## Pt.58 40 CFRCh. 1(7-1-13 Edition)

SCHEDULE D.6-PERMANENT WAIVER FROM INTERIM CONTROLS TEST-Continued [Smelter identification]

Line 1984 1985 1986 1987 1988 1989 1990 Total

7

. Discountfactors
.................. 10

............ ............ ............ ............ ............ ............ ............ X X X X 8. Present value of future

cashflows
........................... 11

............ ............ .. .......... ............ ... ......... ... ......... ............ X X X X B.Net presentvalue: 1.Horizonvalue

..................... 12 XXXX XXXX XXXX XXXX XXXX XXXX XXXX

............ 2. Discountfactor

................... 13 XXXX XXXX XXXX XXXX XXXX XXXX XXXX

............ 3. Present value of horizon

value

.................................... 14 XXXX XXXX XXXX XXXX XXXX XXXX XXXX

............ 4. Present value of future

cash flows

........................... 15 XXXX XXXX XXXX XXXX XXXX XXXX XXXX

............ 5.Total presentvalue

............. 16 XXXX XXXX XXXX XXXX XXXX XXXX XXXX

............ 6. Current salvagevalue 17 XXXX XXXX XXXX XXXX XXXX XXXX XXXX

............ 7. Net presentvalue

............... 18 XXXX XXXX XXXX XXXX XXXX XXXX XXXX I

SCHEDULE D.7-HORIZON VALUE OF CASH FLOWS [Smelter identification]

Final forecast Horizon years Line years Total

1989 1990 1991 1992 1993 1994 1995

A.Depreciation-free horizon value: 1.Netcashflow projections 01

........................ XXXX XXXX XXXX XXXX XXXX XXXX 2. Depreciationtaxsavings:
a. Depreciation and

amortization

.......... 02

......................... XXXX XXXX XXXX XXXX XXXX XXXX b. Marginaltax rate

.. 03

......................... XXXX XXXX XXXX XXXX XXXX XXXX

c. Taxsavings

.......... 04

......................... XXXX XXXX XXXX XXXX XXXX XXXX 3. Depreciation-free net cash

flows:

a. Nominal dollarvalues........................ 05
......................... XXXX XXXX XXXX XXXX XXXX XXXX b. 1990 dollarvalues 06

......................... XXXX XXXX XXXX XXXX XXXX XXXX

c.

Average

................ 07 XXXX XXXX XXXX XXXX XXXX XXXX XXXX

............ 4. Horizonfactor

..................... 08 XXXX XXXX XXXX XXXX XXXX XXXX XXXX

............ 5. Depreciation-free horizon

value

.................................... 09 XXXX XXXX XXXX XXXX XXXX XXXX XXXX

............ B. Depreciation tax savings over the

horizon period: 1. Depreciation and amortization

...................................... 10 XX XX XXXX

............ ....... ....... ............ ............ XXXX 2. M arginaltax rate

................ 11 XXXX XXXX

............ ............ ............ ............ ............ XXXX 3. Taxsavings

........................ 12 XXX X XXXX

............ ....... ....... ............ ............ XXXX 4. Discountfactors

.................. 13 XXXX XXXX

............ ............ ............ ............ ............ XXXX 5. Present value of tax saving

s ...................................... 14 XXX X XXXX

............ ....... ....... ............ ......... X X X X 6. Total present value of tax

savings

................................ 15 XXXX XXXX XXXX XXXX XXXX XXXX XXXX

............ C. HorizonValue

................................... 16 XXXX XXXX XXXX XXXX XXXX XXXX XXXX I



## PART58-AMBIENT AIRQUALITY SURVEILLANCE

Subpart A-General Provisions

Sec. 58.1 Definitions. 58.2 Purpose. 58.3 Applicability. SubpartB-Monitoring Network

58.10 Annual monitoring network plan and periodic network assessment. 58.11 Network technical requirements. 58.12 Operating schedules. 58.13 Monitoringnetwork completion. 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 Special purpose monitors (SPM).

## Environmental Protection Agency SubpartD-Comparability ofAmbient Data totheNAAQS
58.30 Special considerations for data com- parisons totheNAAQS. SubpartE[Reserved] Subpart F-AirQualityIndex Reporting
58.50 Indexreporting. Subpart G-Federal Monitoring
58.60 Federalmonitoring. 58.61 Monitoringotherpollutants.

APPENDIX A TO PART 58 QUALITY ASSURANCE REQUIREMENTS FOR STATE AND LOCAL AIR MONITORING STATIONS (SLAMS) APPENDIX B TO PART 58 [RESERVED] APPENDIX C TO PART 58-AMBIENT AIR QUALITY 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 AMBIENT AIR QUALITY MONITORING APPENDIX F TO PART 58 [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, and 7619.

SOURCE: 44 FR 27571, May 

## 10, 1979; 59 FR 41628, Aug. 12, 1994,unless otherwise noted. 

## SubpartA-General Provisions

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

## otherwisenoted.
§58.1 Definitions.



## As usedin thispart,allterms notdefined herein have the meaning given them inthe Act.

AADT means the annual average dailytraffic.

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 oftheEnvironmental Protection Agency (EPA) or his or her authorized representative.

Air Quality System (AQS) means EPA's computerized system for storing and reporting ofinformation relating to ambientairquality data. 

# §58.1

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 region.

Area-widemeans all monitors sitedat neighborhood, urban, and regional scales, as well as those monitors sited
at either micro- or middle-scale that

are representative of many such locations in the same CBSA.

CO means carbon monoxide. Combined statisticalarea(CSA) is defined by theU.S. Office ofManagement and Budget as a geographical area consisting of two or more adjacent Core Based Statistical Areas (CBSA) with employment interchange ofat 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).

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 counties having a high degree ofsocial 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/populationlestimates/metro-city/Listl.txt).

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

a short test cell is inserted into the optical measurement beam ofthe instrument. When the pollutant concentration measured by the analyzer in such

## 40 CFRCh. 1(7-1-13 Edition)

a test includes both the pollutant concentration in the test cell and the concentration in the atmosphere, the atmospheric pollutant concentration mustbe subtracted from the test measurement to obtain the corrected concentration test result. The corrected concentration is equal to the measured concentration minusthe average ofthe atmospheric pollutant concentrations measured (without the test cell)immediately before and immediately after the test.

Design value means the calculated concentration according tothe applicable appendix ofpart 50 of this chapter for the highest sitein an attainment or nonattainment area.

EDOmeans environmental data operations.

Effective concentration pertains to testing an open path analyzer with a high-concentration calibration or audit standard gas contained in a short test cell inserted into the optical measurement 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 the high-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 of the path length of the test cell to the actual atmospheric monitoring path length.

Federal equivalent method (FEM)

means amethod for measuring theconcentration of an air pollutant in the ambient air that has been designated

as an equivalent method in accordance with part53 of this chapter; it does not include a method for which an equivalent method designation has been canceled in accordance with §53.11 or §53.16 ofthis chapter.

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 of this chapter, or a method that has been designated as a reference method in accordance with thispart; it does not include a method for which a reference method designation has been canceled in accordance with §53.11 or §53.16 of this chapter.

HN03 means nitric acid. Localagency means any local government agency, other than the State agency, which is charged by a State with the responsibility for carrying out

a portion 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, sampler, analyzer, or other device that

measures or assists in the measurement ofatmospheric air pollutants and which is acceptable for use in ambient air surveillance under the applicable provisions ofappendix C tothis part.

Monitoringagency means a State or local agency responsible for meeting the requirements ofthispart.

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

assurance regulations apply.

Monitoringpathfor an open path analyzer means the actual path in space between two geographical locations

over which thepollutant concentration is measured 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 concentration measurement (path-averaged concentration) is determined. See also, opticalmeasurementpathlength.

Monitoring planning area (MPA)

means a contiguous geographic area with established, well defined boundaries, suchas a CBSA,county or State, having a common area that is used for planning monitoring locations for PM2. 5 .

### An MPA may cross Stateboundaries, 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 

# §58.1

## Environmental Protection Agency
200,000, but for convenience, those portions ofa State that arenot associated with CBSAscan be considered as a single MPA.

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

NCore means the National Core multipollutant monitoring stations. Monitors at these sites arerequired to
measure particles (PM2

## ., speciated PM2

## . 5

## , PMl( 2.5), 

## 03, SO2

## , CO, nitrogen oxides (NO/NO2/NOy), Pb, and basic meteorology.

Near-roadNO2

## Monitormeans anyN02 monitor meeting the specifications in 4.3.2 of appendix D and paragraphs 2, 4(d), 6.1, and 6.4 of appendix E ofthis part.

Networkmeans all stations of agiven type ortypes.

NH 3

## meansammonia. NO2 

## means nitrogen dioxide. NO

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

sum of the concentrations ofNO2 

## and NO.

NO, means the sum of all total reac- tive nitrogen oxides, including NO, N0 2

## ,and othernitrogen oxidesreferred to asNOz.

03meansozone. Openpath analyzer means an automated analytical method that meas-
ures the average atmospheric pollutant concentration in situ along one or more monitoring pathshaving a monitoring path length of5meters or more and that has been designated as areference or equivalent method under the provisions ofpart 53ofthischapter.

Optical measurement path length

means the actual length ofthe optical beam over which measurement of the pollutant isdetermined. The path-integrated pollutant concentration measured by the analyzer is divided by the optical measurementpathlengthto determine the path-averaged concentration. Generally, the optical measurementpath length is:

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

# §58.1

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 assessment monitoring stations.

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

PM means PM 1

### o, PM10C, PM 2

### . 5

### , PM 10-2,3, or particulate matter of unspecified sizerange.

PM2. means 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 part 53 of this chapter, or by an approved regional method designated in accordance with appendix C to this part.

PM 0 

### 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 ofthis chapter and designated in accordance with part 53 of this chapter or by an equivalent method designated in accordance with part 53 ofthis chapter.

PM 1 0

### c 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 0 ofpart 50 ofthis chapter and designated in accordance with part 53 of this chapter or by an equivalent method designated in accordance with part 53 ofthis chapter.

PM1o 2.5means 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 reference method based on appendix 0 to part 50 of this chapter and designated in accordance with part53 ofthis chapter or by an equivalent method designated in accordance with part 53 of this chapter.

## 40 CFRCh. 1(7-1-13 Edition)

Point analyzer means an automated analytical method that measures pollutant concentration in an ambient air sample extracted from the atmosphere
at a 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, commercial areas, recreational areas, industrial areas where workers from more than one company are located, and other areas where a substantial number 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 SPM networks mustbe associated with one, and only one, primary quality assurance organization.

Probe means 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 of the 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 datatoEPA.

Sitemeansa geographic location. One

or more stations may be at the same site.

SLAMS means State orlocal air monitoring 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. S0 2

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

means a monitor included in an agency's monitoring network that the agency has designated as a special purpose monitor station in its monitoring network plan andin 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 ofmonitors ofvarious types.

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

a plan under theAct.

State speciation site means a supplemental PM 2

### .3speciation station that is not part of the speciation trends network.

Stationmeans a single monitor, or a group ofmonitors with a shared objective, located ata particular site.

STNstation means a PM2._ 

### speciation station designated to be part of the 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 aNIST-traceable Reference Material (NTRM) or a NIST-certified GasManufacturer's Internal Standard (GMIS).

TSP (total suspended particulates)

means particulate matter as measured by the method described in appendix B ofpart50 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 ofeachUrbanized Area.

VOC means volatile organic compounds. [71 FR 61296, Oct. 17, 2006, as amended at 75 FR 6534, Feb. 9,2010; 78 FR3281, Jan. 15, 2013] 

# §58.1

## Environmental Protection Agency

§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 anddatahandling.

(2) Methodology used in monitoring stations.

(3)Operating schedule. (4)Sitingparameters forinstruments

or instrumentprobes.

(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 ofthe network design requirements, including minimum numbers and placement of monitors of each type.

(6)Airquality datareporting, andre- quirements for the daily reporting of

anindex ofambient airquality.

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

(c) This part also acts to establish a national ambient air quality monitoring network forthe purpose ofproviding timely air quality data upon which tobase national assessments and policy decisions.
§58.3 Applicability.



## This partapplies 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 ofproposed

sources.



## Subpart B-MonitoringNetwork

SOURCE: 71 FR 61298, Oct. 17, 2006, unless 

## otherwisenoted.
§58.10 Annual monitoring network plan and periodic network assessment. 

## (a)(1) Beginning July 1, 2007, the State, or where applicable local, agen- §58.10

cy shall adopt and submit to the Regional Administrator an annual monitoring network plan which shall provide for the establishment andmaintenance 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 ofpurposes 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 toEPA.

(2) Any annual monitoring network plan that proposes SLAMS network modifications (including new monitoring sites, new determinations that data are not of sufficient quality to be compared to the NAAQS, and changes in identification of monitors as suitable or not suitable for comparison against the annual PM 2

### .5NAAQS) 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 comment opportunity, and has submitted the received comments together with the plan, the Regional Administrator is not required to provide a separate opportunity for comment.

(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 byJanuary 1, 2011.

(4) Aplan for establishing source-oriented Pb monitoring sites in accordance withthe requirements ofappendix D to this part for Pb sources emitting 1.0 tpy orgreater shall be submitted to the EPA Regional Administrator no later than July 1,2009, as part of the

## 40 CFRCh. 1(7-1-13 Edition)

annual network plan required in paragraph (a)(1) of this section. The plan shall provide for the required sourceoriented 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 Pb monitoring sites in 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)(i) A plan for establishing or identifying an area-wide NO2 

### monitor, in accordance with the requirements of Appendix D, section 4.3.3 to this part, shall be submitted as part of the Annual Monitoring Network Plan to the EPA Regional Administratorby July 1, 2012. The plan shall provide for these required monitors to be operational by January 1, 2013.

(ii) A plan for establishing or identifying any NO2 

### monitor intended to characterize vulnerable and susceptible populations, as required in Appendix D, section 4.3.4 to this part, shall be submitted as part of the Annual Monitoring Network Plan to the EPA Regional Administrator by July 1,2012. The plan shall provide for these required monitors to be operational by January 1, 2013.

(iii) A plan for establishing a single near-road NO2 

### monitor in CBSAs having 1,000,000 or more persons, in accordance with the requirements of Appendix D, section 4.3.2 tothispart, shall be submitted as part ofthe Annual Monitoring Network Plan to the EPA Regional Administrator by July 1,2013. The plan shall provide for these required monitors to be operational by January 1, 2014.

(iv) A plan for establishing a second near-road NO2 

### monitor in any CBSA with a population of 2,500,000 or more persons, or a second monitor in any CBSA with a population of 500,000 or
more persons that has one or more roadway segments with 250,000 or greater AADT counts, in accordance with the requirements of Appendix D, section 4.3.2 to this part, shall be submitted as part of the Annual Monitoring Network Plan to the EPA Regional Administrator by July 1,2014. The plan shall provide for these required monitors to be operational by January 1, 2015.

(v) A plan for establishing a single near-road NO2 

### monitor in all CBSAs having 500,000 ormore persons, but less than 1,000,000, not already required by paragraph (a)(5)(iv) of this section, in accordance with the requirements of Appendix D, section 4.3.2 to this part, shall be submitted as part of the Annual Monitoring Network Plan to the EPA Regional Administratorby July 1, 2016. The plan shall provide for these monitors to be operational by January 1, 2017.

(6) A plan for establishing SO2 

### monitoring sites in accordance with the requirements ofappendix D to this part shall be submitted to the EPA Regional Administrator by July 1, 2011 as part of the annual network plan required in paragraph (a) (1). The plan shall provide 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 requirements ofappendix D to this part shall be submitted to the EPA Regional Administrator. Plans for required CO monitors shall be submitted at least six months prior to the date such monitors must be established as required by section 58.13.

(8)(i) A plan for establishing nearroad PM 2. 5 

### monitoring sites in CBSAs having 2.5 million or more persons, in accordance with the requirements of appendix D to this part, shall be submitted as part of the annual monitoring network plan to the EPA Regional Administrator by July 1,2014. The plan shall provide for these required monitoring stations to be operational byJanuary 1, 2015. (ii) A plan for establishing near-road
PM 2

### ._ monitoring sites in CBSAs having 1million or more persons, but less than 2.5 million persons, in accordance with therequirements ofappendix D to this part, shall be submitted as part of the annual monitoring network plan to the EPA Regional Administrator by 

## §58.10

## Environmental Protection Agency
July 1,2016. The plan shall provide for these required monitoring stations to be operational byJanuary 1,2017.

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

(1)The AQS site identification number.

(2)The location, including street address andgeographical coordinates.

(3)The sampling and analysis method(s) foreachmeasuredparameter.

(4)The operating schedules for each monitor.

(5)Any proposals to remove or move
amonitoring station within aperiod of 18monthsfollowing 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 sitesthat arenot suitable forcomparison against the an- nual PM2

## .5 NAAQS as described in §58.30.

(8) The MSA, CBSA, CSA or other

arearepresented bythemonitor.

(9)The designation of any Pb mon- itors as either source-oriented or nonsource-oriented according to Appendix D to40CFRpart 58.

(10) Any source-oriented monitorsfor which a waiver has been requested or granted by the EPARegional 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 sitefor which awaiver has been requested or granted by the EPA Regional Administrator for the

use of Pb-PM1) 

## monitoring in lieu of Pb-TSP monitoring as allowed for under paragraph 2.10 ofAppendix C to 40CFRpart 58.

(12) The identification of required NO2 

## monitors as near-road, area-wide,

or vulnerable and susceptible population monitors in accordance with Appendix D, section4.3ofthispart.

(13) The identification of any PM2

## .5 FEMs and/or ARMs used in the monitoring agency's network where the data are not ofsufficient quality such thatdata arenottobe compared to the NAAQS. For required SLAMS where the agency identifies that the PM 2

## .5 §58.10

Class III FEM orARM does not produce data of sufficient quality for comparison to the NAAQS, the monitoring agency must ensure that an operating
FRM or filter-based FEM meeting the sample frequency requirements described in §58.12 or other Class III PM2.s FEM or ARM with data ofsufficient quality is operating and reporting data to meet the network design criteria described in appendix D to this part.

(c) The annual monitoring network plan must document how state and local agencies provide for thereview of changes toa PM2.3 monitoring network that impact the location ofa violating
PM 2

### .5monitor. 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 theirsubmitted 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, whether new 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. 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 assessments are due every five yearsbeginning July 1, 2010.

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

## 40 CFRCh. 1(7-1-13 Edition)

and periodic network assessments are subject to approval according to §58.14. [71 FR 61298, Oct. 17, 2006, as amended at 72 FR 32210, June 12, 2007; 73 FR 67059, Nov. 12, 2008; 73 FR 77517, Dec. 19, 2008; 75 FR 6534, Feb. 9,2010; 75 FR 35601, June22, 2010; 75 FR 81137, Dec. 27, 2010; 76 FR 54341, Aug. 31, 2011; 78 FR 16188, Mar. 14,2013; 78 FR3282, Jan. 15, 2013] §58.11 Network technical requirements. (a)(1) State and local governments shall follow the applicable quality assurance 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 Awith 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 ofthe SPM site. Alternatives tothe requirements 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 the quality assurance criteriain appendix A to this part that apply to PSD monitoring when operating a PSD site.

(b) Stateand local governments must follow the criteriain appendix Cto 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 the network design criteria contained in appendix D to thispart in designing and maintaining the SLAMS stations. The final network design and all changes in design are subject to approval of the Regional Administrator. NCore, STN, and PAMS network design and changes are also subject to approval of the Administrator. Changes in SPM stations do not require approvals, but a change in the designation of

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

(d) Stateand local governments must follow the criteria contained in appendix E to thispart for siting monitor inlets, paths or probes at SLAMS stations. Appendix E adherence is optional for SPM stations.

(e) State and local governments must

assess data from Class III PM2. 3 

### FEM and ARM monitors operated within their network using the performance criteria described in table C 4 to subpart C of part 53 of this chapter, for

cases where the data are identified as not of sufficient comparability to a collocated FRM, and the monitoring
agency requests that the FEM or ARM data should not be used in comparison
to the NAAQS. These assessments are required in the monitoring agency's annual monitoring network plan described in §58.10(b) for cases where the FEM orARM is identified as not ofsufficient comparability to a collocated FRM. For these collocated PM 25 

### monitors the performance criteria apply with the following additional provisions:

(1) The acceptable concentration range (Rj), pg/m 3 

### may include values down to0pg i 3



### .

(2) The minimum number oftest sites shall be at least one; however, the number of test sites will generally include all locations within an agency's network with collocated FRMs and FEMs orARMs.

(3) The minimum number ofmethods shall include at least one FRM and at least one FEM or ARM.

(4) Since multiple FRMs and FEMs may not be present at each site; the precision statistic requirement does
not apply, even if precision data are available.

(5) All seasons must be covered with

no more than thirty-six consecutive months ofdata in total aggregated together.

(6) The key statistical metric to include in an assessment is thebias (both additive and multiplicative) of the
PM 2

### ._ continuous FEM(s) compared to 

## §58.11

## Environmental Protection Agency

a collocated FRM(s). Correlation isre- quired to be reported in the assess- ment, but failure to meet the correlation criteria, by itself,is not cause to exclude data from a continuous FEM monitor. [71 FR 61298, Oct. 17, 2006, as amended at 78 

## FR3282,Jan.15,2013]
§58.12 Operatingschedules.



## State and local governments shall collect ambient airquality 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 bythe Regional Administrator.

(b) ForPb 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)ForPAMS VOC samplers, samples must be collected as specified in section 5ofappendix D to thispart. Areaspecific PAMS operating schedules must be included as part ofthe PAMS network description and must be approved by the Regional Administrator.

(d)Formanual PM2.5 samplers: (1)(i) Manual PM 2

## .5samplers at required SLAMS stations without a collocated continuously operating PM2

## .5 monitor must operate on at least a 1- in-3 dayschedule.

(ii)For SLAMS PM2.5 sites withboth manual and continuousPM2

## .5

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

## .5sampling orfor seasonal sampling from the EPA Regional Administrator. TheEPA Regional Administrator maygrant sampling frequency reductions after consideration of factors, including but not limited to the historical PM2

## ._ data quality assessments, the location of current PM2

## .5 design value sites, andtheirregulatory data needs. Required SLAMS stations whose measurements determine the design value for their area and that are within plus or minus 10percent ofthe NAAQS; and all required sites where

one or more 24-hour values have ex- 

## §58.12

ceeded the NAAQS each yearfor a consecutive 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 24-hour design value for their area and whose data are within plus or minus 5percent of the level of the 24-hour PM 2

### .5 NAAQS must have an FRM or FEM operate on a daily schedule if that area's design value for the annual NAAQS is less than the level ofthe annual PM 2

### .5 standard. A continuously operating FEM or ARM PM 2

### .3monitor satisfies this requirement unless it is identified in the monitoring agency's annual monitoring network plan as not appropriate forcomparison tothe NAAQS.

(2) Manual PM 2

### . 5 

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

(3) Manual PM 2

### . 3 

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

(e) For PM 1)

### samplers, a 24-hour sample must be taken from midnight to midnight (local standard time) to ensure national consistency. The minimum monitoring schedule for the site in the area of expected maximum concentration shall be based on the relative level of that monitoring site concentration 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 ofthe PM1 24-hour standard, the increased sampling frequency for those periods or seasons may be exempted by the Regional Administrator and permitted to revertback to once 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 ofdatamustbeconsidered 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

## 40 CFRCh. 1(7-1-13 Edition)

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 made on the basis of the 5-year network assessment. The site having the highest concentration in the most current 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 PM1o emissions or in sampling site characteristics could influence the location of the expected maximum 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 current air quality status and to provide stability to the network. This 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 during the 5-year network assessment process. Minimum data completeness criteria, number of years of data and sampling frequency for judging attainment of the NAAQS are discussed in appendix K ofpart50 ofthis chapter.



## Every SixthDay

EveryOtherDay

EveryDay 

# {

0.8 0.9 1.0 1.1 1.2 1.3 1.4


# Figure 1

- RatiotoStandard

(f)Formanual PM 1)2.5 

### samplers: 

## (1) Manual PM ) 2.5 

## samplers at NCore stations must operate on at least a 1-in-3 day schedule at sites without a collocated continuously op

## erating federal equivalent PM1 2.5 

### method that has been designated in accordance withpart 53 ofthis chapter.

(2) [Reserved] (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 notedin §58.12 (a). [71 FR 61298, Oct. 17, 2006, as amended at 72 FR 32210, June 12, 2007; 75 FR 35601, June 22, 2010; 78FR 3282,Jan. 15,2013] 

## §58.13 Monitoring network completion. (a) The network of NCore multipollutant sites must be physically established no later than January 1, 2011, and at that time, operating underall of the requirements of this part, including the requirements of appendices A, C, D. E, and G to thispart. NCore sites 

## §58.13

## Environmental Protection Agency
required to conduct Pb monitoring as required under40CFRpart 58 appendix 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 December27, 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 ofrequired monitors specified in this part, additional required mon- itors mustbe identified in thenext 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 NetworkPlans, onlymonitoring 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 NO2

## monitors required under Appendix D, section 4.3 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,nolater than:

(1)January 1, 2013, forarea-wide NO2 

## monitors required in Appendix D, section4.3.3;

(2)January 1,2013, for NO2

## monitors intended to characterize vulnerable and susceptible populations that are requiredinAppendixD, section 4.3.4;

(3) January 1, 2014, for an initial near-road NO2 

## monitor in CBSAs having 1,000,000 million or more persons that isrequired in AppendixD,section 4.3.2;

(4)January 1, 2015, fora second near- road NO2

## monitorinCBSAsthathavea population of2,500,000 or more persons
or a second monitorin any CBSA with

a population of500,000 or more persons that has one or more roadway segments with 250,000 or greater AADT counts that is required in Appendix D, section4.3.2:

(5) January 1, 2017, for a near-road NO2

## monitorinCBSAs having 500,000 or 

# §58.14

more persons, but less than 1,000,000,
not already required by paragraph (c)(4) ofthis section, that is required in Appendix D, section 4.3.2.

(d) The network of SO2 

### monitors must be 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, and E 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 monitors.

(f) PM 2

### .3monitors required in nearroad environments as described in appendix D to this part, must be physically established and operating under all ofthe requirements of thispart, including the requirements ofappendices A, C, D, and E to this part, no later than:



## (1)January 

## 1,2015 forPM 2.5

### monitors in CBSAs having 2.5 million persons or more; or

(2) January 1,2017 forPM 2

### ._monitors in CBSAshaving 1million or more, but less than 2.5million persons. [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 FR 54341, Aug. 31, 2011; 78FR 16188, Mar. 14, 2013; 78 FR 3283, Jan. 15,2013]

§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 5 years 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

## 40 CFRCh. 1(7-1-13 Edition)

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 for public 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 ofthe following criteria are met and if the requirements of appendix D to this part, if any, continue to be met. Other requests for discontinuation may also be approved on a case-by-case basis if discontinuance does not compromise data collection needed for implementation of a NAAQS and if therequirements of appendix D to this part, if any, continue to bemet.

(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 notbediscontinued.

(2) Any SLAMS monitor for CO, PM1), 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 higher reading ofthe two monitors beingcompared.

(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 monitor has 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 quality ofthe affected county in the absence of actual monitoring data.

(4) A PM 2

### . 5 

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

(5) A SLAMS monitor that is designed to measure concentrations upwind ofan urban area for purposes 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 also characterizing transport.

(6) A SLAMS monitor not eligible for removal under any of the criteria in 

# §58.14

## Environmental Protection Agency
paragraphs (c)(1) through (c)(5) ofthis sectionmaybe movedtoanearby location withthe same scale ofrepresentation if logistical problems beyond the State's control make it impossible to continue operation atitscurrent site. §58.15 Annual airmonitoringdatacertification. 

## (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 thatmeet 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 assurance findings.

(1)Through2009, the annual datacertification letter is due by July 1 of eachyear.

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

(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 submitted fordata collected from January 1to December 31 ofthe 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 thecertification letter,un- less an approved alternative dateis included in the plan. The annual sum- mary serves as the record ofthe specific data that is the object ofthe certification letter.

(c) Alongwith each certification letter, the State shall submit to the Administrator (through the appropriate Regional Office) a summary ofthe precision and accuracy data for all ambi- 

## §58.16

ent 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 accuracy must be submitted on the same schedule as thecertification letter, unless an approved alternative date is included in theplan. §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 dataand associated quality assurance data for SO2

### ; CO; O; NO2

### ; NO; NOy; NOx; Pb-TSP mass concentration; Pb-PMo mass concentration; PMIo

mass 

### concentration; PM2.5 mass con

### centration; for filter-based PM 2

### .3FRM/ FEM the field blank mass, samplergenerated average daily temperature, and sampler-generated average daily pressure: chemically speciated PM 2.5


## mass concentration data PM 1 2.5 

## mass concentration; meteorological data from NCore and PAMS sites; average daily temperature and average daily pressure for Pb sites if not already reported from sampler generated records; and metadata records and information specified bythe AQSData Coding Manual (http://www.epa.gov/ttn/airslairsaqsl manualsimanuals.htm). The state, or where appropriate, local agency, may report site specific meteorological measurements 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 the AQS 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

## 40 CFRCh. 1(7-1-13 Edition)

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 HN03 data, from PAMS sites to AQS within 6 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 upon request.

(f) The state, or where applicable, local agency shall archive all PM 2.5, 

## PM1), 

## and PM 102,5 

## filters from manual low-volume samplers (samplers having flow rates less than 200 liters/minute) from all SLAMS sites for a minimum period of5years after collection. These filters shall be made available for supplemental analyses, including destructive analyses if necessary, at the request ofEPA orto provide information to state and local agencies on particulate matter composition. Other Federal agencies may request access to filters for purposes of supporting air quality management or community healthsuch as biological assay through the applicable EPA Regional Administrator. The filters shall be archived according to procedures approved by the Administrator, which shall include cold storage of filters after post-sampling laboratory analyses for at least 12 months following field sampling. The EPA recommends that particulate matter filters be archived for longer periods, especially for key sites in making NAAQS-related decisions orfor supporting health-related airpollution studies.

(g) Any State or, where applicable, local agency operating a continuous SO2

### analyzer shall report the maximum 5-minute S02 

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

### average. [71 FR 61298, Oct. 17, 2006, as amended at 73 FR 67059, Nov. 12, 2008; 75 FR 6534, Feb. 9, 2010; 75 FR 35602, June 22, 2010; 78 FR 3283, Jan. 15,2013] 

## Subpart C-Special Purpose Monitors

SOURCE: 71 FR 61302, Oct. 17, 2006, unless otherwise noted. §58.20 Special purpose monitors (SPM). (a)An SPMis defined asany 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 of monitors ofvarious types. Any SPM operated by an air monitoring agency mustbeincluded in the periodic assessments 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 a monitor

as an SPM after January 1, 2007 only if it is a new monitor, i.e., a SLAMS monitorthat is not included in thecurrently applicable monitoring plan or, for a monitor included in the monitoring plan prior to January 1, 2007, if the Regional Administrator has approved the discontinuation ofthe monitor asa SLAMS site.

(b) Any SPM data 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 Ato thispart oran 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 those requirements. Data collected at an SPM 

## §58.20

## Environmental Protection Agency

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 agencymustalso submit to AQS an indication of whether each SPM reporting data to AQS monitor meets the requirements of appendices A andEto thispart.

(c) All data from an SPM using an FRM, FEM, or ARM which has operated formorethan 24months are eligible for comparison to the relevant NAAQS, subject to the conditions of §§58.11(e) and58.30, unlessthe airmonitoring agency demonstrates that the data came from a particular period during which the requirements of appendix A, appendix C, or appendix E to this part were not met, subject to review andEPARegional Office approval

as part ofthe annual monitoring networkplandescribed in § 58.10. (d)IfanSPM using anFRM, FEM, or ARM is discontinued within 24 months of start-up, the Administrator will not base aNAAQS violation determination forthe PM2

## .5

## or ozone NAAQS solelyon data fromtheSPM.

(e) IfanSPM using anFRM, FEM, or ARM is discontinued within 24 months of start-up, the Administrator will not designate an area asnonattainmentfor the CO, SO2

## , NO2

## , or 24-hour PM 0 

## NAAQS solely on thebasis ofdatafrom the SPM. Such data areeligible for use in determinations of whether a nonattainment area has attained one of these NAAQS.

(f)Prior approvalfromEPAisnotrequired fordiscontinuance ofan SPM. [71 FR61298, Oct. 17, 2006, as amended at 72 FR 32210, June 12, 2007; 73 FR67060, Nov. 12, 2008; 78FR3283,Jan. 15,2013] 

## Subpart D-Comparability of Ambient Data tothe NAAQS

SOURCE: 71 FR 61302, Oct. 17, 2006, unless otherwise noted. §58.30 Special considerations for data comparisons tothe NAAQS. 

## (a) ComparabilityofPM2

## .5data.The primary and secondary annual and 24- hour PM 2

## ._s NAAQS are described in part 50 ofthis chapter. Monitors that follow the network technical require- 

## §58.50

ments specified in §58.11 are eligible for comparison to the NAAQS subject to the additional requirements ofthis section. PM 2.5

### measurement data from all eligible monitors are comparable to the 24-hour PM2.5 NAAQS. PM2.5 measurement data from all eligible monitors that are representative of areawide air quality are comparable to the annual PM2.5 

### NAAQS. Consistent with appendix D to this part, section 4.7.1, when micro- or middle-scale PM 2.5 

### monitoring sites collectively identify a larger region oflocalized high ambient PM 2

### .5concentrations, such sites would be considered representative of an area-wide locationand, therefore, eligible for comparison to the annual PM 2

### .5 NAAQS. PM 2

### .5measurement data from monitors that are not representative of area-wide air quality but rather ofrelatively unique micro-scale, orlocalized hot spot, or unique middle-scale impact sites are not eligible for comparison to the annual PM 2

### ._s NAAQS. PM 2

### .5 measurement data from these monitors

are eligible for comparison to the 24- hour PM 2

### . 5 

### NAAQS. For example, if a micro- or middle-scale PM2.5 monitoring site is adjacent to a unique dominating local PM 2

### .5 source, then the PM2.5 measurement data from such

a site would only be eligible for comparison to the 24-hour PM2._s NAAQS. Approval of sites that are suitable and sites that are not suitable for comparison with the annual PM25 NAAQS is provided foras part ofthe annual monitoring network plan described in §58.10.

(b) [Reserved] [71 FR 61302, Oct. 17, 2006, as amended at 78 FR 3283, Jan. 15,2013] 

## Subpart E[Reserved]
Subpart F-AirQuality Index Reporting §58.50 Indexreporting.

(a) The State or where applicable, local agency shall report tothe general public on a daily basis through prominent notice an air quality index that complies with the requirements ofappendix Gto thispart.

## 40 CFRCh. 1(7-1-13 Edition)

(b) Reporting is required for all individual MSA with a population exceeding 350,000.

(c) The population of a MSA for purposes ofindex reporting is the mostrecent decennial U.S. census population. [71FR 61302, Oct.17,2006]



## Subpart G-Federal Monitoring

SOURCE: 44 FR 27571, May 10, 1979, unless otherwise noted. Rodesignated at 58 FR 8467, Feb. 12, 1993.
§58.60 Federalmonitoring.

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 assessments required in §58.10, a SLAMS station at a site which is necessary in thejudgment ofthe Regional Administrator to meet theobjectives defined in appendix Dtothis part. [71FR 61303, Oct. 17,2006] 

## §58.61 Monitoring otherpollutants.

The Administrator may promulgate criteria similar to that referenced in subpart Bofthis part for monitoring a pollutant forwhich anNAAQS does not exist. Such an action would be taken whenever the Administrator determines that a nationwide monitoring program is necessary tomonitor sucha pollutant. [71FR 61303, 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 CheckRequirements 4.Calculations forDataQuality Assessments 5.ReportingRequirements 6.References

1.GeneralInformation. (a)Each monitoring organization is re- quired to implement a quality system that provides sufficient information to assessthe quality ofthe monitoring data. The quality system must,ataminimum, includethe specific requirements described inthisappendix ofthis subpart. Failure toconduct orpass a required check orprocedure, ora seriesofrequired checks or procedures, does not by itself invalidate data for regulatory decision making. Rather, monitoring agencies and EPA shall use the checks and procedures required in this appendix in combination with other data quality information, reports, and similar documents showing overall compliance with part 58. Accordingly, EPA and monitoring agencies shall use a "weight of evidence" approach when determining the suitability of data for regulatory decisions. The EPAreserves the authority to use ornot

use monitoring data submitted by a monitoring organization when making regulatory decisions based on the EPA's assessment of the quality ofthe data. Generally, consensus built validation templates or validation criteria already approved in Quality Assurance Project Plans (QAPPs) should be used as the basis for theweight ofevidence approach.

(b)This appendix specifies the minimum quality system requirements applicable to SLAMS air monitoring data and PSD data for the pollutants SO2, NO
, 03, CO, Pb, PM 2

### ., PM o and PM 12,5 

### submitted to EPA. This appendix also applies to all SPM stations using FRM, FEM, or ARM methods which also meet the requirements of appendix E ofthis part, unless alternatives tothis appendix for SPMs have been approvedin accordance with §58.11(a)(2). Monitoring organizations are encouraged to develop and maintain quality systems more extensive than the required minimums. The permitgranting 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 (see reference 10ofthis 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, SPMs if applicable, andPSD are the

same. Affected SPMs are subject to all the SLAMS requirements, even where not specifically stated in each section. TableA 1 of this appendix summarizes themajor 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 use aFRM, FEM, orARM;

(d) The use ofcalibration standards traceable to NIST or other primary standard;

(e) Performance evaluations and systems. 

## §58.60

## Environmental Protection Agency

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 withtheowner/operator seeking the permit. The monitoring duration for SLAMS is indefinite, whereas for PSD the duration is usually 12months. Whereas thereporting period for precision and accuracy data is on an annual or calendar quarter basis for SLAMS, it is on a continuing sampler quarter basis for PSD, since the monitoring may not commence 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 conductedby personnel different from those who perform routine span checks andcalibrations, whereas for SLAMS, it is thepreferred butnottherequired condition. ForPSD, the evaluation rate is 100 percent ofthe sitesperreporting quarter whereas for SLAMS it is 25percent of the sites or instruments quarterly. Monitoring for sulfur dioxide (SO,) and nitrogen dioxide (NO,) for PSD must be done with automated analyzers-the manual bubbler methods are not permitted.

1.1.3 The requirements for precision assessment for the automated methods are the

same forboth SLAMS andPSD. However, for manual methods, only one collocated site is required forPSD.

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 tobe reported to the AQS, 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 to be followedby 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 atrue concentration orestimate that are related to the measurement process and not to spatial ortemporal population attributes of the air being"measured. Monitoring organizations must develop quality assurance project plans (QAPP) which describe how the organization intends to control 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 neededtomeet the monitoring objective is sometimes referred to theData Quality Objectives Process. Data quality indicators associated with measurement uncertainty include: 

## Pt.58, App.A

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

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

causes errorsin one direction.

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

(d)Completeness. Ameasure 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 ofa characteristic that a method specific procedure canreliablydiscern.

1.3 Measurement Quality Checks. The SLAMS measurement quality checks described in sections 3.2 and 3.3 ofthis appendix shallbe reported to AQS andare included in the data required for certification. The PSD network is required to implement the
measurement quality checks and submit this information quarterly along withassessment information to the permit-granting authority.

1.4 Assessments and Reports. Periodic assessments and documentation of data quality are required tobe reported to EPA or to the permitgranting 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 sections 3, 4, and 5 of this appendix. On the other hand, the selection and extent ofthe quality assurance and quality control activities used by a monitoring organization depend on a number of local factors such as field and laboratory conditions, the objectives for monitoring, the level ofdata 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 todevelop a quality systemthat is most efficient and effective for its own circumstances while achieving the data quality objectives required for the SLAMS sites.

2. QUALITY SYSTEM REQUIREMENTS

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, assessing and reporting work performed by an organization and for carrying out required

## Pt.58, App.A

quality assurance and quality 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 assurance project plans (QAPP) toensure thatthe monitoringresults:

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

(b) Provide data ofadequate quality for the intended monitoring objectives

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

(e)Comply with statutory (and other) requirements ofsociety and

(f) Reflect consideration of cost and economics.

2.1.1 The QMP describes the quality system in terms 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 accordance withEPArequirements (reference 2 ofthis appendix), and approved bythe appropriate Regional Administrator, orhis or her representative. The quality system will be reviewed during the systemsaudits 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 the QMP 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 delega- tion 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 orcircumstances related to data quality.

2.1.2 The QAPP isa formal document describing, in sufficient detail, the quality system that must be implemented to ensure that the results ofwork performed will satisfy the statedobjectives. Thequality assurance 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 3 ofthisappendix).

2.1.3 The monitoring organization's quality system must have adequate resources 

## 40 CFRCh. 1(7-1-13 Edition)

bothin personnel and funding to plan, implement, assess and report on the achievement of the requirements of this 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 the quality 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 of environmental 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 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 ofdata needed to support the objectives ofthe SLAMS stations. DQO will be developed by EPA to support the primary SLAMS objectives for each criteria pollutant.As they are developed they willbe 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 canbe affected by population uncertainty (spatial or temporal uncertainty) and measurement uncertainty (uncertainty associated with collecting, analyzing, reducing and reporting concentration data). This appendix focuses on assessing and controlling measurementuncertainty.

2.3.1.1 Measurement Uncertainty for Automated and Manual PM,_ Methods. The goal for acceptable measurement uncertainty is defined as 10 percent coefficient of variation (CV) for totalprecision and plus or minus 10 percent for totalbias.

2.3.1.2 Measurement Uncertainty for Automated Ozone Methods. The goal for acceptable measurement uncertainty is defined for precision as an upper 90 percent confidence limit for the coefficient variation (CV) of7 percent and for bias as an upper 95 percent confidence limit for the absolute bias of7 percent.

2.3.1.3 Measurement Uncertainty for PM,2_ Methods. The goal for acceptable

## Environmental Protection Agency

measurement uncertainty is defined for precision as an upper 90 percent confidence limit for the coefficient variation (CV) of 15 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 measurement 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 absolutebias of15percent.

2.3.1.5 Measurement Uncertainty for NO,. The goal for acceptable measurement uncertainty is defined for precision as an upper90 percent confidence limit for the coefficient ofvariation (CV) of15percent andfor bias as
an upper 95 percent confidence limit for the absolute biasof 15percent.

2.3.1.6 Measurement Uncertainty for S02. The goal for acceptable measurement uncertainty for precision is defined as an upper90 percent confidence limit for the coefficient ofvariation (CV) of10percent andfor bias as
an upper 95 percent confidence limit for the absolute biasof 10percent.

2.4 National Performance Evaluation Programs. Monitoring plans or the QAPP shall provide for the implementation ofa program of independent and adequate audits of all monitors providing data for SLAMS andPSD includingthe provision ofadequateresources for such audit programs. A monitoring plan (or QAPP) which provides for monitoring organization 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 attheAir 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 auditsofeach 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. 

## Pt.58, App.A

2.6.1 Gaseous pollutant concentration standards (permeation devices or cylinders of compressed gas) used to obtain test concentrations for carbon monoxide (CO),sulfur dioxide (SO2), nitrogen oxide (NO), and nitrogen dioxide (NO,) mustbe traceable to either

a National Institute of Standards 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 of this appendix. Vendors advertising certification with the procedures provided in reference 4 ofthis 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 Dto part 50 ofthis chapter, orby means ofa certified 03 transfer standard. Consult references 7 and 8 of this appendix for guidance on primary and transfer standards for 03.

2.6.3 Flow rate measurements must be made by aflow measuring instrument thatis traceable to an authoritative volume or other applicable standard. Guidance for certifying some types offlowmeters is provided in reference 10ofthis appendix.

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 systemfor SLAMS. Many specific quality control checks and specifications for methods are included in the respective reference methods described in part 50 ofthis 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 ofthe flow rate verifications (sections 3.2.3 and 3.3.2 of this appendix), data from these checks are required to be submitted to the AQS within the same time frame asroutine ambient concentration data. Section 3.2 ofthis appendix describes checks ofautomated orcontinuous instruments while section 3.3 describe checks

## Pt.58, App.A

associated with manual sampling instruments. Other quality control samples are identified in thevarious references described earlier and can be used to control certain aspects ofthe measurement system.

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

or a coordinated aggregation of such organizations that is responsible for a set of stations that monitors the same pollutant and for which data quality assessments can logically be pooled. Each criteria pollutant sampier/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 organization shall be defined such that measurement uncertainty among all stations in the organization can be expected to be reasonably homogeneous, as a result ofcommon factors. Common factors thatshould be considered bymonitoring organizations in defining 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;

(c) Common calibration facilities and standards;

(d)Oversight by a common quality assurance 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 assurance organizations shall be subject to final approval by the appropriate EPA Regional Office during scheduled network reviews or systems audits.

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

3.2 Measurement Quality Checks ofAutomated Methods. Table A-2 of this appendix provides a summary of the types and frequency of the measurement quality checks thatwill be describedin this section.

3.2.1 One-Point Quality Control Check for S02, N0 2, 03, and CO. A one-point quality control (QC) check must be performed at least once every 2 weeks on each automated analyzer used to measure S0 2, NO, 03 and CO. The frequency of QC checks may be reduced based upon review, assessment and approval of the EPA Regional Administrator. However, with the advent ofautomated cali

## 40 CFRCh. 1(7-1-13 Edition)

bration systems more frequent checking is encouraged. See Reference 10 of this appendix for guidance on the review procedure. The QC check is made bychallenging the analyzer with a QC check gas of known concentration (effective concentration for open path analyzers) between 0.01 and 0.10 parts per million (ppm) for SO,, NO,, and O, and between 1and 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 normally 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 orbelow the levels identified, use check gases of appropriate concentrations as approved by the appropriate EPA Regional Administrator or their designee. The standards from which check concentrations are obtained must meet the specifications of section2.6 ofthis appendix.

3.2.1.1 Except for certain CO analyzers described below, point analyzers must operate in their normal sampling mode during the QC check, andthe testatmosphere 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. If permitted 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 thanthe normal sample inlet, provided that the analyzer's response is not likely to be altered by these deviations from the normal operational mode. If aQC check is made in conjunction with a zero or span adjustment, it must be 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 measurement beam oftheinstrument. 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 accommodate 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 monitoringpathmaybe used. The actual concentration ofthe QC check gas in the test cell must be selected to produce an effective concentration in therange specified earlier in this section. Generally, the QC test

## Environmental Protection Agency

concentration measurement will be the sum of the atmospheric pollutant concentration and the QC 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 by the open path instrument under test immediately before and 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 thetest result and repeat the test.If possible, open path analyzers should be tested during periods when the atmospheric pollutant concentrations are relatively low and steady.

3.2.1.3 Report the audit concentration (effective concentration for open path analyzers) ofthe QC gas and the corresponding measured concentration (corrected concentration, if applicable, for open path analyzers) indicated by the analyzer. The percent differences between these concentrations are used to assess the precision and 

## Pt.58, App.A

bias of the monitoring data as described in sections 4.1.2 (precision) and 4.1.3 (bias) of this appendix.

3.2.2 Annual performance evaluation for SO, NO,, 0
, or CO. Each calendar quarter (during which analyzers are operated), evaluate at least 25 percent of the SLAMS ana

### lyzers that 

### monitor for SO2, NO

, 03, OP CO such thateach analyzer is evaluated atleast

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 theroutine site operator.

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

Concentration range, ppm Auditlevel 01 S02 NO, 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 bytheinitial three selected.

3.2.2.2 (a) NO, 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 audit gas to levels closer to typical ambient NO concentrations atthe site.

(b) To evaluate SLAMS analyzers operating on ranges higher than 0 to 1.0 ppm for SO,, NO2, and 03 or 0 to 50 ppm for CO,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 of section2.6 ofthis appendix. The gas standards and equipment used for evaluations must notbe the same as the standards andequipment usedfor calibration

or calibration span adjustments. For SLAMS sites, the auditor should not be the operator

or analyst who conducts the routine monitoring, calibration, and analysis. For PSD sites the auditor must not be the operator or analyst who conducts the routine monitoring, calibration, andanalysis.

3.2.2.4 Forpoint 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 asis practicable. The exception provided in section 3.2.1 ofthis appendix for certain CO analyzers does not apply for evaluations.

## Pt.58, App.A

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, as appropriate, reflecting devices should be used during the evaluation, and the normal monitoring configuration ofthe instrument should be modified as little as possible to accommodate thetest cell for the evaluation. However, if permitted 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 of this 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 of the atmospheric concentrations measured by the 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 test result for that concentration level and repeat the test for that level. If possible, open path analyzers 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 3 percent to validate the evaluation, since the monitoring path length is critical
to the determination of the effective concentration.

3.2.2.6 Report both the evaluation concentrations (effective concentrations for open path analyzers) ofthe 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 ofthe monitoring data as described in section 4.1.4 ofthis 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 PMlo, PM -2,5 and PM 2 . The verification is made by checking the operational flow rate of the analyzer. If 

## 40 CFRCh. 1(7-1-13 Edition)

the verification is made in conjunction with

a flow rate adjustment, it must be made prior to such flow rate adjustment. Randomization ofthe flow rate verification with respect to time of day, day ofweek, and routine 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 ofthe 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 flow rates are used to assess the bias of the monitoring data as described in section 4.2.2 of this appendix (usingflow rates in lieu ofconcentrations).

3.2.4 Semi-Annual Flow Rate Audit for Particulate Matter. Every 6 months, audit the flow rate ofthe PM1o, PM1,2_s and PM25 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 flow rate using a flow rate transfer standard certified in accordance with section 2.6 of this appendix. The flow rate standard 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 orvolume standard. Great care must be used in auditing the flow
rate to be certain thattheflow 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 flow ratemeasured (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 ofthis appendix.

3.2.5 Collocated Sampling Procedures for PM 2 For each pair ofcollocated monitors, designate one sampler as the primary monitor whose concentrations will be used to report air quality for the site, and designate the other astheaudit monitor.

3.2.5.1 Each EPA designated Federal reference method (FRM) or Federal equivalent method (FEM) within a primary quality assurance organization must:

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

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

## Environmental Protection Agency

3.2.5.2 In addition, monitors selected for collocation mustalso meet the following requirements:

(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, 50 percent ofthe monitors designated for collocation 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. If there

are an oddnumber ofcollocated monitors required, the additional monitor shall be an FRM audit monitor. An example ofthis procedure is foundin Table A 3 ofthis appendix.

3.2.5.3 The collocated monitors should be deployed according to the following protocol:

(a) 80 percent ofthe collocated audit monitors shouldbe deployed at sites with annual average or daily concentrations estimated to be within +20 percent of the applicable NAAQS and theremainder at whatthe monitoring organizations designate as high value sites;

(b) If an organization hasno sites with annual average or daily concentrations within ±20 percent ofthe annual NAAQS (or 24-hour NAAQS if that is affecting the area), 60 percent ofthe collocated audit monitors should be deployed at those sites with the annual

mean concentrations (or 24-hour NAAQS if that is affecting the area)among the highest 25 percent for all sitesin thenetwork.

3.2.5.4 In determiningthe numberofcollocated sites required for PM,, monitoring networks for visibility assessments should not be treated independently from networks for particulate matter, as the separate networks may share one ormore common samplers. However, for Class I visibility areas, EPA will accept visibility aerosol mass measurement instead of a PM 2. measurement if the latter measurement is unavailable. Any PM,2 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 of sites 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 concentration mustbeselected.

3.2.5.6 The two collocated monitors must be within 4meters ofeach other and atleast 2meters apart for flow rates greater than 200 liters/min or atleast 1meter apart for samplers having flow rates less than 200 liters/ min topreclude airflow interference. Awaiver allowing up to 10 meters horizontal distance and up to 3 meters vertical distance (inlet to inlet) between a primary and collo

## Pt.58, App.A

cated sampler may be approved by the Regional Administrator for sites at a neighborhood or larger scale of representation. This waiver may be approved during the annual network plan approval process. Calibration, sampling, and analysis mustbe the same for all the collocated samplers in each agency's network.

3.2.5.7 Sample the collocated audit monitor for SLAMS sites on a 12-day schedule; sample PSD sites on a 6-day schedule or every thirdday for PSD daily monitors. If a primary quality assurance organization has only one collocated monitor, higher sampling frequencies than the 12-day schedule may be needed in order to produce about 25 valid sample pairs a year. Report the measurements 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 PM 15 For the PM

### 1,2_s 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 concentrations will be 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 PM 2_s 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 numberofmonitors 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 can be located atthe same site.

3.2.6.2 The Regional 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 PM o1,s site, sites considered 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 PM -2,5 network is deployed, the first sites implementing FEMs shallbe required toperform collocation until there is a larger distribution of FEM monitors implemented in the network.

3.2.6.3 The two collocated monitors must be within 4meters ofeach other and atleast 2meters apart for flow rates greater than 200 liters/min or atleast 1meter apart for samplers having flow rates less than 200 liters/

## Pt.58, App.A

min topreclude airflow interference. Awaiver allowing up to 10 meters horizontal distance and up to 3 meters vertical distance (inlet to inlet) between a primary and a collocated sampler may be approved by the Regional Administrator for sites at a neighborhood orlarger scale ofrepresentation taking into consideration safety, logistics, and space availability. This waiver may be approved during the annual network plan approval process. Calibration, sampling, and analysis must be the same for all the collocated samplers in each agency'snetwork.

3.2.6.4 Sample the collocated audit monitor for SLAMS sites on a 12-day schedule. Report the measurements frombothprimary 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 ofthisappendix.

3.2.7 PM,5 Performance Evaluation Program (PEP) Procedures. The PEP is an independent assessment used to estimate total measurement systembias. 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 withless than or equal tofive monitoring sites, five valid performance evaluation audits must be collected and reported each year. For primary quality assurance organizations 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 3pg/m 3

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

(1) Have each method designation evaluated each year: and,

(2) Have all FRM orFEM samplers subject to a PEP audit at leastonce every six years: which equates to approximately 15percent of the monitoring sitesaudited each year.

(b)Additional information concerning the Performance Evaluation Program is contained in reference 10 ofthis appendix. The calculations for evaluating bias between the primary monitor and the performance evaluation monitor for PM 2.5 are described in section 4.3.2 ofthis appendix.

3.2.8 PM os Performance Evaluation Program. For the PMio-,s network, all automated methods will be designated as federal equivalent methods (FEMs). One performance evaluation audit, as described in section 3.2.7 must be performed at one PMl0,5 site in each primary quality assurance organization each year. The calculations forevaluating bias between the primary monitor(s) 

## 40 CFRCh. 1(7-1-13 Edition)

and the performance evaluation monitors for PM1,2_s are described in section 4.1.3 ofthis appendix.

3.3 Measurement Quality Checks of Manual Methods. Table A-2 ofthis appendix provides a summary of the types and frequency ofthe measurement quality checks that will be described in this section.

3.3.1 Collocated Sampling Procedures for PM o. For each network of manual PM1o methods, select 15 percent (or atleast one) of the monitoring sites within the primary quality assurance organization for collocated sampling. Forpurposes ofprecision assessment, networks for measuring total suspended particulate (TSP) and PM o shall be considered separately from one another. However, PM

### 10samplers used in the PM 10-2,5 network, may be counted along with the PM 1osamplers in the PM1onetwork as long

as the PM o samplers in both networks are the same method designation. PM oandTSP sites having annual meanparticulate matter concentrations among the highest 25percent of the annual mean concentrations for all the sites in the network mustbe selected or, if such sites are impractical, alternative sites approved by the EPA Regional Administratormay beselected.

3.3.1.1 In determiningthe numberofcollocated sites required for PM o, monitoring networks for lead (Pb) should be treated independently from networks for particulate matter (PM), even though the separate networks may share one ormore common samplers. However, a single pair of samplers 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 for both networks.

3.3.1.2 The two collocated monitors must be within 4meters ofeach other and atleast 2meters apart for flow rates greater than 200 liters/min or atleast 1meter apart for samplers having flow rates less than 200 liters/ min to preclude airflow interference. Calibration, sampling, analysis and verification/ validation procedures must be the same for both collocated samplers andthe same as for allother samplers in thenetwork.

3.3.1.3 For each pair of collocated samplers, designate one sampler as the primary sampler whose samples 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. If a primary quality assurance organization has only 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

## Environmental Protection Agency

site. The calculations for evaluating precision between the two collocated samplers are described in section 4.2.1ofthis appendix.

3.3.2 Flow Rate Verification for Particulate Matter. Follow the same procedure as described in section 3.2.3 ofthis appendix for PM,.
, PM (low-volume instruments), and PM 10-2. High-volume PM

### 1oand 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 ofthemonitoring 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 ofthis appendix for PM2

### ,, PM o, PM 12,1 and TSP instruments. The percent differences between these flow rates are used to validate the onepoint flow rate verification checks used to estimate bias as described in section 4.2.3 of this appendix. Great care mustbe used in auditing high-volume particulate matter samplers having flow regulators because the introduction ofresistance 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 PbMethods. 3.3.4.1 Flow Rates. For the Pb Reference Methods (40 CFR Part 50, appendix G and appendix Q) and associated FEMs, the flow rates ofthe Pb samplers shallbe verified and audited using the same procedures described in sections 3.3.2 and3.3.3 ofthis appendix.

3.3.4.2 Pb Analysis Audits. Each calendar quarter or sampling quarter (PSD), audit the Pb Reference Method analytical procedure using filters containing a known quantity of Pb. These auditfilters are prepared bydepositing a Pb solution on unexposed filters and allowing them to dry thoroughly. The audit samples must be prepared using batches of reagents different from those used to calibrate the Pb analytical equipmentbeing audited. Prepare audit samplesin the following concentration ranges:
Range [ Equivalent ambient Pbcon- ng centration, g/M3

1

............ 30-100%ofPb NAAQS. 2

............ 200-300%of Pb NAAQS.

(a) Audit samples must be extracted using the same extraction procedure used for exposed filters.

(b) Analyze three audit samples in each of the two ranges each quarter samples are analyzed. The audit sample analyses shall be 

## Pt.58, App.A

distributed as much as possible over the entire calendarquarter.

(c) Report the audit concentrations (in pg 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 in section4.1.3 ofthis appendix.

(d) The audits ofan equivalent Pb method

are conducted and assessed in the same manner asfor the reference method. Theflow 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 the highest Pb concentrations in the network. If the site is impractical, alternative sites, approved by theEPA 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 requirements 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 section 3.2.7 ofthis appendix, mustbe performed at one Pb site in each primary quality assurance organization thathasless than or equal 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 lessthan or equalto 5 sites and six collocated samples at primary quality assurance organizations with greater 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 PM._s. Follow the same procedure as described in section 3.2.5 of this appendix. PM,._ samplers used in the PM o_, network, may be counted along with the PM2.5 Samplers in the PM 2.5network as long as the PM,._ samplers in both networks are the

same method designation.

3.3.6 Collocated Sampling Procedures for PM
_,. All designated FRMs within the PM 12. monitoring network must have 15 percent ofthemonitors collocated (values of 0.5 and greater round up) at the PM

.

## Pt.58, App.A

sites. All FRM method designations can be aggregated.

3.3.6.1 The EPA shall ensure that each designated FEM within the PM(25 monitoringnetwork 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 numberofmonitors 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 can be located atthe same site.

3.3.6.2 The Regional Administrator for the EPA Region where the FRM orFEMs are implemented will select the sites for collocated monitoring. The collocation site selection process shall consider sites atprimary quality assurance organizations or States with

more than one PMM 2.1 site; primary quality

assurance organizations already monitoring for PMlo and PM2,5 using FRMs or FEMs; and an appropriate distribution among rural and urban NCore sites. Monitoring organizations implementing PM10samplers and PMs
FRM samplers ofthe same method designation as the PM 0 2 FRM can include the PM 2_s monitors in their respective PMl and PM,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 o.s Performance Evaluation Program (PEP) Procedures. Oneperformance evaluation audit, asdescribed in section 3.2.7 of this appendix must be performed at one PM 2_site in each primary quality assurance organization each year. Monitoring organizations implementing PM 2., FRM samplers ofthe same method designation inboth the PM2,5 and the PM 2,5 networks can indlude the PM o0. performance evaluation audit in their respective PM,2_s performance evaluation count as longas the performance evaluation isconducted at the PM 0 2, Site. The calculations for evaluating bias between the primary monitor(s) and the performance evaluation monitors for PM 0-2.5 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. 

## 40 CFRCh. 1(7-1-13 Edition)

(b)The EPA will provide annual assessments ofdata quality aggregated by site and primary quality assurance organization for SO,, NO,, 0, and CO and by primary quality

assurance organization for PM j, PM, PM, 2.,and 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 thefollowing limits:

(1)

TSP: 20 pig/M 3

. (2) Pb: 0.02pg/m3

. (3) PM ,o (Hi-Vol): 15 g/m3

. (4) PMlo(Lo-Vol): 3 ig/m3

. (5) PMo 9 .s

and PM, :3pg/m 3

. 4.1 Statistics for the Assessment of QC Checks for SO2, NO
,

### 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: 

## Equation ]

meas- audit
audit
where, meas isthe concentration indicated by the monitoring organization's instrument and audit is the audit concentration ofthe standardused in the QC check being measured.
4.1.2 Precision Estimate.The precision estimate is used to assess the one-point QC checks for SO', 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 2 ofthissection:


## Equation2

CV 

## = . n-I
x2

01n-1

where, X2o , 1 is the 10th percentile ofa chisquared distribution with n-1 degrees of freedom.
4.1.3 Bias Estimate. The bias estimate is calculated using the one-point QC checks for SO2, NO, 03, orCO described in section 3.2.1

## Environmental Protection Agency

ofthis appendix and theperformance evaluation program for PMl1 2,5 described in sections 3.2.8 and 3.3.8 ofthis appendix. Thebias estimator is an upperbound on themean absolute value ofthe percent differences as described in equation 3 ofthissection:


## Equation3 

# IABI=AB+t 0

### .9

5

### ,n. 

## AS

where, nis the number ofsingle point checks being aggregated t0.95,.1is the 95th quantile of a t-distribution with n 1 degrees offreedom; the quantityAB is the mean of the absolute values of the dis and is calculated using equation 4 of this section: 

## Equation4

AB=-' 

# I 

# Id 1
n j.,

and the quantity AS is the standard deviation oftheabsolute value ofthe d'sand iscalculated using equation 5 ofthis section: 

## Equation5

n 2



### n 

## Idil I 

## AS= i] : n(n-1)

4.1.3.1 Assigning a sign (positive/negative) to the bias estimate. Sincethe bias statistic

as calculated in equation 3of this appendix

uses absolute values, it does not have atendency (negative or positive bias) associated with it. A sign willbe designated by rank ordering 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 shouldbe flagged as positive if both percentiles are positive and negative if both percentiles are negative. The absolute bias upper bound would not be flagged if the25th and 75th percentiles are ofdifferent signs.

4.1.4 Validation of Bias Using the onepoint QC Checks. The annual performance evaluations for SO2, NO, 03, or CO described in section 3.2.2 of this appendix are used to verify the results obtained from the onepoint QC checks andto 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 organization level, probability limits will be 

## Pt.58, App.A

calculated from the one-point QC checks using equations 6 and7 ofthis appendix: 

## Equation6 UpperProbabilityLimit=m+1.96 S

Equation7

LowerProbabilityLimit

-m- 1.96. S

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

## Equation8

1k 

## m=- • 

## di 

## k ijl
where, k is the total number ofonepoint QC checks for the interval being evaluated and S is the standard deviation of the percent differences (equation 9 ofthis appendix) asfollows:


## Equation9

k k 2 

# k.Xd

- i k(k 1)

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

can be compared to the 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 withinthe probability intervalsfor the primary quality assurance organization.

4.2 Statistics for theAssessment ofPM o. 4.2.1 Precision Estimate from Collocated Samplers. Precision is estimated via duplicate measurements from collocated samplers ofthe same type. It is recommended thatthe precision be aggregated at theprimary quality assurance organization level quarterly, annually, and at the 3-year level. The data pair would only be considered valid if both concentrations are greater than the minimum values specified in section 4(c) ofthis appendix. For each collocated data pair, calculate the relative percent difference, di, using equation 10 ofthis appendix:

## 40 CFRCh. 1(7-1-13 Edition)

Equation10

di( X Y)2i .100 (Xi +Yi)/2

where, X is the concentration from the primary sampler and Y is theconcentration value from the audit sampler. The coefficient of variation upper bound is calculated using the equation 11 ofthis appendix: 

## Equation11 

# n

n.Xdi- di


## CV i i 

# n-I 2n(n-1)

where, n is the number ofvalid data pairs being aggregated, andX2 o.., 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 iscalculated 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 sections 3.2.3 and 3.3.2 ofthis appendix, calculate the percent difference in volume using equation 1 of this appendix where

neas is the value indicated by the sampler's volume measurement and auditis the actual volume indicated by the auditing flow meter. The absolute volume biasupper bound is then calculated using equation 3, where nis thenumber offlow rate audits being aggregated; t0.95, iS the 95th quantile ofa t-distribution with n-1 degrees offreedom, the quantity AB is themean ofthe absolute values ofthe d,'s and is calculated using equation 4 of this appendix
, and the quantity AS in equation 3 ofthis appendix is the standard deviation of the absolute values if the dis and is calculated using equation 5 ofthis 4.2.3 Assessment Semi-Annual Flow Rate Audits. Theflow rate audits describedin 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 difference in volume using equation 1ofthis appendix where meas is the value indicated by the sampler's volume measurement and audit isthe actual volume indicated by the auditing flow meter. To quantify this annually andat the3-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 isthetotal number of one-point flow rate verifications for the year and S is the standard deviation of the percent differences asdescribed 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 probability intervals for the one-point flow rate verifications for therespective primary quality assurance organization. Ninety-five percent ofthe individual percent differences (all audit concentration levels) for the performance evaluations should be captured within the probability intervals for primary quality

assurance organization.

4.3 Statistics for the Assessment ofPM2 and PM 2_..

4.3.1 Precision Estimate. Precision for collocated instruments for PM,,_s and PM 2_s may be estimated where both the primary and collocated instruments are the same method designation and when the method designations are not similar. Follow theprocedure described in section 4.2.1 of this appendix. In addition, one may want to perform an estimate ofbias 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 BiasEstimate. Follow the procedure described in section 4.1.3 ofthis appendix for the bias estimate ofPM 1 25,The PM2,5 bias estimate is calculated using the paired routine and the PEP monitor data described in section 3.2.6 ofthis appendix. Calculate the percent difference, di,using equation 1 of this appendix, where rneas is the measured concentration from agency's primary monitor and auditisthe 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 forvarious levels 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 ofthis appendix to the desired level of aggregation using equation 12 ofthis appendix: 

## Equation12

D 

# 1 .nI
D =' 

# Xi

ni il 

## Pt.58, App. A

## Environmental Protection Agency

where, nj is the number of pairs and d1, d, * * *, d,,j are the biases for each of the pairs to be averaged. 

## Pt.58, App.A

4.3.2.2 Confidence intervals can be constructed for these average bias estimates in equation 12 ofthis appendix using equations 13 and 14 ofthis appendix:



## Equation13


## Upper 90%

## Confidence Interval=D+t095 

### , s



## Equation 14

Lower 90% Confidence

Where, to9gaf is the 95th quantile ofa t-distribution with degrees of freedom df = ni

- 1and sis an estimate ofthe variability of the average bias calculated using equation 15 ofthisappendix: 

## Equation15

4.4 Statistics fortheAssessmento Pb. 4.4.1 Precision Estimate. Follow the same procedures as described for PM in section 4.2.1 ofthis appendix usingthe data from the collocated instruments. The data pair would only be considered valid if both concentrations are greater than the minimum values specified in section4(c) ofthis appendix.

4.4.2 BiasEstimate.Forthe Pb analysis audits described in section 3.3.4.2 and the Pb Performance Evaluation Program described in section 3.3.4.4, follow the same procedure

as described 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 PM in section 4.2.2; for the flow rate audits, follow the

same procedures as described in section 4.2.3.

5. REPORTING REQUIREMENTS 5.1 SLAMS Reporting Requirements. For each pollutant, prepare a list of all monitoring sites andtheir AQS site identification codes in each primary quality assurance organization and submit the list to the appropriate EPA Regional Office, with a copy to AQS. Whenever there is a change in this list of monitoring sites in a primary quality assurance organization, report this change to the EPARegional Office andto AQS. 

## Interval=D

- t095,df •s 

# 1,Fn

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 airquality data as setforth in §58.16. The EPA strongly encourages early submission ofthe quality assurance data in order to assist the monitoring organizations control and evaluate the quality ofthe 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 4 ofthis appendix for the pollutants measured. All data used to calculate reported estimates ofprecision and bias including span checks, collocated sampler 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 for Environmental DataCollection andEnvironmental Technology Programs. ANSI/ ASQC E4 2004. February 2004. Available from American Society for Quality Control, 611 EastWisconsin Avenue, Milwaukee, WI 53202.

(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.

## Pt.58, App.A

(3)EPA Requirements for Quality Assurance Project Plans for Environmental Data Operations. EPA QA/R-5. 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 Luther KingDrive, 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) ListofDesignatedReference 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 

## 40 CFRCh. 1(7-1-13 Edition)

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/amic/cpreldoc.ht l.

(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 Luther KingDrive, Cincinnati, 0H 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-454/R-98-004. http://www.epa.gov/ttn/ amtwc/qabook.html.

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

.................................. 1.The development,documentation, and implemen- Sameas SLAMS. tationofan approvedqualitysystem. 2.The assessmentofdataquality. 3. The use of reference, equivalent, or approved

methods. 4.The useofcalibration standardstraceabletoNIST

or otherprimarystandard. 5.The participation inEPA performance evaluations Sameas SLAMS

andthe permissionfor EPAtoconductsystem audits. MonitoringandQA Responsibility State/localagencyviathe "primaryqualityassurance Sourceowner/operator. organization". M

onitoring D uration

......................... Indefinitely

................................................................... U sually upto 12m onths. Annual Performance Evaluation Standards and equipment differentfrom those used Personnel, standards and equip-

(PE). for spanning, calibration,and verifications. Prefer ment different from those used different personnel. for spanning, calibration, and verifications. PEauditrate:

- Automated

..................... 100% peryear
............................................................ 100% perquarter. -Manual

.......................... Variesdependingon pollutant. SeeTableA-2 ofthis 100% perquarter. appendix. PrecisionAssessment: -Automated

..................... One-point OC check biweekly but data quality de- OnepointCCcheckbiweekly. pendent. -Manual

.......................... Variesdependingon pollutant. SeeTableA-2 ofthis One site: 1every6daysor every appendix. third day for daily monitoring (TSPand Pb). Reporting_Automated

..................... Bysite- EPA performs calculationsannually

............ By site-source owner/operator performs calculations each sam- plingquarter. -Manual

.......................... By reporting organization-EPA performs calcula- By site-source owner/operator tionsannually. performs calculations each sam- plingquarter.

## Environmental Protection Agency Pt.58, App.A

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

### SLAMS SITES

Minimum Parameters Method Assessment method Coverage frequency reported

Automated Methods

1 -Point QCfor SO, Responsecheckat Each analyzer

.............. Onceper2weeks Auditconcentration NO2, 03,CO. concentration 0.01- andmeasuredcon- 0.1 ppm SO, NO, centration2

. 03, and 1-10ppm CO. Annual performance Seesection3.2.2of Each analyzer

.............. Onceperyear
.............. Auditconcentration

evaluation forSO,, thisappendix. andmeasuredcon- NO2, 03,CO centration2foreach level. Flowrate verification Checkofsamplerflow Each sampler

............... Onceeverymonth Auditflow rateand

PM1.PM rate. measuredflow rate PM

1 V-5 indicatedbythesam- pler. Semi-annual flowrate Checkofsamplerflow Each sampler

............... Onceevery6months Auditflow rateand

audit PM11. PM25. rateusinginde- measuredflow rate PM 1-5 pendent standard. indicatedbythesam- pler. Collocated sampling Collocated samplers

.... 15%

.............................. Every 12days

.............. Primarysampler con-

PM2,5 PMlo centrationandduplicatesamplercon- centration. Performanceevaluation Collocated samplers

.... 1.5valid auditsforpri- Overall4quarters Primarysampler con-

program PM25, maryQAorgs,with centrationandperPM

1 <5 sites. formance evaluation 2.8valid auditsforpri- samplerconcentramaryQA orgs,with tion. >5sites. 3.All samplersin6

years.

Manual Methods

Collocated sampling

PM1,TSP, PM o05 PM,5, Pb-TSP,PbPMo. Flowrateverification

PMI,(low Vol), PM1025, PM PbPMo. Flowrateverification

PMlo(High-Vol), TSP, Pb-TSP.

Semi-annual flow rate

audit PMjo,TSP, PM1025, PM PbTSP, Pb-PMio. Pbaudit strips Pb-TSP,

Pb-PM1o.

Performance evaluation

program PM25, PM10-5 Collocated samplers

Checkofsamplerflow

rate.

Check ofsamplerflow

rate.

Checkofsamplerflow

rate using independentstandard.

Check ofanalyticalsystem with Pbaudit strips. Collocated samplers Each sampler

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

Each sampler

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

Each sampler,all locations.

Analytical

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

1.5valid auditsforprimaryQA orgs,with <5 sites. 2. 8valid auditsforprimaryQA orgs,with >5 sites. 3. All samplersin6

years. Every 12days PSDevery6 days.

Onceevery month

Onceevery quarter

Onceevery 6months

Each quarter

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

Over all 4quarters Primarysampler concentration and duplicatesamplerconcentration. Auditflow rate and

measured flow rate indicated bythesampler. Auditflow rate and

measuredflow rate indicated bythesampler. Auditflow rate and

measured flow rate indicated bythesampler. Actualconcentration

and audit concentration. Primarysampler concentration and performance evaluation samplerconcentration.

## Pt.58, App.C 40 CFRCh. 1(7-1-13 Edition)

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

### SLAMS SITES-Continued

Minimum Parameters Method Assessment method Coverage frequency reported

Performanceevaluation Collocatedsamplers 1.1valid auditand4 Overall4quarters Primarysampler conprogram Pb-TSP, Pb- collocatedsamples centrationandper- PM 1o. for primary CA orgs, formance evaluation with >5sites. samplerconcentra2.2valid auditsand6 tion.Primary sampler

collocatedsamples concentration and forprimaryCAorgs, duplicatesampler with >5sites. concentration.

IEffectiveconcentration foropenpath analyzers. 2Corrected concentration, ifapplicable,foropen pathanalyzers.

TABLE 

### A-3 OFAPPENDIX 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
Primarysampler No.ofcollocatedmon- method designa- Total no.ofmonitors Total no.collocated No. ofcollocatedFRM itorsofsame method tion designationas 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 72FR 32211, June 12, 2007; 73 FR 67060, Nov. 12, 2008; 75 FR 6534, Feb. 9, 2010; 75 FR 35602, June 22, 2010; 75 FR 81137, Dec. 27, 2010; 78 FR 3283, Jan. 15, 2013]

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 notbe incorporated due toinaccurate amendatory instruction.

APPENDIX B TO PART

## 58 [RESERVED]

APPENDIX CTO PART 58-AMBIENT AIR

QUALITY MONITORING METHODOLOGY

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

1.0 PURPOSE

This appendix specifies the criteria pollutant monitoring methods (manualmethods or automated analyzers) which mustbe used in SLAMS and NCore stations that are a subset ofSLAMS.

2.0 SLAMSAMBIENTAIR MONITORING
NETWORK
2.1 Except as otherwise provided in this appendix, a criteria pollutant monitoring method used for making NAAQS decisions at

a SLAMS site mustbe a reference orequivalent method as defined in §50.1 ofthis chapter. 2.1.1 Any NO2 FRM or FEMused for making primary NAAQS decisions mustbe capable ofproviding hourly averaged concentration data.

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

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

a SLAMS site following cancellation for a reasonable period of time to be determined by theAdministrator.

2.4 Approval of Non-designated Continuous PM,2 Methods as Approved Regional Methods (ARMs) Operated Within a Network of Sites. A method for PM 25 

### that has not been designated as an FRM or FEM as defined in §50.1 of this chapter may be approved as an ARM for purposes of section 2.1 of this appendix at a particular site or network of sites under the following stipulations.

2.4.1 The candidate ARM must be demonstrated to meet the requirements for PM,._ ClassIII equivalent methods asdefined in subpart C ofpart 53 of this chapter. Specifically the requirements for precision, correlation, and additive and multiplicative

## Environmental Protection Agency

bias apply. For purposes ofthis section 2.4, the following requirements shall apply:

2.4.1.1 The candidate ARM shallbe tested at the site(s) in which it isintended to be used. For a network of sites operated by one reporting agency or primary quality assurance 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. If the candidate ARM for a network is already approved for purposes ofthis section in another agency's network, subsequent testing shall minimally occur at one site in a MSA/CSA and one rural area or Micropolitan Statistical Area. There shallbe norequirement for
tests at any other sites.

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

2.4.1.3 No PM,3 samplers shallbe required for the test, as determination ofthe PM,.-/ PMo ratio at the test site shall not be required.

2.4.1.4 The test specification for PM,2.s Class III equivalent methodprecision defined in subpart C of part 53 of this chapter applies however, there is no specific requirement thatcollocated 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 ordata in AQS that can be presented demonstrating the candidate ARM operated will produce data that meets the specification for precision of Class III PM,5methods.

2.4.1.5 Aminimum of90 valid sample pairs per site for the year with no less than 20 valid sample pairs per season must be generated for use in demonstrating thatadditive bias, multiplicative bias and correlation meet the comparability requirements specified in subpart Cofpart53 ofthis chapter.A valid sample pair may be generated with as little as one valid FRM and one valid candidate ARM measurementper day.

2.4.1.6 For purposes of determining bias, FRM data with concentrations less than 3 micrograms per cubic meter (pg/m 3) may be excluded. Exclusion of data does not result in failure of sample completeness specified in this section.

2.4.1.7 Data transformations are allowed
to be used to demonstrate meeting the comparability 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 thetesting.

2.4.2 The monitoring agency wishing to

use an ARM must develop andimplement appropriate quality assurance procedures for 

## Pt.58, App.C

the method. Additionally, the following procedures are required forthe 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 2.8 ofthisappendix

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 averagemeasurements;

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

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 dataquality objectives for a site

over a season oryear maybe cause for recalculating a data transformation, butby itself would not be cause for invalidating the data. Data transformations must be applied prospectively, i.e., in real-time or near realtime, tothe data output from the PM, 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 and equivalent methods.

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

as required under section 3 of appendix A to this part withthefollowing exceptions:

2.4.4.1 Collocation ofARM withFRM/FEM samplers must be maintained at a minimum of 30 percent of the required SLAMS sites with a minimum of1per network;

2.4.4.2 All collocated FRM/FEM samplers must maintain a sample frequency of at least 1in 6 sample days:

2.4.4.3 Collocated FRM/FEM samplers shallbe located at the design value site, with the required FRM/FEM samplers deployed among the largest MSA/CSA in the network, until all required FRM/FEM are deployed; and

## Pt.58, App.C

2.4.4.4 Data from collocatedFRM/FEM are to be substituted for any calendar quarter thatan ARM method has incomplete data.

2.4.4.5 Collocation with an ARM under this part for purposes ofdetermining the coefficient of variation ofthe method shall be conducted at a minimum of7.5 percent ofthe sites with a minimum of 1pernetwork. 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 withthe 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 Atothis part.

2.4.5 Request for approval ofa candidate ARM, that isnot 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 is already approvedin another agency's network are tobe submitted to theEPA Regional Administrator. Requests for approval under section 2.4 of this appendix must include 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 of the site and the particulate matter that is expected to occur there.

2.4.5.2 A detailed description ofthe method and thenature ofthe sampler or analyzer upon which it is based.

2.4.5.3 A brief statement ofthe reason or rationale forrequesting theapproval.

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

2.4.5.5 A detailed description oftheprocedures for assessing the precision and accuracy ofthemethod thatwill be implemented for reporting to AQS.

2.4.5.6 Test results from the comparability tests as required in section 2.4.1 through 2.4.1.4 ofthis appendix.

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

2.4.6 Within 120 days after receiving a request for approval ofthe use ofan ARM at a particular site ornetwork of sitesunder section 2.4 ofthis appendix, the Administrator will approve or disapprove the method by letter to the person or agency requesting such approval. When appropriate for methods that are already approved in another SLAMS network, the EPA Regional Administrator has approval/disapproval authority. In either instance, additional information may be requested to assistwiththe decision.

2.5 [Reserved] 

## 40 CFRCh. 1(7-1-13 Edition)

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 higherthan two times the upper limit specified in table B-1 ofpart 53 of this chapter if:

2.6.2.1 The analyzer hasmore than 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 analyzers purchased before February 18, 1975);

2.6.2.2 The pollutant intended to be measured with the analyzer islikely 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 in which useoftheanalyzer is proposed; 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 of section 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 or ranges proposed to be used;

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

2.6.3.3 An identification anddescription of the geographical area in which useofthe analyzer is proposed

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

occur in concentrations more than two times the upper range limit specified in table B 1 ofpart 53 ofthis chapter in the geographical

area inwhich useoftheanalyzer is proposed and

2.6.3.5 Test data or other information demonstrating the resolution of each proposed range that isbroader than that permittedby section 2.5 ofthis appendix.

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.

## Environmental Protection Agency

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 asprovided in section 2.7.3 of this appendix, each requestmust contain:

2.7.2.1 A statement identifying the analyzer (e.g., by serial number)and themethod ofwhich the analyzer is representative (e.g., by manufacturer andmodel number); and

2.7.2.2 Test data, records, calculations, and test results for the analyzer (or the method of which the analyzer is representative) as specified in subpart B, subpart C, or both (as applicable) ofpart 53 ofthis 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 knowntoEPA from one or more ofthefollowing:

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

2.7.3.2 Testing ofthe method ofwhich the analyzer is representative atthe initiative of the Administrator under §53.7 ofthis 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 neednot be 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 for a decision onthe request.

2.7.6 If the Administrator determines, on the basis ofany available information, that any ofthe determinations or statements on which approval ofa request under this section was based are invalid ornolonger 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 obtainedthe approval an opportunity to submit information and arguments opposing such 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 if it hasbeen modified in a manner 

## Pt.58, App.C

that could significantly alter the performance characteristics ofthe method without prior approval by the Administrator. For purposes ofthis section, "alternative method" means ananalyzer, the use ofwhich has been approved under section 2.4, 2.5, or2.6 of this appendix or some combinationthereof.

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

2.8.3 Each request submitted under this section (2.8) must include:

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 or advantageous;

2.8.3.3 A brief statement of belief concerning the extent towhichthe modification will or may affect the performance characteristics ofthemethod; 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 thatthe applicant maybe asked
toprovide.

2.8.5 A temporary modification that could 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 oris malfunctioning, provided that parts necessary for repair 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 ofthis 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 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 the request will be considered as if a request for prior approval had been made.

2.9 Use of IMPROVE Samplers at a SLAMS Site. "IMPROVE" samplers may be used in SLAMS for monitoring of regional

## Pt.58, App.C

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 all ofthemajor components and many trace constituents of the particulate matter that impair visibility in Federal Class I Areas. Descriptions ofthe IMPROVE samplers and the data they collect are available in references 4, 5, and 6 ofthis appendix.

2.10 UseofPb-PM 1oatSLAMS Sites. 2.10.1 The EPA Regional Administrator may approve the use of a Pb-PM , FRM or Pb-PMl0 FEM sampler in lieu of a Pb-TSP sampler aspart ofthenetwork plan required under part 58.10(a)(4) in the following cases.

2.10.1.1 Pb-PMlo samplers canbe approved for use at the non-source-oriented sites required under paragraph 4.5(b) ofAppendix D to part 58 if there is no existing monitoring data indicating that the maximum arithmetic 3-month mean Pb concentration (either Pb-TSP or Pb-PM 0) at the site was equal to orgreater than 0.10micrograms per cubic meter duringtheprevious 3years.

2.10.1.2 Pb-PMlo 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 or Pb-PM 0) will not equal or exceed 0.10 microgramsper cubic meter onan 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 oflessthan or equal to 10 micrometers.

2.10.2 The approval ofa Pb-PM osampler in lieu ofa Pb-TSP sampler as allowed for in paragraph 2.10.1 above will be revoked if measured Pb-PM o 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-monthperiod in which the arithmetic 3-month Pb-PMlo mean concentration equaled or exceeded 0.10 micrograms per cubic meter to installand begin operation of

a Pb-TSP sampler atthe site.

3.0 NCORE AMBIENTAIR MONITORING STATIONS
3.1 Methods employed in NCore multipollutant sites used to measure SO,, CO, NO, 03, PM2,5, or PM 1,smust be reference

or equivalent methods as defined in §50.1 of this chapter, or an ARM asdefined in section 2.4 of this appendix, for any monitors intended for comparison with applicable NAAQS.

3.2 If alternative SO2, CO, NO2, 03, PM1,

or PM
_,_ monitoring methodologies are proposed for monitors not intended for NAAQS comparison, such techniques must be detailed in the network description re

## 40 CFRCh. 1(7-1-13 Edition)

quired by §58.10 and subsequently approved by the Administrator. Examples oflocations that are notintended to be compared to the NAAQS may be rural background and transport sites or areas where the concentration of the pollutant isso low that it would be

more useful to operate a higher sensitivity methodthat is notan FRMorFEM.

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 §50.1ofthis chapter.

4.2 Methods used for NO, NO, and NOx monitoring at PAMS should be automated reference or equivalent methods as defined for NO2 in §50.1 ofthis chapter.If alternative NO, NO2 or NOx monitoring methodologies

are proposed, such techniques must be detailed in the network description required by §58.10 and subsequently approved by the Administrator.

4.3 Methods for meteorological measurements and speciated VOC monitoring are included in the guidance provided in references 2 and 3 ofthis appendix. If alternative VOC monitoring methodology (including the use of new or innovative 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 ofPM o during air pollution episodes (see §51.152 of this chapter) the measurement method must be:

5.1.1 Either the "Staggered PM ,0" method

or the "PMo Sampling Over Short Sampling Times" method, both ofwhich are based on the reference method for PM o and are described in reference 1: or

5.1.2 Any other method for measuring PM o:

5.1.2.1 Which has a measurement range or ranges appropriate to accurately measure air pollution episode concentration ofPM ,o,

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

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

5.2 PMo methods other than the reference method are not covered under the quality assessment requirements ofappendix to this part. Therefore, States must develop and implement their own quality assessment procedures for those methods allowed under

## Environmental Protection Agency

this section 4. These quality assessment procedures should be similar or analogous to those described in section 3 ofappendix A to this part for thePM oreference 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 ofOzone 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 Handbook forAir Pollution 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 ofthe 81stAnnual Meeting ofthe Air Pollution Control Association, Dallas, Paper 88-54.3, 1988.

7. Data Quality Objectives (DQOs) for Relating Federal Reference Method (FRM) and Continuous PM2_ Measurements to Report

an Air Quality Index (AQI). Office of Air Quality Planning and Standards, U.S. Environmental 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 Criteriafor NCore Sites 

## Pt. 58, App.D

4. Pollutant-Specific Design Criteria for SLAMS Sites 5. Design Criteria for Photochemical Assessment Monitoring Stations (PAMS) 6. References


### 1.MONITOnING OBJECTIVES AND SPATIAL SCALES
The purpose ofthis appendix isto describe monitoring objectives and general 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, PM omass sites, PM,

mass sites,chemically-speciated PM 2 sites, and 03 precursor measurements sites (PAMS). These criteria will be used by EPA in evaluating the adequacy ofthe air pollutant monitoring networks.

1.1 Monitoring Objectives. The ambient air monitoring networksmustbe designed to meet three basic monitoring objectives. These basic objectives are listed below. The appearance ofany one objective in the order of this list isnot 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,and as part ofweather forecasts and public 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 in thedevelopment 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, 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

## Pt.58, App. D

capable of informing managers about many things including the peak air pollution levels, typical levels in populated areas, air pollution transported into and outside ofa 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 concentrations in areas ofhigh population density.

(c) Sites located to determine the impact of significant sourcesor source categories on air quality.

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

(e) Sites locatedtodetermine 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 other welfare-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 requirements provide. The optimum size of a particular network involves trade-offs among data needs and available resources. This regulation intends to provide for national 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 assessment process outlined in §58.10.

1.1.3 This appendix focuses on the relationship between monitoring objectives, site types, and the geographic location of monitoring sites. Included are a rationale and set of general criteria for identifying candidate site locations in terms 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 and horizontal probe and path placement,

are described in appendix E tothis 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 tocorrectly 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 the monitoring objective.

(b)Thus, spatial scale of representativeness is described in terms ofthe physical di

## 40 CFRCh. 1(7-1-13 Edition)

mensions oftheair parcel nearest to a monitoring site throughout which actual pollutant concentrations are reasonably similar. The scales ofrepresentativeness ofmost interest for the monitoring site types described above are as follows:

(1)Microscale-Definesthe concentrations in air volumes associated with area dimensions ranging from several meters up to about 100meters.

(2) Middle scale Defines the concentration typical ofareas up to several cityblocks in size with dimensions ranging from about 100 meters to 0.5 kilometer. (3) Neighborhoodscale Defines concentrations within some extended area ofthe city that hasrelatively uniform landuse 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 air pollutants.

(4) Urban scale Defines concentrations within an area of city-like dimensions, on the order of4 to 50 kilometers. Withina city, the geographic placement ofsources may result in there being no single site that canbe 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)Nationalandglobal scales-Thesemeasurement 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 of sites 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 to be outdoors. Sites located in these

areas are most likely to represent an urban scale ofmeasurement. In this example, physical location was determined by considering

ozone precursor emission patterns, public activity, andmeteorological characteristics affecting ozone formation and dispersion. Thus, spatial scale ofrepresentativeness was not used in the selection process but was a result ofsite location.

(d)In some cases, the physical location of

a site is determined fromjoint consideration of both the basic monitoring objective and the type of monitoring site desired, or required by this appendix. For example, todetermine PM 2s concentrations which are typical over ageographic area having relatively high PMs concentrations, a neighborhood

## Environmental Protection Agency

scale site is more appropriate. Such a site would likely be located in a residential or commercial areahaving a high overall PM2.5 emission density but not in the immediate vicinity ofany single dominant source. Note that in this example, the desired 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 of site.

TABLE D-1 OF APPENDIX D TO PART 58-RELATIONSHIP BETWEEN SITE TYPES AND SCALES OF REPRESENTATIVENESS

Sitetype

1.Highestconcentration

2. Population oriented 3. Source im pact

............... 4. General/background &

regional transport. 5.Welfare-related impacts Appropriate sitingscales

Micro, middle, neighborhood

(sometimes urban or regional for secondarily formed pollutants). Neighborhood, urban Micro, middle, neighborhood. Urban, regional.

Urban, regional.

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

(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 maybe collaborative efforts between regulatory agencies and researchers with specific scientific objectives for each. Data from 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 required 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 

## Pt. 58, App.D

measurements in general, in a selection of metropolitan areas and a limited number of

more rural locations. Continuousmonitoring methods are to be used at the NCore sites when available for a pollutant to be measured, 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 areawide concentrations. The Administrator
must approve theNCore sites.

(d) Monitoring sites designated as SLAMS sites, but not asNCore 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 uses the statistical-based definitions for metropolitan areas provided by the 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 10,000population orgreater is termed a Micropolitan Statistical Area. CSA consist oftwo ormore adjacent CBSA. In this appendix, the term MSA is used to refer to a Metropolitan Statistical Area. By definition, both MSA and CSA have ahigh degree ofintegration; however, many such areas cross State or other politicalboundaries. 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 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 theabsence ofan agreement between the affected agencies and the EPA Regional Administrator.

## Pt.58, App. D

3. DESIGN CRITERIA FORNCORE SITES (a) Each State (i.e. the fifty States, District ofColumbia, 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 withunique 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 orlocal agency
can propose 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 usingthe

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

(b) The NCore sites must measure, at a minimum, PM 2.5particle mass using continuous and integrated/filter-based samplers, speciated PM,5, PMio
, particle mass, speciated PM 00,, 03, SO2, CO, NO/NO, wind speed, wind direction, relative humidity, and ambient temperature. NCore sites in CBSA with a population of500,000 people (as determined in the latest Census) or greater shall also measure Pb either as Pb-TSP or PbPM 1o.The EPARegional 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, isrequired in support of a number ofmonitoring objectives, available commercial instruments may indicate little difference in their measurement of NOy compared to the conventional measurement ofNOx, particularly in areas with relatively fresh sources ofnitrogen emissions. Therefore, in areas with negligible expected difference between NOy and NOx measured concentrations, the Administrator may allow for waivers that permit NOx monitoring to be substituted for the required NOymonitoring at applicable NCore sites.

(2) EPArecognizes 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 is also possiblethat nearby meteorological measurements may be able to fulfill this data need. In these cases, the re

## 40 CFRCh. 1(7-1-13 Edition)

quirement for meteorological monitoring

can be 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 ametropolitan area.

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

area.

4. POLLUTANT-SPECIFIC DESIGN CRITERIA 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 (interms of population and geographic characteristics) and typical peak concentrations (expressed in percentages below, or near the 03 NAAQS). Specific SLAMS 0, site minimum requirements are included in Table D 2 of this appendix. The NCore sites are expected to complement the O data collection thattakes place at singlepollutant SLAMS sites, and both types of sites can be used to meet the network minimum requirements. The total number of0, sites needed to support the basic monitoring objectives ofpublic data reporting, air quality mapping, compliance, and understanding O -related atmospheric processes willinclude

more sites than these minimum numbers required in Table D 2 of this appendix. The EPARegional 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 of data needs in an area.

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

MSA population1,2

>10 million

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

........... 350,000-<4 million Most recent3- year design value

concentrations _>85% ofany 03 NAAQS3

4 3 2 Most recent3- year designvalue

concentrations <85% ofany03

NAAQS3,4

2

## Environmental Protection Agency

TABLE 

### D-2 OF APPENDIX 

### DTO PART 

### 58- SLAMS MINIMUM O MONITORING REQUIREMENTS-Continued

Mostrecent3- Most recent3- yeardesignvalue yeardesignvalue MSA population 1.2 concentrations concentrations >85%ofany0 <85% ofany0,

NAAQS3 NAAQS3.4

50,000-<3 50,000 1 0

IMinimum monitoring requirements applyto the Metropolitan statisticalarea(MSA).

2Populationbased onlatest availablecensusfigures. 3The ozone (03) National Ambient Air Quality Standards (NAAQS) levels andformsaredefined in40CFR part50.

4These minimum monitoring requirements apply inthe ab- senceofadesignvalue. Metropolitan statistical areas (MSA) must contain an ur- banizedareaof50,000ormore population.

(b) Within an 03 network, at least one 03 site for each MSA, or CSA if multiple MSAs
are involved, must be designed to record the maximum concentration for that particular metropolitan area. More than one maximum concentration site may be necessaryin some areas. Table D 2ofthis appendix does notaccount for the full breadth ofadditional factors that would be considered in designing a complete 03 monitoring program foran area. Some of these additionalfactors includegeographic size, population density, complexity of terrainand meteorology, adjacent 03 monitoring programs, air pollution transport from neighboring areas, and measured air quality in comparison to all forms of the 03 NAAQS (i.e., 8-hour and 1-hour forms). Networks must be designedto account for all of these area characteristics. Network designs must be re-examined in periodic network assessments. Deviations from the above 0, requirements are allowed if approved by the EPA RegionalAdministrator.

(c) The appropriate spatial scales for 0, sites are neighborhood, urban, and regional. Since 0, requires appreciable formation time, the mixing of reactants and products
occurs over large volumes of air,and this reduces 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 refersto pollutant concentrations. 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 to the understanding and definition of processes that take periods of hours to occur and hence involve considerable mixing and transport. Under stagnation conditions, a site located in the neighborhood scale may also experience peak concentration levels withina metropolitan area.

(2) Urbanscale Measurement in this scale will be used to estimate concentrations over 

## Pt. 58, App.D

large portions of an urban area with dimensions ofseveral kilometers to 50or more kilometers. Suchmeasurements willbe usedfor determining trends, and designing area-wide control strategies. The urban scale sites would also be used to measure high concentrations downwind of the areahavingthe highest precursor emissions.

(3)Regional scale-This scale of measurement will be used to typify concentrations
over large portions of a metropolitan area and even larger areas with dimensions of as much as hundreds ofkilometers. Such measurements will be useful for assessing the 03 that istransported 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 0 monitoring network design should be used to evaluate the adequacy ofeach existing 0, monitor, to relocate an existing site, or to locateany new 03 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 selected which isalso removed from the influence of major NOx sources. For an urban scale siteto measure the high concentration areas, the emission inventories should be used to define the extent of the area of important nonmethane hydrocarbons and NOx emissions. The meteorological conditions that occur during periods of maximum photochemical activity should be determined. These periods can be identified by examining the meteorological conditions that occur on the highest 03 air quality days. Trajectory analyses, anevaluation of wind and emission patterns on high 0, days, can also be useful in evaluating an 0, monitoring network. In
areas without any previous 0, air quality measurements, meteorological and 03 precursor emissions information would be useful.

(f) Once the meteorological and air quality data are reviewed,the prospective maximum concentration monitor site should be selected in a direction from the city that is most likely to observe the highest 03 concentrations, more specifically, downwind during periods ofphotochemical activity. In many cases, these maximum concentration 0, siteswill be located 10to30 milesor more 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 dayswhichshow the potential for producing high 03 levels. Monitoring agencies are to consult with their EPA Regional Office when considering siting a maximum 03 concentration site.

## Pt.58, App. D

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

same procedures used for theurban 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 areaofhigh density population.

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

as for themaximum concentration sitesmay also inform the decisions for locating regional scale sites. Regional scale sites may be located to provide data on 0, 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 as transport, mustbejointly considered for a regional scale site tobe useful.

(i) Since 03 levels decrease significantly in the colder parts of the year in many areas, 

## O is required to be monitored at SLAMS monitoring sites only during the "ozone season" as designated in the AQS files on a State-by-State basis and described below in Table D 3 ofthis appendix. Deviations from the 0, 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 8tothis appendix.

TABLE D-3 OF APPENDIX D TO PART 58-

OZONE MONITORING SEASON BY STATE

State Begin month End month

Alabama
.......................... Alaska

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

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

......................... California

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

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

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

......................... District of Columbia. Florida

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

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

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

............................... Illin

ois

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

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

................................ Kansas
............................ Kentucky

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

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

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

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

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

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

...................... Missouri

.......................... Montana

.......................... Nebraska

........................ Nevada

........................... New Hampshire

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

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

................. June

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

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

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

................. October October December November December September September October October October

December September October September October October October October December September October September September October October October September October December September 

## 40 CFRCh. 1(7-1-13 Edition)

TABLE 

### D-3 OF APPENDIX 

### DTO PART 58- OZONE MONITORING SEASON BY STATE

### Continued

State Begin month End month

NewJersey

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

................. O

ctober NewMexico

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

........... December NewYork

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

................. O

ctober NorthCarolina

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

................. October NorthDakota

.................. May

................. September O

hio

................................ A

pril

................. O

ctober Oklahoma

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

.............. November Oregon ............................ M

ay ................. September Pennsylvania

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

................. October Puerto Rico

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

........... December Rhode Island

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

................. September South Carolina

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

................. October South Dakota

.................. June

................ September Tennessee
...................... March

.............. October TexasAGCR 106,153, January

........... December 213,214, 216. TexasAQCR022, 210, March

.............. October 211, 212, 215, 217, 218 Utah

.......... ........ May
................. September Vermont

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

................. September Virginia

............................ A

pril

................. O

ctober W

ashington

..................... May
................. September W

estVirginia

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

................. O

ctober Wisconsin

....................... April 15
............ October 15 W

yoming

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

................. O

ctober 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 NO, monitor, asrequired 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 NO, monitor, only one CO monitor isrequired tobe collocated with a near-road NO, 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 butis not a near-road NO, monitoring site, then theEPA Regional Administrator may approve a request by a state to use such an alternate near-road location for a CO monitor in place 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 require additional CO monitors above the minimum number ofmonitors required in 4.2.1 of this part, where the minimum monitoring requirements are not sufficient tomeet monitoring objectives. The Regional Administrator mayrequire, at his/her discretion, additional monitors in situations where data or other information suggest that CO concentrations maybe approaching orexceeding

## Environmental Protection Agency

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 levelCO concentrationsparticularly due to or enhanced by topographical and meteorological impacts. The Regional Administrator and the responsible 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 network plan.

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 majorroadways 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 concentrations atthe microscale.

(2) Middle scale Middle scale measurements are intended to represent areas with dimensions from 100 meters to 0.5kilometer. In certain 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 quality along

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 similar such areas across the larger urban

area. Neighborhood scale measurements provide relative area-wide concentration data which are useful for providing relative urban background concentrations, supporting 

## Pt. 58, App.D

health and scientific research, and for use in modeling.

4.3 Nitrogen Dioxide (NO2) Design Criteria 4.3.1 General Requirements (a) State and, where appropriate, local agencies must operate a minimum number of required NO, monitoring sites as described below.

4.3.2 Requirement for Near-road NO2 Monitors

(a) Within the NO, network, there must be

one microscale near-road NO, monitoring station in each CBSA with a population of 500,000 ormore 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 NO, 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 NO2 monitoring 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, considering fleet mix, roadway design, congestion patterns, terrain, and meteorology, where maximum hourly NO, concentrations

are expected to occur and siting criteria can be met in accordance with appendix E ofthis part. Where a State or local air monitoring agency identifies multiple acceptable candidate siteswhere maximumhourly NO2concentrations are expected to occur, the monitoring 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 ofthe following factors: fleetmix; congestion patterns terrain; geographic area within the CBSA or different route, interstate, orfreeway designation.

(b) Measurements at required near-road NO, monitor sites utilizing chemiluminescence FRMs must include at a minimum: NO, NO, andNOx.

4.3.3 Requirement for Area-wide NO2 Monitoring

(a) Within the NO, network, 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 concentrations representing the neighborhoodorlarger spatial scales. PAMS sites collecting NO2 data that are situated in an area of expected high NO2 concentrations at the neighborhood or larger spatial scale may be

## Pt.58, App. D

used to satisfy this minimum monitoring requirement when the NO, monitor is operated year round. Emission inventories and meteorological analysis shouldbe used to identify the appropriate locations within a CBSA for locating required area-wide NO2 monitoring stations. CBSA populations shall bebased on the latest available censusfigures.

4.3.4 Regional Administrator Required Monitoring

(a) The Regional Administrators, in collaboration with States, must require a minimum of forty additional NO, monitoring stations nationwide in any area, inside or outside ofCBSAs, above the minimum monitoring requirements, 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 ofCBSAsin which:

(i)

The required near-road monitors do not represent all locations ofexpected maximum hourly NO, concentrations in an area and NO, concentrations may be approaching or exceeding theNAAQS in that area;

(ii) Areas that are not required to have a monitor in accordance with the monitoring requirements andNO2 concentrations maybe approaching orexceeding the NAAQS: or

(iii) The minimum monitoring requirements for area-wide monitors are not sufficient tomeet monitoring objectives.

(c) The Regional Administrator and theresponsible State orlocal air monitoring agency should work together to design and/or maintain the most appropriate NO, network to address the data needs for anarea, and include all monitors under this provision in the annualmonitoring network plan.

4.3.5 NO,Monitoring Spatial Scales (a) The most important spatial scale for near-road NO2 monitoring stations to effectively characterize the maximum expected hourly NO, 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 NO,concentrations are the microscale and middle scale. The most important spatial scale for area-wide monitoring ofhighNO2 concentrations is theneighborhood scale.

(1) Microscale This scale represents areas in close proximity to major roadways or point and area sources. Emissions from roadways result in high ground level NO,concentrations 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 N0 moni

## 40 CFRCh. 1(7-1-13 Edition)

toring 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 several 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 concentrations due to proximity to major NO, point,area, and/ornon-road sources.

(3) Neighborhood scale The neighborhood scale represents air quality conditions throughout some relatively uniform landuse
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 NO, concentrations atthe neighborhood scale. Where

a neighborhood site islocated away from immediate NO, sources, 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 of large scale air pollution control strategies. Urban scale sites may also support other monitoring objectives of the NO, monitoring network identified in paragraph 4.3.4 above.

4.3.6 NOy Monitoring (a) NO/NOy measurements are included within the NCore multi-pollutant site requirements and the PAMS program. These NO/NOy measurements will produce conservative estimates for NO, that can be used to

ensure tracking continued compliance with the NO2 NAAQS. NO/NOy monitors are used at these sites because it is important to collect data on total reactive nitrogen species for understanding 03 photochemistry.

4.4 SulfurDioxide(SO2) DesignCriteria.
4.4.1 GeneralRequirements. (a) State and, where appropriate, local agencies must operate aminimum number ofrequired SO monitoring sitesasdescribed below.

4.4.2 RequirementforMonitoringby thePopulation WeightedEmissionsIndex. (a)The population weighted emissions index (PWEI) shall be calculated by States for each core based statistical area (CBSA) they contain

or share withanother State or States for use

## Environmental Protection Agency

in the implementation of or adjustment to the SO, monitoring network.The PWEIshall be calculated by multiplying the population ofeach CBSA, usingthe most current census data or estimates, and the total amount of SO2 in tons per year emitted within the CBSA area, using an aggregate ofthe most recent county level emissions data available in theNational EmissionsInventory for each county in each CBSA. The resulting product shall be divided by one million, providing a PWEI value, the units ofwhich 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 SO, monitors are required withinthat CBSA. For any CBSA with a calculated PWEIvalue equal to

or greater than 100,000, but less than 1,000,000, a minimum oftwo S02 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, monitor is required within that CBSA.

(1) The SO, monitoring site(s)required as a result of the calculated PWEI in each CBSA shall satisfy minimum monitoring requirements if the monitor is sited within the boundaries oftheparent CBSA and is one of the following site types (as defined in section 1.1.1 of this appendix): population exposure, highest concentration, source impacts, general background, or regional transport. S02 monitors at NCore stations may satisfy minimum monitoring requirements if that monitor 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 monitoringrequirements for thatCBSA.

4.4.3 RegionalAdministratorRequiredMonitoring. (a) The Regional Administrator may require additional SO, monitoring stations above the minimum number ofmonitors required in 4.4.2 of this part, where the minimum monitoringrequirements are not sufficient tomeet monitoring objectives. The Regional Administrator may require, athis/her discretion, additional monitors in situations where an area has thepotential tohave concentrations that may violate or contribute
to the violation ofthe NAAQS, in areas impacted bysources 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 Administrator and the responsible State or local air monitoring agency shall work together to design and/or maintain the most appropriate SO, network to provide sufficient datatomeet monitoring objectives. 

## Pt. 58, App.D

4.4.4 SO MonitoringSpatialScales. (a)The appropriate spatial scales for SO, SLAMS monitors are the microscale, middle, neighborhood, and urban scales. Monitors sited at the microscale, middle, and neighborhood scales are suitable for determining maximum hourly concentrations for SO, Monitors sited at urban scales are useful for identifying SO, 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 andarea 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 several city blocks in size with dimensions on the order ofapproximately 100 meters to 500 meters. The middle scale may include locations ofexpected maximum short-term concentrations due to proximity to major SO, point,area, and/ornon-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 in high S02 concentrations at the neighborhood scale. Where a neighborhood site is located away from immediate SO2 sources, the site maybe 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 of large scale air pollution control strategies. Urban scale sites may also support other monitoring objectives of the SO, monitoring network such as identifying trends, and when monitors are sited upwind of local sources, background concentrations.

4.4.5 NCore Monitoring. (a) S0 2 measurements are included within the NCore multipollutant site requirements as described in paragraph (3)(b) of this appendix. NCorebased SO, measurements are primarily used
to characterize SO2 trends and assist in understanding S02 transport across representative areas in urban orrural locations and are also used for comparison with the SO2 NAAQS. SO, monitors at NCore sites that exist in CBSAs with minimum monitoring

## Pt.58, App. D

requirements per section 4.4.2 above shall be allowed to count towards those minimum monitoringrequirements.

4.5 Lead(Pb)DesignCriteria.(a) State and, where appropriate, local agencies are required to conduct ambient air Pb monitoring

near Pb sources which are expected to or have been shown to contribute to a maximum 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 site located tomeasure the maximum Pb concentration 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/chiej/ eiinformation.html)or other scientifically justifiable methods and data (such as improved emissions factors or site-specific data) taking into account logistics and the potential for population 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 (or multiple sources). This monitor mustbe sited, taking into account logistics and the potential for population exposure, where the Pb concentration from all sources combined isexpected tobe at itsmaximum.

(ii) TheRegional Administrator maywaive the requirement in paragraph 4.5(a) for monitoring near Pb sources if the State or,where appropriate, local agency can demonstrate the Pb source will not contribute to a maximum 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 partofthenetwork assessment requiredunder §58.10(d).

(iii) State and, where appropriate, local agencies are required to conduct ambient air Pb monitoring near each ofthe airports listed in Table D-3A for a period of 12 consecutive 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 that exceeds 50 percent ofthe PbNAAQS on a rolling 3-month average (as determined according to40 CFR part 50, AppendixR) shallbecome arequired monitor 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 col

## 40 CFRCh. 1(7-1-13 Edition)

lected shall be submitted to the Air Quality System database according to the requirements of40CFR part 58.16.

TABLE D-3A AIRPORTS To BE MONITORED FOR LEAD Airport County State

M

errillField

........................................ Anchorage A K PryorField Regional

.......................... Limestone AL Pale Alto Airport of Santa Clara SantaClara CA

County. McClellan-Palomar

............................ SanDiego CA Reid-Hillview

...................................... SantaClara CA G

illespie Field

.................................... SanDiego CA San Carlos

......................................... SanM ateo CA Nantucket Memorial

.......................... Nantucket MA Oakland CountyInternational

............ Oakland MI Republic Suffolk

........... NY B rookhaven

....................................... S uffolk

........... N Y Stinson M unicipal

.............................. Bexar

............ TX Northwest Regional

........................... Denton

.......... TX HarveyField

...................................... Snohomish W A Auburn M unicipal

............................... King

.............. W A

(b) State and, where appropriate, local agencies are required toconduct non-sourceoriented Pb monitoring at each NCore site required under paragraph 3 of this 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, butnotlimited to, those

near existing additional industrial sourcesof 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 ground level concentrations at the microscale. In the latter case, themicroscale would represent an area impacted by the plume with dimensions extending up to approximately 100 meters. Pb monitors in areas where thepublichas access, andparticularly

## Environmental Protection Agency

children have access, are desirable because of the higher sensitivity of children to exposures ofelevated Pb concentrations.

(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 example, include schools and playgrounds in center city areas which are close to major Pb point sources. Pb monitors in such areas are desirable because ofthe higher sensitivity of children to exposures of elevated Pb concentrations (reference 3 of this appendix). Emissions frompoint sources frequently impact on areas at which single sites may be located to measure concentrations representing middle spatial scales.

(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. Sites ofthis scalewould provide monitoring data in areas representing conditions where children live and play. Monitoring in such areas is important since this segment ofthe population is more susceptible to the effects of Pb. Where a neighborhood site is located away from immediate Pb sources, the site may be very 

## Pt. 58, App.D

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 references 4 and 5 ofthis appendix. These documents provide additional guidance on locating sites to meet specific urban area monitoring objectives and shouldbe used in locating new sites or evaluating the adequacy of existing sites.

4.6 Particulate Matter (PM1) Design Criteria.<(a) Table D-4 indicates the approximate number ofpermanent stations required in MSAs to characterize national and regional PMl air quality trends and geographical patterns. The number ofPM ,stations in areas where MSApopulations 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 required. A range of monitoring stations is specified in Table D 4because sources ofpollutants and local control efforts can vary from one part ofthe country to another and therefore, some flexibility isallowed in selecting the actual number of stations in any

one locale. Modifications from these PM o monitoring requirements must be approved by theRegional Administrator.

TABLE 

### D-4 OF APPENDIX 

### D TO PART

### 58-PM i: MINIMUM MONITORING REQUIREMENTS (APPROXIMATE NUMBER OF STATIONS PER

### MSA) 1

Population category High concentra- Medium con- Low concentra- tion2 centration tion 45

>1,0 00,000

...................................................................................... 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
1Selectionof urban areasand actual numbersofstations per areawillbejointly determined by EPAand the State agency. 2High concentration areas arethose forwhichambient PMlodata showambientconcentrations exceedingthe PM ,,NAAQS by 20percent or more.

3Medium concentration areas arethose forwhich ambient PM 1odata showambient concentrations exceeding80 percent of the PM 1oNAAQS. 4Low concentration areas are those for whichambient PM 1odata showambient concentrations less than 80 percent of the PM 1oNAAQS.

5These minimum monitoring requirements applyintheabsence ofadesign value.

(b)Although microscale monitoring may be appropriate in some circumstances, the most important spatial scales to effectively characterize the emissions of PMo from both mobile and stationary sources are the middle scales andneighborhood scales.

(1) Microscale-This scale would typify

areas such asdowntown street canyons, traffic corridors, and fence line stationary

source monitoring locations where the general public could be exposed to maximum PM , concentrations. Microscale particulate
matter sitesshouldbe locatednear inhabited buildings orlocations where the general public can be expected to be exposed to the concentration measured. Emissions from stationary sources such as primary and secondary smelters, power plants, and other large industrialprocesses may, under certain plume conditions, likewise result in high ground level concentrations at the microscale. In the latter case, themicroscale 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 (PM o) is on this scale and on the neighborhood scale. People moving through downtown areas orliving near major roadways or stationary sources, may encounter particulate pollution that would be adequately

## Pt.58, App. D

characterized by measurements ofthis spatial scale. Middle scale PM 1) 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 notunique 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 astheparking lot and feeder streets associated with shopping centers, stadia, and office buildings. In the case ofPM1o,unpaved

or seldomly swept parking lots associated with these sources could be an important

source in addition tothe 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 themiddle 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 PM1 sitesprovide 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 models that describe the larger-scale concentration patterns, especially those models relying on spatially smoothed emission fields for inputs. The neighborhood scale measurements could also be used for neighborhood comparisons within orbetween cities.

4.7 Fine Particulate Matter (PM,,,) Design Criteria.

4.7.1 General Requirements. (a)State, and where applicable local, agencies must operate the minimum number ofrequired PM2,-S SLAMS sites listed in Table D-5 ofthis appendix. The NCore sites are expected tocomplement the PM,_s data collection that takes place at non-NCore SLAMS sites, and both types of sites can be used to meet the minimum PM,2_s network requirements. Deviations from these PM,_ monitoring requirements must be approved by the EPA Regional Administrator. 

## 40 CFRCh. 1(7-1-13 Edition)

TABLE 

### D-5 OFAPPENDIX 

### DTO PART 58-PM2_5 MINIMUM MONITORING REQUIREMENTS

Mostrecent3- Most recent3- MSA population1,2 yeardesignvalue yeardesignvalue >85%ofany <85% ofany PM2 NAAQS 3 PM,5 NAAQS 34

>1,000,000

............. 3 2 500,000-1,000,000 2 1 50,000-<500,0001 0

' Minimum monitoring requirements applyto the Metropolitan statisticalarea(MSA).

2Populationbased onlatest availablecensusfigures. 3The PM .5 National Ambient Air Quality Standards (NAAQS) levels andformsaredefined in40CFR part50.

4These minimum monitoring requirements apply inthe ab- senceofadesignvalue.

5Metropolitan statistical areas (MSA) must contain an ur- banizedareaof50,000ormore population.

(b) Specific Design Criteria for PM2,5. The required monitoring stations or sites must be sited to represent area-wide air quality. These sites can include sites collocated at PAMS. These monitoring stations will typically be at neighborhood or urban-scale; however, micro-or middle-scale PM2,5 monitoring sites that represent many such locations throughout a metropolitan area are considered to represent area-wide air quality.

(1) At least onemonitoring station is to be sited at neighborhood or larger scale in an
area ofexpected maximum concentration.

(2) For CBSAs with apopulation of1,000,000


### or more persons, at least one PM smonitor is to be collocated at anear-road NO,station required insection 4.3.2(a) ofthis appendix.

(3) For areas with additional required SLAMS, a monitoring station is to be sited in an area ofpoor air quality.

(4) Additional technical guidance for siting PM, monitors is provided in references 6 and 7 ofthis appendix.

(c) The most important spatial scale to effectively characterize the emissions ofparticulate matter from both mobile and stationary sourcesis the neighborhood scale for PM2

. 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. MostPM,2_ monitoring in urban areas should be representative of a neighborhood scale.

(1) Micro-scale. 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 micro-scale is appropriate for particulate sites. SLAMS sites measured at the micro-scale 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, micro-scale particulate matter

## Environmental Protection Agency

sites should be located near inhabited buildings or locations where the general public

can be expected to be exposed to the concentration measured. Emissions from stationary sources such as primary and secondary smelters, power plants, and other large industrialprocesses may, under certain plume conditions, likewise result in high ground level concentrations at the microscale. In the latter case, the micro-scale would represent an area impacted by the plume with dimensions extending up to approximately 100 meters. Data collected at micro-scale sites provide information for evaluating and developing hot spot control

measures.

(2) Middle scale People moving through downtown areas, or living near major roadways, encounter particle 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 publichealth 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 concentrations for other areas with dimensions ofa few hundred meters such asthe parking lot and feeder streets associated with shopping centers, 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 surface characteristics. Much ofthe PM25 exposures are expected to be 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 of the same type in other parts of the city. PM 25 sites ofthis kind provide good information about trends and compliance with standards because they often represent conditions in areas where people commonly live and work for periods comparable to those specified in the NAAQS. In general, most PM 25monitoring in urban areas should have this scale.

(4) Urbanscale This class ofmeasurement wouldbe used tocharacterize the particulate matter concentration over an entire metropolitan or rural area ranging in size from 4
to 50 kilometers. Such measurements would be useful for assessing trends in area-wide 

## Pt. 58, App.D

air quality, and hence, the effectiveness of large scale air pollution control strategies. Community-oriented PM,5 sites may have this scale.

(5) Regional scale These measurements would characterize conditions over areas with dimensions of as 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 measurements 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,,_ transport contributes to elevated particulate concentrations and may affect multiple urban and State entities with large populations such as in the eastern United States. Development ofeffective pollution control strategies requires an understanding at regional geographical scales of the emission sources and atmospheric processes that are responsible for elevated PM 25levels and may also be associated with elevated 03 and regional haze.

4.7.2 Requirement for Continuous PM2,5 Monitoring. The State, orwhere appropriate, local agencies must operate continuous PM 25 analyzers equal to at least one-half (round up)the minimumrequired sites listed in Table D 5 ofthis appendix. At least one required continuous analyzer in each MSA must be collocated with one ofthe required

RM/FEM/ARM monitors, unless at least

one ofthe required FRM/FEM/ARM monitors is itselfa continuous FEM or ARM monitor in which case no collocationrequirement applies. State and local air monitoring agencies must use methodologies and quality assurance/quality control (QA/QC) procedures approved by the EPA Regional Administrator for these required continuous analyzers.

4.7.3 Requirement for PM,._ Background and Transport Sites. Each State shallinstall and operate at least one PM 2.5site to monitor for regional background and atleast one PM7 ._ site to monitor regional transport. These monitoring sites may be at community-oriented sites andthis requirement may be satisfiedby a corresponding monitor in 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 continuous PM25monitors.

4.7.4 PM, Chemical Speciation Site Requirements. Each State shall continue to conduct chemical speciation monitoring and analyses at sites designated tobe part ofthe PM 2.5Speciation Trends Network (STN). The selection and modification of these STN

## Pt.58, App. D

sites must be approved by the Administrator. The PM2,5 chemical speciation urban trends sites shall include analysis for elements, selected anions and cations, and carbon. Samples must be collected using the monitoring methodsand 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.

4.8 Coarse Particulate Matter (PM10,,) Design Criteria.

4.8.1 General Monitoring Requirements. (a)The only required monitors for PM12.s

are those required atNCore Stations.

(b)Although microscale monitoring may be appropriate in some circumstances, middle and neighborhood scale measurements

are the most important station classifications for PM to assess the variation in

coarse particle concentrations thatwould be expected across populated areas that are in proximity to large emissions sources.

(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 mayprovide information useful for evaluating and developing source-oriented control measures.

(2)Middle scale-Peopleliving 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 ofpublic health 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 tomajor 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 

## 40 CFRCh. 1(7-1-13 Edition)

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 still impacted 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 aswell asneighborhoods ofthe

same type in other parts of the city. The comparison of data from middle scale and neighborhood scale sites wouldprovide valuable information for determining the variation of PM0 2s levels across urban areas and assessing the spatial extent of elevated concentrations caused by major industrial point sources and heavily traveled roadways. Neighborhood scale sites would provide concentration data that are relevant to informing a large segment of the population of their exposure levelson a given day.

4.8.2 [Reserved]

5. NETWORKDESIGN FOR PHOTOCHEMICAL ASSESSMENT MONITORING STATIONS (PAMS)
The PAMS program provides more comprehensive data on 0, air pollution in areas classified as serious, severe, or extreme nonattainment 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 of03, 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 0, events. Specific monitoring objectives are associated with each location. The overall design should enable characterization ofprecursor emission sources withinthe
area, transport of 03 and its precursors, and the photochemical processes related to 03 nonattainment. Specific objectives that
must be addressed include assessing ambient trends in 03, oxides ofnitrogen, VOC species, and determining spatial and diurnal variability of 03, oxides ofnitrogen, and VOC species. Specific monitoring objectives associated with each of these sites may result in four distinct site types. Detailed guidance for the locating of these sites may be found in reference 9 ofthisappendix.

(a) Type 1 sites are established to characterize upwind background andtransported 03 and its precursor concentrations entering the area and will identify those areas which

are subjected to transport.

## Environmental Protection Agency

(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 0, concentrationsoccurring 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 transport in other areas.

5.2 Monitoring Period. PAMS precursor monitoring must be conducted annually throughout the months of June, July and 

## Pt. 58, App.D

August (asa minimum) when peak 03 values

are expected in each area. Alternate precursor monitoring periods may be submitted for approval to the Administrator as a part of the annual monitoring network plan required by§58.10.

5.3 Minimum Monitoring Network Requirements. A Type 2 site is required for each area. Overall, only two sites are required for each area, providing all chemical
measurements are made. For example, if a design includes two Type 2 sites, then a third site will be necessary to capture the NOy measurement. The minimum required number and type of monitoring sites and sampling requirements are listed in Table D-6 of this appendix. Any alternative plans may be put in place in lieu ofthese requirements, if approved bytheAdministrator.

TABLE D-6OF APPENDIX D TO PART 58-MINIMUM REQUIRED PAMS MONITORING LOCATIONS AND FREQUENCIES

Measurement Where required Samplingfrequency(alldailyexceptforupper air meteorology)1 SpeciatedVOC2 Two sitesperarea, one ofwhich must be aType During the PAMS monitoring period: (1)Hourly 2site. autoGC, or (2)Eight 3-hour canisters,or (3)1 morning and 1afternoon canister with a3-hour or less averaging time plus Continuous Total Non-methane Hydrocarbon measurement. Carbonyl sampling Type2siteinareasclassifiedasserious orabove 3-hoursamples everydayduringthe PAMS moniforthe8-hour ozonestandard. toring period. NO

............................ All Type2sites

....................................................... Hourlyduring theozone m onitoring season.3 NOy

............................. Onesite perareaattheType3orType 1site Hourlyduring theozone monitoringseason. CO (ppb level)

............ Onesite perareaataType2site

......................... Hourlyduring theozone monitoringseason. O

zone
......................... A llsites

.................................................................... Hourlyduring theozone m onitoringseason. Surface m et

................ All sites

.................................................................... Hourlyduring theozone m onitoring season. Upperairmeteorology One representativelocationwithin PAMSarea Samplingfrequency must be approved as part of the annual monitoring network plan required in 40CFR58.10. Dailyorwith an approvedalternativeplan. 2Speciated VOC isdefined inthe "Technical Assistance Document for Sampling andAnalysis of Ozone Precursors", EPA/ 600-R-98/161, September 1998.

3Approved ozone monitoringseasonasstipulated inTableD-3 ofthisappendix.

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 0, nonattainment area to serious, severe, or extreme, or the designation ofa new area and classification to serious, severe, or extreme 0 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 theapproved PAMS network description providedbythe State. 6. REFERENCES
1. Ball, R.J. and G.E. Anderson. Optimum Site Exposure Criteria for SO, 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., 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. EPA 450/3-75 077, September 1975.

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 and PB91-138420.)

## Pt.58, App. E

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/R 92-009. 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. EPA450/4-87-009. May 1987.

7. Watson et al. Guidance for Network Design and Optimum Site Exposure for PMs and PM o. 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 an 8- Hour Ozone Standard. Prepared for U.S. Environmental Protection Agency, RTP, NC. EPA54/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-93-051. 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; 76 FR 54342, Aug. 31, 2011; 78 FR 3284, Jan. 15, 2013]

APPENDIX E TO PART 58 PROBE AND MONITORING PATH SITING CRITERIA FOR AMBIENT AIR QUALITY MONITORING

1.Introduction. 2. Horizontal and Vertical Placement. 3. Spacingfrom 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 

## 40 CFRCh. 1(7-1-13 Edition)

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 toensure theuniform collection of compatible and comparable air quality data.

(b) The probe and monitoring path siting criteria discussed in this appendix must be followed to the 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 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 the EPAwould consider an application for waiver from these siting criteria are discussed in section 10 of this appendix.

(c) The pollutant-specific probe and monitoring path siting criteria generally apply to all spatial scales except where noted otherwise. Specific siting criteria that are 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

are notrequirements.

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 0, and SO, monitoring sites, and for neighborhood or larger spatial scale Pb, PM1, 

### PM 0-2.5, PM s, NO2, and CO sites. Middle scale PM 1o4,_s sitesare required to have sampler inlets between 2 and 7 meters above ground level. Microscale Pb, PM u,, PM 10 25, and PM 2.5sites 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 7 meters above ground 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 3.5meters above ground level. The probe

or atleast 90 percent ofthe monitoringpath 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. If the probe

or a significant portion of the monitoring path is located near the side ofa building or

## Environmental Protection Agency

wall, then it should be located on the windward side ofthe building relative to the prevailing wind direction during the season of highest concentration potential for the pollutant beingmeasured.

3. SPACING FROM MINOR SOURCES (a) It is important tounderstand the monitoring objective for a particular location in order to interpret this particular requirement. Local minor sources ofa primary pollutant, such as SO2, lead, or particles, can
cause high concentrations ofthat particular pollutant at a monitoring site. If the objective for that monitoring site is to investigate 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. If a monitoring site is to be used to determine air quality over 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 not be located in anunpaved area unless there is vegetative ground cover year round, so that the impact of wind blown dusts willbe keptto a minimum.

(b) Similarly, local sources ofnitric oxide (NO) and ozone-reactive hydrocarbons can have a scavenging effect causing unrepresentatively low concentrations of03 in the vicinity of probes and monitoring paths for 03. To minimize these potential interferences, theprobe or atleast90 percent of the monitoring path must be away from furnace or incineration flues or other minor

sources of SO2 or NO. The separation distance should take into account the heights ofthe flues, type ofwaste orfuel burned, 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 atleast 90 percent ofthemonitoring 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 requirement can be made for measurements taken in street canyons or at source-oriented sites where buildings and other structures

are unavoidable.

(b) Generally, a probe or monitoring path located near or alonga vertical wallis undesirable because air moving along the wall may be subject to possible removal mecha

## Pt. 58,App. E

nisms. A probe, inlet, or monitoring path must have unrestricted airflow in an arc of
at least 180 degrees. This arc must include the predominant wind direction for the season of greatest pollutant concentration potential. Forparticle sampling, a minimum of 2 meters of separation from walls, parapets, and structures isrequired for rooftop site placement.

(c) Special consideration must be given to the use ofopen path analyzers due to their inherent potential sensitivity to certain types of interferences, or optical obstructions. Amonitoring pathmustbe clear ofall trees, brush, buildings, plumes, dust, or 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 of sufficient density to obscure the light beam will affect the ability ofthe openpath analyzer to continuously measure pollutant concentrations. Transient, but significant obscuration of especially longer measurement paths could occur as a resultofcertain meteorological conditions (e.g., heavy fog, rain, snow) and/or aerosol levels that are of

a sufficient density to prevent the openpath analyzer's lighttransmission. If certain 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 ofthe 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 valid data capture rate.

(d)For near-road NO, monitoring stations, the monitor probe shall have an unobstructed air flow, where noobstacles exist at

or above the height ofthemonitor probe, between the monitor probe and the outside nearest edge ofthetraffic lanes ofthetarget road segment.

5.SPACING FROM TREES
(a) Trees can provide surfaces for SO , 03,

or NO adsorption or reactions, and surfaces for particle 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 canopy density to interfere withthe normal airflow around the probe, inlet, or monitoring

## Pt.58, App. E

path. Toreduce this possible interference/obstruction, theprobe, inlet, or at least90 percent ofthemonitoring path mustbe at least 10 meters or further from the drip line of
trees.

(b) The scavenging effect oftrees is greater for O3 than for other criteria pollutants. Monitoring agencies must take steps to consider 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.

6. SPACING FROM ROADWAYS

TABLE E-1 TO APPENDIX EOF PART 58-MINIMUM SEPARATION DISTANCE BETWEEN ROADWAYS AND PROBES OR MONITORING PATHS FOR MONITORING NEIGHBORHOOD AND URBAN SCALE OZONE (03) AND OXIDES OF NITROGEN (NO, NO 2, NOx, NO,)

Roadway Minimum Minimum averagedailytraffic, distance1 distance1.2

vehiclesperday (meters) meters)

<1,0 0 0
................................... 10 10 10

,0

00
.................................... 10 2 0 15

,000

.................................... 20 30 20,000

.................................... 30 40 40,000

.................................... 50 60 70,000

.................................... 100 100 _>

110,000

............................... 250 250
1Distancefromthe edgeofthenearesttrafficlane.Thedistance for intermediate traffic counts should be interpolated fromthetable valuesbasedon theactualtrafficcount.

2Applicable for ozone monitors whose placement has not already beenapprovedasof December 18,2006.

6.1 Spacing for Ozone Probes and Monitoring Paths

In siting an 03 analyzer, it isimportant to minimize destructive interferences form

sources of NO, since NO readily reacts with 0. Table E 1 ofthis appendix provides the required minimum separation distances between aroadway and aprobe 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 closely represent 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 of 10,000 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 ofpotential atmos

## 40 CFRCh. 1(7-1-13 Edition)

pheric interference from automobile emissions. Therefore, this calculation must include thelength ofthemonitoring 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 10percent ofthe total monitoringpath length.

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 or urban street canyon locations shallbe located a minimum distance of 2 meters and a maximum distance of 10 meters from the edge ofthe nearesttraffic lane.

(c) Microscale CO monitor inlet probes in downtown areas or urban street canyon locations shallbe located at least 10 meters 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.

TABLE E-2 OFAPPENDIX ETO PART 58-MINIMUM SEPARATION DISTANCE BETWEEN ROADWAYS AND PROBES OR MONITORING PATHS FOR MONITORING NEIGHBORHOOD SCALE CARBON MONOXIDE
Minimum dis- Roadwayaverage dailytraffic,vehicles per tance i (me day ters)

<10,0 00

.......................................................... 10 1 5,0

00

............................................................ 2 5 20,0 00

............................................................ 45 30,0 00

............................................................ 80 40

,0

00

............................................................ 1 15 50

,0

00

............................................................ 13

5

>6

0,0

00

.......................................................... 15

0 1Distancefromthe edgeofthenearesttrafficlane.Thedistance for intermediate traffic counts should be interpolated fromthetablevalues basedon theactualtrafficcount.

6.3 Spacing for Particulate Matter (PM 2.5, PMi, 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

## Environmental Protection Agency

whether it be from mobile or multiple stationary sources. If the area is primarily affected by mobile sources and the maximum concentration area(s) is judgedtobe 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, thelocation mustbe between 5 and 15 meters from the major roadway. For the microscale street canyon site the location mustbebetween 2 and 10meters from the roadway. For the middle scale site,

a range of acceptable distances from the roadway is shown in figure E-1 ofthis appendix. This figure also includes separation distances between a roadway and neighborhood

or larger scale sites by default.Any site, 2to 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 sampler is set back 10 meters from a 30,000 ADT (average daily traffic) road, the site should be classified as microscale, if the sampler height isbetween 2 and 7 meters. If the sampler height is between 7 and 15 meters, the site should be classified as middle scale. If the sample is20 meters from the same road, it will be classified asmiddle scale; if 40 meters, neighborhood scale: and if 110 meters,

an urban scale.

6.4 Spacing for Nitrogen Dioxide (NO,) Probes andMonitoring Paths.

(a) In siting near-road NO, monitors as required in paragiraph 4.3.2 of appendix D of 

## Pt. 58,App. E

this part,the monitor probe shall be as near

as practicable tothe outside nearest edge of the traffic lanes ofthe target road segment; but shall notbe located at a distance greater than 50 meters, in the horizontal, from the outside nearest edge of the traffic lanes of the targetroad segment.

(b) In siting NO, monitors for neighborhood and larger scale monitoring, it is important to minimize near-road influences. Table E 1 ofthis appendix provides the required minimum separation distances between aroadway and aprobe 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. 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 of 10,000 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 ofpotential atmospheric interference form automobile emissions. Therefore, this calculation must include thelength ofthemonitoring path over the roadway plus any segments ofthe monitoring path that lie in the area between the roadway and minimum separation distance,

as determined form the Table E 1ofthis appendix. The sum ofthese distances must not be greater than 10percent ofthe total monitoring path length.

## 40 CFRCh. I(7-1-13 Edition)



# 60-

40-



# 20-

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 PATHLENGTH (This paragraph applies only to open path analyzers.) The monitoring pathlengthmust 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 due to these temporary optical obstructions. For certain ambient air monitoring scenarios using open path analyzers, shorter path lengths may be needed in order to ensure 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 requirements. Likewise, the Administrator may specify the maximum path length used atNCore monitoring sites. 9. PROBE MATERIAL AND POLLUTANT SAMPLE RESIDENCE TIME (a) For the reactive gases, SO , NO,, and 03, special probe material must be used for point analyzers. Studies2oM24 have been conducted to determine the suitability of materials 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 been found tobe acceptable for use as intake sampling lines for all the reactive gaseous pollutants. Furthermore, the EPA 2 5 has specified borosilicate glass or FEP Teflon ® asthe only acceptable probe materials for delivering test atmospheres in the determination of reference or equivalent methods. Therefore, borosilicate glass, FEP Teflon or their equivalent mustbe the only material in the sampling train (from inlet probe to the back ofthe analyzer) that can be in contact with the ambient air sample for existing and new SLAMs.

(b) For volatile organic compound (VOC) monitoring at PAMS, FEP Teflon ® isunacceptable 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 must be taken to ensure that the sample residence time is kept to 20 seconds orless. 

## Pt.58, App.E

## Environmental Protection Agency

(c)No matter how nonreactive the sampling probe material is initially, after a period ofusereactive 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 isalso 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.26 Other studies21
, 8 indicate that a 10 second or less residence time is easily achievable. Therefore, sampling probes for reactive gas monitors at NCore and atNO, 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 within the limits ofthis appendix. However, some existing sites may not meet these requirements and still produce useful data for some purposes. The EPAwill consider awritten request from the State agency towaive 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 atthatlocation.

10.1 For establishing a new site, a waiver may be granted only if both 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.

10.1.2 The monitor or probe cannot reasonably be located so as to meet the siting 

## Pt. 58,App. E

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 waiver may be granted if either 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 tothe Regional Administrator.

11. SUMMARY
Table E 4 ofthis appendix presents a summary ofthe general requirements for probe and monitoring path siting criteria with respect to distances and heights. It is apparent from Table E 4 that different elevation distances above the ground are shown for the various pollutants. The discussion in this appendix for each of the pollutants describes

reasons for elevating the monitor, probe, or monitoring path.The differences in the specified range of heights are based on the vertical concentration gradients. For CO and near-road NO monitors, the gradients in the vertical direction are very large for the microscale, so a small range ofheights are used. The upper limit of 15 meters isspecified for the consistency between pollutants and to allow the use ofa single manifold or monitoring path for monitoring more than

onepollutant.

TABLE E-4 OFAPPENDIX E TO PART 58-SUMMARY OF PROBE AND MONITORING PATH SITING CRITERIA

Horizontaland Heightfrom verticaldistance Distancefrom Distancefrom Scale(maximum groundto probe, from supporting treestoprobe, roadwaysto Pollutant monitoring path inletor 80% of structures2to inletor90%of probe, inletor length, meters) monitoring path probe, inletor monitoring pathI monitoring path (meters) 90%ofmonitoring (meters) (meters) path' (meters)

Middle(300 m)

Neighborhood Urban, and Regional (1km). Micro[downtown

or street canyon sites], micro [near-road sites], middle (300 m)and Neighborhood (1kin).

Middle(300 m)

Neighborhood, Urban, and Regional (1km). 2-15

2.5-3.5; 2-7; 2-15 >1

2-15 2-10for downtown areas or street canyon microscale; <50 fornear-road microscale; see Table E-2of this appendixfor middle and neighborhood scales. SeeTable E-1 of

this appendixfor all scales. SO 34,56

C0 4

.57

## Pt.58, App. E 40 CFRCh. 1(7-1-13 Edition)

TABLE 

### E-4 OFAPPENDIX E TO PART 58-SUMMARY OF PROBE AND MONITORING PATH SITING CRITERIA-Continued

Horizontal and Heightfrom vertical distance Distancefrom Distancefrom Scale (maximum groundto probe, from supporting treesto probe, roadwaysto Pollutant monitoring path inletor 80% of structures2 to inlet or90% of probe, inlet or length, meters) monitoring path probe, inlet or monitoring pathI monitoring path (meters) 90% ofmonitoring (meters) (meters) path' (meters)

NO23,4,5 Micro(Near-road 2-7 (micro); >1

......................... >10

....................... <50 fornear-road [50-300m]). micro-scale. Middle(300 m) 2-15 (all other scales). Neighborhood, SeeTable E-1 of

Urban, and Re- this appendixfor gional (1km). all other scales. Ozone precursors (for Neighborhood and 2-15

..................... >1

......................... >10

....................... SeeTable E-4 of

PAMS)-.4.5 Urban (1kin). this appendixfor all scales. PM, Pb3
,4
,5 8

.............. Micro, Middle, 2-7 (micro); 2-7 >2 (all scales,hor- >10 (all scales)

.... 2-10 (micro); see Neighborhood, (middle izontal distance Figure E-1 of Urban and Re- PM 1-2,5); 2-7 only). this appendixfor gional. fornear-road; all other scales. 2-15 (all other <50 for nearscales). road. N/A-Not applicable. 1Monitoring path foropenpath analyzers isapplicable onlyto middle orneighborhood scaleCO monitoring,middle, neighborhood, urban,and regional scaleNO2 monitoring, and all applicablescalesfor monitoring SO, 0
,and03 precursors.

2When probe islocated on a rooftop, thisseparation distance is in reference towalls, parapets, orpenthouses located on roof. 3Should be greaterthan 20 metersfrom thedripline oftree(s) and must be 10meters fromthe driplinewhenthe tree(s) actas an obstruction.

4Distance from sampler, probe, or 90 percent of monitoring path to obstacle,such as a building, must be at least twicethe heightthe obstacle protrudesabove thesampler, probe, ormonitoring path. Sitesnot meeting this criterion may be classified as middle scale (seetext).

5Must have unrestricted airflow270 degrees aroundthe probe orsampler; 180 degrees ifthe probe is on thesideof abuild- ing or awall.

6The probe, sampler,or monitoring path should beaway from minor sources,such asfurnace orincineration flues.The sepa- ration distance isdependent on theheight oftheminor source'semission point (such asaflue), thetypeoffuel or wasteburned, and the qualityofthefuel (sulfur,ash, orlead content).This criterion isdesignedtoavoid undueinfluencesfrom minor sources.

7For micro-scale CO monitoring sites,the probe must be >10 meters from a street intersection and preferably at amidblock location.

8Collocated monitors must be within4 meters of each other andat least2 meters apartfor flow ratesgreaterthan 200 liters/ min or at least 1meter apart for samplers having flow rates less than 200 liters/min to preclude airflow interference, unless a waiver is inplaceasapproved bythe RegionalAdministrator pursuanttosection 3 ofAppendixA.

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 ofSouthern California, School of Medicine, Los Angeles, CA. (Presented at 66th Annual Meeting ofAir 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 Dust Near 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 Levels in 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. APCA 77-13.4.)

5. Harrison, P.R. Considerations for Siting Air Quality Monitors in Urban Areas. Cityof 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 at Varying Heights Above Ground. Texas State Department of Health, Air Control Section, Austin, TX. 1970. p.7.

7. Rodes, C.E. and G.F. Evans. Summary of LACS Integrated PollutantData. In:Los Angeles 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. etal.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.

## Environmental Protection Agency

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 Sites for 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. Daimes, 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 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 

## Pt. 58,App. E

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. Proper Sizing of the Sampling Inlet Line for a Continuous AirMonitoring Station. Environ. Sci. andTechnol., 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. EPA450/4-87-009. 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. EPA 600/8-91-215. October 1991.

32. Quality Assurance Handbook for Air Pollution 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.

33. On-Site Meteorological Program Guidance for Regulatory Modeling Applications.

## Pt.58, App.G

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; 78FR 3285,Jan. 15, 2013]

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 I reportthe AQI? 4. What goes intomyAQI report? 5.

Is myAQI report formy MSAonly? 6. How do I get my AQI report to the public?

7. How oftenmust I reporttheAQI? 8. May I make exceptions to these reporting requirements?

CALCULATION

9. How Does the AQI Relate to Air Pollution Levels?

10. What Monitors Should I Use To Get the Pollutant Concentrations for Calculating the AQI?

11. DoIhave to forecast theAQI? 12. HowDoI Calculate theAQI?

BACKGROUND AND REFERENCE MATERIALS
13. What Additional Information Should I Know?

GENERAL REQUIREMENTS

1. WhatIs theAQJ?
The AQI is a tool that simplifies reporting air quality tothe general public. TheAQI incorporates into a single index concentrations of 5 criteria pollutants: ozone (03), particulate matter (PM), carbon monoxide (CO), sulfur dioxide (SO,), and nitrogen dioxide (NO ). The scale oftheindex is divided into general categories that are associated with health messages.
2. WhyReporttheAQI?

The AQI offersvarious advantages:

a. It is simpleto create andunderstand. b. It conveys thehealth implications ofair quality.

c. It promotes uniform use throughout the country.

3. MustIReporttheAQJ?

You must report the AQI daily if yours is

a metropolitan statistical area (MSA)with a population over 350,000. 

## 40 CFRCh. 1(7-1-13 Edition)

4. WhatGoesIntoMy AQIReport?
i. Your AQI report must contain the following:

a. The reporting area(s) (the MSA or subdivision ofthe MSA).

b. The reporting period (the day for which the AQIis reported).

c. The critical pollutant (the pollutant withthe highestindex value).

d. TheAQI (thehighest indexvalue).

e. The category descriptor and indexvalue associated withthe AQIand, if you choose to report in a color format, the associated color. Use only the following descriptors and colors for the six AQI categories:

TABLE 1-AQ CATEGORIES

For thisAQI Usethis descriptor And this color1

0 to50

........................ "Good

....................... Green.

51to 100

.......... "Moderate

................. Yellow.

101to 150

151to200

201to300 "Unhealthyfor Sensitive Groups".

"Unhealthy"

............. Orange.

Red.

"Very Unhealthy" Purple.

301 andabove

........... "Hazardous

.............. Maroon.

1Specificcolors can befound inthe most recent reporting guidance (Guidelinefor PublicReportingofDailyAir Quality- Air QualityIndex (AQI)).

f. The pollutant specific sensitive groups for any reported index value greater than 100. Use the following sensitive groups for each pollutant:

Whenthis pollutant has an index value above 100

Ozone

PMI

. Reportthese sensitivegroups * **

Children and peoplewith asthma are the groups

most at risk.

People with respiratory or heart disease,the elderly and children arethe groupsmost at risk.

PM1 People with respiratory disease are the group most at risk.

CO

........... Peoplewith heart disease are thegroup most at

risk.

SO2

. Peoplewith asthma arethe group most at risk.

NO2 Children and people with respiratory disease are the groupsmost at risk.

ii. When appropriate, your AQI report may also contain the following:

a. Appropriate health and cautionary
statements.

## Environmental Protection Agency

b. The name and index value for otherpollutants, particularly those with an index value greater than 100.

c. The index values for sub-areas of your MSA.

d. Causes forunusual AQI values.

e. Actualpollutant concentrations.

5. IsMy AQIReport forMy MSA Only? Generally, your AQI report applies to your MSA only. However, if a significant air quality problem exists (AQI greater than 100) in

areas significantly impacted by your MSA butnot in it (for example, 03 concentrations

are often highest downwind and outside an urban area), you should identify these areas and reporttheAQI for these areas aswell.

6.HowDoI GetMy 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 thatthe reporting to the various news media be as extensive aspossible. At a minimum, it should include notification to the media with the largest market coverages for the area in question.

7.How OftenMustI ReporttheAQI?
You must report the AQI at least 5 days per week. Exceptions to this requirement are in section 8 ofthis appendix.

8.May IMakeExceptionsto TheseReporting Requirements?
i. If theindexvalue for a particular pollutant remains below 50 for a season or year, then you may exclude the pollutant from your calculation ofthe AQI in section 12.

ii. If all index values remain below 50 for a year, then you may report the AQI at your discretion. In subsequent years, if pollutant levels rise to where the AQI would be above 50, then theAQI mustbe reportedas required in sections 3, 4, 6, and 7ofthisappendix.

CALCULATION
9.How doestheAQIrelateto air pollution 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 indexvalue of 100 is associated with the numerical level of the short-term standard (i.e., averaging time of24-hours or less) for each pollutant. Theindex value of50is associated with thenumerical level ofthe annual 

## Pt. 58, App.G

standard for a pollutant, if there is one, at one-half the level ofthe short-term standard for the pollutant, or at 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 and increasing proportions of the population that are likely to be affected. The index is related to other air pollution concentrations through linear interpolation based onthese levels. TheAQI is equal to the highest of the numbers corresponding to each pollutant. For the purposes ofreporting the AQI, the sub-indexes for PM 1 and PM,2

are to be considered separately. The pollutant responsible for the highest index value (the reported AQI) is called the "critical" pollutant.

10. WhatmonitorsshouldIusetogetthepollutantconcentrations forcalculatingtheAQI?
You must use concentration data from State/Local Air Monitoring Station (SLAMS) or parts ofthe SLAMS requiredby 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 PM,5 monitors required in Appendix D to this part). You may use PM measurements from monitors that are not reference or equivalent methods (for example, continuous PMlo or PM2 7 monitors). Detailed guidance for relating non-approved measurements to approved methods by statistical linear regression is referenced in section 13below.

11. DoIHavetoForecasttheAQI?
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. You can forecast theAQI at least24-hours in advance using the most accurate andreasonable 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 Daily AirQuality."

12. Howdo IcalculatetheAQI?
i. The AQI is the highest value calculated for each pollutant as follows:

a. Identify the highest concentration among all of the monitors within each reporting area and truncate asfollows: (1) Ozone-truncate to 3 decimal places PM 2. truncate to 1decimal place PM w-truncate tointeger

## Pt.58, App.G

CO-truncate to 1decimal place SO2 truncate to integer NO2-truncate to integer

(2) [Reserved] 

## 40 CFRCh. 1(7-1-13 Edition)

b. Using Table 2, find the two breakpoints that containthe concentration.

c. UsingEquation 1,calculate the index. d. Round the index to the nearest integer.

TABLE 2-BREAKPOINTS FORTHE AQ

These breakpoints EqualtheseAQI's

O (ppm) 8- 03(ppm) 1- PM 5(Pbg/m s) PM1o(Pg/ CO (ppm) SO2(ppb) NO2(ppb) AQI Categor hour hour' 24-hour m9)24-hour 8-hour 1-hour 1-hour

0.000-0.059

.................... 0.0-12.0 0-54 0.0-4.4 0-35 0-53 0-50 Good. 0.060-0.075

.................... 12.1-35.4 55-154 4.5-9.4 36-75 54-100 51-100 Moderate. 0.076-0.095 0.125-0.164 35.5-55.4 155-254 9.5-12.4 76-185 101-360 101-150 Unhealthyfor Sensitive Groups. 0.096-0.115 0.165-0.204 355.5-150.4 255-354 12.5-15.4 4186-304 361-649 151-200 Unhealthy. 0.116-0.374 0.205-0.404 3150.5-250.4 355-424 15.5-30.4 4305_604 650-1249 201-300 Very Unhealthy. (2) 0.405-0.504 3250.5-350.4 425-504 30.5-40.4 4605-804 1250-1649 301-400 Hazardous. (2)

.......... 0.505-0.604 3350.5-500.4 505-604 40.5-50.4 4805-1004 1650-2049 401-500

1Areasaregenerally required toreport theAQI basedon 8-hour ozone values.However, there areasmall numberof areas where an AQIbased on 1-hourozone valueswould bemore precautionary. Inthesecases,inadditiontocalculating the8-hour ozone indexvalue,the 1-hourozoneindexvalue maybe calculated,andthe maximum ofthetwovalues reported.

28-hour 03values donot define higher AQI values (_>301). AQI values of301 or greaterarecalculated with 1-hour 03con- centrations.

3Ifadifferent SHLforPM2,5 ispromulgated, these numberswillchange accordingly. 41-hr SO, valuesdo not define higherAQI values (2: 200). AQI values of 200or greater are calculated with 24-hour SO, concentrations.



### ii. Ifthe concentration is equalto abreak- note that in some areas, the AQIbased 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, using 8-hourvalues (see footnote 1to Table Equation 1can stillbe used.The results will 2). Inthese cases, youmay 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 astheAQI for 03.



### Hi- 

## Io (C,

- BPLo) + ILo (Equation 1)

p BPHi_ BPLo



### Where: ample, ifyou observe a PM ovalue of210 g/ I, =the indexvaluefor pollutant m3

, a 1-hour 03 value of 0.156 ppm, and an 8- Cp = the truncated concentration of pollut- hour 0, value of0.130ppm, thendo this: 

### ant, a. Findthe breakpoints forPM )at 210 g/ BP, =the breakpoint that isgreater than or m3 

### as155pg/m3

### and 254pg/m3



### ,corresponding equal to Cp toindex values 101and 150; 

### BPL, =the breakpoint that is less than or b. Find the breakpoints for 1-hour 03 at equal to Cp 0.156 ppm as 0.125 ppm and 0.164 ppm, cor

### Iu,= 

### theAQIvalue corresponding toBFHt responding toindexvalues 101 and 150; I, = 

### theAQIvalue corresponding toBP

... c. Find the breakpoints for 8-hour 03 at

iii. If the concentration is larger than the 0.130 ppm as 0.116 ppm and 0.374 ppm, cor

### highestbreakpoint in Table 2then youmay responding toindexvalues 201 and300;

use the last twobreakpoints in Table 2when d. ApplyEquation 1for210pg/m 3



### ,FMlo:
you apply Equation 1. 

### Example 150

- 101 

## -(210

- 155) + 101 = 128
iv.UsingTable 2andEquation 1,calculate 

## 254

- 

## 155 the index value for each of the pollutants 

### measured and select the one that produces e. Apply Equation 1for 0.156 ppm, 1-hour the highest index value for the AQI. For ex- 0':

## Environmental Protection Agency

150

- 101
0.164

- 0.125 0.125) + 101 = 140

f. Apply Equation 1 for 0.130 ppm, 8-hour 01:



## 300- 201 

## 0.

- 

## 2016 (0.130

- 0.116) +201 0.374

- 0.116

g. Findthe maximum, 206. This is theAQI. The minimalAQI reportwould read:

v. Today, the AQI for my city is 206 which is Very Unhealthy, due to ozone. Children and people with asthma are the groups 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 abrochure onthe AQI that explains the index in detail (The Air Quality Index), Reporting Guidance (Technical Assistance Document for the Reporting of Daily Air Quality-the Air Quality Index (AQI)) that provides associated health effects and cautionary statements, and Forecasting Guidance (Guideline for Developing an Ozone Forecasting Program) that explains the steps necessary to start an air pollution 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,.5 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) Web site, http:// www.epa.gov/ttnamtil/. [64 FR 42547, Aug. 4, 1999, as amended at 73 FR 16513, Mar. 27, 2008; 75 FR 6537, Feb. 9, 2010; 75 FR 35602, June 22, 2010; 78 FR 3286, Jan. 15, 2013] 

## PART59-NATIONAL VOLATILE ORGANIC COMPOUND EMISSION STANDARDS FOR CONSUMER AND COMMERCIAL PRODUCTS

See. 

## Subpart A-General

59.1 Final determinations under Section 183(e)(3)(C) oftheCAA. 

## Subpart B-National Volatile Organic Compound Emission Standards for AutomobileRefinish Coatings

59.100 Applicability anddesignation ofregulated entity. 59.101 Definitions. 59.102 Standards. 59.103 Container labelingrequirements. 59.104 Complianceprovisions. 59.105 Reportingrequirements. 59.106 Variance. 59.107 Addresses ofEPARegional offices. 59.108 Stateauthority. 59.109 Circumvention. 59.110 Incorporations byreference. 59.111 Availability of information and con- fidentiality.
TABLE 

### 1TO SUBPART

### B OF PART 59-VOLATILE ORGANIC COMPOUND (VOC) CONTENT LIMITS FORAUTOMOBILE REFINISH COATINGS 

## Subpart C-National Volatile Organic Compound Emission Standards for Consumer Products

59.201 Applicability anddesignation ofregulated entity. 59.202 Definitions. 59.203 Standardsforconsumer products. 59.204 Innovativeproductprovisions. 59.205 Labeling. 59.206 Variances. 59.207 Test methods. 59.208 Charcoal lightermaterial testingprotocol. 

## Pt.59