance organizations or in assigning specific sites to primary quality assurance organizations should consult with the appropriate EPA Regional Office. All definitions ofprimary quality as-
surance organizations shall be subject to final approval by the appropriate EPA Regional Office during scheduled network re- views or systems audits.

3.1.3 Data quality assessment results shall be reported as specified in section 5 of this appendix.

3.2 Measurement Quality Checks of Automated Methods. Table A-2 of this appendix provides a summary of the types and frequency of the measurement quality checks that will bedescribed inthis section.

3.2.1 One-Point Quality Control Check for SO2, NO2, 03, and CO. A one-point quality control (QC) check must be performed at least once every 2weeks on each automated analyzer used to measure SO2, NO2, 03 and CO. The frequency ofQC checks may be re- duced based uponreview, assessment and approval of the EPA Regional Administrator. However, with the advent ofautomated calibration systems more frequent checking is encouraged. See Reference 10 of this appendix for guidance on the review procedure. The QC check ismade bychallenging the an- alyzer with a QC check gas of known con- centration (effective concentration for open path analyzers) between 0.01 and 0.10 parts per million (ppm) for SO2, NO2, and 03, and between 1 and 10 ppm for CO analyzers. The ranges allow for appropriate check gas selection for SLAMS sites that may be sampling for different objectives, i.e., trace gas monitoring vs. comparison to National Ambient Air Quality Standards (NAAQS). The QC check gas concentration selected should be related to the routine concentrations nor- mally measured at sites within the monitoring network in order to appropriately reflect the precision and bias at these routine concentration ranges. To check the precision and bias of SLAMS analyzers operating at ranges either above or below the levels identified, use check gases of appropriate con- centrations as approved by the appropriate EPA Regional Administrator or their designee. The standards from which check con- centrations are obtainedmustmeet the specifications ofsection 2.6 ofthis appendix.

3.2.1.1 Except for certain CO analyzers described below, point analyzers must operate in their normal sampling mode during the



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## Environmental ProtectionAgency

QC check, and thetest atmosphere mustpass through all filters, scrubbers, conditioners and other components used during normal ambient sampling and as much ofthe ambient air inlet system as is practicable. Ifpermitted by the associated operation or instruction manual, a CO point analyzer may be temporarily modified during the QC check to reduce vent orpurge flows, or the test atmosphere may enter the analyzer at a point other than thenormal sample inlet, provided that the analyzer's response is not likely to be altered by these deviations from the nor- mal operational mode. Ifa QC check is made in conjunction with a zero or span adjustment, it mustbe made prior to such zero or span adjustments.

3.2.1.2 Open path analyzers are tested by inserting a test cell containing a QC check gas concentration into the optical measure- ment beam ofthe instrument. Ifpossible, the normally used transmitter, receiver, and as appropriate, reflecting devices should be used during the test and the normal monitoring configuration of the instrument should be altered as little as possible to ac- commodate the test cell for the test. However, if permitted by the associated operation or instruction manual, an alternate local light source or an alternate optical path that does not include the normal atmospheric monitoring path maybe used. The actual concentration ofthe QC check gas in the test cell must be selected to produce an effective concentration inthe range specified earlier in this section. Generally, the QC test concentration measurement will be the sum of the atmospheric pollutant concentration and the QC test concentration. If so, the re- sult must be corrected to remove the atmospheric concentration contribution. The cor- rected concentration is obtained by subtracting the average ofthe atmospheric con- centrations measured by the open path instrument under test immediately before and 

## Pt.58,App.A

immediately after the QC test from the QC check gas concentration measurement.Ifthe difference between these before and after measurements is greater than 20 percent of the effective concentration of the test gas, discard the test resultand repeat the test.If possible, open path analyzers should be tested during periods when the atmospheric pol- lutant concentrations are relatively low and steady.

3.2.1.3 Report the audit concentration (effective concentration for open path ana- lyzers) of the QC gas and the corresponding measured concentration (corrected con- centration, if applicable, for open path ana- lyzers) indicated by the analyzer. The percent differences between these concentrations are used to assess the precision and bias of the monitoring data as described in sections 4.1.2 (precision) and 4.1.3 (bias) of thisappendix.

3.2.2 Annual performance evaluation for SO

2, NO2, 03, or CO. Each calendar quarter (duringwhich analyzers are operated), evaluate at least 25 percent of the SLAMS ana- lyzers that monitor for SO2, NO2, 03, or CO such that each analyzer is evaluated at least

once per year. If there are fewer than four analyzers for a pollutant within a primary quality assurance organization, it is suggested to randomly evaluate one or more analyzers so that at least one analyzer for that pollutant is evaluated each calendar quarter. The evaluation should be conducted by a trained experienced technician other than the routine site operator.

3.2.2.1 (a)The evaluation is made by challenging the analyzer with auditgas standard ofknown concentration (effective concentration for open path analyzers) from at least three consecutive audit levels. The auditlevels selected should represent or bracket 80 percent ofambient concentrations measured by the analyzer being evaluated:

Audit level Concentration range, ppm

03 S02 NO2 CO

1

.................................................................... 0.02-0.05 0.0003-0.005 0.0002-0.002 0.08-0.10 2

.................................................................... 0.06-0.10 0.006-0.01 0.003-0.005 0.50-1.00 3

.................................................................... 0.11-0.20 0.02-0.10 0.006-0.10 1.50-4.00 4

................................................................... 0.21-0.30 0.11-0.40 0.11-0.30 5-15 5

.................................................................... 0.31-0.90 0.41-0.90 0.31-0.60 20-50

(b) An additional 4th level is encouraged for those monitors that have the potential for exceeding the concentration ranges described by theinitial three selected.

3.2.2.2 (a) NO2 audit gas for chemiluminescence-type NO2 analyzers must also contain at least 0.08 ppm NO. NO concentrations substantially higher than 0.08 ppm, as may occur when using some gas phase titration (GPT) techniques, may lead to evaluation errors in chemiluminescence analyzers due to inevitable minor NO-NOx channel imbalance. Such errors may be atypical ofroutine monitoring errors to the
extent that such NO concentrations exceed typical ambient NO concentrations at the site. These errors may be minimized by modifying the GPT technique to lower the NO concentrations remaining in the NO2



## 263

## 40CFR Ch. 1(7-1-12 Edition)

audit gas to levels closer totypical ambient NOconcentrations at the site.

(b) To evaluate SLAMS analyzers operating onranges higher than 0 to 1.0ppm for S02, NO2, and 03 or 0 to 50 ppm for O, use audit gases of appropriately higher. concentration as approved by the appropriate EPA Regional Administrator or the Administrator's designee.

3.2.2.3 The standards from which audit gas test concentrations are obtained must meet the specifications ofsection 2.6 ofthisappendix. The gas standards and equipment used for evaluations mustnot be the same as the standards and equipment usedfor calibration

or calibration span adjustments. For SLAMS sites, the auditor should notbe the operator

or analyst who conducts the routine monitoring, calibration, and analysis. For PSD sites the auditor must notbe theoperator or analyst who conducts the routine monitoring, calibration, and analysis.

3.2.2.4 For point analyzers, the evaluation shall be carried out by allowing the analyzer
to analyze the audit gas test atmosphere in its normal sampling mode such that the test atmosphere passes through all filters, scrubbers, conditioners, and other sample inlet components used during normal ambient sampling and as much of the ambient air inlet system as is practicable. The exception provided in section 3.2.1 ofthis appendix for certain CO analyzers does not apply for evaluations.

3.2.2.5 Open path analyzers are evaluated by inserting a test cell containing the various audit gas concentrations into the optical measurement beam ofthe instrument. If possible, the normally used transmitter, receiver, and, asappropriate, reflecting devices should be used during the evaluation, and the normal monitoring configuration of the instrument should be modified as little as possible to accommodate thetest cell forthe evaluation. However, ifpermitted by the associated operation orinstruction manual, an alternate local light source or an alternate optical path that does not include the normal atmospheric monitoring path may be used. The actual concentrations ofthe audit gas in the test cell must be selected to produce effective concentrations in the evaluation level ranges specified in this section ofthis appendix. Generally, each evaluation concentration measurement result will be the sum of the atmospheric pollutant concentration and the evaluation test concentration. If so, the result must be corrected toremove the atmospheric concentration contribution. The corrected concentration is obtained by subtracting the average ofthe atmospheric concentrations measured bythe open path instrument under test immediately before and immediately after the evaluation test (or preferably before and after each evaluation concentration level) from the evaluation concentration measurement. If the difference between the before and after measurements is greater than 20 percent ofthe effective concentration ofthe
test gas standard, discard the testresult for that concentration level and repeat the test for that level. If possible, open path ana- lyzers should be evaluated during periods when the atmospheric pollutant concentrations are relatively low and steady. Also, if the open path instrument is not installed in

a permanent manner, the monitoring path length must be reverified to within plus or minus 3percent to validate the evaluation, since the monitoring path length is critical to the determination of the effective con- centration.

3.2.2.6 Report both the evaluation con- centrations (effective concentrations for open path analyzers) of the audit gases and the corresponding measured concentration (corrected concentrations, if applicable, for open path analyzers) indicated or produced by the analyzer being tested. The percent differences between these concentrations are used to assess the quality of the monitoring data as described in section 4.1.4 of this appendix.

3.2.3 Flow Rate Verification for Particulate Matter. A one-point flow rate verification check must be performed at least once every month on each automated analyzer used to measure PM 1 o, PM10- 2. 5 and PM 2.5. The verification is made by checking the operational flow rate ofthe analyzer. If the verification is made in conjunction with

a flow rate adjustment, it must be made prior to suchflow rate adjustment. Randomization ofthe flowrate verification with respect to time ofday, day ofweek, and rou- tine service and adjustments is encouraged where possible. For the standard procedure,

use a flow rate transfer standard certified in accordance with section 2.6 ofthis appendix
to check the analyzer's normal flow rate. Care should be used in selecting and using the flow rate measurement device such that it does not alter the normal operating flow
rate of the analyzer. Report the flow rate of the transfer standard and the corresponding flow rate measured (indicated) by the analyzer. The percent differences between the audit and measured flowratesare used toassess the bias of the monitoring data as described in section 4.2.2 of this appendix (usingflowrates inlieu ofconcentrations).

3.2.4 Semi-Annual Flow Rate Audit for Particulate Matter. Every 6 months, audit the flow rate ofthe PM 1o,PM1 - 2. 5 and PM 2. 5 particulate analyzers. Where possible, EPA strongly encourages more frequent auditing. The audit should (preferably) be conducted by a trained experienced technician other than the routine site operator. The audit is made by measuring the analyzer's normal operating flowrate using aflow rate transfer standard certified in accordance with section 2.6 of this appendix. The flow rate standard



## 264 Pt. 58,App.A

## Environmental ProtectionAgency

used for auditing must notbe the same flow rate standard used to calibrate the analyzer. However, both the calibration standard and the audit standard may be referenced to the

same primary flow rate or volume standard. Great care mustbe used in auditing the flow rate tobe certain that theflow measurement device does not alter the normal operating flow rate of the analyzer. Report the audit flow rate of the transfer standard and the corresponding flowrate measured (indicated) by the analyzer. The percent differences between these flow rates are used to validate the one-point flow rate verification checks used to estimate bias as described in section 4.2.3 ofthisappendix.

3.2.5 Collocated Sampling Procedures for
PM2. 5. For each pair ofcollocated monitors, designate one sampler as the primary mon- itor whose concentrations will be used to re- port air quality for the site, and designate the otheras the audit monitor.

3.2.5.1 Each EPA designated Federal ref-

erence method (FRM) or Federal equivalent method (FEM) within a primary quality as-
surance organization must:

(a) Have 15 percent ofthe monitors collocated (values of 0.5 and greater round up); and

(b) Have at least 1 collocated monitor (if the totalnumber ofmonitors is less than 3). The first collocated monitor must be a designated FRMmonitor.

3.2.5.2 In addition, monitors selected for collocation must also meet the following re- quirements:

(a) A primary monitor designated as an EPA FRM shall be collocated with an audit monitor having the same EPA FRM method designation.

(b) For each primary monitor model designated as an EPA FEM used by the PQAO, 50percent ofthe monitors designated forcollocation shall be collocated with an audit monitor having the same method designation and 50 percent ofthe monitors shall be collocated with an FRM audit monitor. If the primary quality assurance organization only has one FEM monitor it shall be collocated with an FRM audit monitor. Ifthere

are an oddnumber ofcollocated monitors re- quired, the additional monitor shall be an FRM audit monitor. An example ofthis procedure isfound inTable A-3 ofthis appendix.

3.2.5.3 The collocated monitors should be deployed accordingto thefollowing protocol:

(a)80 percent of the collocated audit mon- itors should be deployed at sites withannual average ordaily concentrations estimated to be within ±20 percent of the applicable NAAQS and theremainder atwhat themonitoring organizations designate as high value sites;

(b) Ifan organization has no sites with an- nual average or daily concentrations within ±20percent ofthe annual NAAQS (or 24-hour NAAQS ifthat is affecting the area), 60 per

## Pt.58,App.A

cent ofthe collocated audit monitors should be deployed at those sites with the annual

mean concentrations (or 24-hour NAAQS if thatis affecting the area)among thehighest 25percent for all sites in thenetwork.

3.2.5.4 Indetermining the number ofcollocated sites required for PM2.s, monitoring networks for visibility assessments should notbe treated independently from networks for particulate matter, as the separate networks may share one ormore common sam- plers. However, for Class I visibility areas, EPA will accept visibility aerosol mass measurement instead of a PM2. 5 measure- ment ifthe latter measurement is unavailable. Any PM2 .5 monitoring site which does not have a monitor which is an EPA FRM, FEM or ARM is not required to be included in the number ofsites which are used to determine the number of collocated monitors.

3.2.5.5 For each PSD monitoring network,

one site must be collocated. A site with the predicted highest 24-hour pollutant con- centration mustbe selected.

3.2.5.6 The two collocated monitors must be within 4 meters ofeach other and at least 2meters apart for flowrates greater than200 liters/min or at least 1 meter apart for sam- plers having flow rates less than 200 liters/ min to preclude airflow interference. Calibration, sampling, and analysis must be the

same for both collocated samplers and the

same as for all other samplers in the network.

3.2.5.7 Sample the collocated audit mon- itor for SLAMS sites on a 12-day schedule; sample PSD sites on a 6-day schedule or every third day for PSD daily monitors. Ifa primary quality assurance organization has only one collocated monitor, higher sam- pling frequencies than the 12-day schedule may be needed in order to produce about 25 valid sample pairs a year. Report the meas- urements from both primary and collocated audit monitors at each collocated sampling site. The calculations for evaluating precision between the two collocated monitors

are described in section 4.3.1 of this appendix.

3.2.6 Collocated Sampling Procedures for PM1o-2.5. For the PMIO-2.5 network, all automated methods must be designated as Federal equivalent methods (FEMs). For each pair of collocated monitors, designate one sampler as the primary monitor whose con- centrations willbe used toreport air quality for the site, and designate the other as the audit monitor.

3.2.6.1 The EPA shall ensure that each EPA designated FEM within the national PMo- 2. 5 monitoringnetwork must: (a) Have 15 percent ofthe monitors collocated (values of 0.5 and greater round up); and

(b) Have at least 2 collocated monitors (if thetotal number ofmonitors is lessthan 10).


## 265

### Pt. 58,App.A

The first collocated monitor must be a designated FRM monitor and the second must be a monitor of the same method designation. Both collocated FRM and FEM mon- itors canbelocated atthe samesite.

3.2.6.2 TheRegional Administrator for the EPA Regions where the FEMs are implemented will select the sites for collocated monitoring. The site selection process shall consider giving priority to sites at primary quality assurance organizations or States with more than one PMo-2.5 site, sites con- sidered important from a regional perspective, and sites needed for an appropriate distribution among rural and urban NCore sites. Depending on the speed at which the PMo- 2. 5 network is deployed, the first sites implementing FEMs shall be required to perform collocation until there is a larger distribution of FEM monitors implemented in the network.

3.2.6.3 The two collocated monitors must bewithin 4meters ofeach other and atleast 2meters apart forflowrates greater than 200 liters/min or at least 1meter apart for sam- plers having flow rates less than 200 liters/ min to preclude airflow interference. Calibration, sampling, and analysis must be the

same for both collocated samplers and the

same as for all other samplers in the network.

3.2.6.4 Sample the collocated audit mon- itor for SLAMS sites on a 12-day schedule. Report themeasurements from both primary and collocated audit monitors ateach collocated sampling site. The calculations for evaluating precision between the two collocated monitors are described in section 4.3.1 ofthis appendix.

3.2.7 PM 2.5 Performance Evaluation Program (PEP) Procedures. The PEP isan independent assessment used to estimate total measurement system bias. These evaluations will be performed underthe PM Performance Evaluation Program (PEP) (section 2.4 of this appendix) or a comparable program. Performance evaluations will be performed

on the SLAMS monitors annually within each primary quality assurance organization. For primary quality assurance organizations with less than orequal to five monitoring sites, five valid performance evaluation audits must be collected and reported each year.For primary quality assurance or- ganizations with greater than five monitoring sites, eight valid performance evaluation audits must be collected and reported each year. A valid performance evaluation audit means that both the primary monitor and PEP audit concentrations are valid and above 3gg/m 5

.Additionally, each year, every designated FRM or FEM within a primary quality assurance organization must:

(1) Have each method designation evaluated eachyear; and,

(2)Have allFRM orFEM samplers subject to aPEP audit at leastonce every six years; 

### 40 CFRCh. 1 (7-1-12 Edition)

which equates to approximately 15 percent of themonitoring sitesaudited eachyear.

(b) Additional information concerning the Performance Evaluation Program is con- tained in reference 10 of this appendix. The calculations forevaluating bias between the primary monitor and the performance evaluation monitor for PM 2.

5 are described in section4.3.2 ofthis appendix.

3.2.8 PMio-2.5 Performance Evaluation Program. For the PM,0 -2.5 network, all automated methods will be designated as federal equivalent methods (FEMs). One perform-

ance evaluation audit, as described in sec- tion 3.2.7 must be performed at one PMIO-2.5 site in each primary quality assurance orga- nization each year. The calculations for evaluating bias between the primary monitor(s) and the performance evaluation monitors for PMao-2.5 are described in section 4.1.3 ofthis appendix.

3.3 Measurement Quality Checks of Manual Methods. TableA-2 ofthis appendix provides a summary ofthe types and frequency ofthe measurement quality checks that will be described inthis section.

3.3.1 Collocated Sampling Procedures for PMIo. For each network of manual PMo methods, select 15percent (orat leastone) of the monitoring sites within the primary quality assurance organization for collocated sampling. Forpurposes ofprecision as- sessment, networks for measuring total sus- pended particulate (TSP) and PMso shall be considered separately from one another. However, PMo samplers used in the PM1o-2.s network, may be counted along with the PMo samplers in the PMso network as long

as the PMIo samplers in both networks are the same method designation. PMIo and TSP sites having annual mean particulate matter concentrations among the highest 25percent of the annual mean concentrations for all the sites inthe network mustbe selected or, if such sites are impractical, alternative sites approved by the EPA Regional Administrator may beselected.

3.3.1.1 Indetermining the number ofcollocated sites required for PMo, monitoring networks for lead (Pb) should be treated independently from networks forparticulate matter (PM), even though the separate networks may share one or more common sam- plers. However, a single pair ofsamplers collocated at a common-sampler monitoring site that meets the requirements for both a collocated Pb site and a collocated PM site may serve as a collocated site forboth networks.

3.3.1.2 The two collocated monitors must be within 4 meters ofeach other and at least 2meters apart forflowrates greater than200 liters/min or at least 1 meter apart for sam- plers having flow rates less than 200 liters/ min to preclude airflow interference. Calibration, sampling, analysis and verification/ validation procedures must be the same for



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## Environmental ProtectionAgency

both collocated samplers and the same asfor all othersamplers inthe network.

3.3.1.3 For each pair of collocated samplers, designate one sampler as the primary sampler whosesamples willbe used to report air quality for the site, and designate the other as the audit sampler. Sample SLAMS sites on a 12-day schedule; sample PSD sites

on a 6-day schedule or every third day for PSD daily samplers. Ifa primary quality assurance organization hasonly one collocated monitor, higher sampling frequencies than the 12-day schedule may be needed in order
to produce approximately 25 valid sample pairs a year.Report the measurements from both samplers at each collocated sampling site. The calculations for evaluating precision between thetwo collocated samplers are described in section 4.2.1 ofthis appendix.

3.3.2 Flow Rate Verification for Particulate Matter. Follow the same procedure as described in section 3.2.3 ofthis appendix for PM2 .5, PMo (low-volume instruments), and PM[o- 2.s.High-volume PMIo and TSP instruments can also follow the procedure in section 3.2.3 but the audits are required to be conducted quarterly. The percent differences between the audit and measured flow rates

are used to assess the bias ofthe monitoring data as described in section 4.2.2 ofthis appendix.

3.3.3 Semi-Annual Flow Rate Audit for Particulate Matter. Follow the same procedure as described in section 3.2.4 of this appendix for PM 2.5,PMIO, PMI0-2.5 and TSP instruments. The percent differences between these flowrates are used to validate theonepoint flow rate verification checks used to estimate bias as described in section 4.2.3 of this appendix. Greatcare mustbe used inauditing high-volume particulate matter samplers having flow regulators because the introduction of resistance plates in the audit flow standard device can cause abnormal flow patterns at the point of flow sensing. For this reason, the flow audit standard should be used with a normal filter in place and without resistance plates in auditing flow-regulated high-volume samplers, or other steps should be taken to assure that flow patterns are not perturbed at the point offlow sensing.

3.3.4 Pb Methods. 3.3.4.1 Flow Rates. For the Pb Reference Methods (40 CFR Part50, appendix G and appendix Q) and associated FEMs, the flow rates ofthe Pbsamplers shall be verified and audited using the same procedures described in sections 3.3.2and 3.3.3 ofthis appendix.

3.3.4.2 Pb Analysis Audits. Each calendar quarter orsampling quarter (PSD), audit the Pb Reference Method analytical procedure using filters containing a known quantity of Pb.These audit filters are prepared bydepositing a Pb solution on unexposed filters and allowing them to dry thoroughly. The audit samples must be prepared using batches of 

## Pt.58,App.A

reagents different from those used to calibrate the Pb analytical equipment being au- dited. Prepare audit samples in the following concentration ranges:
Range Equivalentambient Pbcon- centration, pg/m3

1............ 30-100%ofPb NAAOS. 2

............ 200-300%of Pb NAAOS.

(a) Audit samples mustbe extracted using the same extraction procedure used for ex- posed filters.

(b) Analyze three audit samples in each of the two ranges each quarter samples are ana- lyzed. The audit sample analyses shall be distributed as much as possible over the entire calendar quarter.

(c) Report the audit concentrations (in

## gg Pb/filter or strip) and the corresponding measured concentrations (in 

## gg Pb/filter or strip) using AQS unit code 077. The percent differences between the concentrations are used to calculate analytical accuracy as described insection 4.1.3 ofthisappendix.

(d) The audits ofan equivalent Pb method

are conducted and assessed in the same manner as for the reference method.The flow auditing device and Pb analysis audit samples
must be compatible with the specific requirements oftheequivalent method.

3.3.4.3 Collocated Sampling. PQAO that have a combination of source and nonsource-oriented sites (unless the only nonsource-oriented site is an NCore site) will follow the procedures described in sections 3.3.1 ofthis appendix with the exception that the first collocated Pb site selected must be the site measuring thehighest Pb concentrations in the network. If the site is impractical, alternative sites, approved by the EPA Regional Administrator, may be selected. If additional collocated sites are necessary, collocated sites may be chosen that reflect average ambient air Pb concentrations in the network. The collocated sampling re- quirements for PQAO that only have Pb monitoring at a non-source-oriented NCore site for sampling required under 40 CFR 58, Appendix D, paragraph 4.5(b) shall be implemented as described in section 3.2.6 of this appendix with the exception that the collocated monitor will be the same method designation astheprimary monitor.

3.3.4.4 Pb PerformanceEvaluationProgram (PEP)Procedures. Each year, one performance evaluation audit, as described in section3.2.7 ofthisappendix, must beperformed
atone Pbsite in eachprimary quality assurance organization that has lessthan orequal
to 5 sites and two audits at primary quality

assurance organizations with greater than 5 sites. In addition, each year, four collocated samples from primary quality assurance organizations with less than orequal to 5 sites and six collocated samples at primary quality assurance organizations with greater



### 267

### Pt.58, App.A

than 5 sites must be sent to an independent laboratory, the same laboratory as the performance evaluation audit, for analysis.

3.3.5 Collocated Sampling Procedures for PM2. 5. Follow the same procedure as describedin section 3.2.5 ofthis appendix. PM 2. 5 samplers used in the PMo-2. 5 network, may be counted along with the PM2. 5 samplers in the PM 2,5network as long as the PM 2.5samplers in both.networks are the same method designation.

3.3.6 Collocated Sampling Procedures for PM1o-- 2.s. All designated FRMs within the PMo-- 2.s monitoring network must have 15 percent ofthemonitors collocated (values of 0.5 and greater round up) at the PMeo-2.s sites. All FRM method designations can be aggregated.

3.3.6.1 .The EPA shall ensure that each designated FEM within the PM 10-

2.5 monitoring network must:

(a) Have 15 percent of the monitors collocated (values of 0.5 and greater round up); and

(b) Have at least 2 collocated monitors (if the total number ofmonitors isless than 10). The first collocated monitor must be a designated FRM monitor and the second must be a monitor of the same method designation. Both collocated FRM and FEM monitors canbe located atthe same site.

3.3.6.2 TheRegional Administrator forthe EPA Region where theFRM or FEMs are implemented will select the sites for collocated monitoring. The collocation site selection process shall consider sites at primary quality assurance organizations or States with

more than one PM 1 -2.5site; primary quality

assurance organizations already monitoring for PMie andPM2.5usingFRMs orFEMs; and

an appropriate distribution among rural and urban NCore sites. Monitoring organizations implementing PM0 samplers and PM 2.

5 FRM samplers ofthe same method designation as the PMWo-2.5 FRM can include the PMIo. 2.5 monitors in their respective PMio and PM 2.

5 count. Follow the same procedures as described in sections 3.2.6.2 and 3.2.6.3 of this appendix.

3.3.7 PM2 .5 Performance Evaluation Program (PEP) Procedures. Follow the same procedure as described in section 3.2.7 ofthis appendix.

3.3.8 PM 1O2.5 Performance Evaluation Program (PEP) Procedures. Oneperformance evaluation audit, asdescribed in section 3.2.7 of this appendix must be performed at one PMIO-2.5site in each primary quality assurance organization each year. Monitoring organizations implementing PM 2.s FRM samplers ofthe same method designation in both the PM 2 .5 and the PMo-- 2. 5 networks can include the PM 1 0-

2.

5 performance evaluation audit in their respective PM2 .5performance evaluation count as longas the performance evaluation is conducted at the PMo-2.s site. The calculations for evaluating biasbetween 

### 40CFR Ch. 1(7-1-12 Edition)

the primary monitor(s) and the performance evaluation monitors for PMIo-. 2.s are described in section4.1.3 ofthis appendix.

4. CALCULATIONS FOR DATA QUALITY ASSESSMENT (a) Calculations of measurement uncertainty are carried out by EPA according to the following procedures. Primary quality

assurance organizations should report the data for all appropriate measurement quality checks as specified in this appendix even though they may elect to perform some or all of the calculations in this section on their own.

(b) The EPA will provide annual assessments ofdata quality aggregated by site and primary quality assurance organization for SO2, NO2, 0 and CO and by primary quality

assurance organization for PM1o, PM2 .s, PM1o--2.sand Pb.

(c) At low concentrations, agreement between the measurements ofcollocated samplers, expressed as relative percent difference or percent difference, may be relatively poor. For this reason, collocated
measurement pairs are selected for use in the precision and bias calculations only when both measurements are equal to or above the following limits:

(1)TSP: 20gg/m3

. (2) Pb:0.02 gg/m 3

. (3)PMo (Hi-Vol): 15 gg/m 3

. (4) PM 1o(Lo-Vol):3pg/m3

. (5)PM 1O-

2.5and PM2 .5:3gg/i 3

. 4.1 Statistics for the Assessment of QC Checks for SO2, NO2,03 and CO.

4.1.1 Percent Difference. All measurement quality checks startwith a comparison ofan audit concentration or value (flowrate) to the concentration/value measured by the analyzer and use percent difference as thecomparison statistic asdescribed in equation 1of this section. For each single point check, calculate the percent difference, di, as follows: 

### Equation1

= 

### meas

### -audit X100 audit
where, meas is the concentration indicated by the monitoringorganization's instrument and auditis the audit concentration of the standard used in the QC check being measured.

4.1.2 Precision Estimate. The precision estimate is used to assess the one-point QC checks for SO2, NO2, 03, or CO described in section 3.2.1 of this appendix. The precision estimator is the coefficient of variation
upperbound and is calculated using equation 2ofthissection:



### 268

## Environmental ProtectionAgency

Equation2

=
- _

### n-I

where, X2o.1., is the 10thpercentile ofa chisquared distribution with n-1 degrees of freedom. 4.1.3 Bias Estimate. The bias estimate is calculated using the one-point QCchecks for SO2, NO2, 03, or CO described in section 3.2.1 ofthis appendix and theperformance evaluation program for PM 1O-2.5 described in sections 3.2.8 and 3.3.8 ofthis appendix. Thebias estimator is anupper bound onthe mean absolute value ofthe percent differences as described in equation 3ofthissection:


### Equation3

AS JABI =AB+tow9n-I A

where, n isthe numberofsinglepoint checks being aggregated; to.95.- , is the 95th quantile ofa t-distribution with n-1 degrees of freedom; the quantity AB is the mean ofthe absolute values of the d's and is calculated usingequation 4ofthissection: 

### Equation4

1n 

# AB

# = -- . 

# di

1 i=1 and the quantity AS is the standard deviation ofthe absolute value ofthe d's and is calculated usingequation 5ofthis section:


### Equation5

n 2 n 2 

## n. dI

- 

# |di1
AS= i-Ii~ 

### n(n-1)

4.1.3.1 Assigning a sign (positive/negative) tothe bias estimate. Since the bias statistic

as calculated in equation 3 of this appendix

uses absolute values, it does not have a tendency (negative or positive bias) associated withit. A sign will be designated byrank or- dering the percent differences of the QC check samples from a given site for a particular assessment interval.

4.1.3.2 Calculate the 25th and 75th percentiles of the percent differences for each site.The absolute biasupperbound should be flagged as positive if both percentiles are positive and negative ifboth percentiles are negative. The absolute bias upper bound 

## Pt.58,App.A

would notbe flagged ifthe 25th and 75th percentiles are ofdifferent signs.

4.1.4 Validation of Bias Using the onepoint QC Checks. The annual performance evaluations for SO2,NO2,03, orCO described in section 3.2.2 ofthis appendix are used to verify the results obtained from the one- pointQC checks and to validate those results

across a range of concentration levels. To quantify this annually at the site level and
at the 3-year primary quality assurance or- ganization level, probability limits will be calculated from the one-point QC checks usingequations 6and 7ofthis appendix: 

### Equation6 Upper ProbabilityLimit=m+1.96 S

Equation7

LowerProbabilityLimit =m-1.96 -S

where, m is the mean (equation 8of this appendix):


### Equation8

ik 

### m-Yd

where, kis thetotal number ofonepoint QC

checks for the interval beingevaluated and S is the standard deviation of the percent differences (equation 9ofthis appendix) as follows:


### Equation9



## k-1d'

- Xdi

i=1 (i=1



### k(k-1)

4.1.5 Percent Difference. Percent differences for the performance evaluations, calculated using equation 1of this appendix

can be compared tothe probability intervals for the respective site or at the primary quality assurance organization level.Ninetyfive percent of the individual percent differences (all audit concentration levels) for the performance evaluations should be captured within theprobability intervals for the primary qualityassurance organization.

4.2 Statistics forthe Assessment ofPMo. 4.2.1 Precision Estimate from Collocated Samplers. Precision is estimated via duplicate measurements from collocated samplers ofthe sametype. It isrecommended that the



### 269

### Pt. 58, App.A

precision be aggregated at the primary quality assurance organization level quarterly, annually, and at the 3-year level. The data pair would only be considered valid ifboth concentrations are greater than the minimum values specified in section 4(c) of this appendix. For each collocated data pair, calculate the relative percent difference, d;, using equation 10 ofthis appendix:


### Equation10



## d xi-Yi -100

i=(Xi 

### +Yi)/2
where, X is the concentration from the primary sampler and Y,is the concentration value from the audit sampler. The coefficient of variation upper bound is calculated using the equation 11 ofthis appendix: 

### Equation11

n

## CV

# =

where, n is the number of valid data pairs

being aggregated, and X2 0.1., is the 10th percentile of a chi-squared distribution with n-1 degrees offreedom. The factor of 2 in the denominator adjusts for the fact that each di is calculated from two values with error. 4.2.2 Bias Estimate Using One-Point Flow Rate Verifications. For each one-point flow rate verification described in sections3.2.3 and 3.3.2 of this appendix, calculate the percent difference in volume using equation 1 of this appendix where

meas is the value indicated by the sampler's volume measurement and auditis the actual volume indicated by the auditing flow meter. The absolute volume biasupperbound is then calculated using equation 3,where n is the number offlow
rate audits being aggregated; tos95.-1 is the 95th quantile ofa t-distribution with n-1 degrees of freedom, the quantity AB is the mean ofthe absolute values ofthe di'sand is calculated using equation 4 of this appendix , and the quantity AS in equation 3of this appendix is the standard deviation of the absolute values if the d's and is calculated using equation 5ofthis 4.2.3 Assessment Semi-Annual Flow Rate Audits. The flow rate auditsdescribed in sections 3.2.4 and 3.3.3 ofthis appendix are used
to assess the results obtained from the onepoint flow rate verifications and to provide

an estimate of flow rate acceptability. For each flow rate audit, calculate the percent 

### 40 CFRCh. 1(7-1-12 Edition)

difference in volume using equation 1 ofthis appendix where meas is the value indicated by the sampler's volume measurement and auditis the actual volume indicated by the auditing flow meter. To quantify this annually and at the 3-year primary quality assurance organization level, probability limits

are calculated from the percent differences using equations 6 and 7 of this appendix where m is the mean described in equation 8 ofthis appendix and k is the total number of one-point flow rate verifications for the year and S is the standard deviation of the percent differences as described in equation 9of this appendix.

4.2.4 Percent Difference. Percent differences for the annual flow rate audit concentration, calculated using equation 1 of this appendix, can be compared to the prob- ,ability intervals for the one-point flow rate verifications fortherespective primaryquality assurance organization. Ninety-five percent ofthe individual percent differences (all audit concentration levels) for the performance evaluations should be captured within the probability intervals forprimary quality

assurance organization.

4.3 Statistics for the Assessment of PM 2.

5 and PMIO.5.

4.3.1 Precision Estimate. Precision for collocated instruments for PM2. 5 and PMIO-2. 5 may be estimated where both the primary and collocated instruments are the same method designation and when the method designations arenot similar. Follow theprocedure described in section 4.2.1 of this appendix. In addition, one may want to perform an estimate of bias when the primary monitor is an FEM and the collocated monitor is an FRM. Follow the procedure described in section 4.1.3 of this appendix in order to provide an estimate of bias using the collocated data.

4.3.2 Bias Estimate. Follow the procedure described in section 4.1.3 ofthis appendix for the bias estimate of PM o- 2.s.The PM 2.

5 bias estimate is calculated using the paired routine and the PEP monitor data described in section 3.2.6 of this appendix. Calculate the percent difference, di, using equation 1 of this appendix, where meas is the measured concentration from agency's primary monitor and auditis the concentration from the PEP monitor. The data pair would only be considered valid if both concentrations are greater than the minimum values specified in section 4(c) ofthis appendix. Estimates of bias arepresented for variouslevels ofaggregation, sometimes aggregating over time, sometimes aggregating over samplers, and sometimes aggregating over both time and samplers. These various levels of aggregation are achieved using the same basic statistic.

4.3.2.1 This statistic averages the individual biases described in equation 1 of this


## 270

## Environmental ProtectionAgency

appendix to the desired level ofaggregation using equation 12ofthis appendix: 

### Equation12

1 "' D= 1 d

n i 

## Pt.58,App.A

where, ni is the number of pairs and di, d 2, * * *, d, are the biases for each ofthe pairs tobe averaged.
4.3.2.2 Confidence intervals can be con- structed for these average bias estimates in equation 12 ofthis appendix using equations 13and 14 ofthis appendix:



### tion13

Upper90%Confidence Interval =D+t0.9,df



### Equation14

Lower 90% Confidence

Where, tO.95.df is the 95th quantile of a t-distribution with degrees of freedom df = nj

- 1and s is an estimate of the variability of the average bias calculated using equation 15ofthis appendix: 

### Equation15

X(d 1 

## -D) 2

S = i=1

4.4 Statistics fortheAssessmentofPb. 4.4.1 PrecisionEstimate. Follow the same procedures as described for PM 10 in section 4.2.1 ofthis appendix using the data fromthe collocated instruments. The data pair would only be considered valid if both concentrations are greater than the minimum values specified insection 4(c) ofthisappendix.

4.4.2 BiasEstimate.For the Pbanalysis au- dits described in section 3.3.4.2 and the Pb Performance Evaluation Program described in section 3.3.4.4, follow the same procedure

asdescribed in section 4.1.3 for the bias estimate.

4.4.3 Flow rate calculations.For the one point flow rate verifications, follow the same procedures as described for PMio in section 4.2.2; for the flow rate audits, follow the

same procedures asdescribed in section 4.2.3.

5. REPORTING REQUIREMENTS 5.1 SLAMS Reporting Requirements. For each pollutant, prepare a list of all monitoring sites and their AQS site identification codes in each primary quality assurance or- ganization and submit the list to the approS 

### Interval 

## =D

- tO.95,df

priate EPA Regional Office, with a copy to AQS. Whenever there is a change inthis list ofmonitoring sites in a primary quality as-
surance organization, report this change to theEPARegional Office and toAQS.

5.1.1 Quarterly Reports. For each quarter, each primary quality assurance organization shall report to AQS directly (or via the appropriate EPA Regional Office for organizations not direct users ofAQS) the results of all valid measurement quality checks it has carried out during the quarter. The quarterly reports must be submitted consistent with the data reporting requirements specified for air quality data as set forth in 

### § 58.16. The EPA strongly encourages early submission ofthequality assurance data in order to assist the monitoring organizations control and evaluate the quality of the ambient air data.

5.1.2 Annual Reports. 5.1.2.1 When the monitoring organization has certified relevant data for the calendar year, EPA will calculate and report the
measurement uncertainty for the entire calendar year.

5.2 PSD Reporting Requirements. At the end ofeach sampling quarter, the organization must report the appropriate statistical assessments in section 4ofthis appendix for the pollutants measured. All data used to calculate reported estimates ofprecision and bias including span checks, collocated sam- pler and audit results must be made available to the permit granting authority upon request.

6.0 REFERENCES

(1) American National Standard-Specifications andGuidelines for Quality Systems



### 271

### 40CFR Ch. I(7-1-12 Edition)

for Environmental Data Collection and Environmental Technology Programs. ANSI/ ASQC E4-2004. February 2004. Available from American Society for Quality Control, 611 East Wisconsin Avenue, Milwaukee, WI53202.

(2) EPARequirements for Quality Management Plans. EPA QA/R-2. EPA/240/B-01/002. March 2001. Office of Environmental Information, Washington DC 20460. http:// www.epa.gov/quality/qs-docs/r2-final.pdf.

(3) EPA Requirements for Quality Assurance Project Plans for Environmental Data Operations. EPA QA/IR5. EPA/240/B-01/003. March 2001. Office of Environmental Information, Washington DC 20460. http:// www.epa.gov/quality/qs-docs/r5-final.pdf.

(4) EPA Traceability Protocol for Assay and Certification of Gaseous Calibration Standards. EPA-600/R-97/121. September 1997. Available from U.S. Environmental Protection Agency, ORD Publications Office, Center for Environmental Research Information (CERI), 26W. Martin LutherKing Drive, Cincinnati, OH45268.

(5) Guidance for the Data Quality Objectives Process. EPA QA/G-4. EPA/240/B-06/001. February, 2006. Office of Environmental Information, Washington DC 20460. http:// www.epa.gov/quality/qs-docs/g4-final.pdf.

(6) List ofDesignatedReference and Equivalent Methods. Available from U.S. Environmental Protection Agency, National Exposure Research Laboratory, Human Exposure and Atmospheric Sciences Division, MDD205-03, Research Triangle Park, NC 27711. http://www.epa.gov/ttn/amtic/criteria.html.

(7) McElroy, F.F. Transfer Standards for the Calibration of Ambient Air Monitoring Analyzers for Ozone. EPA-600/4-79-056. U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, September, 1979. http://www.epa.gov/ttn/amtic/cpreldoc.html.

(8)Paur, R.J. and F.F. McElroy. Technical Assistance Document for the Calibration of Ambient Ozone Monitors. EPA-600/4-79-057. U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, September, 1979. http://www.epa.gov/ttn/amtic/ cpreldoc.html.

(9) Quality Assurance Handbook for Air Pollution Measurement Systems,Volume 1- A Field Guide to Environmental Quality Assurance. EPA-600/R-94/038a. April 1994. Available from U.S. Environmental Protection Agency, ORD Publications Office, Center for Environmental Research Information (CERI), 26W. Martin LutherKing Drive, Cincinnati, OH 45268. http://www.epa.gov/ ttn/ amtic/qabook.html.

(10) Quality Assurance Handbook for Air Pollution Measurement Systems, Volume II: Part 1-Ambient Air Quality Monitoring Program Quality System Development. EPA-54/R-98-004. http://www.epa.gov/ttn/ amtic/qabook.html.

TABLE A-1 OFAPPENDIX A TO PART 58-DIFFERENCE AND SIMILARITIES BETWEEN SLAMS AND PSD REQUIREMENTS 

### Topic SLAMS PSO

Requirements

..................................

Monitoring and QAResponsibility...

Monitoring Duration

......................... Annual Performance Evaluation

(PE).

PEaudit rate: -Automated

..................... -Manual

..........................
PrecisionAssessment: -Automated

.....................
-Manual

..........................

Reporting -Automated

..................... 1.The development, documentation, and implementationofanapproved qualitysystem. 2.Theassessment ofdataquality............. 3. The use of reference, equivalent, or approved

methods. 4.The useofcalibration standardstraceabletoNIST

orother primarystandard. 5.The participation in EPA performance evaluations

andthe permissionforEPA toconduct systemaudits. State/localagencyviathe "primaryqualityassurance

organization". Indefinitely

................................................................... Standards and equipment different from those used

for spanning, calibration, and verifications. Prefer differentpersonnel.

100% peryear

.......................... Variesdependingon pollutant. SeeTable A-2ofthis

appendix.

One-point OC check biweekly but data quality dependent. Variesdependingon pollutant. SeeTable A-2ofthis

appendix.

Bysite-EPA performs calculationsannually

............ Sourceowner/operator.

Usually up to 12 months. Personnel, standards and equipment different from those used for spanning, calibration, and verifications.

100% perquarter. 100% perquarter.

One pointOC checkbiweekly.

One site: 1every 6days or every

third day for daily monitoring (TSPand Pb).

By site-source owner/operator

performs calculations each samplingquarter.



## 272 Pt. 58,App. A

## Environmental ProtectionAgency Pt.58,App.A

TABLE A-1 OF APPENDIX A TO PART 58-DIFFERENCE AND SIMILARITIES BETWEEN SLAMS AND PSD REQUIREMENTS-Continued

Topic SLAMS PSD

-Manual

.......................... By reporting organization-EPA performs calcula- By site-source owner/operator tions annually. performs calculations each sam- pling quarter.

TABLE A-2 OF APPENDIX A TO PART 58-MINIMUM DATA ASSESSMENT REQUIREMENTS FOR SLAMS SITES

Method Assessment method Coverage freqmu Parprtedrs

Automated Methods

1-PointOC forSO 2, Response checkat Each analyzer. once per2weeks AuditconcentrationI NO

2,03, CO. concentration0.01- and measuredcon- 0.1 ppm SO 2, NO

2, centration 2. 03,and 1-10 ppm CO. Annual performance Seesection3.2.2 of Each analyzer. once peryear. Audit concentration

evaluation forSO

2, thisappendix. and measuredconNO

2 ,03,CO. centration 2foreach level. Flowrateverification Checkof samplerflow Each sampler........once every month Auditflow rate and

PMo. PM 2 3 ,PM-2 3 . rate. measured flow rate indicated bythe sampler. Semi-annual flowrate Checkofsamplerflow Each sampler........Once every 6months Audit flow rate and

auditPM,,, PM 2 5, rate usinginde- measured flow rate PM-2.5. pendent standard. indicated bythe sam- pler. Collocatedsampling Collocatedsamplers

.... 15%

............... Every 12days. Primarysampler conPM

2 . 3.PMo-2 . 5 . centration and duplicatesampler concentration. Performance evaluation Collocated samplers 1.5validauditsfor pri- over all 4quartersPrimary samplercon-

program PM 23

, mary QA org, with centrationand perPM,0 .5. <5 sites. formanceevaluation 2.8validauditsfor pri- samplerconcentramary OAorgs, with tion. >5sites. 3.Allsamplers in6

years.

Manual Methods

Collocatedsampling

PMo.TSP, PMo-23, PM

2 . 3.Pb-TSP, PbPMo

. Flow rateverification

PM,0 (lowVol), PM,,,. PM 2 . 3.PbPM,0. Flow rateverification

PM,0 (High-Vol), TSP, Pb-TSP.

Semi-annual flow rate

auditPM,0,TSP, PM,0 2..PM 2.5,

PbTSP, Pb-PMo. Pbauditstrips Pb-TSP,

Pb-PMo. Collocated samplers

Checkofsampler flow

rate.

Checkofsampler flow

rate.

Checkofsampler flow

rate usingindependent standard.

Checkofanalytical systernwith Pbaudit strips. 15%

..............................

Eachsampler

...............

Eachsampler

...............

Eachsampler,all locations.

Analytical

...................... Every 12days PSDevery 6days.

Onceevery month.

Once everyquarter.

Onceevery 6months

Each quarter

................ Primary sampler con- centration andduplicate samplerconcentration. Auditflow rateand

measured flow rate indicated bythesam- pler. Auditflow rateand

measured flow rate indicated bythesampler. Auditflow rateand

measured flow rate indicated bythe sampler. Actual concentration

and auditconcentration.



## 273

### Pt.58, App.C 40CFR Ch. 1(7-1-12 Edition)

TABLE A-2 OF APPENDIX A TO PART 58-MINIMUM DATA ASSESSMENT REQUIREMENTS FOR SLAMS SITES-Continued

Method Assessment method Coverage Minimum Paraeters

Performance evaluation Collocated samplers

.... 1.5valid auditsforpri- Overall4quarters Primary samplerconprogram PM 25

. maryQA orgs,with centrationandperPM- 25 . S5 sites. formance evaluation 2.8validauditsforpri- sampler concentramaryQA orgs.with tion. >5 sites. 3.Allsamplersin6

years. Performanceevaluation Collocatedsamplers

.... 1.1validauditand4 Over all4quarters

. Primarysamplercon-

program Pb-TSP, Pb- collocatedsamples centrationandperPM.o. forprimaryQAorgs, formance evaluation with>5sites. samplerconcentra2.2validauditsand6 tion. Primarysampler

collocatedsamples concentration and forprimaryQAorgs, duplicate sampler with>5sites. concentration.
Effectiveconcentrationforopen pathanalyzers. 2Correctedconcentration, ifapplicable,foropen pathanalyzers.

TABLE A-3 OF APPENDIX ATO PART 58-SUMMARY OF PM2. 5 NUMBER AND TYPE OFCOLLOCATION (15% COLLOCATION REQUIREMENT) NEEDED AS AN EXAMPLE OF A PRIMARY QUALITY ASSURANCE ORGANIZATION THAT HAS 54 MONITORS AND PROCURED FRMS AND THREE OTHER EQUIVALENT METHOD TYPES
Primary sampler No.ofcollocatedmon- methoddesigna- Total no.ofmonitors Totalno.collocated No.ofcollocated FRM itorsofsamemethod tion designation as primary

FRM

.................... 20 3 3 n/a FEM (A)

.............. 20 3 2 1 FEM(C)

.............. 2 1 1 0 FEM(D)

.............. 12 2 1 1

[71 FR 61303, Oct. 17, 2006, as amended at 72 FR 32211, June 12, 2007; 73 FR 67060, Nov. 12, 2008; 75 FR 6534, Feb. 9,2010; 75FR 35602, June22, 2010; 75 FR81137, Dec.27, 2010]

EDITORIAL NOTE: At 72 FR 32211, June 13, 2007, the last sentence in section 4.2.2.2, was amended in Appendix A to Part 58; however, the amendment could not be incorporated due to inaccurate amendatory instruction.

APPENDIX B TOPART 58 [RESERVED]

APPENDIX CTO PART 58-AMBIENT AIR

QUALITY MONITORING METHODOLOGY

1.0Purpose 2.0 SLAMS AmbientAir Monitoring Stations 3.0 NCore Ambient Air Monitoring Stations 4.0 Photochemical Assessment Monitoring Stations (PAMS) 5.0 Particulate Matter Episode Monitoring 6.0 References

1.0 PURPOSE

Thisappendix specifies the criteria pollutant monitoring methods (manual methods or automated analyzers) which must be used in SLAMSand NCore stations that are a subset ofSLAMS. 2.0 SLAMSAMBIENT AIR MONITORING

NETWORK

2.1 Except as otherwise provided in this appendix, a criteria pollutant monitoring method used for making NAAQS decisionsat

a SLAMS site must be a reference or equivalent method as defined in-§50.1 of this chapter.

2.1.1 Any NO2 FRM or FEM used for making primary NAAQS decisions must be capable of providing hourly averaged concentration data.

2.2 Reserved 2.3 Any manual method or analyzer purchased prior to cancellation of its reference

or equivalent method designation under §53.11 or §53.16 ofthis chapter may be used at

a SLAMS site following cancellation for a reasonable period of time to be determined bythe Administrator.

2.4 Approval of Non-designated Continuous PM2. 5 Methods as Approved Regional



### 274

## Environmental ProtectionAgency

Methods (ARMs) Operated Within a Network of Sites. A method for PM2 . 5 that has not been designated as an FRM or FEM as defined in 

### §50.1 of this chapter may be approved as an ARM forpurposes ofsection 2.1 ofthis appendix at a particular site or network of sites under the following stipulations.

2.4.1 The candidate ARM must be demonstrated to meet therequirements for PM 2.5 Class III equivalent methods as defined in subpart C ofpart 53 of this chapter. Specifically the requirements forprecision, correlation, and additive and multiplicative bias apply. For purposes of this section 2.4, the following requirements shall apply:

2.4.1.1 The candidate ARM shall be tested at the site(s) in which it is intended to be used. For a network of sitesoperated by one reporting agency or primary quality assur-
ance organization, the testing shall occur at

a subset of sites to include one site in each MSA/CSA, up to the first 2 highest population MSA/CSA and at least one rural area
or Micropolitan Statistical Area site. Ifthe candidate ARM for a network is already approved forpurposesofthis section in another agency's network, subsequent testing shall minimally occur at one site in a MSA/CSA and one rural area or Micropolitan StatisticalArea. There shall be no requirement for tests atany other sites.

2.4.1.2 For purposes bf this section, a full year of testing may begin and end in any season, solongas all seasons are covered.

2.4.1.3 No PM 1osamplers shallbe required for the test, as determination ofthe PM 2.5/ PMo ratio at the test site shall not be re- quired.

2.4.1.4 The test specification for PM 2.5 ClassIII equivalent method precision defined in subpart C of part 53 of this chapter applies; however, there is no specific requirement that collocated continuous monitors be operated for purposes of generating a statistic for coefficient of variation (CV). To provide an estimate ofprecision that meets the requirement identified in subpart C of part 53 of this chapter, agencies may cite peer-reviewed published data or data in AQS that can be presented demonstrating the candidate ARM operated will produce data that meets the specification for precision of Class 

### III PM2. 5methods. 2.4.1.5 A minimum of90valid sample pairs per site for the year with no less than 20 valid sample pairs per season must be generated forusein demonstrating thatadditive bias, multiplicative bias and correlation
meet the comparability requirements specified in subpart C ofpart53 ofthis chapter. A valid sample pair may be generated with as little as one valid FRM and one valid can- didate ARM measurement perday.

2.4.1.6 For purposes of determining bias, FRM data with concentrations less than 3 micrograms per cubic meter (gg/m 5) may be 

## Pt.58,App.C

excluded. Exclusion of data does not result in failure ofsamplecompleteness specified in this section.

2.4.1.7 Data transformations are allowed to be used to demonstrate meeting the com- parability requirements specified in subpart C of part 53 of this chapter. Data transformation may be linear or non-linear, but
must be applied in the same way to all sites used in the testing.

2.4.2 The monitoring agency wishing to

use anARM mustdevelop andimplement appropriate quality assurance procedures for the method. Additionally, the following procedures arerequired for the method:

2.4.2.1 The ARM must be consistently operated throughout the network. Exceptions
to a consistent operation must be approved according to section 2.8ofthis appendix;

2.4.2.2 The ARM must be operated on an hourly sampling frequency capable of providing data suitable for aggregation into daily 24-hour average measurements;

2.4.2.3 The ARM must use an inlet and separation device, as needed, that are already approved in either the reference method identified in appendix L to part 50 ofthis chapter or under part 53 of this chapter as approved for use on a PM 2.

5 reference or equivalent method. The only exceptions to this requirement are those methods that by their inherent measurement principle may not need an inlet or separation device that segregates the aerosol; and

2.4.2.4 The ARM must be capable of providing for flow audits, unless by its inherent measurement principle, measured flow is not required. These flow audits are to be performed on the frequency identified in appendix Atothispart.

2.4.2.5 If data transformations are used, they must be described in the monitoring agencies Quality Assurance Project plan (or addendum to QAPP). The QAPP shall describe how often (e.g., quarterly, yearly) and under what provisions the data transformation will be updated. For example, not meeting the data quality objectives for a site

over a season oryearmay be cause for recalculating a data transformation, butby itself would notbe cause for invalidating the data. Data transformations must be applied prospectively, i.e., in real-time or near realtime, to the data output from the PM2. 5 continuous method. See reference 7 of this appendix.

2.4.3 The monitoring agency wishing to

use the method must develop and implement appropriate procedures for assessing and reporting the precision and accuracy of the method comparable to the procedures set forth in appendix A of this part for designated reference andequivalent methods.

2.4.4 Assessments of data quality shall follow the same frequencies and calculations

as required under section 3 ofappendix A to thispartwith the followingexceptions:



## 275

### Pt. 58, App.C

2.4.4.1 Collocation ofARM with FRM/FEM samplers must be maintained at a minimum of 30 percent of the required SLAMS sites with a minimum of1pernetwork;

2.4.4.2 All collocated FRM/FEM samplers
must maintain a sample frequency of at least 1in6 sample days;

2.4.4.3 Collocated FRM/FEM samplers shall belocated atthedesign value site, with the required FRM/FEM samplers deployed
among the largest MSA/CSA inthe network, until all required FRM/FEM are deployed; and

2.4.4.4 Data from collocated FRM/FEM are to be substituted for any calendar quarter that anARM methodhas incomplete data.

2.4.4.5 Collocation with an ARM under this partfor purposes ofdetermining the coefficient ofvariation ofthe method shall be conducted at a minimum of7.5percent ofthe sites with a minimum of1per network. This is consistent with the requirements in appendix A to this part for one-halfof the required collocation of FRM/FEM (15 percent)
tobe collocated with the same method.

2.4.4.6 Assessments of bias with an independent audit ofthe total measurement system shall be conducted with the same frequency as an FEM as identified in appendix Atothispart.

2.4.5 Request for approval ofa candidate ARM, that is not already approved in another agency's network under this section,
must meet the general submittal requirements of section 2.7 of this appendix. Requests for approval under this section when

an ARM isalready approved inanother agency'snetwork aretobe submitted tothe EPA Regional Administrator. Requests for approval under section 2.4 of this appendix
mustinclude thefollowing requirements:

2.4.5.1 A clear and unique description of the site(s) at which the candidate ARM will be used and tested, and a description ofthe
nature or character ofthe site and the particulate matter that is expected to occur there.

2.4.5.2 A detailed description of the methodand thenature ofthesampler or analyzer
uponwhich it is based.

2.4.5.3 A brief statement of the reason or rationale forrequestingthe approval.

2.4.5.4 A detailed description of the quality assurance procedures that have been developed and thatwill be implemented for the method.

2.4.5.5 A detailed description ofthe procedures for assessing the precision and accuracy ofthe method thatwill beimplemented forreporting toAQS.

2.4.5.6 Test results from the comparability tests as required in section 2.4.1 through2.4.1.4 ofthis appendix.

2.4.5.7 Such further supplemental information as may be necessary or helpful to support the required statements and testresults. 

### 40CFRCh. 1 (7-1-12 Edition)

2.4.6 Within 120 days after receiving a request for approval ofthe use ofan ARM ata particular site or network ofsites under section 2.4 of this appendix, the Administrator will approve or disapprove the method by letter to the person or agency requesting such approval. When appropriate for methods thatare already approved in another SLAMS network, the EPA Regional Administrator has approval/disapproval authority. Ineither instance, additional information may be requestedto assist with the decision.

2.5 [Reserved] 2.6 Use ofMethods With Higher, Nonconforming Ranges in Certain Geographical Areas.

2.6.1 [Reserved] 2.6.2 An analyzer may be used (indefinitely) on a range which extends to concentrations higher than two times the upper limit specified in table B-1 ofpart 53 ofthis chapterif:

2.6.2.1 The analyzer has morethan one selectable range and has been designated as a reference or equivalent method on at least

one of its ranges, or has been approved for

use under section 2.5 (which applies to analyzerspurchased before February 18, 1975);

2.6.2.2 The pollutant intended tobe measured with the analyzer is likely to occur in concentrations more than two times the
upper range limit specified in table B-1 of part 53 of this chapter in the geographical

area inwhich use ofthe analyzer isproposed; and

2.6.2.3 The Administrator determines that the resolution of the range or ranges for which approval is sought is adequate for its intended use. For purposes of this section (2.6), "resolution" means the ability of the analyzer to detect small changes in concentration.

2.6.3 Requests for approval under section 2.6.2 of this appendix must meet the submittal requirements ofsection 2.7. Except as provided in section 2.7.3 of this appendix, each request must contain the information specified in section 2.7.2 in addition to the following:

2.6.3.1 The range orranges proposed tobe used;

2.6.3.2 Test data, records, calculations, and test results as specified in section 2.7.2.2 ofthis appendix for each range proposed to be used;

2.6.3.3 An identification anddescription of thegeographical areain which use ofthe analyzer isproposed;

2.6.3.4 Data or other information demonstrating that the pollutant intended to be measured with the analyzer is likely to

occur inconcentrations morethan twotimes the upper range limit specified in table B-i ofpart 53 ofthis chapter inthe geographical

areain which useofthe analyzer isproposed; and



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2.6.3.5 Test data or other information demonstrating the resolution of each proposed range that is broader than that permittedby section 2.5 ofthisappendix.

2.6.4 Any person who has obtained approval ofa request under this section (2.6.2) shall assure that the analyzer for which approval was obtained is used only in the geographical area identified in the request and only while operated in the range or ranges specified in therequest.

2.7 Requests for Approval; Withdrawal of Approval.

2.7.1 Requests for approval under sections 2.4, 2.6.2, or 2.8 ofthis appendix must be submitted to: Director, National Exposure Research Laboratory (MD-D205-03), U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711. For ARM that are already approved in another agency's network, subsequent requests for approval under section 2.4 are to be submitted to the applicable EPA Regional Administrator.

2.7.2 Except as provided in section 2.7.3 of this appendix, eachrequest must contain:

2.7.2.1 A statement identifying the ana- lyzer (e.g., by serial number) and the method ofwhich the analyzer is representative (e.g., by manufacturer and model number); and

2.7.2.2 Test data, records, calculations, and test results for the analyzer (or the method ofwhich the analyzer is representative) as specified in subpart B, subpart C, or both (asapplicable) ofpart 53ofthis chapter.

2.7.3 A request may concern more than

one analyzer or geographical area and may incorporate by reference any data or other information known to EPAfrom one ormore ofthe following:

2.7.3.1 An application for a reference or equivalent method determination submitted toEPA for the method ofwhich the analyzer is representative, or testing conducted by the applicant orby EPA in connection with such anapplication;

2.7.3.2 Testing ofthe method ofwhich the analyzer isrepresentative atthe initiative of the Administrator under 

### §53.7 of this chapter;or

2.7.3.3 A previous or concurrent request for approval submitted to EPA under this section (2.7).

2.7.4 To the extent that such incorporation by reference provides data or information required by this section (2.7) or by sections 2.4, 2.5, or 2.6 of this appendix, independent data or duplicative information need notbe submitted.

2.7.5 After receiving a request under this section (2.7), the Administrator may request such additional testing or information or conduct such tests as may be necessary in hisjudgment fora decision on therequest.

2.7.6 Ifthe Administrator determines, on the basis ofany available information, that any ofthe determinations or statements on 

## Pt. 58,App.C

which approval of a request under this sec- tion was basedare invalid orno longer valid,

or that the requirements of section 2.4, 2.5,

or 2.6, as applicable, have not been met, he/ she may withdraw the approval after affording the person who obtained the approval an opportunity to submit information and arguments opposingsuch action.

2.8 Modifications ofMethods byUsers. 2.8.1 Except as otherwise provided in this section, no reference method, equivalent method, or ARM may be used in a SLAMS network ifit hasbeen modified in a manner that could significantly alter the performance characteristics of the method without prior approval by the Administrator. For purposes of this section, "alternative method" means an analyzer, the use ofwhich has been approved under section 2.4, 2.5, or 2.6 of this appendixor some combination thereof.

2.8.2 Requests for approval under this section (2.8) must meet the submittal requirements ofsections 2.7.1 and 2.7.2.1 ofthis appendix.

2.8.3 Each request submitted under this section (2.8) mustinclude:

2.8.3.1 A description, in such detail as may be appropriate, ofthe desired modification;

2.8.3.2 A brief statement ofthe purpose(s) of the modification, including any reasons for considering it necessary oradvantageous;

2.8.3.3 A brief statement of belief con- cerning the extent to which the modification will or may affect the performance characteristics ofthe method; and

2.8.3.4 Such further information as may be necessary to explain and support the statements required by sections 2.8.3.2 and 2.8.3.3.

2.8.4 The Administrator will approve or disapprove the modification by letter to the person or agency requesting such approval within 75 days after receiving a request for approval under this section and any further information that the applicant maybe asked toprovide.

2.8.5 A temporary modification thatcould alter the performance characteristics of a reference, equivalent, or ARM may be made without prior approval under this section if the method is not functioning or is malfunctioning, provided that partsnecessary forrepair in accordance with the applicable operation manual cannot be obtained within 45 days. Unless such temporary modification is later approved under section 2.8.4 of this appendix, the temporarily modified method shall be repaired in accordance with the applicable operation manual as quickly as practicable but in no event later than 4 months after the temporary modification

was made, unless an extension of time is granted by the Administrator. Unless and until the temporary modification is approved, air quality data obtained with the method as temporarily modified must be



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### Pt.58,App.C

clearly identified as such when submitted in accordance with 

### §58.16 and must be accompanied by a report containing the information specified in section 2.8.3 of this appendix. A request that the Administrator approve a temporary modification may be submitted in accordance with sections 2.8.1 through 2.8.4 ofthis appendix. In such cases therequest will be considered as ifa request for priorapproval hadbeen made.

2.9 Use of IMPROVE Samplers at a SLAMS Site. "IMPROVE" samplers may be used in SLAMS for monitoring of regional background and regional transport concentrations of fine particulate matter. The IMPROVE samplers were developed for use in the Interagency Monitoring of Protected Visual Environments (IMPROVE) network to characterize allofthemajor components and
many trace constituents of the particulate
matter that impair visibility in Federal Class I Areas. Descriptions ofthe IMPROVE samplers and thedata they collect are available inreferences 4,5, and 6ofthisappendix.

2.10 UseofPb-PMoatSLAMS Sites. 2.10.1 The EPA Regional Administrator
may approve the use of a Pb-PMao FRM or Pb-PM1o FEM sampler in lieu of a Pb-TSP sampler as part ofthenetwork plan required under part 58.10(a)(4) in the following cases.

2.10.1.1 Pb-PM1o samplers can be approved for use at the non-source-oriented sites required under paragraph 4.5(b) ofAppendix D
to part 58 ifthere is no existing monitoring data indicating that the maximum arithmetic 3-month mean Pb concentration (either Pb-TSP or Pb-PMo) at the site was equal to or greater than 0.10 micrograms per cubicmeter duringthe previous 3years.

2.10.1.2 Pb-PMo samplers can be approved for use at source-oriented sites required under paragraph 4.5(a) if the monitoring
agency can demonstrate (through modeling

or historic monitoring data from the last 3 years) that Pb concentrations (either PbTSP orPb-PMo) will not equal or exceed0.10 micrograms per cubic meter on an arithmetic 3-month mean and the source is expected to emit a substantial majority of its Pb in the fraction of PM with an aerodynamic diameter ofless than or equal to 10 micrometers.

2.10.2 The approval ofa Pb-PMo sampler in lieu ofa Pb-TSP sampler as allowed forin paragraph 2.10.1 above will be revoked if measured Pb-PM,0 concentrations equal or exceed 0.10 micrograms per cubic meter on

an arithmetic 3-month mean. Monitoring agencies will have up to 6 months from the end ofthe 3-month period in which the arithmetic 3-month Pb-PM0 mean concentration equaled or exceeded 0.10 micrograms per cubic meter to install and begin operation of

aPb-TSP sampler atthe site. 

### 40 CFR Ch. 1(7-1-12 Edition)

3.0 NCORE AMBIENT AIRMONITORING

STATIONS
3.1 Methods employed in NCore multipollutant sites used to measure S02, CO, NO2, 03, PM2. 5, or PM1o-2.5 must be reference

or equivalent methods as defined in 

### §50.1 of thischapter, or anARM asdefined in section 2.4 of this appendix, for any monitors intended for comparison with applicable NAAQS.

3.2 If alternative S0 2, CO, NO2, 03, PM2 .5,

or PMIo-25 monitoring methodologies are proposed for monitors not intended for NAAQS comparison, such techniques must be detailed in the network description required by 

### §58.10 and subsequently approved by the Administrator. Examples oflocations that are not intended to be compared to the NAAQS may be rural background and transport sites or areas where the concentration of the pollutant is so low that it would be

more useful to operate a higher sensitivity method that is not an FRM orFEM.

4.0 PHOTOCHEMICAL ASSESSMENT MONITORING STATIONS (PAMS)
4.1 Methods used for 03 monitoring at PAMS must be automated reference or equivalent methods asdefined in

### §50.1 ofthis chapter.

4.2 Methods used for NO, NO2 and NOx monitoring at PAMS should be automated reference or equivalent methods as defined for NO2 in 

### § 50.1 ofthis chapter. Ifalternative NO, NO2 or NOx monitoring methodologies

are proposed, such techniques must be detailed inthe network description required by 

### §58.10 and subsequently approved by theAdministrator.

4.3 Methods for meteorological measurements and speciated VOC monitoring are included in theguidance provided inreferences 2 and 3 of this appendix. Ifalternative VOC monitoring methodology (including the use of new orinnovative technologies), which is
not included in the guidance, is proposed, it
must be detailed in the network description required by 

### § 58.10 and subsequently approved by theAdministrator.

5.0 PARTICULATE MATTER EPISODE MONITORING
5.1 For short-term measurements ofPMo during air pollution episodes (see 

### §51.152 of this chapter) the measurement method must be:

5.1.1 Either the "Staggered PMao" method

orthe "PMo Sampling Over Short Sampling Times" method, both ofwhich are based on the reference method for PMso and are described inreference 1: or

5.1.2 Any other method for measuring 

### PM,0

### :

5.1.2.1 Which has a measurement range or ranges appropriate to accurately measure air pollutionepisode concentration ofPMo,



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## Environmental ProtectionAgency

5.1.2.2 Which has a sample period appropriate for short-term PMo measurements, and

5.1.2.3 For which a quantitative relationship to a reference or equivalent method for PMso has been established at the use site. Procedures for establishing a quantitative site-specific relationship are contained in reference 1.

5.2 PM 1omethods otherthan the reference method are not covered underthe quality as- sessment requirements of appendix to this part.Therefore, States must develop and implement their own quality assessment procedures for those methods allowed under this section 4. These quality assessment procedures should be similar or analogous tothose described in section 3 ofappendix A to this part for the PM 1oreference method.

6.0 REFERENCES
1. Pelton, D. J. Guideline for Particulate Episode Monitoring Methods, GEOMET Technologies, Inc., Rockville, MD. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Contract No. 68-02-3584. EPA 450/4-83-005. February 1983.

2. Technical Assistance Document For Sampling and Analysis of Ozone Precursors. Atmospheric Research and Exposure Assessment Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711. EPA 600/8-91-215. October 1991.

3. Quality Assurance Handbookfor AirPollution Measurement Systems: Volume IV. Meteorological Measurements. Atmospheric Research and Exposure Assessment Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711. EPA 600/4-90-0003. August 1989.

4. Eldred, R.A., Cahill, T.A., Wilkenson, L.K., et al., Measurements of fine particles and their chemical components in the IMPROVE/NPS networks, in Transactions of the International Specialty Conference on Visibility and Fine Particles, Air and Waste Management Association: Pittsburgh, PA, 1990; pp.187-196.

5. Sisler, J.F., Huffman, D., and Latimer, D.A.; Spatial and temporal patterns and the chemical composition of the haze in the United States: An analysis ofdata from the IMPROVE network, 1988-1991, ISSN No. 0737- 5253-26, National Park Service, Ft. Collins, CO, 1993.

6. Eldred, R.A., Cahill, T.A., Pitchford, M., and Malm, W.C.; IMPROVE-a new remote

area particulate monitoring system for visibility studies, Proceedings ofthe81st Annual Meeting of the Air Pollution Control Association, Dallas,Paper 88-54.3, 1988.

7. Data Quality Objectives (DQOs) for Relating Federal Reference Method (FRM) and Continuous PM 2.5 Measurements to Report

an Air Quality Index (AQI). Office of Air Quality Planning and Standards, U.S. Envi

## Pt.58, App.D

ronmental Protection Agency, Research Triangle Park, NC 27711. EPA 454/B-02-2002. November 2002. [71 FR 61313, Oct. 17, 2006, as amended at 73 FR 67061, Nov. 12, 2008; 75 FR 6534, Feb. 9, 2010]

APPENDIX D TO PART 58-NETWORK DESIGN CRITERIA FOR AMBIENT AIR QUALITY MONITORING

1. Monitoring Objectives and Spatial Scales 2. General Monitoring Requirements 3. Design Criteria for NCore Sites 4. Pollutant-Specific Design Criteria for

SLAMS Sites 5. Design Criteria for Photochemical AssessmentMonitoring Stations (PAMS) 6. References

1. MONITORING OBJECTIVES AND SPATIAL SCALES
Thepurpose ofthis appendix is to describe monitoring objectives andgeneral criteria to be applied in establishing the required SLAMS ambient air quality monitoring stations and for choosing general locations for additional monitoring sites. This appendix also describes specific requirements for the number and location of FRM, FEM, and ARM sites for specific pollutants, NCore multipollutant sites, PMio mass sites, PM 2.

5 mass sites, chemically-speciated PM2 .5 sites, and 03 precursor measurements sites (PAMS). These criteria will be used by EPA in evaluating the adequacy ofthe airpollutantmonitoring networks.

1.1 Monitoring Objectives. The ambient air monitoring networks mustbe designed to meet three basic monitoring objectives. These basic objectives are listed below. The appearance of any one objective in the order of this list is not based upon a prioritized scheme. Each objective is important and
mustbe considered individually.

(a) Provide air pollution data to the general public in a timely manner. Data can be presented to the public in a number of attractive ways including through air quality maps, newspapers, Internet sites, andas part ofweather forecasts andpublic advisories.

(b) Support compliance with ambient air quality standards and emissions strategy development. Data from FRM, FEM, and ARM monitors for NAAQS pollutants will be used for comparing an area's air pollution levels against the NAAQS. Data from monitors of various types canbe used inthedevelopment of attainment and maintenance plans. SLAMS, and especially NCore station data, will be used to evaluate the regional air quality models used in developing emission strategies, and to track trends in air pollution abatement control measures' impact on improving air quality. In monitoring locations 'near major air pollution sources, 

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### Pt. 58, App.D

source-oriented monitoring data can provide insight into how well industrial sources are controlling their pollutant emissions.

(c) Support for air pollution research studies. Air pollution data from the NCore network can be used to supplement data collected by researchers working on health effects assessments andatmospheric processes,
or for monitoring methods development work.

1.1.1 In order to support the air quality management work indicated in the three basic air monitoring objectives, a network must be designed with a variety oftypes of monitoring sites. Monitoring sites must be capable of informing managers about many things including the peak air pollution levels, typical levels inpopulated areas, air pollution transported into and outside of a city

or region, and air pollution levels near specific sources. To summarize some of these sites, here is a listing of six general site types:

(a) Sites located to determine the highest concentrations expected to occur in the area covered bythenetwork.

(b) Sites located to measure typical con- centrations in areas ofhigh population density.

(c) Sites located to determine the impact ofsignificant sources or source categories on airquality.

(d) Sites located to determine general background concentration levels.

(e) Sites located to determine the extent of regional pollutant transport among populated areas; and in support of secondary standards.

(f) Sites located to measure air pollution impacts on visibility,vegetation damage, or otherwelfare-based impacts.

1.1.2 This appendix contains criteria for the basic air monitoring requirements. The total number of monitoring sites that will

serve the variety of data needs will be substantially higher than these minimum re- quirements provide. The optimum size of a particular network involves trade-offs among data needs and available resources. This regulation intends to provide for na- tional air monitoring needs, and to lend support for the flexibility necessary to meet data collection needs of area air quality managers. The EPA, State, and local agencies will periodically collaborate on network design issues through the network assess- ment process outlinedin

### §58.10.

1.1.3 This appendix focuses on the relationship between monitoring objectives, site types, and the geographic location ofmonitoring sites. Included are a rationale and set ofgeneral criteria for identifying candidate sitelocations interms ofphysical characteristics which most closely match a specific monitoring objective. The criteria for more specifically locating the monitoring site, including spacing from roadways and vertical 

### 40CFR Ch. 1 (7-1-12 Edition)

and horizontal probe and path placement,

are described in appendix Etothis part.

1.2 Spatial Scales. (a) To clarify the nature ofthe link between general monitoring objectives, site types, and the physical location ofa particular monitor, the concept of spatial scale ofrepresentativeness is defined. The goal in locating monitors is to correctly match the spatial scale represented by the sample of monitored air with the spatial scale most appropriate for the monitoring site type, air pollutant to be measured, and themonitoring objective.

(b) Thus, spatial scale of representative-

nessis described in terms ofthe physical dimensions ofthe air parcel nearest to a monitoring site throughout which actual pollutant concentrations are reasonably similar. The scales of representativeness ofmost interest for the monitoring site types describedabove are as follows:

(1) Microscale-Defines the concentrations in air volumes associated with area dimensions ranging from several meters up to about100 meters.

(2)Middle scale-Defines the concentration typical ofareas up to several city blocks in size with dimensions ranging from about 100
meters to 0.5 kilometer.

(3) Neighborhoodscale-Defines concentrations within some extended area of the city thathas relatively uniform land use with dimensions in the 0.5 to 4.0 kilometers range. The neighborhood and urban scales listed below have the potential to overlap in applications that concern secondarily formed or homogeneously distributed airpollutants.

(4) Urban scale-Defines concentrations within an area of city-like dimensions, on the order of4to 50 kilometers. Within a city, the geographic placement ofsources may result inthere being no single site that can be said to represent air quality on an urban scale.

(5) Regional scale-Defines usually a rural

area of reasonably homogeneous geography without large sources, and extends from tens tohundreds ofkilometers.

(6) National andglobal scales-These measurement scales represent concentrations characterizing the nation and the globe as a whole.

(c) Proper siting of a monitor requires specification of the monitoring objective, the types ofsites necessary to meet the objective, and then the desired spatial scale of representativeness. For example, consider the case where the objective is to determine NAAQS compliance by understanding the maximum ozone concentrations for an area. Such areas would most likely be located downwind ofa metropolitan area, quite likely in a suburban residential area where children and other susceptible individuals are likely tobe outdoors. Sites located in these

areas are most likely to represent an urban



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## Environmental ProtectionAgency

scale ofmeasurement. Inthis example, physical location was determined by considering

ozone precursor emissionpatterns, public ac- tivity,and meteorological characteristics affecting ozone formation and dispersion. Thus, spatial scale ofrepresentativeness was not used in the selection process but was a resultofsite location.

(d) In some cases, the physical location of

a siteis determined fromjoint consideration of both the basic monitoring objective and the type of monitoring site desired, or re- quired by this appendix. For example, to determine PM 2
.

5 concentrations which are typical over a geographic areahaving relatively high PM 2.

5 concentrations, a neighborhood scale site is more appropriate. Such a site would likely be located in a residential or commercial area having a high overall PM 2

_

5 emission density but not in the immediate vicinity of any singledominant source. Note thatin this example, thedesired scale ofrepresentativeness was an important factor in determining the physical location of the monitoring site.

(e) In either case, classification of the monitor by its type and spatial scale ofrepresentativeness is necessary and will aid in interpretation of the monitoring data for a particular monitoring objective (e.g., public reporting, NAAQS compliance, or research support).

(f) Table D-1 of this appendix illustrates the relationship between the various site types that can be used to support the three basic monitoring objectives, and the scales of representativeness that are generally most appropriate for thattype ofsite.

TABLE D-1 OF APPENDIX 

### D TO PART 58-RELATIONSHIP BETWEEN SITE TYPES AND SCALES OF REPRESENTATIVENESS

Sitetype Appropriate sitingscales

1.Highest concentration

.... Micro, middle, neighborhood (sometimes urban or regional tor secondarily tormed pollutants). 2. Population oriented.Neighborhood, urban. 3.Source impact

............... Micro, middle, neighborhood. 4.General/background & Urban, regional.

regional transport. 5.Weltare-related impacts Urban, regione.

2. GENERAL MONITORING REQUIREMENTS (a) The National ambient air monitoring system includes several types ofmonitoring stations, each targeting a key data collection need and each varying in technical so- phistication.

(b) Research grade sites are platforms for scientific studies, either involved with health or welfare impacts, measurement methods development, or other atmospheric studies. These sites may be collaborative efforts between regulatory agencies and re

## Pt.58,App. D

searchers with specific scientific objectives for each. Datafrom these sites might be collected with both traditional and experimental techniques, and data collection might involve specific laboratory analyses not common in routine measurement programs. The research grade sites are not re- quired by regulation; however, they are included here due to their important role in supporting the air quality management program.

(c) The NCore multipollutant sites are sites that measure multiple pollutants in order to provide support to integrated air quality management data needs. NCore sites include both neighborhood and urban scale measurements in general, in a selection of metropolitan areas and a limited number of

more rural locations. Continuous monitoring methods are to be used at the NCore sites when available for a pollutant to be meas- ured, as it is important to have data collected over common time periods for integrated analyses. NCore multipollutant sites

are intended to be long-term sites useful for

a variety of applications including air quality trends analyses, model evaluation, and tracking metropolitan area statistics. As such, the NCore sites should be placed away from direct emission sources that could substantially impact the ability to detect area- wide. concentrations. The Administrator mustapprove theNCore sites.

(d) Monitoring sites designated as SLAMS sites, but not as NCore sites, are intended to address specific air quality management interests, and as such, are frequently singlepollutant measurement sites. The EPA Regional Administrator must approve the SLAMS sites.

(e) This appendix usesthe statistical-based definitions for metropolitan areas provided bythe Office ofManagement andBudget and the Census Bureau. These areas are referred to as metropolitan statistical areas (MSA), micropolitan statistical areas, core-based statistical areas (CBSA), and combined statistical areas (CSA). A CBSA associated with at least one urbanized area of 50,000 population or greater is termed a Metropolitan Statistical Area (MSA). A CBSA associated with at least one urbanized cluster of at least 10,000 population orgreater is termed a Micropolitan Statistical Area. CSA consist oftwo ormore adjacent CBSA. Inthis appendix, the term MSA is used to refer to a Metropolitan Statistical Area. By definition, both MSA and CSA have a high degree ofintegration; however, many such areas cross State or otherpolitical boundaries. MSA and CSA may also cross more than one air shed. The EPArecognizes that State orlocal agencies must consider MSA/CSA boundaries and their own political boundaries and geographical characteristics in designing their air monitoring networks. The EPA recognizes that there may be situations where the



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### Pt. 58, App. D

EPA Regional Administrator and the affected State or local agencies may need to augment or to divide the overall MSA/CSA monitoring responsibilities and requirements among these various agencies to achieve an effective network design. Full monitoring requirements apply separately to each affected State orlocal agency in the absence ofan agreement between the affected agencies and the EPA Regional Administrator.

3. DESIGN CRITERIA FORNCORE SITES (a) Each State (i.e. the fifty States, District of Columbia, Puerto Rico, and the Virgin Islands) is required to operate at least

one NCore site. States may delegate this requirement to a local agency. States with many MSAs often also have multiple air sheds with unique characteristics and, often, elevated air pollution. These States include,
at a minimum, California, Florida, Illinois, Michigan, New York, North Carolina, Ohio, Pennsylvania, and Texas. These States are required to identify one to two additional NCore sites in order to account for their unique situations. These additional sites shall be located to avoid proximity to large emission sources. Any State or local agency

canpropose additional candidate NCore sites

or modifications to these requirements for approval by the Administrator. The NCore locations should be leveraged with other multipollutant air monitoring sites including PAMS sites, National Air Toxics Trends Stations (NATTS) sites, CASTNET sites, and STN sites. Siteleveraging includes using the

same monitoring platform and equipment to meet the objectives of the variety of programswhere possible and advantageous.

(b) The NCore sites must measure, at a minimum, PM 2.

5 particle mass using continuous and integrated/filter-based samplers, speciated PM 2. 5, PM1o.2.5particle mass, speciated PM 1o-

2. 5, 03, SO2 , CO, NOINOy, wind speed, wind direction, relative humidity, and ambient temperature. NCore sites in CBSA with apopulation of500,000 people (as determined in the latest Census) or greater shall also measure Pb either as Pb-TSP or PbPM 1 

## o.The EPA Regional Administrator may approve an alternative location for the Pb
measurement where the alternative location would be more appropriate for logistical reasons and the measurement would provide data on typical Pb concentrations in the CBSA.

(1)Although the measurement ofNO 5 is required in support ofa number ofmonitoring objectives, available commercial instruments may indicate little difference in their
measurement of NO, compared to the con- ventional measurement ofNOx, particularly in areas with relatively fresh sources of nitrogen emissions. Therefore, in areas with negligible expected difference between NO, 

### 40CFR Ch. 1(7-1-12 Edition)

and NOx measured concentrations, the Administrator may allow for waivers that permitNOx monitoring to be substitutedforthe required NO, monitoring atapplicable NCore sites.

(2)EPA recognizes that, in some cases, the physical location ofthe NCore site may not be suitable for representative meteorological
measurements due to the site's physical surroundings.It isalsopossible thatnearby me- teorological measurements may be able to fulfill this data need. In these cases, the requirement for meteorological monitoring

canbe waived bytheAdministrator.

(c) [Reserved) (d) Siting criteria are provided for urban and rural locations. Sites with significant historical records that do not meet siting criteria may be approved as NCore by the Administrator. Sites with the suite ofNCore measurements that are explicitly designed for other monitoring objectives are exempt from these siting criteria (e.g., a near-roadway site).

(1) Urban NCore stations are to be generally located at urban or neighborhood scale to provide representative concentrations of exposure expected throughout the metropolitan area; however, a middle-scale site may be acceptable in cases where the site can represent many such locations throughout a metropolitan area.

(2) Rural NCore stations are to be located
to the maximum extent practicable at a regional or larger scale away from any large local emission source, so that they represent ambient concentrations over an extensive

area.

4. POLLUTANT-SPECIFIc DESIGNCRITERIA FOR SLAMS SITES

4.1 Ozone (03) Design Criteria. (a) State, and where appropriate, local agencies must operate 03 sites for various locations depending upon area size (in terms of population and geographic characteristics) and typical peak concentrations (expressed in percentages below, or near the 03 NAAQS). Specific SLAMS 03 site minimum requirements are included in Table D-2 of this appendix. The NCore sites are expected to complement the 03 data collection that takes place at singlepollutant SLAMS sites, and both types of sites can be used to meet the network minimum requirements. The total number of 03 sites needed to support the basic monitoring objectives ofpublic data reporting, airquality mapping, compliance, and understanding 0 3

-related atmospheric processes will include

more sites than these minimum numbers required in Table D-2 of this appendix. The EPA Regional Administrator and theresponsible State or local air monitoring agency must work together to design and/or maintain the most appropriate 03 network to service the variety ofdata needs in an area.



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### Environmental Protection Agency

TABLE D-2 OF APPENDIX D TO PART 58- SLAMS MINIMUM 03 MONITORING REQUIREMENTS

Most recent 3- Most recent3- yeardesignvalue yeardesignvalue MSA population'. 2 concentrations concentrations >85% ofany03 <85% ofany 03

NAAOS3 NAAOS34

>10 million

............. 4 2 4-10 million

........... 3 1 350,00Qc4 million 2 1 50,000-<350,0005 1 0

1Minimum monitoring requirements apply to the Metropoli- tan statisticalarea (MSA).

2POpulation based on latestavailablecensusfigures. 3The ozone (03) National Ambient Air Quality Standards (NAAOS) levels andforms are defined in40 CFR part50.

4These minimum monitoring requirements apply inthe ab- senceofadesignvalue.

sMetropolitan statistical areas (MSA) must contain an ur- banizedareaof50,000 ormore population.

(b) Within an 03 network, at least one 03 site for each MSA, or CSA if multiple MSAs

are involved, mustbe designed to record the maximum concentration for that particular metropolitan area. More than one maximum concentration site may be necessary in some
areas. Table D-2 ofthisappendix does not ac- count for the full breadth of additional factors that would be considered in designing a complete 03monitoring program for an area. Some ofthese additional factors include geographic size, population density, complexity ofterrain and meteorology, adjacent 03mon- itoring programs, air pollution transport from neighboring areas, and measured air quality in comparison to all forms ofthe 03 NAAQS (i.e., 8-hour and 1-hour forms). Networks must be designed to account for all of these area characteristics. Network designs must be re-examined in periodic network as- sessments. Deviations from the above 03 re- quirements are allowed if approved by the EPA Regional Administrator.

(c) The appropriate spatial scales for 03 sites are neighborhood, urban, and regional. Since 03 requires appreciable formation time, the mixing of reactants and products

occurs over large volumes ofair, and this re- duces the importance of monitoring small scale spatial variability.

(1) Neighborhood scale-Measurements in this category represent conditions throughout some reasonably homogeneous urban sub-region, with dimensions of a few kilometers. Homogeneity refers to pollutantcon- centrations. Neighborhood scale data will provide valuable information for developing, testing, and revising concepts and models that describe urban/regional concentration patterns. These data will be useful tothe un- derstanding and definition ofprocesses that take periods ofhours to occur and hence involve considerable mixing and transport. Under stagnation conditions, a site located in the neighborhood scale may also experi

### Pt. 58,App. D

encepeak concentration levelswithin ametropolitan area.

(2) Urbanscale-Measurement in this scale willbe used to estimate concentrations over large portions ofan urban area with dimensions ofseveral kilometers to 50 or morekilometers. Such measurements will be used for determining trends, and designing area-wide control strategies. The urban scale sites would also be used to measure high con- centrations downwind ofthe area having the highest precursor emissions.

(3) Regional scale-This scale of measure- ment will be used to typify concentrations

over large portions of a metropolitan area and even larger areas with dimensions of as much ashundreds ofkilometers. Such meas- urements will be useful for assessing the 03 that is transported to and from a metropolitan area, as well as background concentrations. In some situations, particularly when considering very large metropolitan areas with complex source mixtures, regional scale sites can be the maximum concentration location.

(d)EPA's technical guidance documents on 03 monitoring networkdesign should be used to evaluate the adequacy ofeach existing 03 monitor, to relocate an existing site, or to locate anynew03 sites.

(e) For locating a neighborhood scale site to measure typical city concentrations, a reasonably homogeneous geographical area
near the center of the region should be se- lected which is also removed from the influ-

ence of major NOx sources. For an urban scale site to measure the high concentration
areas, the emission inventories should be used to define the extent ofthe area ofimportant nonmethane hydrocarbons and NOx emissions. The meteorological conditions that occur during periods ofmaximum photochemical activity should be determined. These periods canbe identified by examining the meteorological conditions that occur on the highest 03 air quality days. Trajectory analyses, an evaluation ofwind and emission patterns on high 03 days, can also be useful in evaluating an 03 monitoring network. In

areas without any previous 03 air quality measurements, meteorological and 03 pre-
cursor emissions information would be use- ful.

(f) Once the meteorological and air quality data are reviewed, the prospective maximum concentration monitor site should be se- lected in a direction from the city that is most likely to observe the highest 03 con- centrations, more specifically, downwind during periods ofphotochemical activity. In many cases, these maximum concentration 03 siteswill be located 10to 30miles ormore downwind from the urban area where maximum 03 precursor emissions originate. The downwind direction and appropriate distance should be determined from historical meteorological data collected on dayswhich show



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### Pt. 58,App. D

the potential for producing high 03 levels. Monitoring agencies are to consult with their EPA Regional Office when considering siting amaximum 03 concentration site.

(g) In locating a neighborhood scale site which is to measure high concentrations, the

same procedures used forthe urban scale are followed except that the site should be located closer to the areas bordering on the
center city or slightly further downwind in

an area ofhigh densitypopulation.

(h) For regional scale background monitoring sites, similar meteorological analysis

as forthe maximum concentration sites may also inform the decisions for locating regional scale sites. Regional scale sites may be located to provide data on 03 transport between cities, as background sites, or for other data collection purposes. Consideration of both area characteristics, such as meteorology, and the data collection objectives, such astransport, mustbejointly considered for a regional scale site to be useful.

(i) Since 03 levels decrease significantly in the colder parts ofthe year in many areas, 03 is required to be monitored at SLAMS monitoring sitesonly during the "ozone season" as designated in the AQS files on a State-by-State basis and described below in Table D-3 of this appendix. Deviations from the 03 monitoring season must be approved by the EPA Regional Administrator, documented within the annual monitoring network plan, and updated in AQS. Information

on how to analyze 03 data to support a change to the 03 season in support ofthe 8- hour standard for a specific State can be foundin reference 8to thisappendix.

TABLE D-3 TO APPENDIX D OF PART 58-

OZONE MONITORING SEASON BY STATE

State I Begin month Endmonth

Alabama

.......................... Alaska

............................. Arizona

............................ Arkansas

......................... Califomia

......................... Colorado

......................... Connecticut

..................... Delaware

......................... District ofColumbia. Florida

............................. Georgia

........................... Hawaii

............................. Idaho

............................... Illinois

.............................. Indiana

............................ Iowa

................................ Kansas

............................ Kentucky

......................... LouisianaAQCR 019,022 LouisianaAQCR 106. Maine

.............................. Maryland

......................... Massachusetts

................ Michigan

......................... Minnesota

....................... Mississippi

...................... March

.............. April

................. January

........... March

.............. January

........... March

.............. April

................. April

................. April

................. March

.............. March

.............. January

........... May

................. April

................. April

................. April

................. April

................. March

.............. March

......... January

........... April

................. April

................. April

................. April

................. April

................. March

.............. October October December November December September September October October October October December September Octoiber September October October October October December September October September September October October 

### 40CFR Ch. 1(7-1-12 Edition)

TABLE D-3TO APPENDIX D OF PART 58- OZONE MONITORING SEASON BY STATEContinued

State Begin month End month

M

issouri

.......................... April

................. October Montana

.......................... June

................ September Nebraska

............ Aprl......... October Nevada

........................... January

........... December New Hampshire

.............. April

................. September NewJersey

..................... April

................. October New Mexico

.................... January

........... December NewYork

........................ April

................. October NorthCarolina

................ April

................. October North Dakota

.................. May

................. September O

hio

................................ April

................. October Oklahoma

....................... March

.............. November Oregon

............................ May

................. September Pennsylvania

.......... April

................. October Puerto Rico

..................... January

........... December Rhode Island

.................. April

................. September South Carolina

................ April

................. October South Dakota

.................. June

................ September Tennessee

...................... March

.............. October TexasAOCR 106,153, January

........... December

213, 214,216. TexasAQCR 022,210, March

.............. October

211, 212,215,217, 218. Utah

................................ M ay

................. September Vermont

.......................... April

................. September Virginia

............................ April

................. October Washington

..................... May

................. September WestVirginia

.................. April

................. October Wisconsin

....................... April 15

............ October 15 W

yoming

......................... April

................. October American Samoa

............ January

........... December Guam

.............................. January

........... December Virgin Islands

.................. January

........... December

4.2 CarbonMonoxide(CO) DesignCriteria

4.2.1 General Requirements. (a) Except as provided in subsection (b), one CO monitor is required to operate collocated with one required near-road NO2 monitor, as required in Section 4.3.2 ofthis part, in CBSAs having a population of 1,000,000 or more persons. If a CBSA has more than one required near-road NO2 monitor, only one CO monitor is required to be collocated with a near-road NO2 monitor withinthat CBSA.

(b) If a state provides quantitative evidence demonstrating that peak ambient CO concentrations would occur in a near-road location which meets microscale siting criteria in Appendix E ofthis part but is not a near-road NO2monitoring site,then the EPA Regional Administrator may approve a request by a state to use such an alternate near-road location for a CO monitor inplace of collocating a monitor at near-road NO2 monitoring site.

4.2.2 Regional Administrator Required Monitoring. (a) The Regional Administrators, in collaboration with states, may re- quire additional CO monitors above the minimum number ofmonitorsrequired in4.2.1 of this part, where the minimum monitoring



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## Environmental ProtectionAgency

requirements arenot sufficient to meet mon- itorihg objectives. The Regional Administrator may require, athis/her discretion, additional monitors in situations where data or other information suggest that CO con- centrations may be approaching orexceeding the NAAQS. Such situations include, but are not limited to, (1)characterizing impacts on ground-level concentrations due to stationary CO sources, (2) characterizing CO concentrations in downtown areas or urban street canyons, and (3) characterizing CO concentrations in areas that are subject to high ground level CO concentrations particularly due to or enhanced by topographical and meteorological impacts. The Regional Administrator and the respongible State or local air monitoring agency shall work together to design and maintain the most appropriate CO network to address the data needs for an area, and include all monitors under this provision in the annual monitoring networkplan.

4.2.3 CO Monitoring Spatial Scales. (a) Microscale and middle scale measurements

are the most useful site classifications for CO monitoring sites since most people have the potential for exposure on these scales. Carbon monoxide maxima occur primarily in

areas near major roadways and intersections with high traffic density and often in areas withpoor atmospheric ventilation.

(1) Microscale-Microscale measurements typically represent areas in close proximity to major roadways, within street canyons, over sidewalks, and in some cases, point and

area sources. Emissions on roadways result in high ground level CO concentrations at the microscale, where concentration gradients generally exhibit a marked decrease with increasing downwind distance from major roads, or within downtown areas including urban street canyons. Emissions from stationary point and area sources, and non-road sources may, under certain plume conditions, result in high ground level con- centrations at themicroscale.

(2) Middle scale-Middle scale measure- ments are intended to represent areas with dimensions from 100 meters to 0.5 kilometer. Incertain cases, middle scale measurements may apply to areas that have a total length of several kilometers, such as "line" emission source areas. This type of emission

sources areas wouldinclude air qualityalong

a commercially developed street or shopping plaza, freeway corridors, parking lots and feeder streets.

(3)Neighborhoodscale-Neighborhood scale measurements are intended to represent

areas with dimensions from 0.5 kilometers to 4 kilometers. Measurements of CO in this category would represent conditions throughout some reasonably urban sub-regions. In some cases, neighborhood scale data may represent not only the immediate neighborhood spatial area, but also other 

## Pt.58, App.D

similar such areas across the larger urban

area. Neighborhood scale measurements provide relative area-wide concentration data which are useful forproviding relative urban background concentrations, supporting health and scientific research, and foruse in modeling.

4.3 Nitrogen Dioxide (NO2)Design Criteria 4.3.1 General Requirements (a) State and, where appropriate, local agencies mustoperate a minimum number of required NO2 monitoring sites as described below.

4.3.2 Requirement forNear-road NO2 Monitors

(a)Within the NO2 network, there must be

one microscale near-road NO2 monitoring station in each CBSA with a population of 500,000 or more persons to monitor a location ofexpected maximum hourly concentrations sited near a major road with high AADT counts as specified in paragraph 4.3.2(a)(1) of this appendix. An additional near-road NO2 monitoring station is required for any CBSA with a population of 2,500,000 persons or more, or in any CBSA with a population of 500,000 ormore persons that has one or more roadway segments with 250,000 or greater AADT counts to monitor a second location of expected maximum hourly concentrations. CBSA populations shall be based on the latest available census figures.

(1) The near-road NO2monitoring stations shall be selected by ranking all road segments within a CBSA by AADT and then identifying a location or locations adjacent to those highest ranked road segments, con- sidering fleet mix, roadway design, congestion patterns, terrain, and meteorology, where maximum hourly NO2 concentrations

are expected to occur and siting criteria can be metin accordance with appendix E ofthis part. Where a State or local air monitoring agency identifies multiple acceptable can- didate sites where maximum hourly NO2 con- centrations are expected to occur, themonitoring agency shall consider the potential for population exposure in the criteria utilized to select the final site location. Where

one CBSA is required to have two near-road NO2 monitoring stations, the sites shall be differentiated from each other by one or
more ofthefollowing factors: fleetmix; con- gestion patterns; terrain; geographic area within the CBSA; or different route, interstate, orfreeway designation.

(b) Measurements at required near-road NO2 monitor sites utilizing chemiluminescence FRMs must include at a minimum: NO, NO2,andNOx.

4.3.3 Requirement for Area-wide NO2 Monitoring

(a) Within theNO2network, there must be

one monitoring station in each CBSA with a population of 1,000,000 or more persons to monitor a location of expected highest NO2 

## 285

### Pt.58,App. D

concentrations representing the neighborhood orlarger spatial scales. PAMS sites collecting NO2data that are situated in an area of expected high NO2 concentrations at the neighborhood or larger spatial scale may be used to satisfythis minimum monitoring requirement when the NO2monitor is operated year round. Emission inventories and meteorological analysis shouldbe usedto identify the appropriate locations within a CBSA for locating required area-wide NO2 monitoring stations. CBSA populations shall bebased on thelatest available censusfigures.

4.3.4 Regional Administrator Required Monitoring

(a) The Regional Administrators, in collaboration with States, must require a minimum of forty additional NO2 monitoring stations nationwide in any area, inside or outside ofCBSAs, above the minimum monitoringrequirements, with aprimary focus on siting these monitors in locations to protect susceptible and vulnerable populations. The Regional Administrators, working with States, may also consider additional factors described in paragraph (b) below to require monitors beyond the minimum network requirement.

(b) The Regional Administrators may require monitors to be sited inside or outside ofCBSAs inwhich:

(i)The required near-road monitors do not represent all locations ofexpectedmaximum hourly NO2 concentrations in an area and NO2 concentrations may be approaching or exceeding theNAAQS inthat area;

(ii) Areas that are not required to have a monitor in accordance with the monitoring requirements and NO2concentrations maybe approaching orexceeding theNAAQS; or

(iii) The. minimum monitoring requirements for area-wide monitors are not sufficientto meet monitoring objectives.

(c) The Regional Administrator and the re- sponsible State orlocal airmonitoring agency should work together to design and/or maintain the most appropriate NO2 network
toaddress the data needs for an area, and include all monitors under this provision in theannual monitoring networkplan.

4.3.5 NO2Monitoring Spatial Scales (a) The most important spatial scale for near-road NO2 monitoring stations to effectively characterize the maximum expected hourly NO2 concentration due to mobile

source emissions on major roadways is the microscale. The most important spatial scales for other monitoring stations characterizing maximum expected hourly NO2 con- centrations are the microscale and middle scale. The most important spatial scale for area-wide monitoring ofhigh NO2 concentrationsis theneighborhood scale.

(1)Microscale-This scale represents areas in close proximity to major roadways or pointand area sources. Emissions fromroadways result in high ground level NO2 con

### 40CFR Ch. 1(7-1-12 Edition)

centrations at the microscale, where concentration gradients generally exhibit a marked decrease with increasing downwind distance from major roads. As noted in appendix E of this part, near-road NO2 monitoring stations are required to be within 50 meters of target road segments in order to

measure expected peak concentrations. Emissions from stationary point and area sources, and non-road sources may, under certain plume conditions, result in high ground level concentrations at the microscale. The microscale typically represents an area impacted by the plume with dimensions extending up to approximately 100 meters.

(2) Middle scale-This scale generally represents air quality levels in areas up to sev- eral city blocks in size with dimensions on the order ofapproximately 100 meters to 500
meters. The middle scale may include locations of expected maximum hourly con- centrations due to proximity to major NO2 point,area, and/or non-road sources.

(3) Neighborhood scale-The neighborhood scale represents air quality conditions throughout somerelatively uniform land use
areas with dimensions in the 0.5 to 4.0 kilometer range. Emissions from stationary point and area sources may, under certain plume conditions, result in high NO2 concentrations at theneighborhood scale. Where

a neighborhood site is locatedaway from immediate NO2 sources, the site may be useful in representing typical air quality values for

alarger residential area, and therefore suitable forpopulation exposureand trends analyses.

(4) Urbanscale-Measurements in this scale would be used to estimate concentrations

over large portions ofan urban area with dimensions from 4 to 50 kilometers. Such
measurements would be useful for assessing trends in area-wide air quality, and hence, the effectiveness oflarge scale air pollution control strategies. Urban scale sites may also support other monitoring objectives of the NO2 monitoring network identified in paragraph 4.3.4 above.

4.3.6 NO Monitoring (a) NO/NO2 measurements are included within the NCore multi-pollutant site re- quirements and the PAMS program. These NO/NO measurements will produce conservative estimates for NO2 that can be used to

ensure tracking continued compliance with the NO2 NAAQS. NO/NO monitors are used
at these sites because it is important to collect data on total reactive nitrogen species forunderstanding 03 photochemistry.

4.4 SulfurDioxide(SO2 )DesignCriteria.

4.4.1 GeneralRequirements. (a) State and, where appropriate, local agencies must operate a minimum number ofrequired SO 2 monitoring sitesas describedbelow.



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## Environmental Protection Agency

4.4.2 RequirementforMonitoringby the Population WeightedEmissionsIndex. (a)The population weighted emissions index (PWEI) shall be calculated by States for each core based statistical area (CBSA) they contain

or share with another State or States for use in the implementation of or adjustment to the SO2monitoring network. The PWEI shall be calculated by multiplying the population ofeach CBSA, using the most current census data or estimates, and the total amount of SO2 in tons per year emitted within the CBSA area, using an aggregate of the most recent county level emissions data available in the National Emissions Inventory for each county in each CBSA. The resulting product shall be divided by one million, providing a PWEI value, the units of which are million persons-tons per year. For any CBSA with a calculated PWEI value equal to or greater than 1,000,000, a minimum ofthree SO2 mon- itors are required within that CBSA. For any CBSA with a calculated PWEI value equal to

or greater than 100,000, but less than 1,000,000, a minimum oftwo SO2 monitors are required within that CBSA. For any CBSA with a calculated PWEI value equal to or greater than 5,000, but less than 100,000, a minimum of one SO 2 monitor is required within that CBSA.

(1)The SO2monitoring site(s) required as a result ofthe calculated PWEI in each CBSA shall satisfy minimum monitoring requirements if the monitor is sited within the boundaries ofthe parent CBSA and is one of the following site types (as defined insection 1.1.1 of this appendix): population exposure, highest concentration, source impacts, general background, or regional transport. SO2 monitors at NCore stations may satisfy minimum monitoring requirements ifthat mon- itor is located within a CBSA with minimally required monitors under this part. Any monitor that is sited outside ofa CBSA with minimum monitoring requirements to

assess the highest concentration resulting from the impact of significant sources or
source categories existing within that CBSA shall be allowed to count towards minimum monitoring requirements for that CBSA.

4.4.3 RegionalAdministratorRequiredMonitoring. (a) The Regional Administrator may require additional SO2 monitoring stations above the minimum number of monitors re- quired in 4.4.2 of this part, where the minimum monitoring requirements are not sufficient to meet monitoring objectives. The Regional Administrator may require, athis/her discretion, additional monitors in situations where anarea has the potential to have con- centrations that may violate or contribute to the violation ofthe NAAQS, in areas impacted by sources which are not conducive to modeling, or in locations with susceptible and vulnerable populations, which are not monitored under the minimum monitoring provisions described above. The Regional Ad

## Pt.58, App.D

ministrator and the responsible State or local air monitoring agency shall work together to design and/or maintain the most appropriate SO2 network to provide sufficient data to meet monitoring objectives.

4.4.4 SO2MonitoringSpatialScales. (a)The appropriate spatial scales for SO2 SLAMS monitors are the microscale, middle, neighborhood, and urban scales. Monitors sited at the microscale, middle, and neighborhood scales are suitable for determining max- imum hourly concentrations for SO2. Monitors sited at urban scales are useful for identifying SO2 transport, trends, and, if sited upwind of local sources, background concentrations.

(1) Microscale-This scale would typify

areas in close proximity to SO2 point and

area sources. Emissions from stationary point and.area sources, and non-road sources may, under certain plume conditions, result in high ground level concentrations at the microscale. The microscale typically represents an area impacted by the plume with dimensions extending up to approximately 100 meters.

(2) Middle scale-This scale generally represents air quality levels in areas up to sev- eral city blocks in size with dimensions on the order ofapproximately 100 meters to 500 meters. The middle scale may include locations of expected maximum short-term con- centrations due to proximity to major SO2 point, area,and/or non-road sources.

(3) Neighborhood scale-The neighborhood scale would characterize air quality conditions throughout some relatively uniform land use areas with dimensions in the 0.5 to 4.0 kilometer range. Emissions from stationary point and area sources may, under certain plume conditions, result inhigh SO2 concentrations at the neighborhood scale. Where a neighborhood site is located away from immediate SO2sources, the site may be useful in representing typical air quality values for a larger residential area, and therefore suitable for population exposure and trends analyses.

(4) Urbanscale-Measurements in this scale would be used to estimate concentrations

over large portions ofan urban area with dimensions from 4 to 50 kilometers. Such measurements would be useful for assessing trends in area-wide air quality, and hence, the effectiveness oflarge scale air pollution control strategies. Urban scale sites may also support other monitoring objectives of the SO2 monitoring network such as identifying trends, and when monitors are sited upwind of local sources, background con- centrations.

4.4.5 NCore Monitoring. (a) SO2 measurements are included within the NCore multipollutant site requirements as described in paragraph (3)(b) of this appendix. NCorebased SO2 measurements are primarily used


## 287

### Pt. 58, App. D

to characterize SO2 trends and assist in understanding SO2 transport across representative areas in urban orrural locations and are also used for comparison with the SO2 NAAQS. SO2 monitors at NCore sites that exist in CBSAs with minimum monitoring requirements per section 4.4.2 above shall be allowed to count towards those minimum monitoring requirements.

4.5 Lead(Pb) DesignCriteria.(a) State and, where appropriate, local agencies are required to conduct ambient air Pbmonitoring

near Pb sources which are expected to or have been shown to contribute to a max- imum Pb concentration in ambient air in excess of the NAAQS, taking into account the logistics and potential for population exposure. At a minimum, there must be one source-oriented SLAMS sitelocated to measure the maximum Pbconcentration in ambient air resulting from each non-airport Pb

source which emits 0.50 or more tons per year and from each airport which emits 1.0

or more tons per year based on either the most recent National Emission Inventory (http://www.epa.gov/ttn/chief/ eiinformation.html)or other scientificallyjustifiable methods and data (such as improved emissions factors or site-specific data) taking into account logistics and the potential forpopulation exposure.

(i) One monitor may be used to meet the requirement in paragraph 4.5(a) for all

sources involved when the location of the maximum Pb concentration due to one Pb

source is expected to also be impacted by Pb emissions from a nearby source (ormultiple sources). This monitor must be sited, taking into account logistics and the potential for population exposure, where the Pb con- centration from all sources combined is expected tobe at its maximum.

(ii) TheRegional Administrator may waive the requirement inparagraph 4.5(a) formonitoring near Pb sources ifthe State or,where appropriate, local agency can demonstrate the Pb source will not contribute to a max- imum Pb concentration in ambient air in excess of 50 percent of the NAAQS (based on historical monitoring data, modeling, or other means). The waiver must be renewed

once every 5years as part ofthe network assessmentrequired under§58.10(d).

(iii) State and, where appropriate, local agencies arerequired to conduct ambient air Pb monitoring near each ofthe airports listed in Table D-3A for a period of12 consecu- tive months commencing no later than December 27, 2011. Monitors shall be sited to

measure the maximum Pb concentration in ambient air, taking into account logistics and the potential for population exposure, and shall use an approved Pb-TSP Federal Reference Method or Federal Equivalent Method. Anymonitor thatexceeds 50 percent ofthe Pb NAAQS on a rolling 3-month aver- age (as determined according to 40 CFR part 

### 40CFR Ch. 1(7-1-12 Edition)

50, AppendixR) shall become a required mon- itor under paragraph 4.5(c) ofthis Appendix, and shall continue to monitor for Pb unless

a waiver is granted allowing it to stop operating as allowed by the provisions in paragraph 4.5(a)(ii) of this appendix. Data collected shall be submitted to the Air Quality System database according to the requirements of40 CFR part 58.16.

TABLE D-3A AIRPORTS To BE MONITORED FOR LEAD

Airport County State

Merrill Field

........................................ Anchorage AK Pryor Field Regional

.......................... Limestone

..... AL Palo Alto Airport ot Santa Clara Santa Clara CA

County. McClellan-Palomar S..............Sn Diego CA Reid-Hillview

...................................... Santa Clara CA GillespieField

.................................... San Diego

..... CA San Carlos

......................................... San Mateo CA Nantucket Memorial

.......................... Nantucket MA Oakland County International

............ Oakland. MI Republic

............................................. Suffolk

........... NY Brookhaven

....................................... Suffolk

........... NY Stinson Municipal

.... Bexar

............ TX Northwest Regional

.............. Denton

.......... TX Harvey Field

...................................... Snohomish WA Auburn Municipal King............... King........WA

(b) State and, where appropriate, local agencies are required toconduct non-sourceoriented Pb monitoring at each NCore site required under paragraph 3 ofthis appendix in a CBSA with a population of 500,000 or
more.

(c) The EPA Regional Administrator may require additional monitoring beyond the minimum monitoring requirements contained in paragraphs 4.5(a) and 4.5(b) where the likelihood ofPb air quality violations is significant or where the emissions density, topography, orpopulation locations are complex and varied. EPA Regional Administrators may require additional monitoring at locations including, but not limited to, those

near existing additional industrial sources of Pb, recently closed industrial sources ofPb, airports where piston-engine aircraft emit Pb, and other sources of re-entrained Pb dust.

(d) The most important spatial scales for source-oriented sites to effectively characterize the emissions from point sources are microscale and middle scale. The most important spatial scale for non-source-oriented sites to characterize typical lead concentrations in urban areas is the neighborhood scale. Monitor siting should be conducted in accordance with 4.5(a)(i) with respect to source-oriented sites.

(1) Microscale-This scale would typify

areas in close proximity to lead point

sources. Emissions from point sources such

as primary and secondary lead smelters, and primary copper smelters may under fumigation conditions likewise result in high



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### Environmental ProtectionAgency

ground level concentrations at the microscale. Inthe lattercase, the microscale would represent an area impacted by the plume with dimensions extending up to approximately 100 meters.Pbmonitors in areas where the public has access, andparticularly children have access, are desirable because of the higher sensitivity of children to expo-
suresofelevated Pbconcentrations.

(2)Middle scale-This scale generally represents Pb air quality levels in areas up to several city blocks in size with dimensions

on the order ofapproximately 100 meters to 500 meters. The middle scale may for exam- ple, include schools and playgrounds in cen- ter city areas which are close to major Pb point sources. Pb monitors in such areas are desirable because of thehigher sensitivity of children to exposures of elevated Pb con- centrations (reference 3 of this appendix). Emissions from point sources frequently impact on areas at which single sites may be located to measure concentrations representingmiddle spatial scales.

(3)Neighborhood scale-The neighborhood scale *wouldcharacterize air quality conditions throughout some relatively uniform land use areas with dimensions in the 0.5 to 4.0 kilometerrange. Sites ofthis scale would provide monitoring data in areas representing conditions where children live and play. Monitoring in such areas is important sincethis segment ofthepopulation is more 

### Pt. 58,App. D

susceptible to the effects of Pb. Where a neighborhood site is located away from immediate Pb sources, the site may be very useful in representing typical air quality values for a larger residential area, and therefore suitable for population exposure and trends analyses.

(d) Technical guidance is found in ref-

erences 4 and 5ofthis appendix. These documents provide additional guidance on locating sites to meet specific urban area monitoring objectivesand should be usedin locating new sites or evaluating the adequacy of existing sites.

4.6 Particulate Matter (PM0) Design Criteria.5(a) Table D-4 indicates the approximate number ofpermanent stations required in MSAs to characterize national and re- gional PMio air quality trends and geographical patterns. The number ofPMso stations in areas where MSA populations exceed 1,000,000 must be in the range from 2 to 10 stations, while in low population urban
areas, no more than two stations are re- quired. A range of monitoring stations is specified in Table D-4 because sources ofpol- lutants and local control efforts can vary from one part ofthe country to another and therefore, some flexibility is allowed in se- lecting the actual number of stations in any
one locale. Modifications from these PMo monitoring requirements must be approved bytheRegional Administrator.

TABLE 

### D-4 OFAPPENDIX D To PART 58-PM 10 MINIMUM MONITORING REQUIREMENTS (APPROXIMATE NUMBER OF STATIONS PER MSA) 1

Populationcategory High concentra- Medium con- Lowconcentra- tion2 centration3 tion

### 4,5

>1,000,000

...................................................................................... 6-10 4-8 2-4 500,000-1,000,000

.......................................................................... 4-8 2-4 1-2 250,000-500,000

............................................................................. 3-4 1-2 0-1 100,000-250,000

............................................................................. 1-2 0-1 0

Selection ofurbanareasandactual numbersofstationsper areawillbejointlydetermined byEPA andthe State agency. 2Highconcentration areas are those forwhich ambient PM10 data showambient concentrationsexceeding the PM, 0NAAOS by20 percentor more.

3Medium concentration areas are thoseforwhich ambient PM10data showambient concentrations exceeding 80 percentof the PMoNAAQS.

4Low concentration areas are those forwhich ambient PM10 data show ambient concentrations less than 80 percent of the PMo NAAQS.

5These minimum monitoring requirements apply inthe absenceofadesignvalue.

(b) Although microscale monitoring may be appropriate in some circumstances, the most important spatial scales to effectively characterize theemissions ofPMc from both mobile and stationary sources arethe middle scales and neighborhood scales.

(1) Microscale-This scale would typify

areas sdch as downtown street canyons, traffic corridors, and fence line stationary

source monitoring locations where the general public could be exposed to maximum PM1o concentrations. Microscale particulate matter sites shouldbe located nearinhabited buildings or locationswhere thegeneral public canbe expected to be exposed to the concentration measured. Emissions from stationary sources such as primary and sec- ondary smelters, power plants, and other large industrial processes may, under certain plume conditions, likewise result in high ground level concentrations at the microscale. In thelatter case, the microscale would represent an area impacted by the plume with dimensions extending up to approximately 100 meters. Data collected at microscale sites provide information for evaluating and developing hot spot control

measures.

(2) Middle scale-Much of the short-term public exposure to coarse fraction particles


## 289

### 40 CFRCh. 1 (7-1-12 Edition)

(PM0)is on this scale and on the neighborhood scale. People moving through downtown areas or living near majorroadways or stationary sources, may encounter particulate pollution that would be adequately characterized by measurements of this spatial scale. Middle scale PMio measurements

can be appropriate for the evaluation ofpossible short-term exposure public health effects. In many situations, monitoring sites that are representative of micro-scale or middle-scale impacts are not unique and are representative of many similar situations. This can occur along traffic corridors or other locations in a residential district. In this case, one location is representative of a neighborhood of small scale sites and is appropriate for evaluation of long-term or chronic effects. This scale also includes the characteristic concentrations for other areas with dimensions of a few hundred meters such asthe parking lot andfeeder streets as- sociated with shopping centers, stadia, and office buildings. Inthecase ofPMo, unpaved

or seldomly swept parking lots associated with these sources could be an important

source in addition to the vehicular emissions themselves.

(3) Neighborhood scale-Measurements in this category represent conditions throughout some reasonably homogeneous urban sub-region with dimensions of a few kilometers and of generally more regular shape than the middle scale. Homogeneity refers to the particulate matter concentrations, as well as the land use and land surface characteristics. In some cases, a location carefully chosen to provide neighborhood scale data would represent not only the immediate neighborhood but also neighborhoods ofthe

same type in other parts ofthe city. Neighborhood scale PMo sites provide information about trends and compliance with standards because they often represent conditions in

areas where people commonly live and work for extended periods. Neighborhood scale data could provide valuable information for developing, testing, and revising modelsthat describe the larger-scale concentration patterns, especially those models relying on spatially smoothed emission fields for inputs. The neighborhood scale measurements could alsobe used for neighborhood compari-

sons withinor between cities.

4.7 Fine Particulate Matter (PM2. 5)Design Criteria.

4.7.1 General Requirements. (a) State, and where applicable local, agencies must operate the minimum number of required PM 2.

5 SLAMS sites listed in Table D-5 of this appendix. TheNCore sitesare expected to com- plement the PM 2. 5 data collection that takes place at non-NCore SLAMS sites, and both types ofsites can be used to meet the minimum PM2. 5 network requirements. Deviations from these PM2. 5 monitoring requirements must be approved by the EPA Regional Administrator.

TABLE D-5 OFAPPENDIX D TO PART 58-PM 2.

5 MINIMUM MONITORING REQUIREMENTS

Most recent 3- MSA population 1,2 yeardesignvalue 85%ofany PM

2 .,NAAQSS >1,000,000

............. 3 500,000-1,000,000 2 50,000<500,0006 1 Most recent3- year designvalue

<85%ofany PM

2. 5 NAAQS3

2 1
0 

### 1 Minimum monitoring requirements apply to the Metropoli- tan statisticalarea (MSA).

2Populationbased on latestavailable censusfigures. 3The PM 2. 5 National Ambient Air Quality Standards (NAAOS) levels andforms are definedin40 CFRpart 50.

4These minimum monitoring requirements apply inthe ab- senceof adesignvalue.

5Metropolitan statistical areas (MSA) must contain an ur- banized area of50,000ormore population.

(b) Specific Design Criteria for PM 25. The required monitoring stations or sites must be sited to represent community-wide air quality. These sites can include sites collocated at PAMS. These monitoring stations will typically be at neighborhood or rbanscale; however, in certain instances where population-oriented micro-or middle-scale PM2. 5 monitoring are determined by the Regional Administrator to represent many such locations throughout a metropolitan
area, these smaller scales can be considered
torepresent community-wide air quality.

(1)At least one monitoring station is tobe sited in a population-oriented area of expected maximum concentration.

(2) For areas with more than one required SLAMS, a monitoring station is to be sited in an areaofpoorair quality.

(3)Additional technical guidance for siting PM25 monitors is provided in references 6 and 7ofthisappendix.

(c) The most important spatial scale to effectively characterize the emissions ofparticulate matter from both mobile and stationary sources is the neighborhood scale for PM2. 5. For purposes of establishing monitoring sites to represent large homogenous

areas other than the above scales of representativeness and to characterize regional transport, urban or regional scale sites would also be needed. Most PM 25monitoring in urban areas should be representative ofa neighborhood scale.

(1) Microscale-This scale would typify

areas such as downtown street canyons and traffic corridors where the general public would be exposed to maximum concentrations from mobile sources. In some circumstances, the microscale is appropriate for particulate sites; community-oriented SLAMS sites measured at the microscale level should, however, be limited to urban sites that are representative of long-term human exposure and of many such microenvironments in the area. In general,



### 290 Pt. 58,App. D

## Environmental ProtectionAgency

microscale particulate matter sites should be located near inhabited buildings or locations where the general public can be ex- pected to be exposed to the concentration measured. Emissions from stationary

sources such as primary and secondary smelters, power plants, and other large industrial processes may, under certain plume conditions, likewise result in high ground level concentrations at the microscale. In the latter case, the microscale would represent an area impacted by the plume with dimensions extending up to approximately 100 meters. Data collected at microscale sites provide information for evaluating and developing hot spot control measures. Unless these sites are indicative of population-oriented monitoring, they may be more appropriately classified as SPM.

(2) Middle scale-People moving through downtown areas, or living near major roadways, encounterparticle concentrations that would be adequately characterized by this spatial scale. Thus, measurements of this type would be appropriate for the evaluation ofpossible short-term exposure public health effects of particulate matter pollution. In many situations, monitoring sites that are representative ofmicroscale or middle-scale impacts are not unique and are representative of many similar situations. This can
occur along traffic corridors or other locations in a residential district. In this case, one location is representative ofa number of small scale sites and is appropriate for evaluation of long-term or chronic effects. This scale also includes the characteristic con- centrations for other areas with dimensions ofa few hundred meters such as the parking lot and feeder streets associated with shoppingcenters, stadia, andoffice buildings.

(3) Neighborhood scale-Measurements in this category would represent conditions throughout some reasonably homogeneous urban sub-region with dimensions of a few kilometers and of generally more regular shape than the middle scale. Homogeneity refers to the particulate matter concentrations, as well as the.land use and land sur- face characteristics. Much ofthe PM2. 5 expo-
sures are expected tobe associated with this scale ofmeasurement. In some cases, a location carefully chosen to provide neighborhood scale data would represent the immediate neighborhood as well as neighborhoods ofthe same type in other parts ofthe city. PM 2 5sites ofthiskind provide good information about trends and compliance with standards because they often represent con- ditions in areas where people commonly live and work for periods comparable to those specified in the NAAQS. In general, most PM2 .5monitoring in urban areas should have this scale.

(4) Urbanscale-This class ofmeasurement would beused to characterize the particulate matter concentration over an entire metro

## Pt.58,App.D

politan or rural area ranging in size from 4 to 50 kilometers. Such measurements would be useful for assessing trends in area-wide air quality, and hence, the effectiveness of large scale air pollution control strategies. Community-oriented PM 2.5 sites may have thisscale.

(5) Regional scale-These measurements would characterize conditions over areas with dimensions ofas much as hundreds of kilometers. As noted earlier, using representative conditions for an area implies

some degree of homogeneity in that area. For this reason, regional scale measure- ments would be most applicable to sparsely populated areas. Data characteristics ofthis scale wouldprovide information about larger scale processes of particulate matter emissions, losses and transport. PM 2.

5 transport contributes to elevated particulate con- centrations and may affect multiple urban and State entities with large populations such as in the eastern United States. Development of effective pollution control strategies requires an understanding at regional geographical scales of the emission sources and atmospheric processes that are responsible for elevated PM2.5levels and may also be associated with elevated 03 and regional haze.

4.7.2 Requirement for Continuous PM2 .5 Monitoring. The State, or where appropriate, local agencies mustoperate continuousPM2 .5 analyzers equal to at least one-half (round up) the minimum required sites listed in Table D-5 of this appendix. At least one re- quired continuous analyzer in each MSA must be collocated with one ofthe required FRM/FEM/ARM monitors, unless at least

one ofthe required FRM/FEM/ARM monitors is itself a continuous FEM or ARM monitor in which case no collocation requirement applies. State and local air monitoring agencies must use methodologies and quality as- surance/quality control (QA/QC) procedures approved by the EPA Regional Administrator for these required continuous ana- lyzers.

4.7.3 Requirement for PM 2.5 Background and Transport Sites. Each State shall install and operate at least one PM 2.5site to mon- itor forregional background and at leastone PM 2.5 site to monitor regional transport. These monitoring sites may be at commu- nity-oriented sites and this requirement may be satisfied bya corresponding monitorin an
area having similar air quality in another State. State and local air monitoring agencies must use methodologies and QA/QC procedures approved by the EPA Regional Administrator for these sites. Methods used at these sites mayinclude non-federal reference method samplers such as IMPROVE or con- tinuous PM2. 5monitors. 4.7.4 PM2. 5 Chemical Speciation Site Requirements. Each State shall continue to conduct chemical speciation monitoring and



## 291

### Pt. 58, App. D

analyses at sites designated tobe part ofthe PM 2.5Speciation Trends Network (STN). The selection and modification of these STN sites must be approved by the Administrator. The PM 2.5chemical speciation urban trends sites shall include analysis for elements, selected anions and cations, and carbon. Samples must be collected using the monitoring methods and the sampling schedules approved by the Administrator. Chemical. speciation is encouraged at additional sites where the chemically resolved data would be useful in developing State implementation plans and supporting atmospheric

orhealth effectsrelated studies.

4.7.5 Special Network Considerations Required When Using PM 2.5 Spatial Averaging Approaches. (a) The PM 2.5NAAQS, specified in 40 CFR part 50, provides State and local air monitoring agencies with an option for spatially averaging PM2 .5 air quality data. More specifically, two or more communityoriented (i.e., sites in populated areas) PM 2.5 monitors may be averaged for comparison with the annual PM2. 5 NAAQS. This averaging approach is directly related to epidemiological studies used as the basis for the PM2 . 5 annual NAAQS. Spatial averaging does
not apply to comparisons with the daily PM2. 5 NAAQS. (b) State and local agencies mustcarefully consider their approach for PM 2 .5 network design whenthey intend to spatially average the data for compliance purposes. These State and local air monitoring agencies must define the area overwhich they intend to average PM 2.

5 air quality concentrations. This

area is defined as a Community Monitoring Zone (CMZ), which characterizes an area of relatively similar annual average air quality. State and local agencies can define a CMZ in a number of ways, including as part

or all of a metropolitan area. These CMZ
must be defined within a State orlocal agencies network description, as required in 

### §58.10 ofthis part and approved by the EPA Regional Administrator. When more than

one CMZ is described within an agency's network design plan, CMZs must not overlap in their geographical coverage. The criteria that must be used for evaluating the acceptability of spatial averaging are defined in appendix N to40CFR part 50.

4.8 Coarse Particulate Matter (PMio-2. 5) Design Criteria.

4.8.1 General Monitoring Requirements. (a) The only required monitors for PM1o-2.5

are those required at NCore Stations.

(b) Although microscale monitoring may be appropriate in some circumstances, middle and neighborhood scale measurements

are the most important station classifications for PM 1 -2.5 to assess the variation in

coarse particle concentrations that would be expected across populated areas that are in proximity to large emissions sources. 

### 40CFR Ch. 1 (7-1-12 Edition)

(1)Microscale-This scale would typify relatively small areas immediately adjacent to: Industrial sources; locations experiencing ongoing construction, redevelopment, and soil disturbance; and heavily traveled roadways. Data collected at microscale stations would characterize exposure over areas of limited spatial extent and population exposure, and may provide information useful for evaluating and developing source-oriented control measures.

(2) Middle scale-People living or working

near major roadways or industrial districts
encounter particle concentrations that would be adequately characterized by this spatial scale. Thus, measurements of this type would be appropriate for the evaluation ofpublichealth effects ofcoarse particle exposure. Monitors located in populated areas that are nearly adjacent to large industrial point sources of coarse particles provide suitable locations for assessing maximum population exposure levels and identifying

areas of potentially poor air quality. Similarly, monitors located in populated areas that border dense networks of heavily-traveled traffic are appropriate for assessing the impacts ofresuspended road dust. This scale also includes the characteristic concentrations for other areas with dimensions of a few hundred meters such as school grounds and parks that are nearly adjacent to major roadways and industrial point sources, locations exhibiting mixed residential and commercial development, and downtown areas featuring office buildings, shopping centers, and stadiums.

(3) Neighborhood scale-Measurements in this category would represent conditions throughout some reasonably homogeneous urban sub-region with dimensions of a few kilometers and of generally more regular shape than the middle scale. Homogeneity refers to the particulate matter concentrations, as well as the land use and land surface characteristics. This category includes suburban neighborhoods dominated by residences that are somewhat distant from major roadways and industrial districts but stillimpacted by urban sources, and areas of diverse land use where residences are interspersed with commercial and industrial neighborhoods. In some cases, a location carefully chosen to provide neighborhood scale data would represent the immediate neighborhood as well asneighborhoods ofthe

same type in other parts of the city. The comparison of data from middle scale and neighborhood scale sites would provide valuable information for determining the variation of PMI 1 2.5 levels across urban areas and assessing the spatial extent ofelevated concentrations caused by major industrial point sources and heavily traveled roadways.



### 292

## Environmental ProtectionAgency

Neighborhood scale sites would provide con- centration data that are relevant to informing a large segment of the population of their exposure levels on agiven day.

4.8.2 PMO-- 2.

5Chemical Speciation SiteRequirements. PM10-2.5 chemical speciation monitoring and analyses is required at NCore sites. The selection and modification of these sites must be approved by the Administrator. Samples must be collected using the monitoring methods and the sam- pling schedules approved by the Administrator.

5. NETWORK DESIGN FORPHOTOCHEMICAL
ASSESSMENT MONITORING STATIONS (PAMS)
The PAMS program provides more com- prehensive data on 03 air pollution in areas classified as serious, severe, or extreme non- attainment for 03 than would otherwise be achieved through the NCore and SLAMS sites. More specifically, the PAMS program includes measurements for 03, oxides of nitrogen, VOC, and meteorology.

5.1 PAMS Monitoring Objectives. PAMS design criteria are site specific. Concurrent measurements of 03, oxides ofnitrogen, speciated VOC, CO, and meteorology are obtained at PAMS sites. Design criteria for the PAMS network are based on locations relative to 03 precursor source areas and predominant wind directions associated with high 03 events. Specific monitoring objectives are associated with each location. The overall design should enable characterization ofprecursor emission sources within the
area, transport of 03 and itsprecursors, and the photochemical processes related to 03 nonattainment. Specific objectives that mustbe addressed include assessing ambient trends in 03, oxides ofnitrogen, VOC species, and determining spatial and diurnal variability of0, oxides ofnitrogen, and VOC species. Specific monitoring objectives associated with each of these sites may result in four distinct site types. Detailed guidance 

## Pt.58, App.D

for the locating of these sites may be found inreference 9ofthisappendix.

(a) Type 1 sites are established to characterizeupwind background andtransported 03 and its precursor concentrations entering the area and will identify those areas which

are subjectedto transport.

(b)Type 2 sites are established to monitor the magnitude and type of precursor emissions in the area where maximum precursor emissions are expected to impact and are suited for the monitoring ofurban air toxic pollutants.

(c) Type 3 sites are intended to monitor maximum 03concentrations occurring downwind from the area of maximum precursor emissions.

(d) Type 4 sites are established to characterize the downwind transported 03 and its precursor concentrations exiting the area and will identify those areas which are potentially contributing to overwhelming transportin other areas.

5.2 Monitoring Period. PAMS precursor monitoring must be conducted annually throughout the months of June, July and August (asa minimum) when peak 03 values

are expected in each area. Alternate pre-
cursor monitoring periods may be submitted for approval to the Administrator as a part of the annual monitoring network plan re- quired by 

### §58.10.

5.3 Minimum Monitoring Network Requirements. A Type 2 site is required for each area. Overall, only two sites are re- quired for each area, providing all chemical measurements are made. For example, if a design includes two Type 2sites, then a third site will be necessary to capture the NOy measurement. The minimum required num- ber and type of monitoring sites and sam- pling requirements are listed in Table D-6 of this appendix. Any alternative plans may be put in place in lieu ofthese requirements, if approved by theAdministrator.

TABLE D-6 OF APPENDIX D TO PART 58-MINIMUM REQUIRED PAMS MONITORING LOCATIONS AND FREQUENCIES

Measurement Where required Samplingfrequency (alldaily exceptfor upperair meteorology)1
SpeciatedVOC2. Twosites per area, one ofwhich must be aType During the PAMS monitoring period: (1) Hourly 2site, auto GO, or (2)Eight 3-hour canisters, or(3) 1 morning and 1aftemnoon canister with a3-hour
or less averaging time plus Continuous Total Non-methane Hydrocarbon measurement. Carbonyl sampling Type 2site inareas classifiedasserious or above 3-hour samples every day duringthe PAMS monitor the8-hour ozonestandard. toring period. NOx

.............. AllType 2sites

......................... Hourlyduring theozone monitoringseason. 3 NO

........................... One siteper ares attheType 3or Type 1site Hourly during theozone monitoringseason. CO(ppb level). One siteper ares ataType 2site

............. Hourly durng theozone monitoringseason. Ozone

............. Allsites

............................... Hourly during theozone monitoring season. Surface met

......... Allsites

....................................................... Hourly during theozonemonitoring season. Upper airmeteorology One representative location within PAMS area Sampling frequency must be approved as part of the annual monitoring network plan required in 40 CFR 58.10. Daily orwith an approved alternative plan.



## 2932Speciated VOC isdefined inthe "Technical Assistance Document for Sampling and Analysis ofOzone Precursors", EPA/ 600-R-98/161, September1998.

3Approved ozone monitoringseason as stipulatedinTable D-3 ofthis appendix.

5.4 Transition Period. A transition period is allowed for phasing in the operation of newly required PAMS programs (due generally toreclassification ofan areainto serious, severe, or extreme nonattainment for ozone). Following the date of redesignation

or reclassification of any existing 03 nonattainment area to serious, severe, or extreme, or the designation of a new area and classification to serious, severe, or extreme 03 nonattainment, a State is allowed 1 year to develop plans for its PAMS implementation strategy. Subsequently, a minimum of

one Type 2 site must be operating by the first month ofthe following approved PAMS

season. Operation of the remaining site(s) must, at a minimum, be phased in at the
rate of one site per year during subsequent years as outlined in the approved PAMS network description provided by the State.

6.REFERENCES

1. Ball, R.J. and G.E. Anderson. Optimum Site Exposure Criteria for S0 2 Monitoring. The Center for the Environment and Man, Inc., Hartford, CT. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Publication No. EPA450/3-77-013. April 1977.

2. Ludwig, F.F., J.H.S. Kealoha, and E. Shelar. Selecting Sites for Carbon Monoxide Monitoring. Stanford Research Institute, Menlo Park, CA. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Publication No. EPA450/3-75--077, September1975.

3. Air Quality Criteria for Lead. Office of Research and Development, U.S. Environmental Protection Agency, Washington D.C. EPA Publication No. 600/8-89-049F. August 1990. (NTIS document numbers PB87-142378 andPB91-138420.)

4. Optimum Site Exposure Criteria for Lead Monitoring. PEDCo Environmental, Inc. Cincinnati, OH. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Contract No. 68-02-3013. May 1981.

5. Guidance for Conducting Ambient Air Monitoring for Lead Around Point Sources. Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA-454/R92-009. May 1997.

6. Koch, R.C. and H.E. Rector. Optimum Network Design and Site Exposure Criteria for Particulate Matter. GEOMET Technologies, Inc., Rockville, MD. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Contract No. 68-02-3584. EPA 450/4-87-009. May 1987. 7.Watson et al. Guidance for Network Design and Optimum Site Exposure for PM 2.5 and PM 1o. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA-454/R-99-022, December 1997.

8. Guideline for Selecting and Modifying the Ozone Monitoring Season Based on an8- Hour Ozone Standard. Prepared for U.S. Environmental Protection Agency, RTP, NC. EPA-454/R-98-001, June 1998.

9. Photochemical Assessment Monitoring Stations Implementation Manual. Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA-454/B-9051. March 1994. [71 FR 61316, Oct. 17, 2006, as amended at 72 FR 32211, June 12, 2007; 73 FR 67062, Nov. 12, 2008; 75 FR 6534, Feb. 9, 2010; 75 FR 35602, June 22, 2010; 75FR 81137, Dec. 27, 2010; 76FR 54342, Aug. 31, 2011]

APPENDIX E TO PART 58-PROBE AND MONITORING PATH SITING CRITERIA FOR AMBIENT AIR QUALITY MONITORING

1.Introduction. 2.Horizontal andVertical Placement. 3.Spacing from Minor Sources. 4.Spacing From Obstructions. 5.Spacing From Trees. 6.Spacing From Roadways. 7. Cumulative Interferences on a Monitoring

Path. 8. Maximum Monitoring Path Length. 9. Probe Material and Pollutant Sample Residence Time. 10. WaiverProvisions. 11. Summary. 12. References.

1.INTRODUCTION

(a)This appendix contains specific location criteria applicable to SLAMS, NCore, and PAMS ambient air quality monitoring probes, inlets, and optical paths after the general location has been selected based on the monitoring objectives and spatial scale ofrepresentation discussed in appendix D to this part. Adherence to these siting criteria is necessary to ensure the uniform collection of compatible and comparable air quality data.

(b) The probe and monitoring path siting criteria discussed in this appendix must be followed tothe maximum extent possible. It is recognized that there may be situations where some deviation from the siting criteria maybe necessary. In any such case, the

reasons must be thoroughly documented in a



### 294 Pt. 58,App. E 40CFR Ch. I (7-1-12 Edition)

## Environmental ProtectionAgency

written request for a waiver that describes how and why the proposed siting deviates from the criteria. This documentation should help to avoid later questions about the validity of the resulting monitoring data. Conditions under which theEPA would consider an application forwaiver from these siting criteria are discussed in section 10 of thisappendix.

(c) The pollutant-specific probe and monitoringpath siting criteria generally apply to all spatial scales except where noted otherwise. Specific sitingcriteria thatare phrased with a "must" are defined as requirements and exceptions must be approved through the waiver provisions. However, siting criteria that are phrased with a "should" are defined as goals to meet for consistency but

arenot requirements.

2.HORIZONTAL ANDVERTICAL PLACEMENT
The probe or at least 80 percent of the monitoring path must be located between 2 and 15 meters above ground level for all 03 and 802 monitoring sites, and for neighborhood or larger spatial scale Pb, PM 1o, PM 1o-

2. 5, PM 2.

5, NO2, and CO sites. Middle scale PM 1O-

2.

5sites are required to have sam- pler inlets between 2 and 7 meters above ground level. Microscale Pb, PMo, PM,0-2- 5, and PM 2 . 5 sites are required to have sampler inlets between 2 and 7 meters above ground level. Microscale near-road NO2 monitoring sites are required to have sampler inlets between 2and 7meters aboveground level. The inlet probes for microscale carbon monoxide monitors that are being used to measure concentrations near roadways must be between 2 and 7 meters above ground level. Those inlet probes for microscale carbon monoxide monitors measuring concentrations near roadways in downtown areas or urban street canyons must be between 2.5 and 3.5 meters above ground level. The probe

or atleast 90 percent ofthe monitoring path must be at least 1 meter vertically or horizontally away from any supporting structure, walls, parapets, penthouses, etc., and away from dusty,or dirty areas. Ifthe probe

or a significant portion of the monitoring path is located near the side ofa building or wall, then it should be located on the windward side of thebuilding relative to the prevailing wind direction during the season of highest concentration potential for the pollutant beingmeasured.

3. SPACINGFROM MINOR SOURCES (a)It isimportant tounderstand the monitoring objective for a particular location in order to interpret this particular requirement.Local minor sources of a primary pollutant, such as S02, lead, or particles, can
cause high concentrations ofthat particular pollutant at a monitoring site. Ifthe objective for that monitoring site is to inves

## Pt.58,App.E

tigate these local primary pollutant emissions, then the site is likely to be properly located nearby. This type ofmonitoring site would in all likelihood be a microscale type ofmonitoring site. Ifa monitoring site is to be used to determine air qualityover a much larger area, such as a neighborhood or city,

a monitoring agency should avoid placing a monitor probe, path, or inlet near local, minor sources. The plume from the local minor sources should not be allowed to inappropriately impact the air quality data collected at a site. Particulate matter sites should notbe located in an unpaved area un- less there is vegetative ground cover year round, so that the impact of wind blown dusts willbe kept to a minimum.

(b) Similarly, local sources of nitric oxide (NO) and ozone-reactive hydrocarbons can have a scavenging effect causing unrepresentatively low concentrations of 03 in the vicinity of probes and monitoring paths for 03. To minimize these potential interferences, the probe or atleast 90percent of the monitoring path must be away from furnace or incineration flues or other minor

sources of S02 or NO. The separation distance should take into account the heights ofthe flues, typeofwaste orfuelburned, and the sulfur content ofthe fuel.

4. SPACING FROM OBSTRUCTIONs (a) Buildings and other obstacles may possibly scavenge S02, 03, orNO2,andcan act to restrict airflow for any pollutant. To avoid this interference, the probe, inlet, or at least 90 percent ofthe monitoring path must have unrestricted airflow and be located away from obstacles. The distance from the obstacle to the probe, inlet, or monitoring path must be at least twice the height that the obstacle protrudes above the probe, inlet, or monitoring path. An exception to this re- quirement can be made for measurements takenin street canyons or at source-oriented sites where buildings and other structures

are unavoidable.

(b) Generally, a probe or monitoring path located near or along a vertical wall is undesirable because air moving along the wall may be subject to possible removal mechanisms. A probe, inlet, or monitoring path must have unrestricted airflow in an arc of at least 180 degrees. This are must include the predominant wind direction for the sea-
son of greatest pollutant concentration potential. For particle sampling, a minimum of 2 meters of separation from walls, parapets, and structures is required for rooftop site placement.

(c) Special consideration must be given to the use of open path analyzers due to their inherent potential sensitivity to certain types of interferences, or optical obstructions. Amonitoring path must be clear ofall trees, brush, buildings, plumes, dust, or


## 295

### Pt.58, App. E

other optical obstructions, including potential obstructions that may move due to wind, human activity, growth ofvegetation, etc. Temporary optical obstructions, such as rain, particles, fog, or snow, should be considered when siting an open path analyzer. Any of these temporary obstructions that

are ofsufficient density to obscure the light beam will affect the ability ofthe open path analyzer to continuously measure pollutant concentrations. Transient, but significant obscuration of especially longer measurement paths could occur as a result ofcertain meteorological conditions (e.g., heavy fog, rain, snow) and/or aerosol levels that are of

a sufficient density toprevent the open path analyzer's lighttransmission. Ifcertain compensating measures are not otherwise implemented at the onset of monitoring (e.g., shorter path lengths, higher light source intensity), data recovery during periods of greatest primary pollutant potential could be compromised. For instance, if heavy fog

or high particulate levels are coincident with periods of projected NAAQS-threatening pollutant potential, the representativeness of the resulting data record in reflecting maximum pollutant concentrations may be substantially impaired despite the fact that the site may otherwise exhibit an acceptable, even exceedingly high overall validdata capture rate.

(d) For near-road NO2 monitoring stations, the monitor probe shall have an unobstructed air flow, where no obstacles exist at

orabove the height ofthe monitorprobe, between the monitor probe and the outside
nearest edge ofthe traffic lanes ofthe target roadsegment.

5. SPACING FROM TREES (a) Trees can provide surfaces for SO2, 03,

or NO2 adsorption or reactions, and surfaces forparticle deposition. Trees can also act as obstructions in cases where they are located between the air pollutant sources or source
areas and the monitoring site, and where the trees are ofa sufficient height and leaf canopydensity to interfere with thenormal airflow around the probe, inlet, or monitoring path. Toreduce thispossible interference/obstruction, theprobe, inlet, or at least 90 percent ofthemonitoring path mustbe atleast 10 meters or further from the drip line of
trees.

(b)The scavenging effect oftrees is greater for 03 than for other criteria pollutants. Monitoring agencies must take steps toconsider the impact of trees on ozone monitoring sites and take steps to avoid this problem.

(c) For microscale sites ofany air pollutant, no trees or shrubs should be located between the probe and the source under investigation, such as a roadway or a stationary

source. 

### 40 CFRCh. 1 (7-1-12 Edition)

6.SPACING FROM ROADWAYS

6.1 Spacing for Ozone Probes and Monitoring Paths

In siting an 03 analyzer, it is important to minimize destructive interferences form

sources of NO, since NO readily reacts with 03. Table E-1 of this appendix provides the required minimum separation distances between a roadway and a probe or,where applicable, at least 90 percent of a monitoring path for various ranges of daily roadway traffic. A sampling site having a point analyzer probe located closer to a roadway than allowed by the Table E-1 requirements should be classified as microscale or middle scale, rather than neighborhood or urban scale, since the measurements from such a site wouldmore closelyrepresent the middle scale. If an open path analyzer is used at a site, the monitoring path(s) must not cross

over a roadway with an average daily traffic
count of10,000 vehicles per day or more. For those situations where a monitoring path

crosses a roadway with fewer than 10,000 vehicles per day, monitoring agencies must consider the entire segment of the monitoring path in the area of potential atmospheric interference from automobile emissions. Therefore, this calculation must include the length ofthe monitoring path over the roadway plus any segments ofthe monitoring path that lie in the area between the roadway and minimum separation distance,

as determined from the Table E-1 ofthis appendix. The sum ofthese distances must not be greater than 10 percent ofthe total monitoring pathlength.

6.2 Spacing for Carbon Monoxide Probes and Monitoring Paths. (a) Near-road microscale CO monitoring sites, including those located in downtown areas, urban
street canyons, and other near-road locations such as those adjacent to highly trafficked roads, are intended to provide a measurement of the influence of the immediate

source onthe pollution exposure onthe adjacent area.

(b) Microscale CO monitor inlets probes in downtown areas orurban street canyon locations shallbe located a minimum distance of 2 meters and a maximum distance of 10 meters from the edge ofthenearest traffic lane.

(c) Microscale CO monitor inlet probes in downtown areas orurban street canyon locations shallbe located atleast 10meters from

an intersection and preferably at a midblock location. Midblock locations are preferable
to intersection locations because intersections represent a much smaller portion of downtown space than do the streets between them. Pedestrian exposure is probably also greater in street canyon/corridors than at intersections.



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## Environmental ProtectionAgency

TABLE E-2 TO APPENDIX E OF PART 58-MINIMUM SEPARATION DISTANCE BETWEEN ROADWAYS AND PROBES OR MONITORING PATHS FOR MONITORING NEIGHBORHOOD SCALE CARBON MONOXIDE

Roadwayaveragedailytraffic,vehiclesper Minimum dis- day tance1I (me- day ters)
10,000

................................................... ....... 10 15,000

.................................................... . ...... 25 20,000

.................................................... . ...... 45 30,000

.................................................... . ...... 80 40,000

............................................................ 115 50,000

............................................................ 135 60,000

.......................................................... 150
'Distance fromthe edgeofthe nearesttraffic lane.Thedistance for intermediate traffic counts should be interpolated fromthetablevalues basedonthe actualtrafficcount.

6.3 Spacing for Particulate Matter (PM 2.5, PM.o, Pb) Inlets. (a) Since emissions associated with the operation of motor vehicles contribute to urban area particulate matter ambient levels, spacing from roadway criteria are necessary for ensuring national consistency in PM sampler siting.

(b) The intent is to locate localized hotspot sites in areas ofhighest concentrations whether it be from mobile or multiple stationary sources. If the area is primarily affected by mobile sources and the maximum concentration area(s)isjudged tobe a traffic corridor or street canyon location, then the monitors should be located near roadways with the highest traffic volume and at separation distances most likely to produce the highest concentrations. For the microscale traffic corridor site, the location mustbe between 5 and 15 meters from the major roadway. For the microscale street canyon site the location mustbe between2and 10 meters from the roadway. For the middle scale site,

a range of acceptable distances from the roadway is shown infigure E-1 ofthis appendix. This figure also includes separation distances between a roadway and neighborhood

orlarger scale sites by default. Any site,2 to 15 meters high, and further back than the middle scale requirements will generally be neighborhood, urban or regional scale. For example, according to Figure E-1 ofthis appendix, if a PM sampler is primarily influenced by roadway emissions and that sam

## Pt.58,App. E

pler is set back 10 meters from a 30,000 ADT (average daily traffic) road, the site should be classified as microscale, if the sampler heightis between 2 and 7meters. Ifthe sam- pler height is between 7 and 15 meters, the site should be classified as middle scale. If the sample is 20 meters from the same road, it will be classified as middle scale; if40 me- ters, neighborhood scale; and if 110 meters,

anurban scale.

6.4 Spacing for Nitrogen Dioxide (NO2 ) Probes and Monitoring Paths.

(a) In siting near-road NO2 monitors as re- quired in paragraph 4.3.2 of appendix D of this part, the monitor probe shall be as near
as practicable to the outside nearest edge of the traffic lanes ofthe target road segment; but shall notbe located at adistance greater than 50 meters, in the horizontal, from the outside nearest edge of the traffic lanes of the targetroad segment.

(b) In siting NO2 monitors for neighborhood and larger scale monitoring, it is important to minimize near-road influences. Table E-1 ofthis appendix provides the re- quired minimum separation distances between aroadway and a probe or,where applicable, at least 90 percent of a monitoring path for various ranges of daily roadway traffic. A sampling site having a point ana- lyzer probe located closer to a roadway than allowed by the Table E-1 requirements should be classified as microscale or middle scale rather than neighborhood or urban scale. Ifan open path analyzer is used at a site, the monitoring path(s) must not cross
over a roadway with an average daily traffic count of10,000 vehicles per day or more. For those situations where a monitoring path

crosses a roadway with fewer than 10,000 ve- hicles per day, monitoring agencies must consider the entire segment of the monitoring path in the area of potential atmospheric interference form automobile emissions. Therefore, this calculation must include the length ofthe monitoring pathover the roadway plus any segments of the monitoring path that lie in the area between the roadway and minimum separation distance,

as determined form the Table E--1 ofthis appendix. The sum ofthese distances must not be greater than 10 percent ofthe total monitoring pathlength.



## 297

### 40 CFRCh. 1 (7-1-12 Edition)



## .80-

S60~! S

40.

Q
H 

### 2o

## 0 20 40 60 80 100 120 140 160

FigureE-1. Distance ofPMsamplerstonearesttrafficlane (meters)

7. CUMULATIVE INTERFERENCES ON A MONITORING PATH (This paragraph applies only to open path analyzers.) The cumulative length orportion of a monitoring path that is affected by minor sources, trees, or roadways must not exceed 10 percent of the total monitoring pathlength.

8.MAXIMUM MONITORING PATH LENGTH (This paragraph applies only to open path analyzers.) The monitoring pathlength must not exceed 1 kilometer for

-analyzers in neighborhood, urban, or regional scale. For middle scale monitoring sites, the monitoring path length must not exceed 300 meters. In areas subject to frequent periods of dust,fog, rain, or snow, consideration should be given to a shortened monitoring path length to minimize loss of monitoring data dueto these temporary optical obstructions. For certain ambient air monitoring sce- narios using open path analyzers, shorter path lengths may be needed in order to en-
sure that the monitoring site meets the objectives and spatial scales defined in appendix D to this part. The Regional Administrator may require shorter path lengths, as needed on anindividual basis, to ensure that the SLAMS sites meet the appendix D re- quirements. Likewise, the Administrator may specify the maximum path length used
at NCore monitoring sites. 9. PROBE MATERIAL AND POLLUTANT SAMPLE RESIDENCE TIME (a) For the reactive gases, SO2, NO2, and 03, special probe material must be used for point analyzers. Studies 20-24 have been conducted to determine the suitability ofmaterials such as polypropylene, polyethylene, polyvinyl chloride, Tygon®, aluminum, brass, stainless steel, copper, Pyrex® glass and Teflon®for use asintake sampling lines. Of the above materials, only Pyrex® glass and Teflon®have beenfound tobe acceptable for use as intake sampling lines for all the reactive gaseous pollutants. Furthermore, the EPA2 5 has specified borosilicate glass or FEP Teflon® as the only acceptable probe materials for delivering test atmospheres in the determination ofreference orequivalent methods. Therefore, borosilicate glass, FEP Teflon® ortheir equivalent must be the only material in the sampling train (from inlet probe to the back of the analyzer) that can be in contact with the ambient air sample for existing andnew SLAMs.

(b) For volatile organic compound (VOC) monitoring at PAMS, FEP Teflon® is unacceptable as the probe material because of VOC adsorption and desorption reactions on the FEP Teflon®. Borosilicate glass, stainless steel, or its equivalent are the acceptable probe materials for VOC and carbonyl sampling. Care mustbe taken to ensure that the sample residence time is kept to 20 seconds or less.



### 298 Pt. 58, App. E

## Environmental ProtectionAgency

(c) No matter how nonreactive the sampling probe material is initially, after a periodofuse reactive particulate matter is deposited on the probe walls. Therefore, the time it takes the gas to transfer from the probe inlet to the sampling device is also critical. Ozone in the presence of nitrogen oxide (NO) will show significant losses even in the most inert probe material when the residence time exceeds 20 seconds. 6 Other studies27emP;2z indicate that a 10 second

or less residence time is easily achievable. Therefore, sampling probes for reactive gas monitors at NCore and at NO2 sites must have a sample residence time less than 20 seconds.

10.WAIVER PROVISIONS

Most sampling probes or monitors can be located so that they meet the requirements of this appendix. New sites with rare exceptions, canbe located withinthe limits ofthis appendix. However, some existing sites may not meet these requirements and still produce useful data for some purposes. The EPA will consider a written request from the State agency to waive one ormore siting criteria for some monitoring sites providing that the State can adequately demonstrate the need (purpose) for monitoring or establishing a monitoring site at thatlocation.

10.1 For establishing a new site, a waiver may be granted only ifboth ofthe following criteria are met:

10.1.1 The site can be demonstrated to be

as representative of the monitoring area as it would be if the siting criteria were being met. 

## Pt.58,App.E

10.1.2 The monitor or probe cannot reasonably be located so as to meet the siting criteria because ofphysical constraints (e.g., inability to locate the required type of site the necessary distance from roadways or obstructions).

10.2 However, for an existing site, a waiv-

er may be granted ifeither ofthe criteria in sections 10.1.1 and 10.1.2 ofthis appendix are met.

10.3 Cost benefits, historical trends, and other factors may be used to add support to the criteria in sections 10.1.1 and 10.1.2 of this appendix, however, they in themselves, will notbe acceptable reasons for granting a waiver. Written requests for waivers mustbe submitted to theRegional Administrator.

11. SUMMARY
Table H-A ofthis appendix presents a summary ofthe general requirements for probe and monitoring path siting criteria with respect to distances and heights. It isapparent from Table H-A that different elevation distances above the ground are shown for the various pollutants. Thediscussion in this appendix for each of the pollutants describes

reasons for elevating the monitor, probe, or monitoring path. The differences inthe specified range of heights are based on the vertical concentration gradients. For CO and near-road NO2 monitors, thegradients in the vertical direction are very large for the microscale, so a small range ofheights are used. The upper limit of 15 meters is specified for the consistency between pollutants and to allow the use of a single manifold or monitoring path for monitoring more than

onepollutant.

TABLE E-4 OF APPENDIX E TO PART 58-SUMMARY OF PROBE AND MONITORING PATH SITING CRITERIA

Horizontal and

Scale (max- Heightfrom verticaldistance Distancefrom Distancefrom imum moni- ground to fsuurn treestoprobe, roadwaysto Pollutant trinnat 8 pioa probe, inletor inletor 90%of probe, inletor length, meters)1 80%ofmoni- 90%ofmoni- monitonrng monitonrng toringpath1 toring path' path1 (meters) path' (meters) (meters)

S02345e

........................................



### CO457

............................................ Middle(300 m) Neighborhood Urban,and Regional(1 km). Micro[downtownor street canyonsites], micro[nearroad sites], middle(300 m)and Neighborhood (1km). 2-15

..........

### 1>1....... > 10

...... N/A.

2.5-3.5; 2-7;2-

15. > 1

................ I> 10

................. 2-10for downtown areasor streetcanyon microscale; 50 fornear- road microscale;

see Table E2ofthis appendix for middle and neighborhood scales.



## 299

### Pt.58, App. E 40CFR Ch. I(7-1-12 Edition)

TABLE E-4 OFAPPENDIX E TO PART 58-SUMMARY OF PROBE AND MONITORING PATH SITING CRITERIA-Continued

Horizontaland

Scale (max- Heightfrom vertical distance Distancefrom Distancefrom 

## imummoni- tground to sructures2 to treestoprobe, roadways to toring path oe,inletor probe, inletor inletor90% of probe, inletor length, metera) 80% ofmoni- monitoring monitoring toring path' toring path pathI(meters) path' (meters) (meters)

03345..........

................ Middle (300m) 2-15

............... > 1.......... 10.........See TableE-1 Neighbor- ofthia appenhood, Urban, dix forall and Regional scales. (1km). N0 2 345...................... Micro (Near- 2-7 (micro); 2- >1..........> 10.........50 meterafor road [50- 15(allother near-road 300]) Middle scales). microscale; (300m) See Table E-1 Neighbor- ofthia appenhood, Urban, dix forall and Regional other scales. (1km). Ozone precursors (for PAMS) 3 4 5 Neighborhood 2

-15

................. . . . . . . . . . 10

. . . . . . . . . See Table E

-4
and Urban (1 of this appenkm). dix forall scales. PM, Pb 3456

### 8

............................. Micro: Middle, 2-7 (micro); 2- >2(allacalea, >10 (all acales) 2-10 (micro); Neighbor- 7(middle horizontal dis- aee Figure Ehood, Urban PMI0 2 );2- tance only). 1ofthia apand Regional. 15(allother pendix forall scales). other scale.
N/A-Not applicable. 'Monitoring path foropen path analyzera isapplicable only to middleor neighborhood acaleCO monitoring, middle, neighbor. hood,urban, and regionalscale NO2monitoring, and all applicableacalesfor monitoring S0 2,03,and 03 precuraors.

2When probe ialocated onarooftop, thia aeparation distance iainreference towalla, parapets, orpenthouaea located on roof.

3Should be >20 wetera from the dnip-line of tree(a) and muat be 10metera fromthe drip-linewhen the tree(s) act asan obstruction.

4Distance from sampler, probe, or 90% of monitoring path to.obstacle, such ax abuilding, must be at least twice the height theobstacle protrudes abovethe sampler, probe, or monitoring path. Sites notmeeting this criterion maybe classified as middle scale (seetest).

5Must have unrestricted airflow 270 degrees around the probeor sampler; 180 degrees iftheprobe ison theaide of abuilding orawall.

'The probe, sampler, ormonitoring path should beawayfrom minor sources, such asfumnace or incineration flues.The sepa- rationdistance isdependent onthe heightofthe minor source's emission point (suchasa flue),the typeoffuel or wasteburned, andthe qualityof thefuel (sulfur, ash, or leadcontent).This criterion isdesignedto avoid undue influences from minor sources.

'For microscale CO monitoring sites indowntown areas or street canyons (not at near-road NO 2 monitoring sites),the probe must be > 10 meters from astreetintersection and preferablyat awidblock location. 'Collocated monitors must be within 4meters of each other and at least 2meters apart forflow rates greaterthan 200 litersl min or at least 1meterapart for samplershaving flow rates lessthan 200 liters/win to preclude airflow interference.

12. REFERENCES

1.Bryan, R.J., R.J. Gordon, and H. Menck. Comparison ofHigh Volume Air Filter Samples at Varying Distances from Los Angeles Freeway. University of Southern California, School of Medicine, Los Angeles, CA. (Presented at 66th Annual Meeting of Air Pollution Control Association. Chicago, IL. June 24-28, 1973.APCA 73-158.)

2.Teer, E.H. Atmospheric Lead Concentration Above an Urban Street. Master of Science Thesis, Washington University, St. Louis, MO. January 1971.

3. Bradway, R.M., F.A. Record, and W.E. Belanger. Monitoring and Modeling ofResuspended Roadway DustNear Urban Arterials. GCA Technology Division, Bedford, MA. (Presented at 1978 Annual Meeting ofTransportation Research Board, Washington, DC. January 1978.) 4. Pace, T.G., W.P. Freas, and E.M. Afify. Quantification of Relationship Between Monitor Height and Measured Particulate Levelsin Seven U.S. Urban Areas. U.S. Environmental Protection Agency, Research Triangle Park, NC. (Presented at 70th Annual Meeting of Air Pollution Control Association, Toronto, Canada. June 20-24, 1977. APCA77-13.4.)

5. Harrison, P.R. Considerations for Siting Air Quality Monitors inUrban Areas. City of Chicago, Department ofEnvironmental Control, Chicago, IL. (Presented at 66th Annual Meeting of Air Pollution Control Association, Chicago, IL. June 24-28, 1973. APCA 73- 161.)

6. Study of Suspended Particulate Measurements atVarying Heights Above Ground. Texas State Department ofHealth, Air Control Section,Austin, TX. 1970. p.7.



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## Environmental ProtectionAgency

7. Rodes, C.E. and G.F. Evans. Summary of LACS Integrated Pollutant Data. In: LosAngeles Catalyst Study Symposium. U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Publication No. EPA600/4-77-034. June 1977.

8. Lynn, D.A. et al. National Assessment of the Urban Particulate Problem: Volume 1, National Assessment. GCA Technology Division, Bedford, MA. U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Publication No. EPA-450/3-75-024. June 1976.

9. Pace, T.G. Impact of Vehicle-Related Particulates on TSP Concentrations and Rationale for Siting Hi-Vols in the Vicinity of Roadways. OAQPS, U.S. Environmental Protection Agency, Research Triangle Park, NC. April 1978.

10. Ludwig, F.L., J.H. Kealoha, and E. Shelar. Selecting Sitesfor Monitoring Total Suspended Particulates. Stanford Research Institute, Menlo Park, CA. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Publication No. EPA-450/3-77-018. June 1977, revised December 1977.

11. Ball, R.J. and G.E. Anderson. Optimum Site Exposure 

### Criteria for SO2 Monitoring. The Center for the Environment and Man, Inc., Hartford, CT. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Publication No. EPA450/3-77-013. April 1977.

12. Ludwig, F.L. and J.H.S. Kealoha. Selecting Sites for Carbon Monoxide Monitoring. Stanford Research Institute, Menlo Park, CA. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Publication No. EPA-450/3-75-077. September 1975.

13. Ludwig, F.L. and E. Shelar. Site Selection for the Monitoring of Photochemical Air Pollutants. Stanford Research Institute, Menlo Park, CA. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Publication No. EPA450/3-78-013. April 1978.

14. Lead Analysis for Kansas City and Cincinnati, PEDCo Environmental, Inc., Cincinnati, OH. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Contract No. 66-02-2515. June 1977.

15. Barltrap, D. and C.D. Strelow. Westway Nursery Testing Project. Report to the Greater London Council. August 1976.

16. Daines, R. H., H. Moto, and D. M. Chilko. Atmospheric Lead: Its Relationship to Traffic Volume and Proximity to Highways. Environ. Sci. and Technol., 4:318, 1970.

17. Johnson, D. E., et al. Epidemiologic Study of the Effects of Automobile Traffic

on Blood Lead Levels, Southwest Research Institute, Houston, TX. Prepared for U.S. Environmental Protection Agency, Research 

## Pt.58, App. E

Triangle Park, NC. EPA-600/1-78-055, August 1978.

18. Air Quality Criteria for Lead. Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC EPA-600/8-83-028 aF-dF, 1986, and supplements EPA-600/8-89/049F, August 1990. (NTIS document numbers PB87-142378 and PB91- 138420.)

19. Lyman, D. R. The Atmospheric Diffusion of Carbon Monoxide and Lead from an Expressway, Ph.D. Dissertation, University ofCincinnati, Cincinnati, OH. 1972.

20. Wechter, S.G. Preparation of Stable Pollutant Gas Standards Using Treated Aluminum Cylinders. ASTM STP. 598:40-54, 1976.

21. Wohlers, H.C., H. Newstein and D. Daunis. Carbon Monoxide and Sulfur Dioxide Adsorption On and Description From Glass, Plastic and Metal Tubings. J. Air Poll. Con. Assoc. 17:753, 1976.

22. Elfers, L.A. Field Operating Guide for Automated Air Monitoring Equipment. U.S. NTIS. p. 202, 249, 1971.

23. Hughes, E.E. Development of Standard Reference Material for Air Quality Measurement. ISATransactions, 14:281-291, 1975.

24. Altshuller, A.D. and A.G. Wartburg. The Interaction ofOzone with Plastic and Metallic Materials in a Dynamic Flow System. Intern. Jour. Air and Water Poll., 4:70-78, 1961.

25. Code of Federal Regulations. Title 40 part 53.22, July 1976.

26. Butcher, S.S. and R.E. Ruff. Effect of Inlet Residence Time on Analysis ofAtmospheric Nitrogen Oxides and Ozone, Anal. Chem., 43:1890, 1971.

27. Slowik, A.A. and E.B. Sansone. Diffusion Losses of Sulfur Dioxide in Sampling Manifolds. J. Air. Poll. Con. Assoc., 24:245, 1974.

28. Yamada, V.M. and R.J. Charlson. Prop-

er Sizing of the Sampling Inlet Line for a Continuous AirMonitoring Station. Environ. Sci. and Technol., 3:483, 1969.

29. Koch, R.C. and H.E. Rector. Optimum Network Design and Site Exposure Criteria for Particulate Matter, GEOMET Technologies, Inc., Rockville, MD. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Contract No. 68-02-3584. EPA 450/4-87-009. May 1987.

30. Burton, R.M. and J.C. Suggs. Philadelphia Roadway Study. Environmental Monitoring Systems Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, N.C. EPA-600/4-84-070 September 1984.

31. Technical Assistance Document For Sampling and Analysis ofOzone Precursors. Atmospheric Research and Exposure Assessment Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711. EPA600/8-91-215. October 1991.

32. Quality Assurance Handbook for Air Pollution Measurement Systems: Volume IV. Meteorological Measurements. Atmospheric



## 301

### Pt.58, App.G

Research and Exposure Assessment Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711. EPA 600/4-90-0003. August 1989.

33. On-Site Meteorological Program Guidance for Regulatory Modeling Applications. Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711. EPA 450/4-87-013. June 1987F. [71 FR 61323, Oct. 17, 2006, as amended at 75 FR 6535, Feb. 9, 2010; 76 FR 54342, Aug. 31, 2011]

APPENDIX F TO PART 58 [RESERVED]

APPENDIX G TO PART 58--UNIFORM AIR QUALITY INDEX (AQI) AND DAILY REPORTING

GENERAL REQUIREMENTS 1.What is theAQI? 2.Why report theAQI? 3.Must Ireport the AQI? 4.What goes intomyAQI report? 5.Ismy AQIreport formyMSA only? 6. How do I get my AQI report to the public?

7.How oftenmustI reportthe AQI? 8. May I make exceptions to these reportingrequirements?

CALCULATION 9. How Does the AQI Relate to Air Pollution Levels?

10. WhatMonitors Should I Use To Get the Pollutant Concentrations for Calculating the AQI?

11. DoIhave to forecast theAQI? 12. HowDo ICalculate theAQI?

BACKGROUND AND REFERENCE MATERIALS
13. What Additional Information Should I Know?

GENERAL REQUIREMENTS

1. WhatIstheAQI?
The AQI is a tool that simplifies reporting airquality to the general public. The AQI incorporates intoa single indexconcentrations of5 criteria pollutants: ozone (03), particulatematter (PM), carbon monoxide (CO), sulfur dioxide (SO2), and nitrogen dioxide (NO2)- The scale ofthe index is divided into general categories that are associated with health messages.

2. Why ReporttheAQI?

The AQI offers various advantages:

a.It is simple to create and understand. b. It conveys thehealth implications ofair quality.

c. It promotes uniform use throughout the country. 

### 40 CFRCh. 1 (7-1-12 Edition)

3. MustIReporttheAQI?

You must report the AQI daily ifyours is

a metropolitan statistical area (MSA) with a population over350,000.

4. WhatGoesIntoMyAQIReport?
i. Your AQI report must contain the following:

a. The reporting area(s) (the MSA or subdivision oftheMSA).

b. The reporting period (the day for which the AQI isreported).

c. The critical pollutant (the pollutant with thehighest indexvalue).

d. The AQI (thehighest indexvalue).

e. The category descriptor and index value associated with theAQI and, ifyou choose to report in a color format, the associated color. Use only the following descriptors and colors for the sixAQI categories:

TABLE 1-AQI CATEGORIES

ForthisAQI Usethisdescriptor Andthis color1

0to 50

............ "Good"

....................... Green.

51to 100

......... "Moderate"

................. Yellow.

101to 150

.................. "Unhealthy for Sen- Orange. sitiveGroups".

151to 200

.................. "Unhealthy"

................ Red.

201 to 300

.................. "Very Unhealthy" Purple.

301 and above

........... "Hazardous"

.............. Maroon.'

1Specificcolors can befound inthe most recent reporting guidance (Guidelinefor PublicReportingofDaily AirQuality-

irQuality Index(AQl)).
f. The pollutant specific sensitive groups for any reported index value greater than 100. Use the following sensitive groups for each pollutant:

When this pollutant has an index Report these sensitivegroups* value above 100

Ozone Children and peoplewith asthma are the groups mostatrisk.

PM

2. 5 People with respiratory or heartdisease, theelderlyand childrenarethegroups mostatrisk.

PMo

........ People with respiratory disease are the group most at risk.

CO

........... People with heart disease are thegroup most at risk.

SO

.......... People withasthma are thegroup most atrisk.

NO

2

. Children and peoplewith respiratory.diseaseare thegroups mostatrisk.



### 302

## Environmental ProtectionAgency

ii. When appropriate, your AQI report may alsocontain the following:

a. Appropriate health and cautionary statements.

b. The name and index value for otherpollutants, particularly those with an index value greater than 100.

c. The index values for sub-areas ofyour MSA.

d. Causes forunusual AQI values.

e. Actual pollutant concentrations.

5. IsMy AQIReport forMy MSA Only? Generally, your AQI report applies to your MSA only. However, ifa significantair quality problem exists (AQI greater than 100) in

areas significantly impacted by your MSA but not in it (forexample, 03 concentrations

are often highest downwind and outside an urban area), you should identify these areas andreport theAQI forthese areas aswell.

6.HowDoIGetMy AQIReportto thePublic?

You must furnish the daily report to the appropriate news media (radio, television, and newspapers). You must make the daily report publicly available at one or more places of public access, or by any other
means, including a recorded phone message,
a public Internet site, or facsimile transmission. When the AQI value is greater than 100, it is particularly critical that thereporting to the various news media be as extensive aspossible. At aminimum, it should include notification to the media with the largest market coverages for the area in question.

7.How OftenMustIReporttheAQI?

You must report the AQI at least 5 days per week.Exceptions to thisrequirement are in section 8ofthis appendix.

8. MayIMakeExceptionsto These Reporting Requirements?
i. Iftheindex value for a particular pollutant remains below 50 for a season or year, then you may exclude the pollutant from your calculation oftheAQI insection 12.

ii. Ifall indexvalues remain below 50 for a year, then you may report the AQI at your discretion. In subsequent years, ifpollutant levels rise to where the AQI would be above 50, thenthe AQI mustbe reported asrequired in sections 3, 4,6, and 7ofthisappendix.

CALCULATION

9. HowDoestheAQIRelatetoAirPollution Levels?

For each pollutant, the AQI transforms ambient concentrations to a scale from 0 to 500. The AQI is keyed as appropriate to the national ambient air quality standards (NAAQS) for each pollutant. In most cases, the index value of100 is associated with the 

## Pt.58,App.G

numerical level ofthe short-term (i.e., aver- aging time of 24-hours or less) standard for each pollutant. The index value of50is associated with one ofthe following: the numerical level ofthe annual standard for apollutant, ifthere is one; one-halfthe level of the short-term standard for thepollutant; or the level at which it is appropriate to begin to provide guidance on cautionary language. Higher categories of the index are based on increasingly serious health effects that affect increasing proportions of the population. Anindex value is calculated each day for each pollutant (asdescribed in section 12 of this appendix), unless that pollutant is specifically excluded (seesection 8ofthis appendix). The pollutant with the highest index value forthe day is the "critical" pollutant, and must be included in the daily AQI report. As a result, the AQI for any given day is equal to the index value of the critical pollutant for that day. For the purposes of reporting the AQI, the indexes for PM0 and PM2. 5 are to be considered separately.

10. WhatMonitorsShouldI Use To Getthe Pollutant Concentrationsfor Calculating the AQI?

You must use concentration data from population-oriented State/Local Air Monitoring Station (SLAMS) or parts of the SLAMS required by 40 CFR 58.10 for each pollutant except PM. For PM, calculate and report the AQI on days for which you have measured air quality data (e.g., from continuous PM2. 5

### monitors required inAppendix D to this part). You may use PM measurements from monitors that are not reference

or equivalent methods (for example, contin-

uous PMio or PM 2.

5 monitors). Detailed guid-

ance for relating non-approved measurements to approved methods by statistical linear regression is referenced in section 13 below.

11. DoIHave to ForecasttheAQI?

You should forecast the AQI to provide timely air quality information to the public, but this is not required. If you choose to forecast the AQI, then you may consider both long-term and short-term forecasts. Youcan forecast the AQI at least24-hours in advance usingthe most accurate and reasonable procedures considering meteorology, topography, availability of data, and forecasting expertise. The document "Guideline for Developing an Ozone Forecasting Program" (the Forecasting Guidance) will help you start a forecasting program. You can also issue short-term forecasts by predicting 8-hour ozone values from 1-hour ozone values using methods suggested in the Reporting Guidance, "Guideline for Public Reporting of DailyAir Quality."



## 303

### Pt.58, App.G

12.How DoI CalculatetheAQI?

i. The AQI is the highest value calculated for each pollutantas follows:

a. Identify the highest concentration among all of the monitors within each reporting area and truncate the pollutant concentration to one more than the significant 

### 40 CFRCh. 1(7-1-12 Edition)

digits usedto express the level ofthe NAAQS for that pollutant. This is equivalent to the roundingconventions usedin the NAAQS.

b. Using Table 2, find the two breakpoints thatcontain the concentration.

c. Using Equation 1,calculatethe index. d. Round the index to the nearest integer.

TABLE 2-BREAKPOINTS FOR THE AQI

These breakpoints Equal theseAQI's

03 (ppm) 03 (ppm) PM 2.5 PM1o CO (ppm) SO 2(ppm) NO 2(ppm) AQl Category 8-hour 1-hourI (pg/m3) (pg/m 3) 1-hour 1-hour

0.000-0.059 0.0-15.4 0-54 0.0-4.4 0-0.035 0-0.053 0-50 Good. 0.060-0.075 15.5-40.4 55-154 4.5-9.4 0.036-0.075 0.054-0.100 51-100 Moderate. 0.076-0.095 0.125-0.164 40.5-65.4 155-254 9.5-12.4 0.076-0.185 0.101-0.360 101-150 Unhealthyfor Sensitive Groups. 0.096-0.115 0.165-0.204 

## 365.5-150.4 255-354 12.5-15.4 40.186-0.304 0.361-0.64 151-200 Unhealthy. 0.116-0.374 0.205-0.404 

### 3150.5-250.4 355-424 15.5-30.4 40.305-0.604 0.65-1.24 201-300 Very Unhealthy. (2)

................ 0.4050.504 

### 3250.5-350.4 425-504 30.5-40.4 40.605-0.804 1.25-1.64 301-400 (2)

................ 0.505-0.604 

### 3350.5-500.4 505-604 40.5-50.4 40.805-1.004 1.65-2.04 401-500 Hazardous.

'Areas aregenerally required to report the A0lbased on 8-hourozone values. However,there areasmall number ofareas where anAQl basedon 1-hour ozonevalueswould be more precautionary. Inthesecases, inadditiontocalculating the 8-hour
ozone indexvalue,the 1-hour ozone indexvaluemay becalculated, andthemaximum ofthetwovalues reported.

28-hour03 values do notdefine higher AOI values ( 301). AQl valuesof 301 or greaterare calculated with 1-hour 03 con- centrations.

31f

adifferent SHLfor PM 2 .,is promulgated,thesenumbers willchange accordingly. 41-hr SO 2values do not detine higher AGl values ( 200). AQl valuesof 200 or greater are calculated with 24-hour SO 2 concentrations.

ii. If the concentration is equal to a break- note that in some areas, the AQI based on 1- point, then the index is equal to the cor- hour 03 will be more precautionary than responding index value in Table 2. However, uaing 8-hour values (see footnote 1 to Table Equation 1can still be used. The results will 2). In these cases, you may use 1-hour values be equal. If the concentration is between two as well as 8-hour values to calculate index breakpoints, then calculate the index ofthat values and then use the maximum index pollutant with Equation 1. You must also value as the AQI for03.



### a 

### BP8h -s 

### wLe rC

- 

### BPvl + 1 

### c a 

### (Equation 1)

Where: measured and select the one that produces
Ip =the index valuefor pollutant, the highest index value for the AQI. For exC,, = the truncated concentration of pollut- ample, if you observe a PM1o value of 210 g

antp i 3

, a 1-hour 03 value of 0.156 ppm, and an 8- BPi = the breakpoint that is greater than or hour 03 value of 0.130 ppm, then do this:

equal to C, a. Find the breakpoints for PMe at 210 pg/ BPu = the breakpoint that is less than or M 3 as 155 pg/i 3 and 254 pg/i 3

, corresponding equal to C, to indexvalues 101 and 150; Ii = the AQI value corresponding to BPw b. Find the breakpoints for 1-hour 03 at I1o = the AQIvalue corresponding to BP. 0.156 ppm as 0.125 ppm and 0.164 ppm, coriii. If the concentration is larger than the responding to index values 101 and 150; highest breakpoint in Table 2 then you may c. Find the breakpoints for 8-hour 03 at

use the last two breakpoints in Table 2when 0.130 ppm as 0.116 ppm and 0.374 ppm, coryou apply Equation 1. responding to index values 201 and300;
Example d. Apply Equation 1for 210 pg/in', FMIO:

iv. Using Table 2and Equation 1,calculate the index value for each of the pollutants



### 304

## Environmental ProtectionAgency

150

- 

### 101 540- 155 (210

- 155) + 101 = 128 254

- 155 

## Pt.59

e. Apply Equation 1 for 0.156 ppm, 1-hour 03:



### 150

- 101 

### 0 (0.156

- 0.125) + 101 = 

### 140 

### 0.164

- 0.125

f. Apply Equation 1 for 0.130 ppm, 8-hour 03:



## 300

- 201 04- 01 (0.130

- 0.116) +201 = 206 0.374

- 0.116

g. Find themaximum, 206. This is theAQI. Theminimal AQIreport wouldread:

v. Today, the AQI for my city is 206 which is Very Unhealthy, due to ozone. Children and people with asthma are thegroups most atrisk.

13. WhatAdditionalInformationShouldI Know?

The EPA has developed a computer program to calculate the AQI for you. The program prompts for inputs, and it displays all the pertinent information for the AQI (the index value, color, category, sensitive group, health effects, and cautionary language). The EPAhas also prepared a brochure on the AQI that explains the index in detail (The Air Quality Index), Reporting Guidance (Guideline for Public Reporting ofDaily Air Quality) that provides associated health effects and cautionary statements, and Forecasting Guidance (Guideline for Developing

an Ozone Forecasting Program) that explains the stepsnecessary to start an airpollution forecasting program. You can download the program and the guidance documents at www.airnow.gov. Reference for relating non-approved PM measurements to approved methods (Eberly, S., T. Fitz-Simons, T. Hanley, L. Weinstock., T. Tamanini, G. Denniston, B. Lambeth, E. Michel, S. Bortnick. Data Quality Objectives (DQOs) For Relating Federal Reference Method (FRM) and Continuous PM 25

. Measurements to Report an Air Quality Index (AQI). U.S. Environmental Protection Agency, research Triangle Park, NC. EPA-454/B02-002, November 2002) can be found on the Ambient Monitoring Technology Information Center (AMTIC) www.epa.gov/ttnamtil/. Web site, http://

[64 FR 42547, Aug. 4, 1999, as amended at 73 FR 16513, Mar. 27, 2008; 75 FR 6537, Feb. 9, 2010; 75 FR35602, June 22, 2010]



## PART 59-NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS

Sec. 

### Subpart

## A-General

59.1 Final determinations under Section 183(e)(3)(C) ofthe CAA. 

## Subpart B-National Volatile Organic Compound Emission Standards for Automobile Refinish Coatings

59.100 Applicability and designation ofregulatedentity. 59.101 Definitions. 59.102 Standards. 59.103 Container labeling requirements. 59.104 Compliance provisions. 59.105 Reporting requirements. 59.106 Variance. 59.107 Addresses ofEPA Regional offices. 59.108 State authority. 59.109 Circumvention. 59.110 Incorporations byreference. 59.111 Availability of information and confidentiality.



### 305