Environmental Protection Agency

PART 58-AMBIENT AIR QUALITY

SURVEILLANCE

Subpart A--General Provisions

Sec.

58.1

58.2

58.3

Definitions.

Purpose.

Applicability.

Subpart B-Monitoring Network

58.10 Annual monitoring network plan and

periodic network assessment.

58.11 Network technical requirements.

58.12 Operating schedules.

58.13 Monitoring network 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).

Subpart D-Comparability of Ambient

Data to NAAQS

58.30 Special considerations for data comparisons to the NAAQS.

Subpart E [Reserved]

Subpart F-Air Quality Index Reporting

58.50 Index reporting.

Subpart G-Federal Monitoring

58.60 Federal monitoring.

58.61 Monitoring other pollutants.

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 QUALrrY MONITORING METHODOLOGY

APPENDIX D TO PART 58--NETWORK DESIGN

CRITERIA FOR AMBIENT AIR

QUALITYMONITORING

APPENDIX E TO PART 58-PROBE AND MONITORING PATH SITING CRITERIA FOR 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.

§ 58.1

Subpart A-General Provisions

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

otherwise noted.

§ 58.1 Definitions.

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

them in the Act.

AADT means the annual average

daily traffic.

Act means the Clean Air Act as

amended (42 U.S.C. 7401, et seq.)

Additive and multiplicative bias means 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 of the Environmental Protection

Agency (EPA) or his or her authorized

representative.

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

and reporting of information relating

to ambient air quality data.

Approved regional method (ARM) means a continuous PM 2.5 method that

has been approved specifically within a

State or local air monitoring network

for purposes of comparison to the

NAAQS and to meet other monitoring

objectives.

AQCR means air quality control re- gion.

CO means carbon monoxide.

Combined statistical area (CSA) is defined by the U.S. Office of Management

and Budget as a geographical area con- sisting of two or more adjacent Core

Based Statistical Areas (CBSA) with

employment interchange of at least 15

percent. Combination is automatic if

the employment interchange is 25 percent and determined by local opinion if more than 15 but less than 25 percent

(http://www.census.gov/population/estimates/metro-city/List6.txt).

Community monitoring zone (CMZ) means an optional averaging area with

established, well defined boundaries,

such as county or census block, within

an MPA that has relatively uniform

concentrations of annual PM2.

5 as defined by appendix N of part 50 of this

chapter. Two or more community-oriented SLAMS monitors within a CMZ

that meet certain requirements as set

forth in appendix N of part 50 of this

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

chapter may be averaged for making

comparisons to the annual PM2 .

5

NAAQS.

Core-based statistical area (CBSA) is

defined by the U.S. Office of Management and Budget, as a statistical geographic entity consisting of the county

or counties associated with at least one urbanized area/urban cluster of at least

10,000 population, plus adjacent coun- ties having a high degree of social and

economic integration. Metropolitan

Statistical Areas (MSAs) and

micropolitan statistical areas are the

two categories of CBSA (metropolitan areas have populations greater than

50,000; and micropolitan areas have

populations between 10,000 and 50,000).

In the case of very large cities where

two or more CBSAs are combined,

these larger areas are referred to as combined statistical areas (CSAs)

(http://www.census.gov/population/estimates/rnetro-city/ListL.txt).

Corrected concentration pertains to

the result of an accuracy or precision

assessment test of an open path ana- lyzer in which a high-concentration

test or audit standard gas contained in a short test cell is inserted into the optical measurement beam of the instrument. When the pollutant concentration measured by the analyzer in such a test includes both the pollutant con- centration in the test cell and the con- centration in the atmosphere, the atmospheric pollutant concentration

must be subtracted from the test meas- urement to obtain the corrected con- centration test result. The corrected

concentration is equal to the measured

concentration minus the average of the

atmospheric pollutant concentrations

measured (without the test cell) immediately before and immediately after

the test.

Design value means the calculated

concentration according to the applicable appendix of part 50 of this chapter

for the highest site in an attainment or nonattainment area.

EDO means environmental data operations.

Effective concentration pertains to

testing an open path analyzer with a high-concentration calibration or audit

standard gas contained in a short test

cell inserted into the optical measure- ment beam of the instrument. Effective concentration is the equivalent

ambient-level concentration that

would produce the same spectral absorbance over the actual atmospheric

monitoring path length as produced by

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 ac- tual atmospheric monitoring path

length.

Federal equivalent method (FEM)

means a method for measuring the concentration of an air pollutant in the

ambient air that has been designated

as an equivalent method in accordance

with part 53 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 of this chapter.

Federal reference method (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 this part; it does not include a method for which a reference

method designation has been canceled

in accordance with §53.11 or §53.16 of

this chapter.

HNO3 means nitric acid.

Local agency means any local government agency, other than the State

agency, which is charged by a State

with the responsibility for carrying out

a portion of the plan.

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 of 50,000 population

or greater. The central county plus adjacent counties with a high degree of

integration comprise the area.

Monitor means an instrument, sam- pler, analyzer, or other device that measures or assists in the measurement of atmospheric air pollutants and

which is acceptable for use in ambient

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§$58.1
Environmental Protection Agency

air surveillance under the applicable

provisions of appendix C to this part.

Monitoring agency means a State or local agency responsible for meeting

the requirements of this part.

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

Monitoring path for an open path ana- lyzer means the actual path in space

between two geographical locations over which the pollutant 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 con- centration measurement (path-averaged concentration) is determined. See

also, optical measurement path length.

Monitoring planning area (MPA) means a contiguous geographic area with established, well defined boundaries, such as a CBSA, county or State,

having a common area that is used for

planning monitoring locations for

PM2.

5. An MPA may cross State boundaries, such as the Philadelphia PA-NJ

MSA, and be further subdivided into

community monitoring zones. MPAs are generally oriented toward CBSAs or CSAs with populations greater than

200,000, but for convenience, those portions of a State that are not associated

with CBSAs can be considered as a single MPA.

NATTS means the national air toxics

trends stations. This network provides

hazardous air pollution ambient data.

NCore means the National Core

multipollutant monitoring stations.

Monitors at these sites are required to measure particles (PM2.5, speciated

PM2.

5, PM10-2.5), 0, SO2 , CO, nitrogen

oxides (NO/NO 2/NOy), Pb, and basic me- teorology.

Near-road NO2 Monitor means any NO2 monitor meeting the specifications in

4.3.2 of appendix D and paragraphs 2,

4(d), 6.1, and 6.4 of appendix E of this

part.

Network means all stations of a given

type or types.

NH3 means ammonia.

NO2 means nitrogen dioxide. NO

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

§ 58.1

sum of the concentrations of NO2 and

NO.

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

NO2, and other nitrogen oxides referred

to as NOz.

03 means ozone.

Open path analyzer means an automated analytical method that meas- ures the average atmospheric pollutant

concentration in situ along one or more monitoring paths having a monitoring path length of 5 meters or more

and that has been designated as a ref- erence or equivalent method under the

provisions of part 53 of this chapter.

Optical measurement path length

means the actual length of the optical

beam over which measurement of the

pollutant is determined. The path-integrated pollutant concentration meas- ured by the analyzer is divided by the

optical measurement path length to determine the path-averaged concentration. Generally, the optical measure- ment path length is:

(1) Equal to the monitoring path

length for a (bistatic) system having a

transmitter and a receiver at opposite

ends of the monitoring path;

(2) Equal to twice the monitoring

path length for a (monostatic) system

having a transmitter and receiver at one end of the monitoring path and a

mirror or retroreflector at the other

end; or

(3) Equal to some multiple of the

monitoring path length for more complex systems having multiple passes of

the measurement beam through the

monitoring path.

PAMS means photochemical assessment monitoring stations.

Pb means lead.

Plan means an implementation plan

approved or promulgated pursuant to

section 110 of the Act.

PM means PMo, PM11oc, PM2.5,

PM1O-2.5, or particulate matter of unspecified size range.

PM2.5 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 of part 50 of this chapter

and designated in accordance with part

53 of this chapter, by an equivalent

method designated in accordance with

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

part 53 of this chapter, or by an approved regional method designated in

accordance with appendix C to this

part.

PMIo means particulate matter with an aerodynamic diameter less than or equal to a nominal 10 micrometers as measured by a reference method based on appendix J of part 50 of this chapter

and designated in accordance with part

53 of this chapter or by an equivalent

method designated in accordance with

part 53 of this chapter.

PMIoc 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 of part 50 of this chapter

and designated in accordance with part

53 of this chapter or by an equivalent

method designated in accordance with

part 53 of this chapter.

PM10 -2.5 means particulate matter

with an aerodynamic diameter less

than or equal to a nominal 10 micrometers and greater than a nominal 2.5

micrometers as measured by a ref- erence method based on appendix 0 to

part 50 of this chapter and designated

in accordance with part 53 of this chapter or by an equivalent method designated in accordance with part 53 of

this chapter.

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 of this chapter.

Population-oriented monitoring (or

sites) means residential areas, commer- cial areas, recreational areas, industrial areas where workers from more than one company are located, and

other areas where a substantial num- ber of people may spend a significant

fraction of their day.

Primary quality assurance organization 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 must be 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 station means any station operated for the purpose of establishing 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) of this chapter.

Regional Administrator means the Administrator of one of the ten EPA Regional Offices or his or her authorized

representative.

Reporting organization means an entity, such as a State, local, or Tribal

monitoring agency, that collects and

reports air quality data to EPA.

Site means a geographic location. One or more stations may be at the same site.

SLAMS means State or local air mon- itoring stations. The SLAMS make up

the ambient air quality monitoring

sites that are primarily needed for

NAAQS comparisons, but may serve other data purposes. SLAMS exclude

special purpose monitor (SPM) stations

and include NCore, PAMS, and all

other State or locally operated stations that have not been designated as SPM stations.

SO2 means sulfur dioxide.

Special purpose monitor (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 and in the Air Quality System, and which the agency does not

count when showing compliance with

the minimum requirements of this subpart for the number and siting of mon- itors of various types.

State agency means the air pollution

control agency primarily responsible

for development and implementation of a plan under the Act.

State speciation site means a supplemental PM2.

5 speciation station that is

not part of the speciation trends network.

Station means a single monitor, or a group of monitors with a shared objective, located at a particular site.

STN station means a PM2.5 speciation

station designated to be part of the

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§ 58.1
Environmental Protection Agency

speciation trends network. This network provides chemical species data of

fine particulate.

Traceable means that a local standard

has been compared and certified, either

directly or via not more than one intermediate standard, to a National Institute of Standards and Technology

(NIST)-certified primary standard such

as a NIST-traceable Reference Material

(NTRM) or a NIST-certified Gas Manufacturer's Internal Standard (GMIS).

TSP (total suspended particulates)

means particulate matter as measured

by the method described in appendix B

of part 50 of this chapter.

Urbanized area means 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 be part of each Urbanized Area.

VOC means volatile organic compounds.

[71 FR 61296, Oct. 17, 2006, as amended at 75

FR 6534, Feb. 9, 20101

§ 58.2 Purpose.

(a) This part contains requirements

for measuring ambient air quality and

for reporting ambient air quality data

and related information. The monitoring criteria pertain to the following

areas:

(1) Quality assurance procedures for

monitor operation and data handling.

(2) Methodology used in monitoring

stations.

(3) Operating schedule.

(4) Siting parameters for instruments

or instrument probes.

(5) Minimum ambient air quality

monitoring network requirements used

to provide support to the State implementation plans (SIP), national air

quality assessments, and policy decisions. These minimums are described

as part of the network design requirements, including minimum numbers

and placement of monitors of each

type.

§58.10

(6) Air quality data reporting, and re- quirements for the daily reporting of an index of ambient air quality.

(b) The requirements pertaining to

provisions for an air quality surveillance system in the SIP are contained

in this part.

(c) This part also acts to establish a national ambient air quality monitoring network for the purpose of providing timely air quality data upon

which to base national assessments and

policy decisions.

§ 58.3 Applicability.

This part applies to:

(a) State air pollution control agencies.

(b) Any local air pollution control

agency to which the State has delegated authority to operate a portion of

the State's SLAMS network.

(c) Owners or operators of proposed

sources.

Subpart B-Monitoring Network

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

otherwise noted.

§ 58.10 Annual monitoring network

plan and periodic network assess- ment.

(a)(1) Beginning July 1, 2007, the

State, or where applicable local, agency shall adopt and submit to the Regional Administrator an annual monitoring network plan which shall provide for the establishment and mainte- nance of an air quality surveillance

system that consists of a network of

SLAMS monitoring stations including

FRM, FEM, and ARM monitors that

are part of SLAMS, NCore stations,

STN stations, State speciation stations, SPM stations,. and/or, in serious,

severe and extreme ozone nonattainment areas, PAMS stations, and SPM

monitoring stations. The plan shall include a statement of purposes for each

monitor and evidence that siting and

operation of each monitor meets the

requirements of appendices A, C, D,

and E of this part, where applicable.

The annual monitoring network plan

must be made available for public inspection for at least 30 days prior to

submission to EPA.

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

(2) Any annual monitoring network

plan that proposes SLAMS network

modifications including new monitoring sites is subject to the approval

of the EPA Regional Administrator,

who shall provide opportunity for public comment and shall approve or disapprove the plan and schedule within

120 days. If the State or local agency

has already provided a public comment

opportunity on its plan and has made no changes subsequent to that com- ment opportunity, and has submitted

the received comments together with

the plan, the Regional Administrator is

not required to provide a separate opportunity 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 by January 1, 2011.

(4) A plan for establishing source-oriented Pb monitoring sites in accord- ance with the requirements of appendix

D to this part for Pb sources emitting

1.0 tpy or greater shall be submitted to

the EPA Regional Administrator no later than July 1, 2009, as part of the

annual network plan required in paragraph (a)(1) of this section. The plan

shall provide for the required source- oriented Pb monitoring sites for Pb sources emitting 1.0 tpy or greater to

be operational by January 1, 2010. A

plan for establishing source-oriented

Pb monitoring sites in accordance with

the requirements of appendix D to this

part for Pb sources emitting equal to or greater than 0.50 tpy but less than

1.0 tpy shall be submitted to the EPA

Regional Administrator no later than

July 1, 2011. The plan shall provide for

the required source-oriented Pb monitoring sites for Pb sources emitting

equal to or greater than 0.50 tpy but

less than 1.0 tpy to be operational by

December 27, 2011.

(5) A plan for establishing NO 2 monitoring sites in accordance with the re- quirements of appendix D to this part

shall be submitted to the Administrator by July 1, 2012. The plan shall

provide for all required monitoring stations to be operational by January 1,

2013.

(6) A plan for establishing S02 monitoring sites in accordance with the requirements of appendix D to this part

shall be submitted to the EPA Regional Administrator by July 1, 2011 as part of the annual network plan re- quired in paragraph (a) (1). The plan

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 re- quirements of appendix D to this part

shall be submitted to the EPA Regional Administrator. Plans for re- quired CO monitors shall be submitted

at least six months prior to the date

such monitors must be established as required by section 58.13.

(b) The annual monitoring network

plan must contain the following information for each existing and proposed

site:

(1) The AQS site identification num- ber.

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

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

(4) The operating schedules for each

monitor.

(5) Any proposals to remove or move a monitoring station within a period of

18 months following plan submittal.

(6) The monitoring objective and spatial scale of representativeness for

each monitor as defined in appendix D

to this part.

(7) The identification of any sites

that are suitable and sites that are not

suitable for comparison against the an- nual PM2.

5 NAAQS as described in

§ 58.30.

(8) The MSA, CBSA, CSA or othei area represented by the monitor.

(9) The designation of any Pb monitors as either source-oriented or non- source-oriented according to Appendix

D to 40 CFR part 58.

(10) Any source-oriented monitors for

which a waiver has been requested or granted by the EPA Regional Administrator as allowed for under paragraph

4.5(a)(ii) of Appendix D to 40 CFR part

58.

(11) Any source-oriented or non- source-oriented site for which a waiver

has been requested or granted by the

EPA Regional Administrator for the use of Pb-PMo monitoring in lieu of

Pb-TSP monitoring as allowed for

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§58.10
Environmental Protection Agency

under paragraph 2.10 of Appendix C to

40 CFR part 58.

(12) The identification of required

NO2 monitors as either near-road or

area-wide sites in accordance with appendix D, section 4.3 of this part.

(c) The annual monitoring network

plan must document how States and

local agencies provide for the review of

changes to a PM2.

5 monitoring network

that impact the location of a violating

PM2.

5 monitor or the creation/change

to a community monitoring zone, including a description of the proposed use of spatial averaging for purposes of

making comparisons to the annual

PM2 .

5 NAAQS as set forth in appendix

N- to part 50 of this chapter. The affected State or local agency must document the process for obtaining public

comment and include any comments

received through the public notification process within their submitted

plan.

(d) The State, or where applicable

local, agency shall perform and submit

to the EPA Regional Administrator an assessment of the air quality surveillance system every 5 years to determine, at a minimum, if the network

meets the monitoring objectives defined in appendix D to this part, 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 of susceptible

individuals (e.g., children with asthma), and, for any sites that are being

proposed for discontinuance, the effect on data users other than the agency

itself, such as nearby States and Tribes or health effects studies. For PM2.

5 , the

assessment also must identify needed

changes to population-oriented sites.

The State, or where applicable local,

agency must submit a copy of this 5-

year assessment, along with a revised

annual network plan, to the Regional

Administrator. The first assessment is

due July 1, 2010.

(e) All proposed additions and

discontinuations of SLAMS monitors

in annual monitoring network plans

§58.11

and periodic network assessments are subject to approval according to §58.14.

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

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, June 22, 2010; 75 FR

81137, Dec. 27, 2010; 76 FR 54341, Aug. 31, 2011]

§ 58.11 Network technical requirements.

(a)(1) State and local governments

shall follow the applicable quality as- surance criteria contained in appendix

A to this part when operating the

SLAMS networks.

(2) Beginning January 1, 2009, State

and local governments shall follow the

quality assurance criteria contained in

appendix A to this part that apply to

SPM sites when operating any SPM

site which uses a FRM, FEM, or ARM

and meets the requirements of appendix E to this part, unless the Regional

Administrator approves an alternative

to the requirements of appendix A with

respect to such SPM sites because

meeting those requirements would be

physically and/or financially impractical due to physical conditions at the

monitoring site and the requirements are not essential to achieving the intended data objectives of the SPM site.

Alternatives to the requirements of appendix A may be approved for an SPM

site as part of the approval of the annual monitoring plan, or separately.

(3) The owner or operator of an existing or a proposed source shall follow

the quality assurance criteria in appendix A to this part that apply to PSD

monitoring when operating a PSD site.

(b) State and local governments must

follow the criteria in appendix C to this

part to determine acceptable monitoring methods or instruments for use

in SLAMS networks. Appendix C criteria are optional at SPM stations.

(c) State and local governments must

follow the network design criteria contained in appendix D to this part in designing and maintaining the SLAMS

stations. The final network design and

all changes in design are subject to approval 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

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

a monitoring site from SLAMS to SPM

requires approval of the Regional Administrator.

(d) State and local governments must

follow the criteria contained in appendix E to this part for siting monitor inlets, paths or probes at SLAMS stations. Appendix E adherence is optional

for SPM stations.

§ 58.12 Operating schedules.

State and local governments shall

collect ambient air quality data at any

SLAMS station on the following operational schedules:

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

(1) Periods of routine maintenance,

(2) Periods of instrument calibration, or

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

(b) For Pb manual methods, at least one 24-hour sample must be collected

every 6 days except during periods or seasons exempted by the Regional Administrator.

(c) For PAMS VOC samplers, samples

must be collected as specified in sec- tion 5 of appendix D to this part. Areaspecific PAMS operating schedules

must be included as part of the PAMS

network description and must be approved by the Regional Administrator.

(d) For manual PM2.

5 samplers:

(1)(i) Manual PM2.

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

5 monitor must operate on at least a 1-

in-3 day schedule.

(ii) For SLAMS PM2.

5 sites with both

manual and continuous PM2.

5 monitors

operating, the monitoring agency may

request approval for a reduction to 1-

in-6 day PM2.

5 sampling or for seasonal

sampling from the EPA Regional Administrator. The EPA Regional Administrator may grant sampling frequency

reductions after consideration of factors, including but not limited to the

historical PM2.5 data quality assess- ments, the location of current PM2.5 design value sites, and their regulatory

data needs. Required SLAMS stations

whose measurements determine the design value for their area and that are within plus or minus 10 percent of the

NAAQS; and all required sites where

one or more 24-hour values have ex- ceeded the NAAQS each year for a con- secutive period of at least 3 years are required to maintain at least a 1-in-3

day sampling frequency. A continuously operating FEM or ARM PM2.

5 monitor satisfies this requirement.

(iii) Required SLAMS stations whose

measurements determine the design

value for their area and that are within

plus or minus 5 percent of the daily

PM2.

5 NAAQS must have an FRM or FEM operate on a daily schedule. A

continuously operating FEM or ARM

PM2.

5 monitor satisfies this requirement.

(2) Manual PM2.

5 samplers at NCore

stations and required regional background and regional transport sites

must operate on at least a 1-in-3 day

sampling frequency.

(3) Manual PM2.

5 speciation samplers

at STN stations must operate on at

least a 1-in-3 day sampling frequency.

(e) For PM1o samplers, a 24-hour sam- ple must be taken from midnight to

midnight (local standard time) to en- sure national consistency. The minimum monitoring schedule for the site

in the area of expected maximum con- centration shall be based on the relative level of that monitoring site con- centration with respect to the 24-hour

standard as illustrated in Figure 1. If

the operating agency demonstrates by

monitoring data that during certain

periods of the year conditions preclude

violation of the PM1o 24-hour standard,

the increased sampling frequency for

those periods or seasons may be ex- empted by the Regional Administrator

and permitted to revert back 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 of data must be considered to estimate the air quality status at the site near the area of maximum concentration. Statistical models such as analysis of concentration frequency distributions as described in "Guideline

for the Interpretation of Ozone Air

Quality Standards," EPA-450/479-003,

U.S. Environmental Protection Agency, Research Triangle Park, NC, January 1979, should be used. Adjustments

to the monitoring schedule must be

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§ 58.12
Environmental Protection Agency

made on the basis of the 5-year network assessment. The site having the

highest concentration in the most cur- rent year must be given first consideration when selecting the site for the more frequent sampling schedule.

Other factors such as major change in sources of PM10 emissions or in sam- pling site characteristics could influ- ence the location of the expected max- imum concentration site. Also, the use of the most recent 3 years of data

might, in some cases, be justified in

order to provide a more representative

database from which to estimate cur- rent air quality status and to provide

stability to the network. This

§ 58.13

multiyear consideration reduces the

possibility of an anomalous year biasing a site selected for accelerated sampling. If the maximum concentration

site based on the most current year is

not selected for the more frequent operating schedule, documentation of the

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

of part 50 of this chapter.

Every Sixth Day

I Every Other Day

Every Day

0.8 0.9 1.0 1.1 1.2 1.3 1.4

Figure 1 - Ratio to Standard

(f) For manual PM, 2 .

5 samplers:

(1) Manual PM1o-2.s samplers at NCore

stations must operate on at least a 1-

in-3 day schedule at sites without a

collocated continuously operating federal equivalent PM1o-2.5 method that

has been designated in accordance with

part 53 of this chapter.

(2) Manual PM1o-2.

5 speciation samplers at Nore stations must operate

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

(g) For continuous SO2 analyzers, the

maximum 5-minute block average concentration of the twelve 5-minute

blocks in each hour must be collected

except as noted in §58.12 (a).

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

FR 32210, June 12, 2007; 75 FR 35601, June 22,

2010]

§ 58.13 Monitoring network comple- tion.

(a) The network of NOore multipollutant sites must be physically established no later than January 1, 2011,

and at that time, operating under all of

the requirements of this part, including the requirements of appendices A,

C, D, E, and G to this part. NCore sites

required to conduct Pb monitoring as

required under 40 CFR part 58 appendix

253
40 CFR Ch. 1 (7-1-12 Edition)

D paragraph 3(b), or approved alternative non-source-oriented Pb monitoring sites, shall begin Pb monitoring

in accordance with all of the requirements of this part, including the requirements of appendices A, C, D, E,

and G to this part no later than December 27, 2011.

(b) Not withstanding specific dates

included in this part, beginning January 1, 2008, when existing networks are not in conformance with the minimum

number of required monitors specified

in this part, additional required monitors must be identified in the next applicable annual monitoring network

plan, with monitoring operation beginning by January 1 of the following

year. To allow sufficient time to prepare and comment on Annual Monitoring Network Plans, only monitoring

requirements effective 120 days prior to

the required submission date of the

plan (i.e., 120 days prior to July 1 of

each year) shall be included in that

year's annual monitoring network

plan.

(c) The network of NO2 monitors

must be physically established no later

than January 1, 2013, and at that time,

must be operating under all of the re- quirements of this part, including the

requirements of appendices A, C, D,

and E to this part.

(d) The network of S02 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 this part.

(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

this part, no later than:

(1) January 1, 2015 for CO monitors in

CBSAs having 2.5 million persons or more; or

(2) January 1, 2017 for other CO mon- itors.

[71 FR 61298, Oct. 17, 2006, as amended at 73

FR 67059, Nov. 12, 2008; 75 FR 6534, Feb. 9,

2010; 75 FR 35601, June 22, 2010; 75 FR 81137,

Dec. 27, 2010; 76 FR 54341, Aug. 31, 2011]

§ 58.14 System modification.

(a) The State, or where appropriate

local, agency shall develop and implement a plan and schedule to modify 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 the plan and schedule available to the public for 30 days prior to

submission to the EPA Regional Administrator. The final plan and schedule with respect to the SLAMS network are subject to the approval of the

EPA Regional Administrator. Plans

containing modifications to NCore 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 the Regional Administrator. Each monitoring network may

make or be required to make changes

between the 5-year assessment periods,

including for example, site relocations

or the addition of PAMS networks in

bumped-up ozone nonattainment areas.

These modifications must address

changes invoked by a new census and

changes due to changing air quality

levels. The State, or where appropriate

local, agency shall provide written

communication describing the network

changes to the Regional Administrator

for review and approval as these

changes are identified.

(c) State, or where appropriate, local

agency requests for SLAMS monitor

station discontinuation, subject to the

review of the Regional Administrator,

will be approved if any of the following

criteria are met and if the requirements of appendix D to this part, if

any, continue to be met. Other re- quests for discontinuation may also be

254

§ 58.14
Environmental Protection Agency

approved on a case-by-case basis if discontinuance does not compromise data

collection needed for implementation

of a NAAQS and if the requirements of

appendix D to this part, if any, continue to be met.

(1) Any PM2.

5, 03, CO, PM10 , SO2 , Pb, or NO2 SLAMS monitor which has

shown attainment during the previous

five years, that has a probability of

less than 10 percent of exceeding 80 percent of the applicable NAAQS during

the next three years based on the levels, trends, and variability observed in

the past, and which is not specifically

required by an attainment plan or

maintenance plan. In a nonattainment or maintenance area, if the most recent attainment or maintenance plan

adopted by the State and approved by

EPA contains a contingency measure

to be triggered by an air quality concentration and the monitor to be discontinued is the only SLAMS monitor

operating in the nonattainment or

maintenance area, the monitor may

not be discontinued.

(2) Any SLAMS monitor for CO,

PM10 , 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 of the

two monitors being compared.

(3) For any pollutant, any SLAMS

monitor in a county (or portion of a

county within a distinct attainment,

nonattainment, or maintenance area, as applicable) provided the monitor has

not measured violations of the applicable NAAQS in the previous five years,

and the approved SIP provides for a specific, reproducible approach to representing the air quality of the affected

county in the absence of actual monitoring data.

§ 58.15

(4) A PM2.5 SLAMS monitor which

EPA has determined cannot be com- pared to the relevant NAAQS because

of the siting of the monitor, in accordance with §58.30.

(5) A SLAMS monitor that is designed to measure concentrations

upwind of an 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

paragraphs (c)(1) through (c)(5) of this

section may be moved to a nearby location with the same scale of representation if logistical problems beyond the

State's control make it impossible to

continue operation at its current site.

§ 58.15 Annual air monitoring data cer- tification.

(a) The State, or where appropriate

local, agency shall submit to the EPA

Regional Administrator an annual air

monitoring data certification letter to

certify data collected at all SLAMS

and at all FRM, FEM, and ARM SPM

stations that meet criteria in appendix

A to this part from January 1 to December 31 of the previous year. The

senior air pollution control officer in

each agency, or his or her designee,

shall certify that the previous year of

ambient concentration and quality assurance data are completely submitted

to AQS and that the ambient con- centration data are accurate to the

best of her or his knowledge, taking

into consideration the quality assur- ance findings.

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

each year.

(2) Beginning in 2010, the annual data

certification letter is due by May 1 of

each year.

(b) Along with each certification letter, the State shall submit to the Administrator (through the appropriate

Regional Office) an annual summary

report of all the ambient air quality

data collected at all SLAMS and at

SPM stations using FRM, FEM, or

ARMs. The annual report(s) shall be

255
40 CFR Ch. I (7-1-12 Edition)

submitted for data collected from January 1 to December 31 of the previous

year. The annual summary report(s)

must contain all information and data

required by the State's approved plan

and must be submitted on the same schedule as the certification letter, un- less an approved alternative date is included in the plan. The annual summary serves as the record of the specific data that is the object of the cer- tification letter.

(c) Along with each certification letter, the State shall submit to the Administrator (through the appropriate

Regional Office) a summary of the precision and accuracy data for all ambient air quality data collected at all

SLAMS and at SPM stations using

FRM, FEM, or ARMs. The summary of

precision and accuracy shall be submitted for data collected from January

1 to December 31 of the previous year.

The summary of precision and accu- racy must be submitted on the same schedule as the certification letter, un- less an approved alternative date is included in the plan.

§ 58.16 Data submittal and archiving requirements.

(a) The State, or where appropriate,

local agency, shall report to the Administrator, via AQS all ambient air

quality data and associated quality as- surance data for SO2 ; CO; 03; NO2; NO;

NOv; NOx; Pb-TSP mass concentration;

Pb-PMIO mass concentration; PMo mass concentration; PM2.

5mass con- centration; for filter-based PM2.sFRM/

FEM the field blank mass, samplergenerated average daily temperature,

and sampler-generated average daily

pressure; chemically speciated PM2.

5 mass concentration data; PMIO-2. 5 mass concentration; chemically speciated

PM1o-2.5 mass concentration data; me- teorological 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 by

the AQS Data Coding Manual (http://

www.epa.gov/ttn/airs/airsaqs/manuals/

manuals.htm). The State, or where appropriate, local agency, may report

site specific meteorological measure- ments generated by onsite equipment

(meteorological instruments, or sampler generated) or measurements from

the nearest airport reporting ambient

pressure and temperature. Such air

quality data and information must be

submitted directly to the AQS via electronic transmission on the specified

quarterly schedule described in paragraph (b) of this section.

(b) The specific quarterly reporting

periods are January 1-March 31, April

1-June 30, July 1-September 30, and October 1-December 31. The data and information reported for each reporting

period must contain all data and information gathered during the reporting

period, and be received in the AQS

within 90 days after the end of the

quarterly reporting period. For example, the data for the reporting period

January 1-March 31 are due on or before June 30 of that 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) of this 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, NH 3, and HNO3

data, from PAMS sites to AQS within 6

months following the end of each quarterly reporting period listed in paragraph (b) of this 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 PM2 .5 , PMao, and PMIO-2.5 filters from manual

low-volume samplers (samplers having

flow rates less than 200 liters/minute)

from all SLAMS sites for a minimum

period of 1 year after collection. These

filters shall be made available during

the course of that year for supplemental analyses at the request of EPA

or to provide information to State and

local agencies on particulate matter

composition. Other Federal agencies

256

§ 58.16
Environmental Protection Agency

may request access to filters for purposes of supporting air quality management or community health-such as biological assay-through the applicable

EPA Regional Administrator. The filters shall be archived according to procedures approved by the Administrator. The EPA recommends that particulate matter filters be archived for

longer periods, especially for key sites

in making NAAQS related decisions or for supporting health-related air pollution studies.

(g) Any State or, where applicable,

local agency operating a continuous

SO2 analyzer shall report the maximum

5-minute SO2 block average of the

twelve 5-minute block averages in each

hour, in addition to the hourly SO2 average.

[71 FR 61298, Oct. 17, 2006, as amended at 73

FR 67059, Nov. 12, 2008; 75 FR 6534, Feb. 9,

2010; 75 FR 35602, June 22, 2010]

Subpart C-Special Purpose Monitors

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

otherwise noted.

§ 58.20 Special purpose monitors

(SPM).

(a) An SPM is defined as any monitor

included in an agency's monitoring

network that the agency has designated as a special purpose monitor in

its annual monitoring network plan

and in AQS, and which the agency does

not count when showing compliance

with the minimum requirements of

this subpart for the number and siting

of monitors of various types. Any SPM

operated by an air monitoring agency

must be included in the periodic assess- ments and annual monitoring network

plan required by § 58.10. The plan shall

include a statement of purposes for

each SPM monitor and evidence that

operation of each monitor meets the

requirements of appendix A or an approved alternative as provided by

§58.11(a)(2) where applicable. The monitoring agency may designate a monitor as an SPM after January 1, 2007 only if

it is a new monitor, i.e., a SLAMS

monitor that is not included in the cur- rently applicable monitoring plan or, for a monitor included in the monitoring plan prior to January 1, 2007, if

§58.20

the Regional Administrator has approved the discontinuation of the monitor as a 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 A to this part or an approved alternative to appendix A to this part.

Compliance with appendix E to this

part is optional but encouraged except

when the monitoring agency's data objectives are inconsistent with those requirements. Data collected at an SPM

using a FRM, FEM, or ARM meeting

the requirements of appendix A must

be submitted to AQS according to the

requirements of §58.16. Data collected

by other SPMs may be submitted. The

monitoring agency must also submit to

AQS an indication of whether each

SPM reporting data to AQS monitor

meets the requirements of appendices

A and E to this part.

(c) All data from an SPM using an

FRM, FEM, or ARM which has operated for more than 24 months is eligible for comparison to the relevant

NAAQS, subject to the conditions of

§58.30, unless the air monitoring agency demonstrates that the data came from a particular period during which

the requirements of appendix A, appendix C, or appendix E to this part were

not met in practice.

(d) If an SPM using an FRM, FEM, or

ARM is discontinued within 24 months

of start-up, the Administrator will not

base a NAAQS violation determination

for the PM2.

5 or ozone NAAQS solely on data from the SPM.

(e) If an SPM using an FRM, FEM, or

ARM is discontinued within 24 months

of start-up, the Administrator will not

designate an area as nonattainment for

the CO, S02, NO2, or 24-hour PM10

NAAQS solely on the basis of data from

the SPM. Such data are eligible for use

in determinations of whether a nonattainment area has attained one of

these NAAQS.

(f) Prior approval from EPA is not required for discontinuance of an SPM.

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

FR 32210, June 12, 2007; 73 FR 67060, Nov. 12,

2008]

257
40 CFR Ch. 1 (7-1-12 Edition)

Subpart D-National Air

Monitoring Stations (NAMS)

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

otherwise noted.

§ 58.30 Special considerations for data

comparisons to the NAAQS.

(a) Comparability of PM2.

5 data. (1)

There are two forms of the PM2.

5 NAAQS described in part 50 of this

chapter. The PM2.

5 monitoring site

characteristics (see appendix D to this

part, section 4.7.1) impact how the re- sulting PM2.

5 data can be compared to

the annual PM2.5 NAAQS form. PM2.

5 data that are representative, not of

areawide but rather, of relatively

unique population-oriented microscale,

or localized hot spot, or unique population-oriented middle-scale impact

sites are only eligible for comparison

to the 24-hour PM2.

5 NAAQS. For exam- ple, if the PM2.

5 monitoring site is adjacent to a unique dominating local

PM2.5 source or can be shown to have

average 24-hour concentrations representative of a smaller than neighborhood spatial scale, then data from a monitor at the site would only be eligible for comparison to the 24-hour PM2.

5

NAAQS.

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

scale PM2.

5 monitoring sites are determined by the Regional Administrator

to collectively identify a larger region

of localized high ambient PM2.

5 con- centrations. In those cases, data from

these population-oriented sites would

be eligible for comparison to the an- nual PM2.5 NAAQS.

(b) [Reserved]

Subpart E [Reserved]

Subpart F-Air Quality Index

Reporting

§ 58.50 Index reporting.

(a) The State or where applicable,

local agency shall report to the general

public on a daily basis through prominent notice an air quality index that

complies with the requirements of appendix G to this part.

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

(c) The population of a MSA for purposes of index reporting is the most re- cent decennial U.S. census population.

[71 FR 61302, Oct. 17, 2006]

Subpart G-Federal Monitoring

SOURCE: 44 FR 27571, May 10, 1979, unless

otherwise noted. Redesignated at 58 FR 8467,

Feb. 12, 1993.

§ 58.60 Federal monitoring.

The Administrator may locate and

operate an ambient air monitoring site

if the State or local agency fails to locate, or schedule to be located, during

the initial network design process, or as a result of the 5-year network as- sessments required in §58.10, a SLAMS

station at a site which is necessary in

the judgment of the Regional Administrator to meet the objectives defined in

appendix D to this part.

[71 FR 61303, Oct. 17, 2006]

§ 58.61 Monitoring other pollutants.

The Administrator may promulgate

criteria similar to that referenced in

subpart B of this part.for monitoring a pollutant for which an NAAQS does not

exist. Such an action would be taken

whenever the Administrator determines that a nationwide monitoring

program is necessary to monitor such a pollutant.

[71 FR 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 Check Requirements

4. Calculations for Data Quality Assessments

5. Reporting Requirements

6. References

1. General Information.

This appendix specifies the minimum quality system requirements applicable to

SLAMS air monitoring data and PSD data

for the pollutants SO2, NO2 , 03, CO, Pb,

PM2.

5 , PM10 and PMI 2.5 submitted to EPA.

This appendix also applies to all SPM stations using FRM, FEM, or ARM methods

258

§ 58.30
Environmental Protection Agency

which also meet the requirements of Appendix E of this part. Monitoring organizations

are encouraged to develop and maintain

quality systems more extensive than the required minimums. The permit-granting authority for PSD may require more frequent or more stringent requirements. Monitoring

organizations may, based on their quality

objectives, develop and maintain quality systems beyond the required minimum. Additional guidance for the requirements reflected in this appendix can be found in the

"Quality Assurance Handbook for Air Pollution Measurement Systems", volume II, part

1 (see reference 10 of this appendix) and at a national level in references 1, 2, and 3 of this

appendix.

1.1 Similarities and Differences Between

SLAMS and PSD Monitoring. In most cases,

the quality assurance requirements for

SLAMS, SPMs if applicable, and PSD are the

same. Affected SPMs are subject to all the

SLAMS requirements, even where not specifically stated in each section. Table A-1 of

this appendix summarizes the major similarities and differences of the requirements for

SLAMS and PSD. Both programs require:

(a) The development, documentation, and

implementation of an approved quality system;

(b) The assessment of data quality;

(c) The use of reference, equivalent, or approved methods. The requirements of this

appendix do not apply to a SPM that does

not use a FRM, FEM, or ARM;

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

(e) Performance evaluations and systems.

1.1.1 The monitoring and quality assurance responsibilities for SLAMS are with the

State or local agency, hereafter called the

monitoring organization, whereas for PSD

they are with the owner/operator seeking the

permit. The monitoring duration for SLAMS

is indefinite, whereas for PSD the duration is

usually 12 months. Whereas the reporting 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 com- mence at the beginning of a calendar quarter.

1.1.2 The annual performance evaluations

(described in section 3.2.2 of this appendix)

for PSD must be conducted by personnel different from those who perform routine span

checks and calibrations, whereas for SLAMS,

it is the preferred but not the required condition. For PSD, the evaluation rate is 100 percent of the sites per reporting quarter whereas for SLAMS it is 25 percent of the sites or

instruments quarterly. Monitoring for sulfur

dioxide (SO 2 ) and nitrogen dioxide (NO2 ) for

PSD must be done with automated analyzers--the manual bubbler methods are not

permitted.

Pt. 58, App. A

1.1.3 The requirements for precision as- sessment for the automated methods are the same for both SLAMS and PSD. However, for

manual methods, only one collocated site is

required for PSD.

1.1.4 The precision, accuracy and bias

data for PSD are reported separately for

each sampler (site), whereas for SLAMS, the

report may be by sampler (site), by primary

quality assurance organization, or nationally, depending on the pollutant. SLAMS

data are required to be reported to 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 followed by both SLAMS and PSD networks unless directly specified in a particular section.

1.2 Measurement Uncertainty. Measurement uncertainty is a term used to describe

deviations from a true concentration or estimate that are related to the measurement

process and not to spatial or temporal population attributes of the air being measured.

Monitoring organizations must develop quality assurance project plans (QAPP) which describe how the organization intends to con- trol measurement uncertainty to an appropriate level in order to achieve the objectives for which the data are collected. The

process by which one determines the quality

of data needed to meet the monitoring objective is sometimes referred to the Data Quality Objectives Process. Data quality indicators associated with measurement uncertainty include:

(a) Precision. A measurement of mutual

agreement among individual measurements

of the same property usually under prescribed similar conditions, expressed generally in terms of the standard deviation.

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

causes errors in one direction.

(c) Accuracy. The degree of agreement between an observed value and an accepted reference value. Accuracy includes a combination of random error (imprecision) and systematic error (bias) components which are

due to sampling and analytical operations.

(d) Completeness. A measure of the amount

of valid data obtained from a measurement

system compared to the amount that was expected to be obtained under correct, normal

conditions.

(e) Detectability. The low critical range

value of a characteristic that a method specific procedure can reliably discern.

1.3 Measurement Quality Checks. The

SLAMS measurement quality checks described in sections 3.2 and 3.3 of this appendix shall be reported to AQS and are included

in the data required for certification. The

PSD network is required to implement the

measurement quality checks and submit this

259
Pt. 58, App. A

information quarterly along with assessment

information to the permit-granting authority.

1.4 Assessments and Reports. Periodic as- sessments and documentation of data quality are required to be reported to EPA or to

the permit granting authority (PSD). To provide national uniformity in this assessment

and reporting of data quality for all networks, specific assessment and reporting

procedures are prescribed in detail in sec- tions 3, 4, and 5 of this appendix. On the

other hand, the selection and extent of the

quality assurance and quality 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 of data quality needed, the expertise of assigned personnel, the cost of control procedures, pollutant concentration levels, etc. Therefore,

quality system requirements in section 2 of

this appendix are specified in general terms

to allow each monitoring organization to develop a quality system that is most efficient

and effective for its own circumstances while

achieving the data quality objectives re- quired for the SLAMS sites.

2. QUALITY SYSTEM REQUIREMENTS

A quality system is the means by which an organization manages the quality of the

monitoring information it.produces in a systematic, organized manner. It provides a framework for planning, implementing, as- sessing and reporting work performed by an organization and for carrying out required

quality assurance 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 assur- ance project plans (QAPP) to ensure that the

monitoring results:

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

(b) Provide data of adequate quality for the

intended monitoring objectives;

(c) Satisfy stakeholder expectations;

(d) Comply with applicable standards specifications;

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

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

2.1.1 The QMP describes the quality system in terms of the organizational structure,

functional responsibilities of management

and staff, lines of authority, and required

interfaces for those planning, implementing,

assessing and reporting activities involving

environmental data operations (EDO). The

QMP must be suitably documented in ac- cordance with EPA requirements (reference 2

of this appendix), and approved by the appro40 CFR Ch. I (7-1-12 Edition)

priate Regional Administrator, or his or her

representative. The quality system will be

reviewed during the systems audits described

in section 2.5 of this 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 of the recipient's QMP by

the appropriate Regional Administrator or his or her representative, may allow delegation of the authority to review and approve

the QAPP to the recipient, based on adequacy of quality assurance procedures described and documented in the QMP. The

QAPP will be reviewed by EPA during systems audits or circumstances related to data

quality.

2.1.2 The QAPP is a formal document describing, in sufficient detail, the quality system that must be implemented to ensure that the results of work performed will satisfy the stated objectives. The quality assur- ance policy of the 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 must be suitably documented in accordance with EPA requirements (reference 3 of this appendix).

2.1.3 The monitoring organization's quality system must have adequate resources both in 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 of the overall management system of the 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

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Environmental Protection Agency

data to collect and specify the tolerable levels of potential decision errors that will be

used as a basis for establishing the quality

and quantity of data needed to support the

objectives of the SLAMS stations. DQO will

be developed by EPA to support the primary

SLAMS objectives for each criteria pollutant. As they are developed they will be added

to the regulation. DQO or the results of

other systematic planning processes for PSD or other monitoring will be the responsibility of the monitoring organizations. The

quality of the conclusions made from data

interpretation can be affected by population

uncertainty (spatial or temporal uncertainty) and measurement uncertainty (uncertainty associated with collecting, ana- lyzing, reducing and reporting concentration

data). This appendix focuses on assessing and

controlling measurement uncertainty.

2.3.1.1 Measurement Uncertainty for

Automated and Manual PM2.

5 Methods. The

goal for acceptable measurement uncer- tainty is defined as 10 percent coefficient of

variation (CV) for total precision and plus or minus 10 percent for total bias.

2.3.1.2 Measurement Uncertainty for

Automated Ozone Methods. The goal for ac- ceptable measurement uncertainty is defined

for precision as an upper 90 percent confidence limit for the coefficient variation

(CV) of 7 percent and for bias as an upper 95

percent confidence limit for the absolute

bias of 7 percent.

2.3.1.3 Measurement Uncertainty for

PMO 25 Methods. The goal for acceptable

measurement uncertainty is defined for precision as an upper 90 percent confidence

limit for the coefficient variation (CV) 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 measure- ment uncertainty is defined for precision as

an upper 90 percent confidence limit for the

coefficient variation (CV) of 20 percent and

for bias as an upper 95 percent confidence

limit for the absolute bias of 15 percent.

2.3.1.5 Measurement Uncertainty for NO2. The goal for acceptable measurement uncer- tainty is defined for precision as an upper 90

percent confidence limit for the coefficient

of variation (CV) of 15 percent and for bias as an upper 95 percent confidence limit for the

absolute bias of 15 percent.

2.3.1.6 Measurement Uncertainty for SO2. The goal for acceptable measurement uncer- tainty for precision is defined as an upper 90

percent confidence limit for the coefficient

of variation (CV) of 10 percent and for bias as an upper 95 percent confidence limit for the

absolute bias of 10 percent.

2.4 National Performance Evaluation Programs. Monitoring plans or the QAPP shall

provide for the implementation of a program

of independent and adequate audits of all

Pt. 58, App. A

monitors providing data for SLAMS and PSD

including the provision of adequate resources for such audit programs. A monitoring plan

(or QAPP) which provides for monitoring or- ganization participation in EPA's National

Performance Audit Program (NPAP) and the

PM Performance Evaluation Program (PEP)

program and which indicates the consent of

the monitoring organization for EPA to

apply an appropriate portion of. the grant

funds, which EPA would otherwise award to

the monitoring organization for monitoring

activities, will be deemed by EPA to meet

this requirement. For clarification and to

participate, monitoring organizations should

contact either the appropriate EPA Regional

Quality Assurance (QA) Coordinator at the

appropriate EPA Regional Office location, or the NPAP Coordinator at the Air Quality Assessment Division, Office of Air Quality

Planning and Standards, U.S. Environmental

Protection Agency in Research Triangle

Park, North Carolina.

2.5 Technical Systems Audit Program.

Technical systems audits of each 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 of this appendix. For further

instructions, monitoring organizations

should contact the appropriate EPA Regional QA Coordinator.

2.6 Gaseous and Flow Rate Audit Standards.

2.6.1 Gaseous pollutant concentration

standards (permeation devices or cylinders

of compressed gas) used to obtain test con- centrations for carbon monoxide (CO), sulfur

dioxide (SO2 ), nitrogen oxide (NO), and nitrogen dioxide (NO2) must be traceable to either a National Institute of Standards and Technology (NIST) Traceable Reference Material

(NTRM) or a NIST-certified Gas Manufacturer's Internal Standard (GMIS), certified in

accordance with one of the procedures given

in reference 4 of this appendix. Vendors advertising certification with the procedures

provided in reference 4 of this appendix and

distributing gasses as "EPA Protocol Gas"

must participate in the EPA Protocol Gas

Verification Program or not use "EPA" in

any form of advertising.

2.6.2 Test concentrations for ozone (03)

must be obtained in accordance with the

ultra violet photometric calibration procedure specified in appendix D to part 50 of this

chapter, or by means of a 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 a flow measuring instrument that is

traceable to an authoritative volume or

other applicable standard. Guidance for cer- tifying some types of flowmeters is provided

in reference 10 of this appendix.

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Pt. 58, App. A

2.7 Primary Requirements and Guidance.

Requirements and guidance documents for

developing the quality system are contained

in references 1 through 10 of this appendix,

which also contain many suggested procedures, checks, and control specifications.

Reference 10 of this appendix describes specific guidance for the development of a quality system for SLAMS. Many specific quality

control checks and specifications for methods are included in the respective reference

methods described in part 50 of this chapter or in the respective equivalent method descriptions available from EPA (reference 6 of

this appendix). Similarly, quality control

procedures related to specifically designated

reference and equivalent method analyzers are contained in the respective operation or instruction manuals associated with those

analyzers.

3. MEASUREMENT QUALITY CHECK

REQUIREMENTS

This section provides the requirements for

primary quality assurance organizations

(PQAOs) to perform the measurement quality checks that can be used to assess data

quality. With the exception of the flow rate

verifications (sections 3.2.3 and 3.3.2 of this

appendix), data from these checks are re- quired to be submitted to the AQS within

the same time frame as routine ambient con- centration data. Section 3.2 of this appendix

describes checks of automated or continuous

instruments while section 3.3 describe checks

associated with manual sampling instruments. Other quality control samples are identified in the various references described

earlier and can be used to control certain as- pects of the measurement system.

3.1 Primary Quality Assurance Organization. A primary quality assurance organization is defined 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 sam- pler/monitor at a monitoring station in the

SLAMS network must be associated with

one, and only one, primary quality assurance organization.

3.1.1 Each primary quality assurance or- ganization shall be defined such that meas- urement uncertainty among all stations in

the organization can be expected to be rea- sonably homogeneous, as a result of common factors. Common factors that should be con- sidered by monitoring organizations in defining primary quality assurance organizations

include:

(a) Operation by a common team of field

operators according to a common set of procedures;

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

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

(c) Common calibration facilities and

standards;

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

(e) Support by a common management,

laboratory or headquarters.

3.1.2 Primary quality assurance organizations are not necessarily related to the 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 of primary quality as- surance organizations shall be subject to

final approval by the appropriate EPA Regional Office during scheduled network re- views or systems audits.

3.1.3 Data quality assessment results

shall be reported as specified in section 5 of

this appendix.

3.2 Measurement Quality Checks of Automated Methods. Table A-2 of this appendix

provides a summary of the types and frequency of the measurement quality checks

that will be described in this section.

3.2.1 One-Point Quality Control Check for

SO2, NO2, 03, and CO. A one-point quality

control (QC) check must be performed at

least once every 2 weeks on each automated

analyzer used to measure SO2 , NO2, 03 and

CO. The frequency of QC checks may be re- duced based upon review, assessment and approval of the EPA Regional Administrator.

However, with the advent of automated calibration systems more frequent checking is

encouraged. See Reference 10 of this appendix for guidance on the review procedure.

The QC check is made by challenging the an- alyzer with a QC check gas of known con- centration (effective concentration for open

path analyzers) between 0.01 and 0.10 parts

per million (ppm) for SO2 , NO 2, and 03, and

between 1 and 10 ppm for CO analyzers. The

ranges allow for appropriate check gas selection for SLAMS sites that may be sampling

for different objectives, i.e., trace gas monitoring vs. comparison to National Ambient

Air Quality Standards (NAAQS). The QC

check gas concentration selected should be

related to the routine concentrations nor- mally measured at sites within the monitoring network in order to appropriately reflect the precision and bias at these routine

concentration ranges. To check the precision

and bias of SLAMS analyzers operating at

ranges either above or below the levels identified, use check gases of appropriate con- centrations as approved by the appropriate

EPA Regional Administrator or their designee. The standards from which check con- centrations are obtained must meet the specifications of section 2.6 of this appendix.

3.2.1.1 Except for certain CO analyzers described below, point analyzers must operate

in their normal sampling mode during the

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Environmental Protection Agency

QC check, and the test atmosphere must pass

through all filters, scrubbers, conditioners

and other components used during normal

ambient sampling and as much of the 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 or purge flows, or the test atmosphere may enter the analyzer at a point

other than the normal sample inlet, provided

that the analyzer's response is not likely to

be altered by these deviations from the nor- mal operational mode. If a QC 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 measure- ment beam of the instrument. I f possible, the

normally used transmitter, receiver, and as appropriate, reflecting devices should be

used during the test and the normal monitoring configuration of the instrument

should be altered as little as possible to ac- commodate the test cell for the test. However, if permitted by the associated operation or instruction manual, an alternate

local light source or an alternate optical

path that does not include the normal atmospheric monitoring path may be used. The

actual concentration of the QC check gas in

the test cell must be selected to produce an effective concentration in the range specified

earlier in this section. Generally, the QC test

concentration measurement will be the sum of the atmospheric pollutant concentration

and the QC test concentration. If so, the re- sult must be corrected to remove the atmospheric concentration contribution. The cor- rected concentration is obtained by subtracting the average of the atmospheric con- centrations measured by the open path instrument under test immediately before and

Pt. 58, App. A

immediately after the QC test from the QC

check gas concentration measurement. If the

difference between these before and after

measurements is greater than 20 percent of

the effective concentration of the test gas,

discard the test result and repeat the test. If

possible, open path analyzers should be tested during periods when the atmospheric pol- lutant concentrations are relatively low and

steady.

3.2.1.3 Report the audit concentration (effective concentration for open path ana- lyzers) of the QC gas and the corresponding

measured concentration (corrected con- centration, if applicable, for open path ana- lyzers) indicated by the analyzer. The percent differences between these concentrations are used to assess the precision and

bias of the monitoring data as described in

sections 4.1.2 (precision) and 4.1.3 (bias) of

this appendix.

3.2.2 Annual performance evaluation for

SO2 , NO2 , 03, or CO. Each calendar quarter

(during which analyzers are operated), evaluate at least 25 percent of the SLAMS ana- lyzers that monitor for SO2, NO2, 03, or CO

such that each analyzer is evaluated at least once per year. If there are fewer than four

analyzers for a pollutant within a primary

quality assurance organization, it is suggested to randomly evaluate one or more analyzers so that at least one analyzer for

that pollutant is evaluated each calendar

quarter. The evaluation should be conducted

by a trained experienced technician other

than the routine site operator.

3.2.2.1 (a) The evaluation is made by challenging the analyzer with audit gas standard

of known concentration (effective concentration for open path analyzers) from at least

three consecutive audit levels. The audit levels selected should represent or bracket 80

percent of ambient concentrations measured

by the analyzer being evaluated:

Audit level Concentration range, ppm

03 S02 NO 2 CO

1 .................................................................... 0.02-0.05 0.0003-0.005 0.0002-0.002 0.08-0.10 2 .................................................................... 0.06-0.10 0.006-0.01 0.003-0.005 0.50-1.00 3 .................................................................... 0.11-0.20 0.02-0.10 0.006-0.10 1.50-4.00 4 ................................................................... 0.21-0.30 0.11-0.40 0.11-0.30 5-15 5 .................................................................... 0.31-0.90 0.41-0.90 0.31-0.60 20-50

(b) An additional 4th level is encouraged

for those monitors that have the potential

for exceeding the concentration ranges described by the initial three selected.

3.2.2.2 (a) NO 2 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 of routine monitoring errors to the

extent that such NO concentrations exceed

typical ambient NO concentrations at the

site. These errors may be minimized by

modifying the GPT technique to lower the

NO concentrations remaining in the NO2

263
40 CFR Ch. 1 (7-1-12 Edition)

audit gas to levels closer to typical ambient

NO concentrations at the site.

(b) To evaluate SLAMS analyzers operating on ranges higher than 0 to 1.0 ppm for

S02, NO2, and 03 or 0 to 50 ppm for O, use

audit gases of appropriately higher. concentration as approved by the appropriate

EPA Regional Administrator or the Administrator's designee.

3.2.2.3 The standards from which audit gas

test concentrations are obtained must meet

the specifications of section 2.6 of this appendix. The gas standards and equipment used

for evaluations must not be the same as the

standards and equipment used for 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, and analysis.

3.2.2.4 For point analyzers, the evaluation

shall be carried out by allowing the analyzer

to analyze the audit gas test atmosphere in

its normal sampling mode such that the test

atmosphere passes through all filters, scrubbers, conditioners, and other sample inlet

components used during normal ambient

sampling and as much of the ambient air

inlet system as is practicable. The exception

provided in section 3.2.1 of this appendix for

certain CO analyzers does not apply for evaluations.

3.2.2.5 Open path analyzers are evaluated

by inserting a test cell containing the various audit gas concentrations into the optical measurement beam of the instrument. If

possible, the normally used transmitter, receiver, and, as appropriate, reflecting devices

should be used during the evaluation, and

the normal monitoring configuration of the

instrument should be modified as little as

possible to accommodate the test cell for the

evaluation. However, if permitted by the associated operation or instruction manual, an alternate local light source or an alternate

optical path that does not include the normal atmospheric monitoring path may be

used. The actual concentrations of the 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 to remove 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 of the effective concentration of the

test gas standard, discard the test result for

that concentration level and repeat the test

for that level. If possible, open path ana- lyzers should be evaluated during periods

when the atmospheric pollutant concentrations are relatively low and steady. Also, if

the open path instrument is not installed in a permanent manner, the monitoring path

length must be reverified to within plus or minus 3 percent to validate the evaluation,

since the monitoring path length is critical

to the determination of the effective con- centration.

3.2.2.6 Report both the evaluation con- centrations (effective concentrations for

open path analyzers) of the audit gases and

the corresponding measured concentration

(corrected concentrations, if applicable, for

open path analyzers) indicated or produced

by the analyzer being tested. The percent

differences between these concentrations are used to assess the quality of the monitoring

data as described in section 4.1.4 of this appendix.

3.2.3 Flow Rate Verification for Particulate Matter. A one-point flow rate

verification check must be performed at

least once every month on each automated

analyzer used to measure PM1o, PM10- 2.

5 and

PM2 .5 . The verification is made by checking

the operational flow rate of the analyzer. If

the verification is made in conjunction with a flow rate adjustment, it must be made

prior to such flow rate adjustment. Randomization of the flow rate verification with respect to time of day, day of week, and rou- tine service and adjustments is encouraged

where possible. For the standard procedure, use a flow rate transfer standard certified in

accordance with section 2.6 of this appendix

to check the analyzer's normal flow rate.

Care should be used in selecting and using

the flow rate measurement device such that

it does not alter the normal operating flow

rate of the analyzer. Report the flow rate of

the transfer standard and the corresponding

flow rate measured (indicated) by the analyzer. The percent differences between the

audit and measured flow rates are used to assess the bias of the monitoring data as described in section 4.2.2 of this appendix

(using flow rates in lieu of concentrations).

3.2.4 Semi-Annual Flow Rate Audit for

Particulate Matter. Every 6 months, audit

the flow rate of the PM1o, PM1 - 2.

5 and PM2 .

5

particulate analyzers. Where possible, EPA

strongly encourages more frequent auditing.

The audit should (preferably) be conducted

by a trained experienced technician other

than the routine site operator. The audit is

made by measuring the analyzer's normal

operating flow rate using a flow rate transfer

standard certified in accordance with section

2.6 of this appendix. The flow rate standard

264

Pt. 58, App. A
Environmental Protection Agency

used for auditing must not be the same flow

rate standard used to calibrate the analyzer.

However, both the calibration standard and

the audit standard may be referenced to the same primary flow rate or volume standard.

Great care must be used in auditing the flow

rate to be certain that the flow 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 rate measured (indicated)

by the analyzer. The percent differences between these flow rates are used to validate

the one-point flow rate verification checks

used to estimate bias as described in section

4.2.3 of this appendix.

3.2.5 Collocated Sampling Procedures for

PM 2.

5. For each pair of collocated monitors,

designate one sampler as the primary mon- itor whose concentrations will be used to re- port air quality for the site, and designate

the other as the audit monitor.

3.2.5.1 Each EPA designated Federal ref- erence method (FRM) or Federal equivalent

method (FEM) within a primary quality as- surance organization must:

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

and

(b) Have at least 1 collocated monitor (if

the total number of monitors is less than 3). The first collocated monitor must be a designated FRM monitor.

3.2.5.2 In addition, monitors selected for

collocation must also meet the following re- quirements:

(a) A primary monitor designated as an EPA FRM shall be collocated with an audit

monitor having the same EPA FRM method

designation.

(b) For each primary monitor model designated as an EPA FEM used by the PQAO, 50 percent of the monitors designated for collocation shall be collocated with an audit

monitor having the same method designation and 50 percent of the 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 odd number of collocated monitors re- quired, the additional monitor shall be an FRM audit monitor. An example of this procedure is found in Table A-3 of this appendix. 3.2.5.3 The collocated monitors should be

deployed according to the following protocol:

(a) 80 percent of the collocated audit mon- itors should be deployed at sites with annual

average or daily concentrations estimated to

be within ±20 percent of the applicable

NAAQS and the remainder at what the monitoring organizations designate as high value

sites;

(b) If an organization has no sites with an- nual average or daily concentrations within

±20 percent of the annual NAAQS (or 24-hour

NAAQS if that is affecting the area), 60 perPt. 58, App. A

cent of the 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 sites in the network.

3.2.5.4 In determining the number of collocated sites required for PM2.s, monitoring

networks for visibility assessments should

not be treated independently from networks

for particulate matter, as the separate networks may share one or more common sam- plers. However, for Class I visibility areas,

EPA will accept visibility aerosol mass measurement instead of a PM2.

5 measure- ment if the latter measurement is unavailable. Any PM2

.5 monitoring site which does

not have a monitor which is an EPA FRM,

FEM or ARM is not required to be included

in the number 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 con- centration must be selected.

3.2.5.6 The two collocated monitors must

be within 4 meters of each other and at least

2 meters apart for flow rates greater than 200

liters/min or at least 1 meter apart for sam- plers having flow rates less than 200 liters/

min to preclude airflow interference. Calibration, sampling, and analysis must be the same for both collocated samplers and the same as for all other samplers in the network.

3.2.5.7 Sample the collocated audit mon- itor for SLAMS sites on a 12-day schedule;

sample PSD sites on a 6-day schedule or every third day for PSD daily monitors. If a primary quality assurance organization has

only one collocated monitor, higher sam- pling frequencies than the 12-day schedule

may be needed in order to produce about 25

valid sample pairs a year. Report the meas- urements from both primary and collocated

audit monitors at each collocated sampling

site. The calculations for evaluating precision between the two collocated monitors are described in section 4.3.1 of this appendix.

3.2.6 Collocated Sampling Procedures for

PM1o-2.5. For the PMIO-2.5 network, all automated methods must be designated as Federal equivalent methods (FEMs). For each

pair of collocated monitors, designate one sampler as the primary monitor whose con- centrations will be used to report air quality

for the site, and designate the other as the

audit monitor.

3.2.6.1 The EPA shall ensure that each

EPA designated FEM within the national

PMo- 2.

5 monitoring network must:

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

and

(b) Have at least 2 collocated monitors (if

the total number of monitors is less than 10).

265
Pt. 58, App. A

The first collocated monitor must be a designated FRM monitor and the second must

be a monitor of the same method designation. Both collocated FRM and FEM mon- itors can be located at the 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 PMo-2.5 site, sites con- sidered important from a regional perspective, and sites needed for an appropriate distribution among rural and urban NCore

sites. Depending on the speed at which the

PMo- 2.

5 network is deployed, the first sites

implementing FEMs shall be required to perform collocation until there is a larger distribution of FEM monitors implemented in

the network.

3.2.6.3 The two collocated monitors must

be within 4 meters of each other and at least

2 meters apart for flow rates greater than 200

liters/min or at least 1 meter apart for sam- plers having flow rates less than 200 liters/

min to preclude airflow interference. Calibration, sampling, and analysis must be the same for both collocated samplers and the same as for all other samplers in the network.

3.2.6.4 Sample the collocated audit mon- itor for SLAMS sites on a 12-day schedule.

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.

3.2.7 PM2.5 Performance Evaluation Program (PEP) Procedures. The PEP is an independent assessment used to estimate total

measurement system bias. These evaluations

will be performed under the PM Performance

Evaluation Program (PEP) (section 2.4 of

this appendix) or a comparable program.

Performance evaluations will be performed on the SLAMS monitors annually within

each primary quality assurance organization. For primary quality assurance organizations with less than or equal to five monitoring sites, five valid performance evaluation audits must be collected and reported

each year. For primary quality assurance or- ganizations with greater than five monitoring sites, eight valid performance evaluation audits must be collected and reported

each year. A valid performance evaluation

audit means that both the primary monitor

and PEP audit concentrations are valid and

above 3 gg/m5 . 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 or FEM samplers subject

to a PEP audit at least once every six years;

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

which equates to approximately 15 percent of

the monitoring sites audited each year.

(b) Additional information concerning the

Performance Evaluation Program is con- tained in reference 10 of this appendix. The

calculations for evaluating bias between the

primary monitor and the performance evaluation monitor for PM2 .

5 are described in

section 4.3.2 of this appendix.

3.2.8 PMio-2.5 Performance Evaluation

Program. For the PM,0 -2.5 network, all automated methods will be designated as federal

equivalent methods (FEMs). One perform- ance evaluation audit, as described in sec- tion 3.2.7 must be performed at one PMIO-2.5

site in each primary quality assurance orga- nization each year. The calculations for evaluating bias between the primary monitor(s)

and the performance evaluation monitors for

PMao-2.5 are described in section 4.1.3 of this

appendix.

3.3 Measurement Quality Checks of Manual Methods. Table A-2 of this appendix provides a summary of the types and frequency

of the measurement quality checks that will

be described in this section.

3.3.1 Collocated Sampling Procedures for

PMIo. For each network of manual PMo

methods, select 15 percent (or at least one) of

the monitoring sites within the primary

quality assurance organization for collocated sampling. For purposes of precision as- sessment, networks for measuring total sus- pended particulate (TSP) and PMso shall be

considered separately from one another.

However, PMo samplers used in the PM1o-2.s network, may be counted along with the

PMo samplers in the PMso network as long as the PMIo samplers in both networks are the same method designation. PMIo and TSP

sites having annual mean particulate matter

concentrations among the highest 25 percent

of the annual mean concentrations for all

the sites in the network must be selected or,

if such sites are impractical, alternative

sites approved by the EPA Regional Administrator may be selected.

3.3.1.1 In determining the number of collocated sites required for PMo, monitoring

networks for lead (Pb) should be treated

independently from networks for particulate

matter (PM), even though the separate networks may share one or more common sam- plers. 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 4 meters of each other and at least

2 meters apart for flow rates greater than 200

liters/min or at least 1 meter apart for sam- plers having flow rates less than 200 liters/

min to preclude airflow interference. Calibration, sampling, analysis and verification/

validation procedures must be the same for

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Environmental Protection Agency

both collocated samplers and the same as for

all other samplers in the network.

3.3.1.3 For each pair of collocated samplers, designate one sampler as the primary

sampler whose samples will be 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

site. The calculations for evaluating precision between the two collocated samplers are

described in section 4.2.1 of this appendix.

3.3.2 Flow Rate Verification for Particulate Matter. Follow the same procedure as

described in section 3.2.3 of this appendix for

PM2.5, PMo (low-volume instruments), and

PM[o- 2.s. High-volume PMIo and TSP instruments can also follow the procedure in section 3.2.3 but the audits are required to be

conducted quarterly. The percent differences

between the audit and measured flow rates

are used to assess the bias of the monitoring

data as described in section 4.2.2 of this appendix.

3.3.3 Semi-Annual Flow Rate Audit for

Particulate Matter. Follow the same procedure as described in section 3.2.4 of this appendix for PM2.5, PMIO, PMI 0-2.5 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 must be used in auditing high-volume particulate matter samplers having flow regulators because the introduction of resistance plates in the audit

flow standard device can cause abnormal

flow patterns at the point of flow sensing.

For this reason, the flow audit standard

should be used with a normal filter in place

and without resistance plates in auditing

flow-regulated high-volume samplers, or

other steps should be taken to assure that

flow patterns are not perturbed at the point

of flow sensing.

3.3.4 Pb Methods.

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 of the Pb samplers shall be verified and

audited using the same procedures described

in sections 3.3.2 and 3.3.3 of this 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 audit filters are prepared by depositing a Pb solution on unexposed filters and

allowing them to dry thoroughly. The audit

samples must be prepared using batches of

Pt. 58, App. A

reagents different from those used to calibrate the Pb analytical equipment being au- dited. Prepare audit samples in the following

concentration ranges:

Range Equivalent ambient Pb con- centration, pg/m3

1............ 30-100% of Pb NAAOS.

2 ............ 200-300% of Pb NAAOS.

(a) Audit samples must be extracted using

the same extraction procedure used for ex- posed filters.

(b) Analyze three audit samples in each of

the two ranges each quarter samples are ana- lyzed. The audit sample analyses shall be

distributed as much as possible over the entire calendar quarter.

(c) Report the audit concentrations (in gg

Pb/filter or strip) and the corresponding

measured concentrations (in gg Pb/filter or

strip) using AQS unit code 077. The percent

differences between the concentrations are

used to calculate analytical accuracy as described in section 4.1.3 of this appendix.

(d) The audits of an equivalent Pb method

are conducted and assessed in the same manner as for the reference method. The flow auditing device and Pb analysis audit samples

must be compatible with the specific requirements of the equivalent 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 of this 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 the EPA

Regional Administrator, may be selected. If

additional collocated sites are necessary,

collocated sites may be chosen that reflect

average ambient air Pb concentrations in

the network. The collocated sampling re- quirements for PQAO that only have Pb

monitoring at a non-source-oriented NCore

site for sampling required under 40 CFR 58,

Appendix D, paragraph 4.5(b) shall be implemented as described in section 3.2.6 of this

appendix with the exception that the collocated monitor will be the same method designation as the primary monitor.

3.3.4.4 Pb Performance Evaluation Program

(PEP) Procedures. Each year, one performance evaluation audit, as described in section 3.2.7 of this appendix, must be performed

at one Pb site in each primary quality assurance organization that has less 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 less than or equal to 5 sites

and six collocated samples at primary quality assurance organizations with greater

267
Pt. 58, App. A

than 5 sites must be sent to an independent

laboratory, the same laboratory as the performance evaluation audit, for analysis.

3.3.5 Collocated Sampling Procedures for

PM2 .

5 . Follow the same procedure as described in section 3.2.5 of this appendix. PM2.

5

samplers used in the PMo-2.

5 network, may

be counted along with the PM2.

5 samplers in

the PM2,5 network as long as the PM2.5 samplers in both.networks are the same method

designation.

3.3.6 Collocated Sampling Procedures for

PM1o--2.s. All designated FRMs within the

PMo--2.s monitoring network must have 15

percent of the monitors collocated (values of

0.5 and greater round up) at the PMeo-2.s

sites. All FRM method designations can be

aggregated.

3.3.6.1 .The EPA shall ensure that each

designated FEM within the PM10-2.5 monitoring network must:

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

and

(b) Have at least 2 collocated monitors (if

the total number of monitors is less 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 at the same site.

3.3.6.2 The Regional Administrator for the

EPA Region where the FRM or FEMs are implemented will select the sites for collocated

monitoring. The collocation site selection

process shall consider sites at primary quality assurance organizations or States with

more than one PM1 -2.5 site; primary quality

assurance organizations already monitoring

for PMie and PM2.5 using FRMs or FEMs; and

an appropriate distribution among rural and

urban NCore sites. Monitoring organizations

implementing PM0 samplers and PM2.

5 FRM

samplers of the same method designation as

the PMWo-2.5 FRM can include the PMIo. 2.5

monitors in their respective PMio and PM2.

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 of this

appendix.

3.3.8 PM1O2.5 Performance Evaluation

Program (PEP) Procedures. One performance

evaluation audit, as described in section 3.2.7

of this appendix must be performed at one

PMIO- 2.5 site in each primary quality assurance organization each year. Monitoring organizations implementing PM2 .s FRM samplers of the same method designation in both

the PM2.5 and the PMo--2.

5 networks can include the PM10 -2.

5 performance evaluation

audit in their respective PM2

.5 performance

evaluation count as long as the performance

evaluation is conducted at the PMo-2.s site.

The calculations for evaluating bias between

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

the primary monitor(s) and the performance

evaluation monitors for PMIo-.2.s are described in section 4.1.3 of this appendix.

4. CALCULATIONS FOR DATA QUALITY

ASSESSMENT

(a) Calculations of measurement uncertainty are carried out by EPA according to

the following procedures. Primary quality

assurance organizations should report the

data for all appropriate measurement quality checks as specified in this appendix even

though they may elect to perform some or

all of the calculations in this section on

their own.

(b) The EPA will provide annual assessments of data quality aggregated by site and

primary quality assurance organization for

SO2, NO2 , 0 and CO and by primary quality assurance organization for PM1o, PM2.s,

PM1o--2.s and Pb.

(c) At low concentrations, agreement between the measurements of collocated samplers, expressed as relative percent difference or percent difference, may be relatively poor. For this reason, collocated

measurement pairs are selected for use in

the precision and bias calculations only

when both measurements are equal to or

above the following limits:

(1) TSP: 20 gg/m3 .

(2) Pb: 0.02 gg/m3 .

(3) PMo (Hi-Vol): 15 gg/m3 .

(4) PM1o (Lo-Vol): 3 pg/m 3.

(5) PM1O-2.5 and PM2.5

: 3 gg/i 3

.

4.1 Statistics for the Assessment of QC

Checks for SO2, NO2, 03 and CO.

4.1.1 Percent Difference. All measurement

quality checks start with a comparison of an

audit concentration or value (flowrate) to

the concentration/value measured by the analyzer and use percent difference as the comparison statistic as described in equation 1 of

this section. For each single point check,

calculate the percent difference, di, as follows:

Equation 1

= meas -audit X100

audit

where, meas is the concentration indicated

by the monitoring organization's instrument

and audit is the audit concentration of the

standard used in the QC check being measured.

4.1.2 Precision Estimate. The precision estimate is used to assess the one-point QC

checks for SO2, NO2, 03, or CO described in

section 3.2.1 of this appendix. The precision

estimator is the coefficient of variation

upper bound and is calculated using equation

2 of this section:

268
Environmental Protection Agency

Equation 2

= - _ n-I

where, X2

o.1., is the 10th percentile of a 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 , NO2 , 03, or CO described in section 3.2.1

of this appendix and the performance evaluation program for PM1O-2.5 described in sections 3.2.8 and 3.3.8 of this appendix. The bias

estimator is an upper bound on the mean absolute value of the percent differences as described in equation 3 of this section:

Equation 3

JABI = AB + tow9n-I AS A

where, n is the number of single point checks

being aggregated; to.95.- , is the 95th quantile

of a t-distribution with n-1 degrees of freedom; the quantity AB is the mean of the absolute values of the d's and is calculated

using equation 4 of this section:

Equation 4

1n AB = - -. di 1 i=1

and the quantity AS is the standard deviation of the absolute value of the d's and is

calculated using equation 5 of this section:

Equation 5

n 2 n 2

n. dI - |di 1

AS= i-Ii~

n(n-1)

4.1.3.1 Assigning a sign (positive/negative)

to the bias estimate. Since the bias statistic as calculated in equation 3 of this appendix uses absolute values, it does not have a tendency (negative or positive bias) associated

with it. A sign will be designated by rank or- dering the percent differences of the QC

check samples from a given site for a particular assessment interval.

4.1.3.2 Calculate the 25th and 75th percentiles of the percent differences for each

site. The absolute bias upper bound should be

flagged as positive if both percentiles are

positive and negative if both percentiles are negative. The absolute bias upper bound

Pt. 58, App. A

would not be flagged if the 25th and 75th percentiles are of different signs.

4.1.4 Validation of Bias Using the onepoint QC Checks. The annual performance

evaluations for SO2 , NO2 , 03, or CO described

in section 3.2.2 of this appendix are used to

verify the results obtained from the one- point QC checks and to validate those results

across a range of concentration levels. To

quantify this annually at the site level and

at the 3-year primary quality assurance or- ganization level, probability limits will be

calculated from the one-point QC checks

using equations 6 and 7 of this appendix:

Equation 6

Upper Probability Limit = m + 1.96 S

Equation 7

Lower Probability Limit = m -1.96 -S

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

Equation 8

ik

m-Yd

where, k is the total number of one point QC

checks for the interval being evaluated and

S is the standard deviation of the percent

differences (equation 9 of this appendix) as

follows:

Equation 9

k -1d' - Xdi i=1 (i=1

k(k-1)

4.1.5 Percent Difference. Percent differences for the performance evaluations,

calculated using equation 1 of this 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 within the probability intervals for the

primary quality assurance organization.

4.2 Statistics for the Assessment of PMo.

4.2.1 Precision Estimate from Collocated

Samplers. Precision is estimated via duplicate measurements from collocated samplers

of the same type. It is recommended that the

269
Pt. 58, App. A

precision be aggregated at the primary quality assurance organization level quarterly,

annually, and at the 3-year level. The data

pair would only be considered valid if both

concentrations are greater than the minimum values specified in section 4(c) of this

appendix. For each collocated data pair, calculate the relative percent difference, d;,

using equation 10 of this appendix:

Equation 10

d xi-Yi -100

i=(Xi + Yi)/2

where, X is the concentration from the primary sampler and Y, is the concentration

value from the audit sampler. The coefficient of variation upper bound is calculated using the equation 11 of this appendix:

Equation 11

CV = nwhere, n is the number of valid data pairs

being aggregated, and X2 0.1., is the 10th

percentile of a chi-squared distribution

with n-1 degrees of freedom. The factor of

2 in the denominator adjusts for the fact

that each di is calculated from two values

with error.

4.2.2 Bias Estimate Using One-Point Flow

Rate Verifications. For each one-point

flow rate verification described in sections 3.2.3 and 3.3.2 of this appendix, calculate the percent difference in volume

using equation 1 of this appendix where

meas is the value indicated by the sampler's volume measurement and audit is

the actual volume indicated by the auditing flow meter. The absolute volume

bias upper bound is then calculated using

equation 3, where n is the number of flow

rate audits being aggregated; tos95.-1 is

the 95th quantile of a t-distribution with

n-1 degrees of freedom, the quantity AB

is the mean of the absolute values of the

di's and is calculated using equation 4 of

this appendix , and the quantity AS in

equation 3 of this appendix is the standard deviation of the absolute values if

the d's and is calculated using equation

5 of this

4.2.3 Assessment Semi-Annual Flow Rate

Audits. The flow rate audits described in sections 3.2.4 and 3.3.3 of this appendix are used

to assess the results obtained from the onepoint flow rate verifications and to provide

an estimate of flow rate acceptability. For

each flow rate audit, calculate the percent

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

difference in volume using equation 1 of this

appendix where meas is the value indicated

by the sampler's volume measurement and

audit is the actual volume indicated by the

auditing flow meter. To quantify this annually and at the 3-year primary quality assurance organization level, probability limits

are calculated from the percent differences

using equations 6 and 7 of this appendix

where m is the mean described in equation 8

of this appendix and k is the total number of

one-point flow rate verifications for the year

and S is the standard deviation of the percent differences as described in equation 9 of

this appendix.

4.2.4 Percent Difference. Percent differences for the annual flow rate audit concentration, calculated using equation 1 of

this appendix, can be compared to the prob-

,ability intervals for the one-point flow rate

verifications for the respective primary quality assurance organization. Ninety-five percent of the 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 of PM2 .

5 and PMIO.5.

4.3.1 Precision Estimate. Precision for

collocated instruments for PM2.

5 and PMIO- 2.5 may be estimated where both the primary

and collocated instruments are the same

method designation and when the method

designations are not similar. Follow the procedure described in section 4.2.1 of this appendix. In addition, one may want to perform an estimate of bias when the primary

monitor is an FEM and the collocated monitor is an FRM. Follow the procedure described in section 4.1.3 of this appendix in

order to provide an estimate of bias using

the collocated data.

4.3.2 Bias Estimate. Follow the procedure

described in section 4.1.3 of this appendix for

the bias estimate of PM o-2.s. The PM2 .

5 bias

estimate is calculated using the paired routine and the PEP monitor data described in

section 3.2.6 of this appendix. Calculate the

percent difference, di, using equation 1 of

this appendix, where meas is the measured

concentration from agency's primary monitor and audit is the concentration from the

PEP monitor. The data pair would only be

considered valid if both concentrations are

greater than the minimum values specified

in section 4(c) of this appendix. Estimates of

bias are presented for various levels of aggregation, sometimes aggregating over time,

sometimes aggregating over samplers, and

sometimes aggregating over both time and

samplers. These various levels of aggregation are achieved using the same basic statistic.

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

270
Environmental Protection Agency

appendix to the desired level of aggregation

using equation 12 of this appendix:

Equation 12

1 "'

D = 1 d n i 

Pt. 58, App. A

where, ni is the number of pairs and di, d2, * * *, d, are the biases for each of the pairs

to be averaged.

4.3.2.2 Confidence intervals can be con- structed for these average bias estimates in

equation 12 of this appendix using equations

13 and 14 of this appendix:

tion 13

Upper 90% Confidence Interval = D +t0.9,df

Equation 14

Lower 90% Confidence

Where, tO.95.df is the 95th quantile of a t-distribution with degrees of freedom df = nj - 1 and s is an estimate of the variability

of the average bias calculated using equation 15 of this appendix:

Equation 15

X(d1 -D) 2

S = i=1

4.4 Statistics for the Assessment of Pb.

4.4.1 Precision Estimate. Follow the same procedures as described for PM10 in section

4.2.1 of this appendix using the data from the

collocated instruments. The data pair would

only be considered valid if both concentrations are greater than the minimum values

specified in section 4(c) of this appendix.

4.4.2 Bias Estimate. For the Pb analysis au- dits described in section 3.3.4.2 and the Pb

Performance Evaluation Program described

in section 3.3.4.4, follow the same procedure 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 PMio 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 and their AQS site identification

codes in each primary quality assurance or- ganization and submit the list to the approS Interval = D - tO.95,df

priate EPA Regional Office, with a copy to

AQS. Whenever there is a change in this list

of monitoring sites in a primary quality as- surance organization, report this change to

the EPA Regional Office and to AQS.

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 of AQS) the results of

all valid measurement quality checks it has

carried out during the quarter. The quarterly reports must be submitted consistent

with the data reporting requirements specified for air quality data as set forth in § 58.16.

The EPA strongly encourages early submission of the quality assurance data in order to

assist the monitoring organizations control

and evaluate the quality of the ambient air

data.

5.1.2 Annual Reports.

5.1.2.1 When the monitoring organization

has certified relevant data for the calendar

year, EPA will calculate and report the

measurement uncertainty for the entire calendar year.

5.2 PSD Reporting Requirements. At the

end of each sampling quarter, the organization must report the appropriate statistical

assessments in section 4 of this appendix for

the pollutants measured. All data used to

calculate reported estimates of precision and

bias including span checks, collocated sam- pler and audit results must be made available to the permit granting authority upon

request.

6.0 REFERENCES

(1) American National Standard-Specifications and Guidelines for Quality Systems

271
40 CFR Ch. I (7-1-12 Edition)

for Environmental Data Collection and Environmental Technology Programs. ANSI/

ASQC E4-2004. February 2004. Available from

American Society for Quality Control, 611

East Wisconsin Avenue, Milwaukee, WI 53202.

(2) EPA Requirements for Quality Management Plans. EPA QA/R-2. EPA/240/B-01/002.

March 2001. Office of Environmental Information, Washington DC 20460. http://

www.epa.gov/quality/qs-docs/r2-final.pdf.

(3) EPA Requirements for Quality Assurance Project Plans for Environmental Data

Operations. EPA QA/IR5. EPA/240/B-01/003.

March 2001. Office of Environmental Information, Washington DC 20460. http://

www.epa.gov/quality/qs-docs/r5-final.pdf.

(4) EPA Traceability Protocol for Assay

and Certification of Gaseous Calibration

Standards. EPA-600/R-97/121. September 1997.

Available from U.S. Environmental Protection Agency, ORD Publications Office, Center for Environmental Research Information

(CERI), 26 W. Martin Luther King Drive, Cincinnati, OH 45268.

(5) Guidance for the Data Quality Objectives Process. EPA QA/G-4. EPA/240/B-06/001.

February, 2006. Office of Environmental Information, Washington DC 20460. http://

www.epa.gov/quality/qs-docs/g4-final.pdf.

(6) List of Designated Reference and Equivalent Methods. Available from U.S. Environmental Protection Agency, National Exposure Research Laboratory, Human Exposure

and Atmospheric Sciences Division, MDD205-03, Research Triangle Park, NC 27711.

http://www.epa.gov/ttn/amtic/criteria.html.

(7) McElroy, F.F. Transfer Standards for

the Calibration of Ambient Air Monitoring

Analyzers for Ozone. EPA-600/4-79-056. U.S.

Environmental Protection Agency, Research

Triangle Park, NC 27711, September, 1979.

http://www.epa.gov/ttn/amtic/cpreldoc.html.

(8) Paur, R.J. and F.F. McElroy. Technical

Assistance Document for the Calibration of

Ambient Ozone Monitors. EPA-600/4-79-057.

U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, September,

1979. http://www.epa.gov/ttn/amtic/

cpreldoc.html.

(9) Quality Assurance Handbook for Air

Pollution Measurement Systems, Volume 1-

A Field Guide to Environmental Quality Assurance. EPA-600/R-94/038a. April 1994. Available from U.S. Environmental Protection

Agency, ORD Publications Office, Center for

Environmental Research Information

(CERI), 26 W. Martin Luther King Drive, Cincinnati, OH 45268. http://www.epa.gov/ ttn/

amtic/qabook.html.

(10) Quality Assurance Handbook for Air

Pollution Measurement Systems, Volume II:

Part 1-Ambient Air Quality Monitoring

Program Quality System Development.

EPA-54/R-98-004. http://www.epa.gov/ttn/

amtic/qabook.html.

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

PSD REQUIREMENTS

Topic SLAMS PSO

Requirements ..................................

Monitoring and QA Responsibility...

Monitoring Duration .........................

Annual Performance Evaluation

(PE).

PE audit rate:

-Automated .....................

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

Precision Assessment:

-Automated .....................

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

Reporting

-Automated .....................

1. The development, documentation, and implementation of an approved quality system.

2. The assessment of data quality.............

3. The use of reference, equivalent, or approved

methods.

4. The use of calibration standards traceable to NIST

or other primary standard.

5. The participation in EPA performance evaluations

and the permission for EPA to conduct system audits.

State/local agency via the "primary quality assurance organization".

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

Standards and equipment different from those used

for spanning, calibration, and verifications. Prefer

different personnel.

100% per year ..........................

Varies depending on pollutant. See Table A-2 of this

appendix.

One-point OC check biweekly but data quality dependent.

Varies depending on pollutant. See Table A-2 of this

appendix.

By site-EPA performs calculations annually ............

Source owner/operator.

Usually up to 12 months.

Personnel, standards and equipment different from those used

for spanning, calibration, and

verifications.

100% per quarter.

100% per quarter.

One point OC check biweekly.

One site: 1 every 6 days or every

third day for daily monitoring

(TSP and Pb).

By site-source owner/operator

performs calculations each sampling quarter.

272

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

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

PSD REQUIREMENTS-Continued

Topic SLAMS PSD

-Manual .......................... By reporting organization-EPA performs calcula- By site-source owner/operator

tions annually. performs calculations each sam- pling quarter.

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

SITES

Method Assessment method Coverage freqmu Parprtedrs

Automated Methods

1-Point OC for SO2, Response check at Each analyzer. once per 2 weeks Audit concentrationI

NO2, 03, CO. concentration 0.01- and measured con- 0.1 ppm SO2

, NO2, centration 2.

03, and 1-10 ppm CO.

Annual performance See section 3.2.2 of Each analyzer. once per year. Audit concentration

evaluation for SO2

, this appendix. and measured conNO2

, 03, CO. centration 2 for each

level.

Flow rate verification Check of sampler flow Each sampler........once every month Audit flow rate and

PMo. PM23, PM-2 3

. rate. measured flow rate

indicated by the sampler.

Semi-annual flow rate Check of sampler flow Each sampler........Once every 6 months Audit flow rate and

audit PM,,, PM25, rate using inde- measured flow rate

PM-2.5. pendent standard. indicated by the sam- pler.

Collocated sampling Collocated samplers .... 15% ............... Every 12 days. Primary sampler conPM2.

3 . PMo- 2.5

. centration and duplicate sampler concentration.

Performance evaluation Collocated samplers 1. 5 valid audits for pri- over all 4 quartersPrimary sampler con- program PM23, mary QA org, with centration and perPM,0 .5. <5 sites. formance evaluation

2. 8 valid audits for pri- sampler concentramary OA orgs, with tion.

>5 sites.

3. All samplers in 6

years.

Manual Methods

Collocated sampling

PMo. TSP, PMo-23,

PM2.

3 . Pb-TSP, PbPMo .

Flow rate verification

PM,0 (low Vol),

PM,,,. PM2.

3 . PbPM, 0.

Flow rate verification

PM,0 (High-Vol),

TSP, Pb-TSP.

Semi-annual flow rate

audit PM,0 , TSP,

PM,0 2.. PM2.5, PbTSP, Pb-PMo.

Pb audit strips Pb-TSP,

Pb-PMo.

Collocated samplers

Check of sampler flow

rate.

Check of sampler flow

rate.

Check of sampler flow

rate using independent standard.

Check of analytical systern with Pb audit

strips.

15% ..............................

Each sampler ...............

Each sampler ...............

Each sampler, all locations.

Analytical ......................

Every 12 days PSDevery 6 days.

Once every month.

Once every quarter.

Once every 6 months

Each quarter ................

Primary sampler con- centration and duplicate sampler concentration.

Audit flow rate and

measured flow rate

indicated by the sam- pler.

Audit flow rate and

measured flow rate

indicated by the sampler.

Audit flow rate and

measured flow rate

indicated by the sampler.

Actual concentration

and audit concentration.

273
Pt. 58, App. C 40 CFR Ch. 1 (7-1-12 Edition)

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

SITES-Continued

Method Assessment method Coverage Minimum Paraeters

Performance evaluation Collocated samplers .... 1. 5 valid audits for pri- Over all 4 quarters Primary sampler conprogram PM25

. mary QA orgs, with centration and perPM- 25

. S5 sites. formance evaluation

2. 8 valid audits for pri- sampler concentramary QA orgs. with tion.

>5 sites.

3. All samplers in 6

years. Performance evaluation Collocated samplers .... 1. 1 valid audit and 4 Over all 4 quarters . Primary sampler con- program Pb-TSP, Pb- collocated samples centration and perPM.o. for primary QA orgs, formance evaluation

with >5 sites. sampler concentra2. 2 valid audits and 6 tion. Primary sampler collocated samples concentration and

for primary QA orgs, duplicate sampler with >5 sites. concentration.

Effective concentration for open path analyzers. 2Corrected concentration, if applicable, for open path analyzers.

TABLE A-3 OF APPENDIX A TO PART 58-SUMMARY OF PM 2.

5 NUMBER AND TYPE OF COLLOCATION

(15% COLLOCATION REQUIREMENT) NEEDED AS AN EXAMPLE OF A PRIMARY QUALITY ASSURANCE

ORGANIZATION THAT HAS 54 MONITORS AND PROCURED FRMS AND THREE OTHER EQUIVALENT

METHOD TYPES

Primary sampler No. of collocated mon- method designa- Total no. of monitors Total no. collocated No. of collocated FRM itors of same method

tion designation as primary

FRM .................... 20 3 3 n/a

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

FEM (C) .............. 2 1 1 0

FEM (D) .............. 12 2 1 1

[71 FR 61303, Oct. 17, 2006, as amended at 72 FR 32211, June 12, 2007; 73 FR 67060, Nov. 12, 2008;

75 FR 6534, Feb. 9, 2010; 75 FR 35602, June 22, 2010; 75 FR 81137, Dec. 27, 2010]

EDITORIAL NOTE: At 72 FR 32211, June 13, 2007, the last sentence in section 4.2.2.2, was

amended in Appendix A to Part 58; however, the amendment could not be incorporated due

to inaccurate amendatory instruction.

APPENDIX B TO PART 58 [RESERVED]

APPENDIX C TO PART 58-AMBIENT AIR

QUALITY MONITORING METHODOLOGY

1.0 Purpose

2.0 SLAMS Ambient Air Monitoring Stations

3.0 NCore Ambient Air Monitoring Stations

4.0 Photochemical Assessment Monitoring

Stations (PAMS)

5.0 Particulate Matter Episode Monitoring

6.0 References

1.0 PURPOSE

This appendix specifies the criteria pollutant monitoring methods (manual methods or

automated analyzers) which must be used in

SLAMS and NCore stations that are a subset

of SLAMS.

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

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

2.2 Reserved

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

or equivalent method designation under

§53.11 or §53.16 of this chapter may be used at

a SLAMS site following cancellation for a

reasonable period of time to be determined

by the Administrator.

2.4 Approval of Non-designated Continuous PM 2.

5 Methods as Approved Regional

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Environmental Protection Agency

Methods (ARMs) Operated Within a Network

of Sites. A method for PM2.

5 that has not

been designated as an FRM or FEM as defined in §50.1 of this chapter may be approved as an ARM 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 PM2.5

Class III equivalent methods as defined in

subpart C of part 53 of this chapter. Specifically the requirements for precision, correlation, and additive and multiplicative bias

apply. For purposes of this section 2.4, the

following requirements shall apply:

2.4.1.1 The candidate ARM shall be tested

at the site(s) in which it is intended to be

used. For a network of sites operated by one

reporting agency or primary quality assur- ance organization, the testing shall occur at

a subset of sites to include one site in each

MSA/CSA, up to the first 2 highest population MSA/CSA and at least one rural area

or Micropolitan Statistical Area site. If the

candidate ARM for a network is already approved for purposes of this 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 shall be no requirement for

tests at any other sites.

2.4.1.2 For purposes bf 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 PM1o samplers shall be required

for the test, as determination of the PM2.5/

PMo ratio at the test site shall not be re- quired.

2.4.1.4 The test specification for PM2 .5

Class III equivalent method precision defined

in subpart C of part 53 of this chapter applies; however, there is no specific requirement that collocated continuous monitors be

operated for purposes of generating a statistic for coefficient of variation (CV). To

provide an estimate of precision that meets

the requirement identified in subpart C of

part 53 of this chapter, agencies may cite

peer-reviewed published data or data in AQS

that can be presented demonstrating the

candidate ARM operated will produce data

that meets the specification for precision of

Class III PM2.

5 methods.

2.4.1.5 A minimum of 90 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 that additive

bias, multiplicative bias and correlation

meet the comparability requirements specified in subpart C of part 53 of this chapter. A

valid sample pair may be generated with as

little as one valid FRM and one valid can- didate ARM measurement per day.

2.4.1.6 For purposes of determining bias,

FRM data with concentrations less than 3

micrograms per cubic meter (gg/m5 ) may be

Pt. 58, App. C

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 com- parability requirements specified in subpart

C of part 53 of this chapter. Data transformation may be linear or non-linear, but

must be applied in the same way to all sites

used in the testing.

2.4.2 The monitoring agency wishing to

use an ARM must develop and implement appropriate quality assurance procedures for

the method. Additionally, the following procedures are required for the method:

2.4.2.1 The ARM must be consistently operated throughout the network. Exceptions

to a consistent operation must be approved

according to section 2.8 of this appendix;

2.4.2.2 The ARM must be operated on an hourly sampling frequency capable of providing data suitable for aggregation into

daily 24-hour average measurements;

2.4.2.3 The ARM must use an inlet and

separation device, as needed, that are already approved in either the reference method identified in appendix L to part 50 of this

chapter or under part 53 of this chapter as

approved for use on a PM2.

5 reference or

equivalent method. The only exceptions to

this requirement are those methods that by

their inherent measurement principle may

not need an inlet or separation device that

segregates the aerosol; and

2.4.2.4 The ARM must be capable of providing for flow audits, unless by its inherent

measurement principle, measured flow is not

required. These flow audits are to be performed on the frequency identified in appendix A to this 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 data quality objectives for a site

over a season or year may be cause for recalculating a data transformation, but by itself

would not be cause for invalidating the data.

Data transformations must be applied prospectively, i.e., in real-time or near realtime, to the data output from the PM2.5 continuous method. See reference 7 of this appendix.

2.4.3 The monitoring agency wishing to

use the method must develop and implement

appropriate procedures for assessing and reporting the precision and accuracy of the

method comparable to the procedures set

forth in appendix A of this part for designated reference 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 with the following exceptions:

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Pt. 58, App. C

2.4.4.1 Collocation of ARM with FRM/FEM

samplers must be maintained at a minimum

of 30 percent of the required SLAMS sites

with a minimum of 1 per network;

2.4.4.2 All collocated FRM/FEM samplers

must maintain a sample frequency of at

least 1 in 6 sample days;

2.4.4.3 Collocated FRM/FEM samplers

shall be 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

2.4.4.4 Data from collocated FRM/FEM are

to be substituted for any calendar quarter

that an ARM method has incomplete data.

2.4.4.5 Collocation with an ARM under

this part for purposes of determining the coefficient of variation of the method shall be

conducted at a minimum of 7.5 percent of the

sites with a minimum of 1 per network. This

is consistent with the requirements in appendix A to this part for one-half of the required collocation of FRM/FEM (15 percent)

to be collocated with the same method.

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

A to this part.

2.4.5 Request for approval of a candidate

ARM, that is not already approved in another agency's network under this section,

must meet the general submittal requirements of section 2.7 of this appendix. Requests for approval under this section when

an ARM is already approved in another agency's network are to be submitted to the EPA

Regional Administrator. Requests for approval under section 2.4 of this appendix

must include the following 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 of the

nature or character of the site and the particulate matter that is expected to occur

there.

2.4.5.2 A detailed description of the method and the nature of the sampler or analyzer

upon which it is based.

2.4.5.3 A brief statement of the reason or

rationale for requesting the approval.

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

method.

2.4.5.5 A detailed description of the procedures for assessing the precision and accuracy of the method that will 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 of this appendix.

2.4.5.7 Such further supplemental information as may be necessary or helpful to

support the required statements and test results.

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

2.4.6 Within 120 days after receiving a request for approval of the use of an ARM at a

particular site or network of sites under section 2.4 of this appendix, the Administrator

will approve or disapprove the method by

letter to the person or agency requesting

such approval. When appropriate for methods

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 assist with the decision.

2.5 [Reserved]

2.6 Use of Methods With Higher, Nonconforming Ranges in Certain Geographical

Areas.

2.6.1 [Reserved]

2.6.2 An analyzer may be used (indefinitely) on a range which extends to concentrations higher than two times the upper

limit specified in table B-1 of part 53 of this

chapter if:

2.6.2.1 The analyzer has more 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 is likely to occur in

concentrations more than two times the

upper range limit specified in table B-1 of

part 53 of this chapter in the geographical

area in which use of the analyzer 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 and description of

the geographical area in which use of the 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-i

of part 53 of this chapter in the geographical

area in which use of the analyzer is proposed;

and

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Environmental Protection Agency

2.6.3.5 Test data or other information

demonstrating the resolution of each proposed range that is broader than that permitted by section 2.5 of this appendix.

2.6.4 Any person who has obtained approval of a 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 the request.

2.7 Requests for Approval; Withdrawal of

Approval.

2.7.1 Requests for approval under sections

2.4, 2.6.2, or 2.8 of this appendix must be submitted to: Director, National Exposure Research Laboratory (MD-D205-03), U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711. For ARM

that are already approved in another agency's network, subsequent requests for approval under section 2.4 are to be submitted

to the applicable EPA Regional Administrator.

2.7.2 Except as provided in section 2.7.3 of

this appendix, each request must contain:

2.7.2.1 A statement identifying the ana- lyzer (e.g., by serial number) and the method

of which the analyzer is representative (e.g.,

by manufacturer and model number); and

2.7.2.2 Test data, records, calculations,

and test results for the analyzer (or the

method of which the analyzer is representative) as specified in subpart B, subpart C, or

both (as applicable) of part 53 of this chapter.

2.7.3 A request may concern more than one analyzer or geographical area and may

incorporate by reference any data or other

information known to EPA from one or more of the following:

2.7.3.1 An application for a reference or equivalent method determination submitted

to EPA for the method of which the analyzer

is representative, or testing conducted by

the applicant or by EPA in connection with

such an application;

2.7.3.2 Testing of the method of which the

analyzer is representative at the initiative of

the Administrator under §53.7 of this chapter; or 2.7.3.3 A previous or concurrent request

for approval submitted to EPA under this

section (2.7).

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

need not 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

his judgment for a decision on the request.

2.7.6 If the Administrator determines, on the basis of any available information, that

any of the determinations or statements on

Pt. 58, App. C

which approval of a request under this sec- tion was based are invalid or no longer valid, or that the requirements of section 2.4, 2.5, or 2.6, as applicable, have not been met, he/

she may withdraw the approval after affording the person who obtained the approval an

opportunity to submit information and arguments opposing such action.

2.8 Modifications of Methods by Users.

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 has been modified in a manner that could significantly alter the performance characteristics of the method without

prior approval by the Administrator. For

purposes of this section, "alternative method" means an analyzer, the use of which has

been approved under section 2.4, 2.5, or 2.6 of

this appendix or some combination thereof.

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 of this 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, of the desired modification;

2.8.3.2 A brief statement of the purpose(s)

of the modification, including any reasons for considering it necessary or advantageous;

2.8.3.3 A brief statement of belief con- cerning the extent to which the modification

will or may affect the performance characteristics of the method; and

2.8.3.4 Such further information as may

be necessary to explain and support the

statements required by sections 2.8.3.2 and

2.8.3.3.

2.8.4 The Administrator will approve or

disapprove the modification by letter to the

person or agency requesting such approval

within 75 days after receiving a request for

approval under this section and any further

information that the applicant may be asked

to provide.

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 or is 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 of this appendix, the temporarily modified method

shall be repaired in accordance with the applicable operation manual as quickly as practicable but in no event later than 4

months after the temporary modification

was made, unless an extension of time is

granted by the Administrator. Unless and

until the temporary modification is approved, air quality data obtained with the

method as temporarily modified must be

277
Pt. 58, App. C

clearly identified as such when submitted in

accordance with §58.16 and must be accompanied by a report containing the information specified in section 2.8.3 of this appendix. A request that the Administrator approve a temporary modification may be submitted in accordance with sections 2.8.1

through 2.8.4 of this 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

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 of the major components and

many trace constituents of the particulate

matter that impair visibility in Federal

Class I Areas. Descriptions of the IMPROVE

samplers and the data they collect are available in references 4, 5, and 6 of this appendix.

2.10 Use of Pb-PMo at SLAMS Sites.

2.10.1 The EPA Regional Administrator

may approve the use of a Pb-PMao FRM or

Pb-PM1o FEM sampler in lieu of a Pb-TSP

sampler as part of the network plan required

under part 58.10(a)(4) in the following cases.

2.10.1.1 Pb-PM1o samplers can be approved

for use at the non-source-oriented sites required under paragraph 4.5(b) of Appendix 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-PMo) at the site was

equal to or greater than 0.10 micrograms per

cubic meter during the previous 3 years.

2.10.1.2 Pb-PMo samplers can be approved

for use at source-oriented sites required

under paragraph 4.5(a) if the monitoring

agency can demonstrate (through modeling

or historic monitoring data from the last 3

years) that Pb concentrations (either PbTSP or Pb-PMo) will not equal or exceed 0.10

micrograms per cubic meter on an arithmetic 3-month mean and the source is expected to emit a substantial majority of its

Pb in the fraction of PM with an aerodynamic diameter of less than or equal to 10

micrometers.

2.10.2 The approval of a Pb-PMo sampler

in lieu of a Pb-TSP sampler as allowed for in

paragraph 2.10.1 above will be revoked if

measured Pb-PM, 0 concentrations equal or

exceed 0.10 micrograms per cubic meter on

an arithmetic 3-month mean. Monitoring

agencies will have up to 6 months from the

end of the 3-month period in which the arithmetic 3-month Pb-PM0 mean concentration

equaled or exceeded 0.10 micrograms per

cubic meter to install and begin operation of

a Pb-TSP sampler at the site.

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

3.0 NCORE AMBIENT AIR MONITORING

STATIONS

3.1 Methods employed in NCore multipollutant sites used to measure S02, CO,

NO 2, 03, PM2.

5, or PM1o-2.5 must be reference

or equivalent methods as defined in §50.1 of

this chapter, or an ARM as defined in section

2.4 of this appendix, for any monitors intended for comparison with applicable

NAAQS.

3.2 If alternative S0 2, CO, NO 2, 03, PM2.5, or PMIo-25 monitoring methodologies are

proposed for monitors not intended for

NAAQS comparison, such techniques must

be detailed in the network description required by §58.10 and subsequently approved

by the Administrator. Examples of locations

that are not intended to be compared to the

NAAQS may be rural background and transport sites or areas where the concentration

of the pollutant is so low that it would be

more useful to operate a higher sensitivity

method that is not an FRM or FEM.

4.0 PHOTOCHEMICAL ASSESSMENT MONITORING

STATIONS (PAMS)

4.1 Methods used for 03 monitoring at

PAMS must be automated reference or

equivalent methods as defined in §50.1 of this

chapter.

4.2 Methods used for NO, NO 2 and NOx

monitoring at PAMS should be automated

reference or equivalent methods as defined

for NO2 in § 50.1 of this chapter. If alternative

NO, NO 2 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 of this 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 the Administrator.

5.0 PARTICULATE MATTER EPISODE

MONITORING

5.1 For short-term measurements of PMo

during air pollution episodes (see §51.152 of

this chapter) the measurement method must

be:

5.1.1 Either the "Staggered PMao" method

or the "PMo Sampling Over Short Sampling

Times" method, both of which are based on

the reference method for PMso and are described in reference 1: or 5.1.2 Any other method for measuring

PM,0: 5.1.2.1 Which has a measurement range or

ranges appropriate to accurately measure air

pollution episode concentration of PMo,

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Environmental Protection Agency

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

and

5.1.2.3 For which a quantitative relationship to a reference or equivalent method for

PMso has been established at the use site.

Procedures for establishing a quantitative

site-specific relationship are contained in

reference 1.

5.2 PM1o methods other than the reference

method are not covered under the quality as- sessment requirements of appendix to this

part. Therefore, States must develop and implement their own quality assessment procedures for those methods allowed under this

section 4. These quality assessment procedures should be similar or analogous to those

described in section 3 of appendix A to this

part for the PM1o reference method.

6.0 REFERENCES

1. Pelton, D. J. Guideline for Particulate

Episode Monitoring Methods, GEOMET

Technologies, Inc., Rockville, MD. Prepared

for U.S. Environmental Protection Agency,

Research Triangle Park, NC. EPA Contract

No. 68-02-3584. EPA 450/4-83-005. February

1983.

2. Technical Assistance Document For

Sampling and Analysis of Ozone Precursors.

Atmospheric Research and Exposure Assessment Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC

27711. EPA 600/8-91-215. October 1991.

3. Quality Assurance 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.

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 of data 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 of the 81st Annual

Meeting of the Air Pollution Control Association, Dallas, Paper 88-54.3, 1988.

7. Data Quality Objectives (DQOs) for Relating Federal Reference Method (FRM) and

Continuous PM2.5 Measurements to Report an Air Quality Index (AQI). Office of Air

Quality Planning and Standards, U.S. EnviPt. 58, App. D

ronmental Protection Agency, Research Triangle Park, NC 27711. EPA 454/B-02-2002. November 2002.

[71 FR 61313, Oct. 17, 2006, as amended at 73

FR 67061, Nov. 12, 2008; 75 FR 6534, Feb. 9,

2010]

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

QUALITY MONITORING

1. Monitoring Objectives and Spatial Scales

2. General Monitoring Requirements

3. Design Criteria for NCore Sites

4. Pollutant-Specific Design Criteria for

SLAMS Sites

5. Design Criteria for Photochemical Assessment Monitoring Stations (PAMS)

6. References

1. MONITORING OBJECTIVES AND SPATIAL

SCALES

The purpose of this appendix is to 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, PMio mass sites, PM2.

5 mass sites, chemically-speciated PM2.5 sites,

and 03 precursor measurements sites

(PAMS). These criteria will be used by EPA

in evaluating the adequacy of the air pollutant monitoring networks.

1.1 Monitoring Objectives. The ambient

air monitoring networks must be designed to

meet three basic monitoring objectives.

These basic objectives are listed below. The

appearance of any one objective in the order

of this list is not based upon a prioritized

scheme. Each objective is important and

must be 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

of weather 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 can be used in the development

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,

279
Pt. 58, App. D

source-oriented monitoring data can provide

insight into how well industrial sources are

controlling their pollutant emissions.

(c) Support for air pollution research studies. Air pollution data from the NCore network can be used to supplement data collected by researchers working on health effects assessments and atmospheric 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 of types of

monitoring sites. Monitoring sites must be

capable of informing managers about many

things including the peak air pollution levels, typical levels in populated areas, air pollution transported into and outside of a city

or region, and air pollution levels near specific sources. To summarize some of these

sites, here is a listing of six general site

types:

(a) Sites located to determine the highest

concentrations expected to occur in the area

covered by the network.

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

(c) Sites located to determine the impact

of significant sources or source categories on

air quality.

(d) Sites located to determine general

background concentration levels.

(e) Sites located to determine the extent of

regional pollutant transport among populated areas; and in support of secondary

standards.

(f) Sites located to measure air pollution

impacts on visibility, vegetation damage, or 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 re- quirements provide. The optimum size of a particular network involves trade-offs

among data needs and available resources. This regulation intends to provide for na- tional air monitoring needs, and to lend support for the flexibility necessary to meet

data collection needs of area air quality

managers. The EPA, State, and local agencies will periodically collaborate on network

design issues through the network assess- ment process 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 of physical characteristics which most closely match a specific

monitoring objective. The criteria for more specifically locating the monitoring site, including spacing from roadways and vertical

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

and horizontal probe and path placement,

are described in appendix E to this part.

1.2 Spatial Scales. (a) To clarify the nature of the link between general monitoring

objectives, site types, and the physical location of a particular monitor, the concept of

spatial scale of representativeness is defined.

The goal in locating monitors is to correctly

match the spatial scale represented by the

sample of monitored air with the spatial

scale most appropriate for the monitoring

site type, air pollutant to be measured, and

the monitoring objective.

(b) Thus, spatial scale of representative- ness is described in terms of the physical dimensions of the air parcel nearest to a monitoring site throughout which actual pollutant concentrations are reasonably similar.

The scales of representativeness of most interest for the monitoring site types described above are as follows:

(1) Microscale-Defines the concentrations

in air volumes associated with area dimensions ranging from several meters up to

about 100 meters.

(2) Middle scale-Defines the concentration

typical of areas up to several city blocks in

size with dimensions ranging from about 100

meters to 0.5 kilometer.

(3) Neighborhood scale-Defines concentrations within some extended area of the city

that has relatively uniform land use with dimensions in the 0.5 to 4.0 kilometers range.

The neighborhood and urban scales listed

below have the potential to overlap in applications that concern secondarily formed or

homogeneously distributed air pollutants.

(4) Urban scale-Defines concentrations

within an area of city-like dimensions, on

the order of 4 to 50 kilometers. Within a city,

the geographic placement of sources may result in there being no single site that can be

said to represent air quality on an urban

scale.

(5) Regional scale-Defines usually a rural

area of reasonably homogeneous geography

without large sources, and extends from tens

to hundreds of kilometers.

(6) National and global scales-These measurement scales represent concentrations

characterizing the nation and the globe as a

whole.

(c) Proper siting of a monitor requires

specification of the monitoring objective,

the types 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 of a 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

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Environmental Protection Agency

scale of measurement. In this example, physical location was determined by considering ozone precursor emission patterns, public ac- tivity, and meteorological characteristics affecting ozone formation and dispersion.

Thus, spatial scale of representativeness was not used in the selection process but was a result of site location.

(d) In some cases, the physical location of a site is determined from joint consideration

of both the basic monitoring objective and

the type of monitoring site desired, or re- quired by this appendix. For example, to determine PM2.

5 concentrations which are typical over a geographic area having relatively

high PM2 .

5 concentrations, a neighborhood

scale site is more appropriate. Such a site

would likely be located in a residential or commercial area having a high overall PM2 _5 emission density but not in the immediate

vicinity of any single dominant source. Note

that in this example, the desired scale of representativeness 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 of representativeness 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 that type of site.

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

OF REPRESENTATIVENESS

Site type Appropriate siting scales

1. Highest concentration .... Micro, middle, neighborhood

(sometimes urban or regional

tor secondarily tormed pollutants).

2. Population oriented.Neighborhood, urban.

3. Source impact ............... Micro, middle, neighborhood.

4. General/background & Urban, regional. regional transport. 5. Weltare-related impacts Urban, regione.

2. GENERAL MONITORING REQUIREMENTS

(a) The National ambient air monitoring

system includes several types of monitoring stations, each targeting a key data collection need and each varying in technical so- phistication.

(b) Research grade sites are platforms for

scientific studies, either involved with

health or welfare impacts, measurement

methods development, or other atmospheric

studies. These sites may be collaborative efforts between regulatory agencies and rePt. 58, App. D

searchers 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 re- quired by regulation; however, they are included here due to their important role in

supporting the air quality management program.

(c) The NCore multipollutant sites are sites that measure multiple pollutants in

order to provide support to integrated air

quality management data needs. NCore sites

include both neighborhood and urban scale

measurements in general, in a selection of

metropolitan areas and a limited number of more rural locations. Continuous monitoring

methods are to be used at the NCore sites

when available for a pollutant to be meas- ured, as it is important to have data collected over common time periods for integrated analyses. NCore multipollutant sites are intended to be long-term sites useful for a variety of applications including air quality trends analyses, model evaluation, and

tracking metropolitan area statistics. As

such, the NCore sites should be placed away

from direct emission sources that could substantially impact the ability to detect area- wide. concentrations. The Administrator

must approve the NCore sites.

(d) Monitoring sites designated as SLAMS

sites, but not as NCore sites, are intended to

address specific air quality management interests, and as such, are frequently singlepollutant measurement sites. The EPA Regional Administrator must approve the

SLAMS sites.

(e) This appendix uses the statistical-based

definitions for metropolitan areas provided

by the Office of Management and Budget and

the Census Bureau. These areas are referred

to as metropolitan statistical areas (MSA),

micropolitan statistical areas, core-based

statistical areas (CBSA), and combined statistical areas (CSA). A CBSA associated with

at least one urbanized area of 50,000 population or greater is termed a Metropolitan

Statistical Area (MSA). A CBSA associated

with at least one urbanized cluster of at

least 10,000 population or greater is termed a Micropolitan Statistical Area. CSA consist

of two or more adjacent CBSA. In this appendix, the term MSA is used to refer to a Metropolitan Statistical Area. By definition,

both MSA and CSA have a high degree of integration; however, many such areas cross State or other political boundaries. MSA and

CSA may also cross more than one air shed.

The EPA recognizes that State or local agencies must consider MSA/CSA boundaries and

their own political boundaries and geographical characteristics in designing their

air monitoring networks. The EPA recognizes that there may be situations where the

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Pt. 58, App. D

EPA Regional Administrator and the affected State or local agencies may need to

augment or to divide the overall MSA/CSA

monitoring responsibilities and requirements among these various agencies to

achieve an effective network design. Full

monitoring requirements apply separately to

each affected State or local agency in the absence of an agreement between the affected

agencies and the EPA Regional Administrator.

3. DESIGN CRITERIA FOR NCORE SITES

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

one NCore site. States may delegate this requirement to a local agency. States with

many MSAs often also have multiple air

sheds with unique characteristics and, often,

elevated air pollution. These States include,

at a minimum, California, Florida, Illinois,

Michigan, New York, North Carolina, Ohio,

Pennsylvania, and Texas. These States are

required to identify one to two additional

NCore sites in order to account for their

unique situations. These additional sites

shall be located to avoid proximity to large

emission sources. Any State or local agency

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. Site leveraging includes using the

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, PM2.

5 particle mass using continuous and integrated/filter-based samplers,

speciated PM2.

5 , PM1o.2.5 particle mass, speciated PM1o-2.

5 , 03, SO 2

, CO, NOINOy, wind

speed, wind direction, relative humidity, and

ambient temperature. NCore sites in CBSA

with a population of 500,000 people (as determined in the latest Census) or greater shall

also measure Pb either as Pb-TSP or PbPM1

o. The EPA Regional Administrator may

approve an alternative location for the Pb

measurement where the alternative location

would be more appropriate for logistical reasons and the measurement would provide

data on typical Pb concentrations in the

CBSA.

(1) Although the measurement of NO5 is required in support of a number of monitoring

objectives, available commercial instruments may indicate little difference in their

measurement of NO, compared to the con- ventional measurement of NOx, particularly

in areas with relatively fresh sources of nitrogen emissions. Therefore, in areas with

negligible expected difference between NO,

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

and NOx measured concentrations, the Administrator may allow for waivers that permit NOx monitoring to be substituted for the

required NO, monitoring at applicable NCore

sites.

(2) EPA recognizes that, in some cases, the

physical location of the NCore site may not

be suitable for representative meteorological

measurements due to the site's physical surroundings. It is also possible that nearby me- teorological measurements may be able to

fulfill this data need. In these cases, the requirement for meteorological monitoring can be waived by the Administrator.

(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 of NCore

measurements that are explicitly designed

for other monitoring objectives are exempt

from these siting criteria (e.g., a near-roadway site).

(1) Urban NCore stations are to be generally located at urban or neighborhood

scale to provide representative concentrations of exposure expected throughout the

metropolitan area; however, a middle-scale

site may be acceptable in cases where the

site can represent many such locations

throughout a metropolitan area.

(2) Rural NCore stations are to be located

to the maximum extent practicable at a regional or larger scale away from any large

local emission source, so that they represent

ambient concentrations over an extensive

area.

4. POLLUTANT-SPECIFIc 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 (in terms of population

and geographic characteristics) and typical

peak concentrations (expressed in percentages below, or near the 03 NAAQS). Specific

SLAMS 03 site minimum requirements are

included in Table D-2 of this appendix. The

NCore sites are expected to complement the

03 data collection that takes place at singlepollutant SLAMS sites, and both types of

sites can be used to meet the network minimum requirements. The total number of 03

sites needed to support the basic monitoring

objectives of public data reporting, air quality mapping, compliance, and understanding

0 3

-related atmospheric processes will include

more sites than these minimum numbers required in Table D-2 of this appendix. The

EPA Regional Administrator and the responsible 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.

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Environmental Protection Agency

TABLE D-2 OF APPENDIX D TO PART 58-

SLAMS MINIMUM 03 MONITORING REQUIREMENTS

Most recent 3- Most recent 3-

year design value year design value

MSA population'. 2 concentrations concentrations

>85% of any 03 <85% of any 03

NAAOS3 NAAOS3 4

>10 million ............. 4 2

4-10 million ........... 3 1

350,00Qc4 million 2 1

50,000-<350,000 5 1 0

1 Minimum monitoring requirements apply to the Metropoli- tan statistical area (MSA). 2POpulation based on latest available census figures. 3

The ozone (03) National Ambient Air Quality Standards

(NAAOS) levels and forms are defined in 40 CFR part 50. 4 These minimum monitoring requirements apply in the ab- sence of a design value.

sMetropolitan statistical areas (MSA) must contain an ur- banized area of 50,000 or more 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 necessary in some areas. Table D-2 of this appendix does not ac- count for the full breadth of additional factors that would be considered in designing a complete 03 monitoring program for an area. Some of these additional factors include geographic size, population density, complexity

of terrain and meteorology, adjacent 03 mon- itoring 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 designed to account for all of

these area characteristics. Network designs

must be re-examined in periodic network as- sessments. Deviations from the above 03 re- quirements are allowed if approved by the

EPA Regional Administrator.

(c) The appropriate spatial scales for 03

sites are neighborhood, urban, and regional.

Since 03 requires appreciable formation

time, the mixing of reactants and products occurs over large volumes of air, and this re- duces the importance of monitoring small

scale spatial variability.

(1) Neighborhood scale-Measurements in

this category represent conditions throughout some reasonably homogeneous urban

sub-region, with dimensions of a few kilometers. Homogeneity refers to pollutant con- centrations. Neighborhood scale data will

provide valuable information for developing,

testing, and revising concepts and models

that describe urban/regional concentration

patterns. These data will be useful to the un- derstanding 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 experiPt. 58, App. D

ence peak concentration levels within a metropolitan area. (2) Urban scale-Measurement in this scale

will be used to estimate concentrations over large portions of an urban area with dimensions of several kilometers to 50 or more kilometers. Such measurements will be used for

determining trends, and designing area-wide

control strategies. The urban scale sites

would also be used to measure high con- centrations downwind of the area having the

highest precursor emissions.

(3) Regional scale-This scale of measure- ment will be used to typify concentrations over large portions of a metropolitan area and even larger areas with dimensions of as much as hundreds of kilometers. Such meas- urements will be useful for assessing the 03

that is transported to and from a metropolitan area, as well as background concentrations. In some situations, particularly when

considering very large metropolitan areas with complex source mixtures, regional scale

sites can be the maximum concentration location.

(d) EPA's technical guidance documents on

03 monitoring network design should be used

to evaluate the adequacy of each existing 03

monitor, to relocate an existing site, or to

locate any 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 se- lected which is also removed from the influ- ence of major NOx sources. For an urban

scale site to measure the high concentration

areas, the emission inventories should be

used to define the extent 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, an evaluation of wind and emission

patterns on high 03 days, can also be useful

in evaluating an 03 monitoring network. In areas without any previous 03 air quality

measurements, meteorological and 03 pre- cursor emissions information would be use- ful.

(f) Once the meteorological and air quality data are reviewed, the prospective maximum

concentration monitor site should be se- lected in a direction from the city that is

most likely to observe the highest 03 con- centrations, more specifically, downwind

during periods of photochemical activity. In

many cases, these maximum concentration

03 sites will be located 10 to 30 miles or 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 days which show

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Pt. 58, App. D

the potential for producing high 03 levels.

Monitoring agencies are to consult with

their EPA Regional Office when considering

siting a maximum 03 concentration site.

(g) In locating a neighborhood scale site

which is to measure high concentrations, the

same procedures used for the urban scale are

followed except that the site should be located closer to the areas bordering on the

center city or slightly further downwind in

an area of high density population.

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

as for the maximum concentration sites may

also inform the decisions for locating regional scale sites. Regional scale sites may

be located to provide data on 03 transport

between cities, as background sites, or for

other data collection purposes. Consideration of both area characteristics, such as

meteorology, and the data collection objectives, such as transport, must be jointly considered for a regional scale site to be useful.

(i) Since 03 levels decrease significantly in

the colder parts of the year in many areas,

03 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 of this appendix. Deviations from

the 03 monitoring season must be approved

by the EPA Regional Administrator, documented within the annual monitoring network plan, and updated in AQS. Information

on how to analyze 03 data to support a

change to the 03 season in support of the 8-

hour standard for a specific State can be

found in reference 8 to this appendix.

TABLE D-3 TO APPENDIX D OF PART 58-

OZONE MONITORING SEASON BY STATE

State I Begin month End month

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

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

Arkansas ......................... Califom ia .........................

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

Connecticut ..................... Delaware .........................

District of Columbia.

Florida ............................. Georgia ...........................

Hawaii ............................. Idaho ...............................

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

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

Iowa ................................ Kansas ............................

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

Louisiana AQCR 019,022

Louisiana AQCR 106.

Maine .............................. Maryland ......................... Massachusetts ................

Michigan ......................... Minnesota .......................

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

March .............. April .................

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

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

January ........... March ..............

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

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

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

March .............. January ...........

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

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

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

April ................. March ..............

March .........

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

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

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

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

April ................. March ..............

October

October

December

November

December

September

September

October

October

October

October

December

September

Octoiber

September

October

October

October

October

December

September

October

September

September

October

October

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

TABLE D-3 TO APPENDIX D OF PART 58-

OZONE MONITORING SEASON BY STATEContinued

State Begin month End month

M issouri .......................... April ................. October

Montana .......................... June ................ September

Nebraska ............ Aprl......... October

Nevada ........................... January ........... December

New Hampshire .............. April ................. September

New Jersey ..................... April ................. October

New Mexico .................... January ........... December

New York ........................ April ................. October

North Carolina ................ April ................. October

North Dakota .................. May ................. September

O hio ................................ April ................. O ctober

Oklahoma ....................... March .............. November

Oregon ............................ May ................. September

Pennsylvania .......... April ................. October

Puerto Rico ..................... January ........... December

Rhode Island .................. April ................. September

South Carolina ................ April ................. October

South Dakota .................. June ................ September

Tennessee ...................... March .............. October

Texas AOCR 106,153, January ........... December

213, 214, 216.

Texas AQCR 022, 210, March .............. October

211, 212, 215, 217,

218.

Utah ................................ M ay ................. Septem ber

Vermont .......................... April ................. Septem ber

Virginia ............................ April ................. October

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

W est Virginia .................. April ................. October

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

W yom ing ......................... April ................. October

American Samoa ............ January ........... December

Guam .............................. January ........... December

Virgin Islands .................. January ........... December

4.2 Carbon Monoxide (CO) Design Criteria

4.2.1 General Requirements. (a) Except as provided in subsection (b), one CO monitor is

required to operate collocated with one required near-road NO2 monitor, as required in

Section 4.3.2 of this part, in CBSAs having a

population of 1,000,000 or more persons. If a

CBSA has more than one required near-road

NO2 monitor, only one CO monitor is required to be collocated with a near-road NO2 monitor within that 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 of this part but is not a

near-road NO 2 monitoring site, then the EPA

Regional Administrator may approve a request by a state to use such an alternate

near-road location for a CO monitor 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 re- quire additional CO monitors above the minimum number of monitors required in 4.2.1 of

this part, where the minimum monitoring

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Environmental Protection Agency

requirements are not sufficient to meet mon- itorihg objectives. The Regional Administrator may require, at his/her discretion, additional monitors in situations where data or other information suggest that CO con- centrations may be approaching or exceeding

the NAAQS. Such situations include, but are not limited to, (1) characterizing impacts on ground-level concentrations due to stationary CO sources, (2) characterizing CO

concentrations in downtown areas or urban

street canyons, and (3) characterizing CO

concentrations in areas that are subject to

high ground level CO concentrations particularly due to or enhanced by topographical

and meteorological impacts. The Regional

Administrator and the respongible State or local air monitoring agency shall work together to design and maintain the most appropriate CO network to address the data

needs for an area, and include all monitors

under this provision in the annual monitoring 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 major roadways and intersections

with high traffic density and often in areas with poor atmospheric ventilation.

(1) Microscale-Microscale measurements

typically represent areas in close proximity

to major roadways, within street canyons, over sidewalks, and in some cases, point and area sources. Emissions on roadways result

in high ground level CO concentrations at

the microscale, where concentration gradients generally exhibit a marked decrease

with increasing downwind distance from

major roads, or within downtown areas including urban street canyons. Emissions

from stationary point and area sources, and

non-road sources may, under certain plume

conditions, result in high ground level con- centrations at the microscale.

(2) Middle scale-Middle scale measure- ments are intended to represent areas with

dimensions from 100 meters to 0.5 kilometer.

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 would include air quality along a commercially developed street or shopping

plaza, freeway corridors, parking lots and

feeder streets.

(3) Neighborhood scale-Neighborhood scale

measurements are intended to represent areas with dimensions from 0.5 kilometers to

4 kilometers. Measurements of CO in this

category would represent conditions

throughout some reasonably urban sub-regions. In some cases, neighborhood scale

data may represent not only the immediate

neighborhood spatial area, but also other

Pt. 58, App. D

similar such areas across the larger urban area. Neighborhood scale measurements provide relative area-wide concentration data

which are useful for providing relative urban

background concentrations, supporting

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 NO2 monitoring sites as described

below.

4.3.2 Requirement for Near-road NO2 Monitors

(a) Within the NO2 network, there must be one microscale near-road NO 2 monitoring

station in each CBSA with a population of

500,000 or more persons to monitor a location

of expected 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 2 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 or more 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, con- sidering fleet mix, roadway design, congestion patterns, terrain, and meteorology,

where maximum hourly NO 2 concentrations are expected to occur and siting criteria can be met in accordance with appendix E of this

part. Where a State or local air monitoring

agency identifies multiple acceptable can- didate sites where maximum hourly NO2 con- centrations are expected to occur, 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 of the following factors: fleet mix; con- gestion patterns; terrain; geographic area within the CBSA; or different route, interstate, or freeway designation.

(b) Measurements at required near-road

NO2 monitor sites utilizing

chemiluminescence FRMs must include at a minimum: NO, NO2 , and NOx.

4.3.3 Requirement for Area-wide NO2 Monitoring

(a) Within the NO 2 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

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Pt. 58, App. D

concentrations representing the neighborhood or larger spatial scales. PAMS sites collecting NO 2 data that are situated in an area of expected high NO2 concentrations at the

neighborhood or larger spatial scale may be

used to satisfy this minimum monitoring requirement when the NO2 monitor is operated

year round. Emission inventories and meteorological analysis should be used to identify

the appropriate locations within a CBSA for

locating required area-wide NO2 monitoring

stations. CBSA populations shall be based on

the latest available census figures.

4.3.4 Regional Administrator Required

Monitoring

(a) The Regional Administrators, in collaboration with States, must require a minimum of forty additional NO2 monitoring

stations nationwide in any area, inside or

outside of CBSAs, above the minimum monitoring requirements, with a primary 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

of CBSAs in which:

(i) The required near-road monitors do not

represent all locations of expected maximum

hourly NO2 concentrations in an area and

NO2 concentrations may be approaching or

exceeding the NAAQS in that area;

(ii) Areas that are not required to have a

monitor in accordance with the monitoring

requirements and NO2 concentrations may be

approaching or exceeding the NAAQS; or (iii) The. minimum monitoring requirements for area-wide monitors are not sufficient to meet monitoring objectives.

(c) The Regional Administrator and the re- sponsible State or local air monitoring agency should work together to design and/or

maintain the most appropriate NO2 network

to address the data needs for an area, and include all monitors under this provision in

the annual monitoring network plan.

4.3.5 NO 2 Monitoring Spatial Scales

(a) The most important spatial scale for

near-road NO2 monitoring stations to effectively characterize the maximum expected

hourly NO2 concentration due to mobile source emissions on major roadways is the

microscale. The most important spatial

scales for other monitoring stations characterizing maximum expected hourly NO 2 con- centrations are the microscale and middle

scale. The most important spatial scale for

area-wide monitoring of high NO2 concentrations is the neighborhood 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 NO2 con40 CFR Ch. 1 (7-1-12 Edition)

centrations at the microscale, where concentration gradients generally exhibit a

marked decrease with increasing downwind

distance from major roads. As noted in appendix E of this part, near-road NO2 monitoring stations are required to be within 50

meters of target road segments in order to

measure expected peak concentrations.

Emissions from stationary point and area

sources, and non-road sources may, under

certain plume conditions, result in high

ground level concentrations at the

microscale. The microscale typically represents an area impacted by the plume with

dimensions extending up to approximately

100 meters.

(2) Middle scale-This scale generally represents air quality levels in areas up to sev- eral city blocks in size with dimensions on

the order of approximately 100 meters to 500

meters. The middle scale may include locations of expected maximum hourly con- centrations due to proximity to major NO2

point, area, and/or non-road sources.

(3) Neighborhood scale-The neighborhood

scale represents air quality conditions

throughout 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 NO2 concentrations at the neighborhood scale. Where

a neighborhood site is located away from immediate NO2 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) Urban scale-Measurements in this scale

would be used to estimate concentrations

over large portions of an 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 NO2 monitoring network identified in

paragraph 4.3.4 above.

4.3.6 NO Monitoring

(a) NO/NO2 measurements are included

within the NCore multi-pollutant site re- quirements and the PAMS program. These

NO/NO measurements will produce conservative estimates for NO 2 that can be used to

ensure tracking continued compliance with

the NO2 NAAQS. NO/NO monitors are used

at these sites because it is important to collect data on total reactive nitrogen species

for understanding 03 photochemistry.

4.4 Sulfur Dioxide (SO 2) Design Criteria.

4.4.1 General Requirements. (a) State and,

where appropriate, local agencies must operate a minimum number of required SO2 monitoring sites as described below.

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Environmental Protection Agency

4.4.2 Requirement for Monitoring by the Population Weighted Emissions Index. (a) The population weighted emissions index (PWEI)

shall be calculated by States for each core based statistical area (CBSA) they contain or share with another State or States for use in the implementation of or adjustment to

the SO2 monitoring network. The PWEI shall

be calculated by multiplying the population

of each CBSA, using the most current census data or estimates, and the total amount of

SO 2 in tons per year emitted within the

CBSA area, using an aggregate of the most

recent county level emissions data available

in the National Emissions Inventory for each

county in each CBSA. The resulting product

shall be divided by one million, providing a PWEI value, the units of which are million

persons-tons per year. For any CBSA with a calculated PWEI value equal to or greater

than 1,000,000, a minimum of three SO2 mon- itors are required within that CBSA. For any

CBSA with a calculated PWEI value equal to or greater than 100,000, but less than

1,000,000, a minimum of two SO2 monitors are required within that CBSA. For any CBSA

with a calculated PWEI value equal to or greater than 5,000, but less than 100,000, a minimum of one SO2 monitor is required

within that CBSA.

(1) The SO 2 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 of the parent 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. SO 2 monitors at NCore stations may satisfy minimum monitoring requirements if that mon- itor is located within a CBSA with minimally required monitors under this part.

Any monitor that is sited outside of a CBSA

with minimum monitoring requirements to assess the highest concentration resulting

from the impact of significant sources or source categories existing within that CBSA

shall be allowed to count towards minimum

monitoring requirements for that CBSA.

4.4.3 Regional Administrator Required Monitoring. (a) The Regional Administrator may

require additional SO2 monitoring stations

above the minimum number of monitors re- quired in 4.4.2 of this part, where the minimum monitoring requirements are not sufficient to meet monitoring objectives. The Regional Administrator may require, at his/her

discretion, additional monitors in situations

where an area has the potential to have con- centrations that may violate or contribute

to the violation of the NAAQS, in areas impacted by sources which are not conducive to

modeling, or in locations with susceptible

and vulnerable populations, which are not

monitored under the minimum monitoring

provisions described above. The Regional AdPt. 58, App. D

ministrator and the responsible State or local air monitoring agency shall work together to design and/or maintain the most

appropriate SO2 network to provide sufficient data to meet monitoring objectives.

4.4.4 SO2 Monitoring Spatial Scales. (a) The

appropriate spatial scales for SO2 SLAMS

monitors are the microscale, middle, neighborhood, and urban scales. Monitors sited at

the microscale, middle, and neighborhood

scales are suitable for determining max- imum hourly concentrations for SO2. Monitors sited at urban scales are useful for

identifying SO2 transport, trends, and, if

sited upwind of local sources, background

concentrations.

(1) Microscale-This scale would typify areas in close proximity to SO2 point and area sources. Emissions from stationary

point and.area sources, and non-road sources may, under certain plume conditions, result

in high ground level concentrations at the

microscale. The microscale typically represents an area impacted by the plume with

dimensions extending up to approximately

100 meters.

(2) Middle scale-This scale generally represents air quality levels in areas up to sev- eral city blocks in size with dimensions on the order of approximately 100 meters to 500

meters. The middle scale may include locations of expected maximum short-term con- centrations due to proximity to major SO2 point, area, and/or non-road sources.

(3) Neighborhood scale-The neighborhood

scale would characterize air quality conditions throughout some relatively uniform

land use areas with dimensions in the 0.5 to

4.0 kilometer range. Emissions from stationary point and area sources may, under

certain plume conditions, result in high SO2 concentrations at the neighborhood scale.

Where a neighborhood site is located away

from immediate SO 2 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) Urban scale-Measurements in this scale

would be used to estimate concentrations over large portions of an 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 SO2 monitoring network such as identifying trends, and when monitors are sited

upwind of local sources, background con- centrations.

4.4.5 NCore Monitoring. (a) SO2 measurements are included within the NCore multipollutant site requirements as described in

paragraph (3)(b) of this appendix. NCorebased SO2 measurements are primarily used

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Pt. 58, App. D

to characterize SO2 trends and assist in understanding SO2 transport across representative areas in urban or rural locations and are

also used for comparison with the SO2 NAAQS. SO 2 monitors at NCore sites that

exist in CBSAs with minimum monitoring

requirements per section 4.4.2 above shall be

allowed to count towards those minimum

monitoring requirements.

4.5 Lead (Pb) Design Criteria. (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 max- imum Pb concentration in ambient air in excess of the NAAQS, taking into account the

logistics and potential for population exposure. At a minimum, there must be one

source-oriented SLAMS site located to measure 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/chief/

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 must be sited, taking

into account logistics and the potential for

population exposure, where the Pb con- centration from all sources combined is expected to be at its maximum.

(ii) The Regional Administrator may waive

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 max- imum Pb concentration in ambient air in excess of 50 percent of the NAAQS (based on

historical monitoring data, modeling, or

other means). The waiver must be renewed

once every 5 years as part of the network assessment required under § 58.10(d).

(iii) State and, where appropriate, local

agencies are required to conduct ambient air

Pb monitoring near each of the airports listed in Table D-3A for a period of 12 consecu- tive months commencing no later than December 27, 2011. Monitors shall be sited to measure the maximum Pb concentration in

ambient air, taking into account logistics

and the potential for population exposure,

and shall use an approved Pb-TSP Federal

Reference Method or Federal Equivalent

Method. Any monitor that exceeds 50 percent

of the Pb NAAQS on a rolling 3-month aver- age (as determined according to 40 CFR part

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

50, Appendix R) shall become a required mon- itor under paragraph 4.5(c) of this Appendix,

and shall continue to monitor for Pb unless

a waiver is granted allowing it to stop operating as allowed by the provisions in paragraph 4.5(a)(ii) of this appendix. Data collected shall be submitted to the Air Quality

System database according to the requirements of 40 CFR part 58.16.

TABLE D-3A AIRPORTS To BE MONITORED FOR

LEAD

Airport County State

Merrill Field ........................................ Anchorage AK

Pryor Field Regional .......................... Limestone ..... AL

Palo Alto Airport ot Santa Clara Santa Clara CA

County.

McClellan-Palomar S..............Sn Diego CA

Reid-Hillview ...................................... Santa Clara CA

Gillespie Field .................................... San Diego ..... CA

San Carlos ......................................... San Mateo CA

Nantucket Memorial .......................... Nantucket MA

Oakland County International ............ Oakland. MI

Republic ............................................. Suffolk ........... NY

Brookhaven ....................................... Suffolk ........... NY

Stinson Municipal .... Bexar ............ TX

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

Harvey Field ...................................... Snohomish W A

Auburn Municipal King........WA King............... 

(b) State and, where appropriate, local

agencies are required to conduct 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 of Pb air quality violations is

significant or where the emissions density,

topography, or population locations are complex and varied. EPA Regional Administrators may require additional monitoring at

locations including, but not limited to, those

near existing additional industrial sources of

Pb, recently closed industrial sources of Pb,

airports where piston-engine aircraft emit

Pb, and other sources of re-entrained Pb

dust.

(d) The most important spatial scales for

source-oriented sites to effectively characterize the emissions from point sources are

microscale and middle scale. The most important spatial scale for non-source-oriented

sites to characterize typical lead concentrations in urban areas is the neighborhood

scale. Monitor siting should be conducted in

accordance with 4.5(a)(i) with respect to

source-oriented sites.

(1) Microscale-This scale would typify

areas in close proximity to lead point

sources. Emissions from point sources such

as primary and secondary lead smelters, and

primary copper smelters may under fumigation conditions likewise result in high

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Environmental Protection Agency

ground level concentrations at the

microscale. In the latter case, the microscale

would represent an area impacted by the

plume with dimensions extending up to approximately 100 meters. Pb monitors in areas where the public has access, and particularly

children have access, are desirable because of

the higher sensitivity of children to expo- sures of elevated 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 of approximately 100 meters to

500 meters. The middle scale may for exam- ple, include schools and playgrounds in cen- ter city areas which are close to major Pb

point sources. Pb monitors in such areas are desirable because of the higher sensitivity of

children to exposures of elevated Pb con- centrations (reference 3 of this appendix).

Emissions from point sources frequently impact on areas at which single sites may be

located to measure concentrations 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 of this scale would

provide monitoring data in areas representing conditions where children live and

play. Monitoring in such areas is important

since this segment of the population is more

Pt. 58, App. D

susceptible to the effects of Pb. Where a neighborhood site is located away from immediate Pb sources, the site may be very

useful in representing typical air quality values for a larger residential area, and

therefore suitable for population exposure

and trends analyses.

(d) Technical guidance is found in ref- erences 4 and 5 of this appendix. These documents provide additional guidance on locating sites to meet specific urban area monitoring objectives and should be used in locating new sites or evaluating the adequacy of

existing sites.

4.6 Particulate Matter (PM0 ) Design Criteria.5(a) Table D-4 indicates the approximate number of permanent stations required

in MSAs to characterize national and re- gional PMio air quality trends and geographical patterns. The number of PMso stations in areas where MSA populations exceed

1,000,000 must be in the range from 2 to 10

stations, while in low population urban

areas, no more than two stations are re- quired. A range of monitoring stations is

specified in Table D-4 because sources of pol- lutants and local control efforts can vary

from one part of the country to another and

therefore, some flexibility is allowed in se- lecting the actual number of stations in any one locale. Modifications from these PMo

monitoring requirements must be approved

by the Regional Administrator.

TABLE D-4 OF APPENDIX D To PART 58-PM10 MINIMUM MONITORING REQUIREMENTS

(APPROXIMATE NUMBER OF STATIONS PER MSA) 1

Population category High concentra- Medium con- Low concentra- tion 2 centration 3 tion 4,5

>1,000,000 ...................................................................................... 6-10 4-8 2-4

500,000-1,000,000 .......................................................................... 4-8 2-4 1-2

250,000-500,000 ............................................................................. 3-4 1-2 0-1

100,000-250,000 ............................................................................. 1-2 0-1 0

Selection of urban areas and actual numbers of stations per area will be jointly determined by EPA and the State agency. 2 High concentration areas are those for which ambient PM10 data show ambient concentrations exceeding the PM, 0 NAAOS by 20 percent or more. 3Medium concentration areas are those for which ambient PM10 data show ambient concentrations exceeding 80 percent of the 4 PMo NAAQS. Low concentration areas are those for which ambient PM10 data show ambient concentrations less than 80 percent of the PMo NAAQS. 5

These minimum monitoring requirements apply in the absence of a design value.

(b) Although microscale monitoring may

be appropriate in some circumstances, the

most important spatial scales to effectively

characterize the emissions of PMc from both

mobile and stationary sources are the middle

scales and neighborhood scales.

(1) Microscale-This scale would typify areas sdch as downtown street canyons, traffic corridors, and fence line stationary source monitoring locations where the general public could be exposed to maximum

PM1o concentrations. Microscale particulate

matter sites 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 sec- ondary smelters, power plants, and other

large industrial processes may, under certain

plume conditions, likewise result in high

ground level concentrations at the

microscale. In the latter case, the microscale

would represent an area impacted by the

plume with dimensions extending up to approximately 100 meters. Data collected at

microscale sites provide information for

evaluating and developing hot spot control measures.

(2) Middle scale-Much of the short-term

public exposure to coarse fraction particles

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

(PM0 ) is on this scale and on the neighborhood scale. People moving through downtown areas or living near major roadways or

stationary sources, may encounter particulate pollution that would be adequately

characterized by measurements of this spatial scale. Middle scale PMio measurements

can be appropriate for the evaluation of possible short-term exposure public health effects. In many situations, monitoring sites

that are representative of micro-scale or

middle-scale impacts are not unique and are

representative of many similar situations.

This can occur along traffic corridors or

other locations in a residential district. In

this case, one location is representative of a

neighborhood of small scale sites and is appropriate for evaluation of long-term or chronic effects. This scale also includes the

characteristic concentrations for other areas with dimensions of a few hundred meters

such as the parking lot and feeder streets as- sociated with shopping centers, stadia, and

office buildings. In the case of PMo, unpaved

or seldomly swept parking lots associated

with these sources could be an important

source in addition to the vehicular emissions

themselves.

(3) Neighborhood scale-Measurements in

this category represent conditions throughout some reasonably homogeneous urban

sub-region with dimensions of a few kilometers and of generally more regular shape

than the middle scale. Homogeneity refers to

the particulate matter concentrations, as well as the land use and land surface characteristics. In some cases, a location carefully

chosen to provide neighborhood scale data

would represent not only the immediate

neighborhood but also neighborhoods of the

same type in other parts of the city. Neighborhood scale PMo sites provide information

about trends and compliance with standards

because they often represent conditions in areas where people commonly live and work

for extended periods. Neighborhood scale

data could provide valuable information for

developing, testing, and revising 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 compari- sons within or between cities.

4.7 Fine Particulate Matter (PM2.

5) Design

Criteria.

4.7.1 General Requirements. (a) State, and

where applicable local, agencies must operate the minimum number of required PM2.

5 SLAMS sites listed in Table D-5 of this appendix. The NCore sites are expected to com- plement the PM2.

5 data collection that takes

place at non-NCore SLAMS sites, and both

types of sites can be used to meet the minimum PM2.

5 network requirements. Deviations from these PM2.

5 monitoring requirements must be approved by the EPA Regional Administrator.

TABLE D-5 OF APPENDIX D TO PART 58-PM2 .

5

MINIMUM MONITORING REQUIREMENTS

Most recent 3-

MSA population 1,2 year design value

85% of any PM2., NAAQSS

>1,000,000 ............. 3

500,000-1,000,000 2

50,000<500,0006 1

Most recent 3-

year design value

<85% of any

PM2.

5 NAAQS 3

2

1

0

1 Minimum monitoring requirements apply to the Metropoli- tan 2 statistical area (MSA). Population based on latest available census figures. 3The PM2.

5 National Ambient Air Quality Standards

(NAAOS) levels and forms are defined in 40 CFR part 50. 4

These minimum monitoring requirements apply in the ab- sence of a design value. 5 Metropolitan statistical areas (MSA) must contain an ur- banized area of 50,000 or more population.

(b) Specific Design Criteria for PM25. The

required monitoring stations or sites must

be sited to represent community-wide air

quality. These sites can include sites collocated at PAMS. These monitoring stations

will typically be at neighborhood or rbanscale; however, in certain instances where

population-oriented micro-or middle-scale

PM2.

5 monitoring are determined by the Regional Administrator to represent many

such locations throughout a metropolitan

area, these smaller scales can be considered

to represent community-wide air quality.

(1) At least one monitoring station is to be

sited in a population-oriented area of expected maximum concentration.

(2) For areas with more than one required

SLAMS, a monitoring station is to be sited

in an area of poor air quality.

(3) Additional technical guidance for siting

PM25 monitors is provided in references 6

and 7 of this appendix.

(c) The most important spatial scale to effectively characterize the emissions of particulate matter from both mobile and stationary sources is the neighborhood scale for

PM2.

5. For purposes of establishing monitoring sites to represent large homogenous

areas other than the above scales of representativeness and to characterize regional

transport, urban or regional scale sites

would also be needed. Most PM2 5 monitoring

in urban areas should be representative of a

neighborhood scale.

(1) Microscale-This scale would typify

areas such as downtown street canyons and

traffic corridors where the general public

would be exposed to maximum concentrations from mobile sources. In some circumstances, the microscale is appropriate

for particulate sites; community-oriented

SLAMS sites measured at the microscale

level should, however, be limited to urban

sites that are representative of long-term

human exposure and of many such microenvironments in the area. In general,

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Environmental Protection Agency

microscale particulate matter sites should

be located near inhabited buildings or locations where the general public can be ex- pected to be exposed to the concentration

measured. Emissions from stationary sources such as primary and secondary

smelters, power plants, and other large industrial processes may, under certain plume

conditions, likewise result in high ground

level concentrations at the microscale. In

the latter case, the microscale would represent an area impacted by the plume with

dimensions extending up to approximately

100 meters. Data collected at microscale

sites provide information for evaluating and

developing hot spot control measures. Unless

these sites are indicative of population-oriented monitoring, they may be more appropriately classified as SPM.

(2) Middle scale-People moving through

downtown areas, or living near major roadways, encounter particle concentrations that

would be adequately characterized by this

spatial scale. Thus, measurements of this

type would be appropriate for the evaluation

of possible short-term exposure public health

effects of particulate matter pollution. In

many situations, monitoring sites that are representative of microscale or middle-scale

impacts are not unique and are representative of many similar situations. This can occur along traffic corridors or other locations in a residential district. In this case, one location is representative of a number of

small scale sites and is appropriate for evaluation of long-term or chronic effects. This

scale also includes the characteristic con- centrations for other areas with dimensions

of a few hundred meters such as the parking

lot and feeder streets associated with shopping centers, stadia, and office buildings.

(3) Neighborhood scale-Measurements in

this category would represent conditions

throughout some reasonably homogeneous

urban sub-region with dimensions of a few

kilometers and of generally more regular

shape than the middle scale. Homogeneity

refers to the particulate matter concentrations, as well as the. land use and land sur- face characteristics. Much of the PM2.

5 expo- sures are expected to be associated with this

scale of measurement. 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.

PM2 5 sites of this kind provide good information about trends and compliance with

standards because they often represent con- ditions in areas where people commonly live

and work for periods comparable to those

specified in the NAAQS. In general, most

PM2

.5 monitoring in urban areas should have

this scale.

(4) Urban scale-This class of measurement

would be used to characterize the particulate

matter concentration over an entire metroPt. 58, App. D

politan or rural area ranging in size from 4

to 50 kilometers. Such measurements would

be useful for assessing trends in area-wide

air quality, and hence, the effectiveness of

large scale air pollution control strategies.

Community-oriented PM2.5 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 measure- ments would be most applicable to sparsely

populated areas. Data characteristics of this

scale would provide information about larger

scale processes of particulate matter emissions, losses and transport. PM2.

5 transport

contributes to elevated particulate con- centrations and may affect multiple urban

and State entities with large populations

such as in the eastern United States. Development of effective pollution control strategies requires an understanding at regional

geographical scales of the emission sources and atmospheric processes that are responsible for elevated PM2.5 levels and may also

be associated with elevated 03 and regional

haze.

4.7.2 Requirement for Continuous PM2.5 Monitoring. The State, or where appropriate,

local agencies must operate continuous PM2.5 analyzers equal to at least one-half (round

up) the minimum required sites listed in

Table D-5 of this appendix. At least one re- quired continuous analyzer in each MSA

must be collocated with one of the required

FRM/FEM/ARM monitors, unless at least one of the required FRM/FEM/ARM monitors

is itself a continuous FEM or ARM monitor

in which case no collocation requirement applies. State and local air monitoring agencies must use methodologies and quality as- surance/quality control (QA/QC) procedures

approved by the EPA Regional Administrator for these required continuous ana- lyzers.

4.7.3 Requirement for PM2 .5 Background

and Transport Sites. Each State shall install

and operate at least one PM2.5 site to mon- itor for regional background and at least one

PM2.5 site to monitor regional transport.

These monitoring sites may be at commu- nity-oriented sites and this requirement may

be satisfied by 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 may include non-federal reference

method samplers such as IMPROVE or con- tinuous PM2.

5 monitors.

4.7.4 PM2.

5 Chemical Speciation Site Requirements. Each State shall continue to

conduct chemical speciation monitoring and

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Pt. 58, App. D

analyses at sites designated to be part of the

PM2.5 Speciation Trends Network (STN). The

selection and modification of these STN

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 methods and the sampling schedules approved by the Administrator. Chemical. speciation is encouraged at additional

sites where the chemically resolved data

would be useful in developing State implementation plans and supporting atmospheric

or health effects related studies.

4.7.5 Special Network Considerations Required When Using PM2.5 Spatial Averaging

Approaches. (a) The PM2.5 NAAQS, specified

in 40 CFR part 50, provides State and local

air monitoring agencies with an option for

spatially averaging PM2

.5 air quality data.

More specifically, two or more communityoriented (i.e., sites in populated areas) PM2.5

monitors may be averaged for comparison

with the annual PM2.

5 NAAQS. This averaging approach is directly related to epidemiological studies used as the basis for the

PM2

.

5 annual NAAQS. Spatial averaging does

not apply to comparisons with the daily

PM2.

5 NAAQS.

(b) State and local agencies must carefully

consider their approach for PM2

.5 network

design when they intend to spatially average

the data for compliance purposes. These

State and local air monitoring agencies must

define the area over which they intend to average PM2.

5 air quality concentrations. This

area is defined as a Community Monitoring

Zone (CMZ), which characterizes an area of

relatively similar annual average air quality. State and local agencies can define a

CMZ in a number of ways, including as part

or all of a metropolitan area. These CMZ

must be defined within a State or local agencies network description, as required in

§58.10 of this part and approved by the EPA

Regional Administrator. When more than

one CMZ is described within an agency's network design plan, CMZs must not overlap in

their geographical coverage. The criteria

that must be used for evaluating the acceptability of spatial averaging are defined in appendix N to 40 CFR part 50.

4.8 Coarse Particulate Matter (PMio-2.5 )

Design Criteria.

4.8.1 General Monitoring Requirements.

(a) The only required monitors for PM1o-2.5 are those required at NCore Stations.

(b) Although microscale monitoring may

be appropriate in some circumstances, middle and neighborhood scale measurements are the most important station classifications for PM1 -2.5 to assess the variation in

coarse particle concentrations that would be

expected across populated areas that are in

proximity to large emissions sources.

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

(1) Microscale-This scale would typify relatively small areas immediately adjacent to:

Industrial sources; locations experiencing

ongoing construction, redevelopment, and

soil disturbance; and heavily traveled roadways. Data collected at microscale stations

would characterize exposure over areas of

limited spatial extent and population exposure, and may provide information useful for

evaluating and developing source-oriented

control measures.

(2) Middle scale-People living or working

near major roadways or industrial districts

encounter particle concentrations that

would be adequately characterized by this

spatial scale. Thus, measurements of this

type would be appropriate for the evaluation

of public health effects of coarse 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 of resuspended road dust. This scale

also includes the characteristic concentrations for other areas with dimensions of a

few hundred meters such as school grounds

and parks that are nearly adjacent to major

roadways and industrial point sources, locations exhibiting mixed residential and commercial development, and downtown areas

featuring office buildings, shopping centers,

and stadiums.

(3) Neighborhood scale-Measurements in

this category would represent conditions

throughout some reasonably homogeneous

urban sub-region with dimensions of a few

kilometers and of generally more regular

shape than the middle scale. Homogeneity

refers to the particulate matter concentrations, as well as the land use and land surface characteristics. This category includes

suburban neighborhoods dominated by residences that are somewhat distant from

major roadways and industrial districts but

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 as well as neighborhoods of the

same type in other parts of the city. The

comparison of data from middle scale and

neighborhood scale sites would provide valuable information for determining the variation of PMI1 2.5 levels across urban areas

and assessing the spatial extent of elevated

concentrations caused by major industrial

point sources and heavily traveled roadways.

292
Environmental Protection Agency

Neighborhood scale sites would provide con- centration data that are relevant to informing a large segment of the population of

their exposure levels on a given day.

4.8.2 PMO--2 .

5 Chemical Speciation Site Requirements. PM10-2.5 chemical speciation

monitoring and analyses is required at

NCore sites. The selection and modification

of these sites must be approved by the Administrator. Samples must be collected

using the monitoring methods and the sam- pling schedules approved by the Administrator.

5. NETWORK DESIGN FOR PHOTOCHEMICAL ASSESSMENT MONITORING STATIONS (PAMS)

The PAMS program provides more com- prehensive data on 03 air pollution in areas classified as serious, severe, or extreme non- attainment for 03 than would otherwise be

achieved through the NCore and SLAMS

sites. More specifically, the PAMS program

includes measurements for 03, oxides of nitrogen, VOC, and meteorology.

5.1 PAMS Monitoring Objectives. PAMS

design criteria are site specific. Concurrent

measurements of 03, oxides of nitrogen, speciated VOC, CO, and meteorology are obtained at PAMS sites. Design criteria for the

PAMS network are based on locations relative to 03 precursor source areas and predominant wind directions associated with

high 03 events. Specific monitoring objectives are associated with each location. The

overall design should enable characterization of precursor emission sources within the

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 of nitrogen, VOC species,

and determining spatial and diurnal variability of 0, oxides of nitrogen, and VOC species. Specific monitoring objectives associated with each of these sites may result in

four distinct site types. Detailed guidance

Pt. 58, App. D

for the locating of these sites may be found

in reference 9 of this appendix.

(a) Type 1 sites are established to characterize upwind background and transported 03

and its precursor concentrations entering

the area and will identify those areas which are subjected to transport.

(b) Type 2 sites are established to monitor

the magnitude and type of precursor emissions in the area where maximum precursor

emissions are expected to impact and are suited for the monitoring of urban air toxic

pollutants.

(c) Type 3 sites are intended to monitor

maximum 03 concentrations occurring downwind from the area of maximum precursor

emissions.

(d) Type 4 sites are established to characterize the downwind transported 03 and its

precursor concentrations exiting the area and will identify those areas which are potentially contributing to overwhelming

transport in other areas.

5.2 Monitoring Period. PAMS precursor

monitoring must be conducted annually

throughout the months of June, July and

August (as a minimum) when peak 03 values are expected in each area. Alternate pre- cursor monitoring periods may be submitted

for approval to the Administrator as a part

of the annual monitoring network plan re- quired by §58.10.

5.3 Minimum Monitoring Network Requirements. A Type 2 site is required for

each area. Overall, only two sites are re- quired for each area, providing all chemical

measurements are made. For example, if a design includes two Type 2 sites, then a third

site will be necessary to capture the NOy measurement. The minimum required num- ber and type of monitoring sites and sam- pling requirements are listed in Table D-6 of

this appendix. Any alternative plans may be

put in place in lieu of these requirements, if

approved by the Administrator.

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

FREQUENCIES

Measurement Where required Sampling frequency (all daily except for upper air

meteorology) 1

Speciated VOC2. Two sites per area, one of which must be a Type During the PAMS monitoring period: (1) Hourly 2 site, auto GO, or (2) Eight 3-hour canisters, or (3) 1

morning and 1 aftemnoon canister with a 3-hour

or less averaging time plus Continuous Total

Non-methane Hydrocarbon measurement.

Carbonyl sampling Type 2 site in areas classified as serious or above 3-hour samples every day during the PAMS monitor the 8-hour ozone standard. toring period. NOx .............. All Type 2 sites ......................... Hourly during the ozone monitoring season. 3

NO ........................... One site per ares at the Type 3 or Type 1 site Hourly during the ozone monitoring season. CO (ppb level). One site per ares at a Type 2 site ............. Hourly durng the ozone monitoring season. Ozone ............. All sites ............................... Hourly during the ozone monitoring season. Surface met ......... All sites ....................................................... Hourly during the ozone monitoring season.

Upper air meteorology One representative location within PAMS area Sampling frequency must be approved as part of

the annual monitoring network plan required in

40 CFR 58.10.

Daily or with an approved alternative plan.

293
2

Speciated VOC is defined in the "Technical Assistance Document for Sampling and Analysis of Ozone Precursors", EPA/

600-R-98/161, September 1998. 3

Approved ozone monitoring season as stipulated in Table D-3 of this appendix.

5.4 Transition Period. A transition period

is allowed for phasing in the operation of

newly required PAMS programs (due generally to reclassification of an area into serious, severe, or extreme nonattainment for

ozone). Following the date of redesignation

or reclassification of any existing 03 nonattainment area to serious, severe, or extreme, or the designation of a new area and

classification to serious, severe, or extreme

03 nonattainment, a State is allowed 1 year

to develop plans for its PAMS implementation strategy. Subsequently, a minimum of

one Type 2 site must be operating by the

first month of the following approved PAMS

season. Operation of the remaining site(s)

must, at a minimum, be phased in at the

rate of one site per year during subsequent

years as outlined in the approved PAMS network description provided by the State.

6. REFERENCES

1. Ball, R.J. and G.E. Anderson. Optimum

Site Exposure Criteria for S0 2 Monitoring.

The Center for the Environment and Man,

Inc., Hartford, CT. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Publication No. EPA450/3-77-013. April 1977.

2. Ludwig, F.F., J.H.S. Kealoha, and E.

Shelar. Selecting Sites for Carbon Monoxide

Monitoring. Stanford Research Institute,

Menlo Park, CA. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Publication No. EPA450/3-75--077, 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.)

4. Optimum Site Exposure Criteria for

Lead Monitoring. PEDCo Environmental,

Inc. Cincinnati, OH. Prepared for U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Contract No. 68-02-3013.

May 1981.

5. Guidance for Conducting Ambient Air

Monitoring for Lead Around Point Sources.

Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA-454/R92-009. May 1997.

6. Koch, R.C. and H.E. Rector. Optimum

Network Design and Site Exposure Criteria

for Particulate Matter. GEOMET Technologies, Inc., Rockville, MD. Prepared for

U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Contract No.

68-02-3584. EPA 450/4-87-009. May 1987.

7. Watson et al. Guidance for Network Design and Optimum Site Exposure for PM2. 5

and PM1o. 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.

EPA-454/R-98-001, June 1998.

9. Photochemical Assessment Monitoring

Stations Implementation Manual. Office of

Air Quality Planning and Standards, U.S.

Environmental Protection Agency, Research

Triangle Park, NC. EPA-454/B-9051. March

1994.

[71 FR 61316, Oct. 17, 2006, as amended at 72

FR 32211, June 12, 2007; 73 FR 67062, Nov. 12,

2008; 75 FR 6534, Feb. 9, 2010; 75 FR 35602,

June 22, 2010; 75 FR 81137, Dec. 27, 2010; 76 FR

54342, Aug. 31, 2011]

APPENDIX E TO PART 58-PROBE AND

MONITORING PATH SITING CRITERIA

FOR AMBIENT AIR QUALITY MONITORING

1. Introduction.

2. Horizontal and Vertical Placement.

3. Spacing from Minor Sources.

4. Spacing From Obstructions.

5. Spacing From Trees.

6. Spacing From Roadways.

7. Cumulative Interferences on a Monitoring

Path.

8. Maximum Monitoring Path Length.

9. Probe Material and Pollutant Sample Residence Time.

10. Waiver Provisions.

11. Summary.

12. References.

1. INTRODUCTION

(a) This appendix contains specific location

criteria applicable to SLAMS, NCore, and

PAMS ambient air quality monitoring

probes, inlets, and optical paths after the

general location has been selected based on

the monitoring objectives and spatial scale

of representation discussed in appendix D to

this part. Adherence to these siting criteria

is necessary to ensure the uniform collection

of compatible and comparable air quality

data.

(b) The probe and monitoring path siting

criteria discussed in this appendix must be

followed to the maximum extent possible. It

is recognized that there may be situations

where some deviation from the siting criteria may be necessary. In any such case, the reasons must be thoroughly documented in a

294

Pt. 58, App. E 40 CFR Ch. I (7-1-12 Edition)
Environmental Protection Agency

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 EPA would

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 not requirements.

2. HORIZONTAL AND VERTICAL PLACEMENT

The probe or at least 80 percent of the

monitoring path must be located between 2

and 15 meters above ground level for all 03

and 802 monitoring sites, and for neighborhood or larger spatial scale Pb, PM1o,

PM1 o-2.

5 , PM2.

5 , NO2 , and CO sites. Middle

scale PM1O-2.

5 sites are required to have sam- pler inlets between 2 and 7 meters above

ground level. Microscale Pb, PMo, PM,0 -2-5 , and PM2

.

5 sites are required to have sampler

inlets between 2 and 7 meters above ground

level. Microscale near-road NO 2 monitoring

sites are required to have sampler inlets between 2 and 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 3.5 meters above ground level. The probe or at least 90 percent of the monitoring path

must be at least 1 meter vertically or horizontally away from any supporting structure, walls, parapets, penthouses, etc., and

away from dusty, or dirty areas. If the probe or a significant portion of the monitoring

path is located near the side of a building or wall, then it should be located on the windward side of the building relative to the prevailing wind direction during the season of

highest concentration potential for the pollutant being measured.

3. SPACING FROM MINOR SOURCES

(a) It is important to understand the monitoring objective for a particular location in

order to interpret this particular requirement. Local minor sources of a primary pollutant, such as S02, lead, or particles, can cause high concentrations of that particular

pollutant at a monitoring site. If the objective for that monitoring site is to invesPt. 58, App. E

tigate these local primary pollutant emissions, then the site is likely to be properly

located nearby. This type of monitoring site

would in all likelihood be a microscale type

of monitoring 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 an unpaved area un- less there is vegetative ground cover year

round, so that the impact of wind blown

dusts will be kept to a minimum.

(b) Similarly, local sources of nitric oxide

(NO) and ozone-reactive hydrocarbons can have a scavenging effect causing

unrepresentatively low concentrations of 03

in the vicinity of probes and monitoring

paths for 03. To minimize these potential

interferences, the probe or at least 90 percent

of the monitoring path must be away from

furnace or incineration flues or other minor sources of S02 or NO. The separation distance should take into account the heights

of the flues, type of waste or fuel burned, and

the sulfur content of the fuel.

4. SPACING FROM OBSTRUCTIONs

(a) Buildings and other obstacles may possibly scavenge S02, 03, or NO2 , and can act to

restrict airflow for any pollutant. To avoid

this interference, the probe, inlet, or at least

90 percent of the monitoring path must have

unrestricted airflow and be located away

from obstacles. The distance from the obstacle to the probe, inlet, or monitoring path

must be at least twice the height that the

obstacle protrudes above the probe, inlet, or monitoring path. An exception to this re- quirement can be made for measurements

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 along a vertical wall is undesirable because air moving along the wall

may be subject to possible removal mechanisms. A probe, inlet, or monitoring path

must have unrestricted airflow in an arc of

at least 180 degrees. This are must include

the predominant wind direction for the sea- son of greatest pollutant concentration potential. For particle sampling, a minimum of

2 meters of separation from walls, parapets,

and structures is required for rooftop site

placement.

(c) Special consideration must be given to

the use of open path analyzers due to their

inherent potential sensitivity to certain

types of interferences, or optical obstructions. A monitoring path must be clear of all

trees, brush, buildings, plumes, dust, or

295
Pt. 58, App. E

other optical obstructions, including potential obstructions that may move due to

wind, human activity, growth of vegetation,

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 of the open path

analyzer to continuously measure pollutant

concentrations. Transient, but significant

obscuration of especially longer measurement paths could occur as a result of certain

meteorological conditions (e.g., heavy fog,

rain, snow) and/or aerosol levels that are of

a sufficient density to prevent the open path

analyzer's light transmission. 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 of the resulting data record in reflecting maximum pollutant concentrations

may be substantially impaired despite the

fact that the site may otherwise exhibit an

acceptable, even exceedingly high overall

valid data capture rate.

(d) For near-road NO 2 monitoring stations,

the monitor probe shall have an unobstructed air flow, where no obstacles exist at

or above the height of the monitor probe, between the monitor probe and the outside

nearest edge of the traffic lanes of the target

road segment.

5. SPACING FROM TREES

(a) Trees can provide surfaces for SO2 , 03, or NO2 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 of a sufficient height and leaf canopy density to interfere with the normal airflow around the probe, inlet, or monitoring

path. To reduce this possible interference/obstruction, the probe, inlet, or at least 90 percent of the monitoring path must be at least

10 meters or further from the drip line of

trees.

(b) The scavenging effect of trees is greater

for 03 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 of any air pollutant, no trees or shrubs should be located between the probe and the source under investigation, such as a roadway or a stationary source.

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

6. SPACING FROM ROADWAYS

6.1 Spacing for Ozone Probes and Monitoring Paths

In siting an 03 analyzer, it is important to

minimize destructive interferences form

sources of NO, since NO readily reacts with

03. Table E-1 of this appendix provides the

required minimum separation distances between a roadway and a probe or, where applicable, at least 90 percent of a monitoring

path for various ranges of daily roadway

traffic. A sampling site having a point analyzer probe located closer to a roadway than

allowed by the Table E-1 requirements

should be classified as microscale or middle

scale, rather than neighborhood or urban

scale, since the measurements from such a

site would more 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 of potential atmospheric interference from automobile emissions. Therefore, this calculation must include the length of the monitoring path over

the roadway plus any segments of the monitoring path that lie in the area between the

roadway and minimum separation distance,

as determined from the Table E-1 of this appendix. The sum of these distances must not

be greater than 10 percent of the total monitoring path 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 on the pollution exposure on the adjacent area.

(b) Microscale CO monitor inlets probes in

downtown areas or urban street canyon locations shall be located a minimum distance of

2 meters and a maximum distance of 10 meters from the edge of the nearest traffic lane.

(c) Microscale CO monitor inlet probes in

downtown areas or urban street canyon locations shall be 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.

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Environmental Protection Agency

TABLE E-2 TO APPENDIX E OF PART 58-MINIMUM SEPARATION DISTANCE BETWEEN ROADWAYS AND PROBES OR MONITORING PATHS

FOR MONITORING NEIGHBORHOOD SCALE

CARBON MONOXIDE

Roadway average daily traffic, vehicles per Minimum dis- day tance1

I (me- day ters)

10,000 ................................................... ....... 10

15,000 .................................................... . ...... 25

20,000 .................................................... . ...... 45

30,000 .................................................... . ...... 80

40,000 ............................................................ 115

50,000 ............................................................ 135

60,000 .......................................................... 150

' Distance from the edge of the nearest traffic lane. The distance for intermediate traffic counts should be interpolated from the table values based on the actual traffic count.

6.3 Spacing for Particulate Matter (PM2.5,

PM.o, Pb) Inlets. (a) Since emissions associated with the operation of motor vehicles

contribute to urban area particulate matter

ambient levels, spacing from roadway criteria are necessary for ensuring national

consistency in PM sampler siting.

(b) The intent is to locate localized hotspot sites in areas of highest concentrations

whether it be from mobile or multiple stationary sources. If the area is primarily affected by mobile sources and the maximum

concentration area(s) is judged to be a traffic

corridor or street canyon location, then the

monitors should be located near roadways

with the highest traffic volume and at separation distances most likely to produce the

highest concentrations. For the microscale

traffic corridor site, the location must be between 5 and 15 meters from the major roadway. For the microscale street canyon site

the location must be between 2 and 10 meters

from the roadway. For the middle scale site, a range of acceptable distances from the

roadway is shown in figure E-1 of this appendix. This figure also includes separation distances between a roadway and neighborhood or larger scale sites by default. Any site, 2 to

15 meters high, and further back than the

middle scale requirements will generally be

neighborhood, urban or regional scale. For

example, according to Figure E-1 of this appendix, if a PM sampler is primarily influenced by roadway emissions and that samPt. 58, App. E

pler is set back 10 meters from a 30,000 ADT

(average daily traffic) road, the site should

be classified as microscale, if the sampler

height is between 2 and 7 meters. If the sam- pler height is between 7 and 15 meters, the

site should be classified as middle scale. If

the sample is 20 meters from the same road,

it will be classified as middle scale; if 40 me- ters, neighborhood scale; and if 110 meters, an urban scale.

6.4 Spacing for Nitrogen Dioxide (NO 2)

Probes and Monitoring Paths.

(a) In siting near-road NO2 monitors as re- quired in paragraph 4.3.2 of appendix D of

this part, the monitor probe shall be as near as practicable to the outside nearest edge of

the traffic lanes of the target road segment;

but shall not be located at a distance greater

than 50 meters, in the horizontal, from the

outside nearest edge of the traffic lanes of

the target road segment.

(b) In siting NO2 monitors for neighborhood and larger scale monitoring, it is important to minimize near-road influences.

Table E-1 of this appendix provides the re- quired minimum separation distances between a roadway and a probe or, where applicable, at least 90 percent of a monitoring

path for various ranges of daily roadway

traffic. A sampling site having a point ana- lyzer probe located closer to a roadway than

allowed by the Table E-1 requirements

should be classified as microscale or middle

scale rather than neighborhood or urban

scale. 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 ve- hicles per day, monitoring agencies must

consider the entire segment of the monitoring path in the area of potential atmospheric interference form automobile emissions. Therefore, this calculation must include the length of the monitoring path over the roadway plus any segments of the monitoring path that lie in the area between the

roadway and minimum separation distance, as determined form the Table E--1 of this appendix. The sum of these distances must not

be greater than 10 percent of the total monitoring path length.

297
40 CFR Ch. 1 (7-1-12 Edition)

.80-

S60~! S

40.

Q

H 2o0 20 40 60 80 100 120 140 160

Figure E-1. Distance of PM samplers to nearest traffic lane (meters)

7. CUMULATIVE INTERFERENCES ON A

MONITORING PATH

(This paragraph applies only to open path

analyzers.) The cumulative length or portion

of a monitoring path that is affected by

minor sources, trees, or roadways must not

exceed 10 percent of the total monitoring

path length.

8. MAXIMUM MONITORING PATH LENGTH

(This paragraph applies only to open path

analyzers.) The monitoring path length must

not exceed 1 kilometer for - analyzers in

neighborhood, urban, or regional scale. For

middle scale monitoring sites, the monitoring path length must not exceed 300 meters. In areas subject to frequent periods of

dust, fog, rain, or snow, consideration should

be given to a shortened monitoring path

length to minimize loss of monitoring data

due to these temporary optical obstructions.

For certain ambient air monitoring sce- narios using open path analyzers, shorter

path lengths may be needed in order to en- sure that the monitoring site meets the objectives and spatial scales defined in appendix D to this part. The Regional Administrator may require shorter path lengths, as

needed on an individual basis, to ensure that

the SLAMS sites meet the appendix D re- quirements. Likewise, the Administrator

may specify the maximum path length used

at NCore monitoring sites.

9. PROBE MATERIAL AND POLLUTANT SAMPLE

RESIDENCE TIME

(a) For the reactive gases, SO2 , NO2, and

03, special probe material must be used for

point analyzers. Studies 20-24 have been conducted to determine the suitability of materials such as polypropylene, polyethylene,

polyvinyl chloride, Tygon®, aluminum,

brass, stainless steel, copper, Pyrex® glass

and Teflon® for use as intake sampling lines.

Of the above materials, only Pyrex® glass

and Teflon® have been found to be acceptable

for use as intake sampling lines for all the

reactive gaseous pollutants. Furthermore,

the EPA25 has specified borosilicate glass or

FEP Teflon® as the only acceptable probe

materials for delivering test atmospheres in

the determination of reference or equivalent

methods. Therefore, borosilicate glass, FEP

Teflon® or their equivalent must be the only

material in the sampling train (from inlet

probe to the back of the analyzer) that can

be in contact with the ambient air sample

for existing and new SLAMs.

(b) For volatile organic compound (VOC)

monitoring at PAMS, FEP Teflon® is unacceptable as the probe material because of

VOC adsorption and desorption reactions on

the FEP Teflon®. Borosilicate glass, stainless steel, or its equivalent are the acceptable probe materials for VOC and carbonyl

sampling. Care must be taken to ensure that

the sample residence time is kept to 20 seconds or less.

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Pt. 58, App. E
Environmental Protection Agency

(c) No matter how nonreactive the sampling probe material is initially, after a period of use reactive particulate matter is deposited on the probe walls. Therefore, the

time it takes the gas to transfer from the

probe inlet to the sampling device is also

critical. Ozone in the presence of nitrogen

oxide (NO) will show significant losses even

in the most inert probe material when the

residence time exceeds 20 seconds. 6 Other

studies 27 emP;2z indicate that a 10 second

or less residence time is easily achievable.

Therefore, sampling probes for reactive gas

monitors at NCore and at NO2 sites must

have a sample residence time less than 20

seconds.

10. WAIVER PROVISIONS

Most sampling probes or monitors can be

located so that they meet the requirements

of this appendix. New sites with rare exceptions, can be located within the limits of this

appendix. However, some existing sites may

not meet these requirements and still

produce useful data for some purposes. The

EPA will consider a written request from the

State agency to waive one or more siting criteria for some monitoring sites providing

that the State can adequately demonstrate

the need (purpose) for monitoring or establishing a monitoring site at that location.

10.1 For establishing a new site, a waiver

may be granted only if both of the following

criteria are met:

10.1.1 The site can be demonstrated to be as representative of the monitoring area as it would be if the siting criteria were being

met.

Pt. 58, App. E

10.1.2 The monitor or probe cannot reasonably be located so as to meet the siting

criteria because of physical constraints (e.g.,

inability to locate the required type of site

the necessary distance from roadways or obstructions).

10.2 However, for an existing site, a waiv- er may be granted if either of the criteria in

sections 10.1.1 and 10.1.2 of this 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 not be acceptable reasons for granting a waiver. Written requests for waivers must be

submitted to the Regional Administrator.

11. SUMMARY

Table H-A of this appendix presents a summary of the general requirements for probe

and monitoring path siting criteria with respect to distances and heights. It is apparent

from Table H-A 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 NO2 monitors, the gradients in the

vertical direction are very large for the

microscale, so a small range of heights are used. The upper limit of 15 meters is specified for the consistency between pollutants

and to allow the use of a single manifold or monitoring path for monitoring more than one pollutant.

TABLE E-4 OF APPENDIX E TO PART 58-SUMMARY OF PROBE AND MONITORING PATH SITING

CRITERIA

Horizontal and

Scale (max- Height from vertical distance Distance from Distance from

imum moni- ground to fsuurn trees to probe, roadways to Pollutant trinnat 8 pioa probe, inlet or inlet or 90% of probe, inlet or

length, meters)1 80% toring of path1 moni- 90% toring of path' moni- path1 monitonrng monitonrng (meters) path' (meters)

(meters)

S0 2 345e ........................................

CO 457 ............................................

Middle (300 m)

Neighborhood

Urban, and

Regional (1

km).

Micro [downtown or street

canyon sites],

micro [nearroad sites],

middle (300

m) and

Neighborhood

(1 km).

2-15 ..........1>1....... > 10 ...... N/A.

2.5-3.5; 2-7; 2-

15.

> 1 ................ I > 10 ................. 2-10 for downtown areas or

street canyon

microscale;

50 for near- road

microscale;

see Table E2 of this appendix for

middle and

neighborhood

scales.

299
Pt. 58, App. E 40 CFR Ch. I (7-1-12 Edition)

TABLE E-4 OF APPENDIX E TO PART 58-SUMMARY OF PROBE AND MONITORING PATH SITING

CRITERIA-Continued

Horizontal and

Scale (max- Height from vertical distance Distance from Distance from

imum moni- to sructures tground 2 to trees to probe, roadways to

toring path oe, inlet or probe, inlet or inlet or 90% of probe, inlet or

length, metera ) 80% of moni- monitoring monitoring toring path' toring path path I (meters) path' (meters)

(meters)

03345.......... ................ Middle (300 m) 2-15 ............... > 1.......... 10.........See Table E-1

Neighbor- of thia appenhood, Urban, dix for all

and Regional scales.

(1 km). N0 2 345...................... Micro (Near- 2-7 (micro); 2- > 1..........> 10.........50 metera for

road [50- 15 (all other near-road

300]) Middle scales). microscale;

(300m) See Table E-1

Neighbor- of thia appenhood, Urban, dix for all

and Regional other scales.

(1 km).

Ozone precursors (for PAMS) 3 4 5 Nei ghb orho od 2 - 15 ................. . . . . . . . . . 10 . . . . . . . . . See Tabl e E- 4

and Urban (1 of this appenkm). dix for all

scales.

PM, Pb3 4

56

8 ............................. Micro: Middle, 2-7 (micro); 2- > 2 (all acalea, > 10 (all acales) 2-10 (micro);

Neighbor- 7 (middle horizontal dis- aee Figure Ehood, Urban PMI0 2 ); 2- tance only). 1 of thia apand Regional. 15 (all other pendix for all

scales). other scale.

N/A-Not applicable. ' Monitoring path for open path analyzera is applicable only to middle or neighborhood acale CO monitoring, middle, neighbor. hood, urban, and regional scale NO 2 monitoring, and all applicable acales for monitoring S0 2,0 3 2 , and 03 precuraors. When probe ia located on a rooftop, thia aeparation distance ia in reference to walla, parapets, or penthouaea located on roof. 3Should be > 20 wetera from the dnip-line of tree(a) and muat be 10 metera from the drip-line when the tree(s) act as an obstruction. 4Distance from sampler, probe, or 90% of monitoring path to. obstacle, such ax a building, must be at least twice the height the obstacle protrudes above the sampler, probe, or monitoring path. Sites not meeting this criterion may be classified as middle

scale (see test). 5 Must have unrestricted airflow 270 degrees around the probe or sampler; 180 degrees if the probe is on the aide of a building or a wall.

'The probe, sampler, or monitoring path should be away from minor sources, such as fumnace or incineration flues. The sepa- ration distance is dependent on the height of the minor source's emission point (such as a flue), the type of fuel or waste burned, and the quality of the fuel (sulfur, ash, or lead content). This criterion is designed to avoid undue influences from minor sources. ' For microscale CO monitoring sites in downtown areas or street canyons (not at near-road NO2 monitoring sites), the probe must be 10 meters from a street intersection and preferably at a widblock > location.

'Collocated monitors must be within 4 meters of each other and at least 2 meters apart for flow rates greater than 200 litersl

min or at least 1 meter apart for samplers having flow rates less than 200 liters/win to preclude airflow interference.

12. REFERENCES

1. Bryan, R.J., R.J. Gordon, and H. Menck.

Comparison of High Volume Air Filter Samples at Varying Distances from Los Angeles

Freeway. University of Southern California,

School of Medicine, Los Angeles, CA. (Presented at 66th Annual Meeting of Air Pollution Control Association. Chicago, IL. June

24-28, 1973. APCA 73-158.)

2. Teer, E.H. Atmospheric Lead Concentration Above an Urban Street. Master of

Science Thesis, Washington University, St.

Louis, MO. January 1971.

3. Bradway, R.M., F.A. Record, and W.E.

Belanger. Monitoring and Modeling of Resuspended Roadway Dust Near Urban Arterials.

GCA Technology Division, Bedford, MA.

(Presented at 1978 Annual Meeting of Transportation 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. City of

Chicago, Department of Environmental 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.

300
Environmental Protection Agency

7. Rodes, C.E. and G.F. Evans. Summary of

LACS Integrated Pollutant Data. 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. et al. National Assessment of

the Urban Particulate Problem: Volume 1,

National Assessment. GCA Technology Division, Bedford, MA. U.S. Environmental Protection Agency, Research Triangle Park, NC.

EPA Publication No. EPA-450/3-75-024. June

1976.

9. Pace, T.G. Impact of Vehicle-Related

Particulates on TSP Concentrations and Rationale for Siting Hi-Vols in the Vicinity of

Roadways. OAQPS, U.S. Environmental Protection Agency, Research Triangle Park, NC.

April 1978.

10. Ludwig, F.L., J.H. Kealoha, and E.

Shelar. Selecting 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. Daines, R. H., H. Moto, and D. M.

Chilko. Atmospheric Lead: Its Relationship

to Traffic Volume and Proximity to Highways. Environ. Sci. and Technol., 4:318, 1970.

17. Johnson, D. E., et al. Epidemiologic

Study of the Effects of Automobile Traffic on Blood Lead Levels, Southwest Research

Institute, Houston, TX. Prepared for U.S.

Environmental Protection Agency, Research

Pt. 58, App. E

Triangle Park, NC. EPA-600/1-78-055, August

1978.

18. Air Quality Criteria for Lead. Office of

Research and Development, U.S. Environmental Protection Agency, Washington, DC

EPA-600/8-83-028 aF-dF, 1986, and supplements EPA-600/8-89/049F, August 1990. (NTIS

document numbers PB87-142378 and PB91-

138420.)

19. Lyman, D. R. The Atmospheric Diffusion of Carbon Monoxide and Lead from an Expressway, Ph.D. Dissertation, University

of Cincinnati, 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. ISA Transactions, 14:281-291, 1975.

24. Altshuller, A.D. and A.G. Wartburg. The

Interaction of Ozone 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 of Atmospheric Nitrogen Oxides and Ozone, Anal.

Chem., 43:1890, 1971.

27. Slowik, A.A. and E.B. Sansone. Diffusion Losses of Sulfur Dioxide in Sampling

Manifolds. J. Air. Poll. Con. Assoc., 24:245,

1974.

28. Yamada, V.M. and R.J. Charlson. Prop- er Sizing of the Sampling Inlet Line for a Continuous Air Monitoring Station. Environ.

Sci. and Technol., 3:483, 1969.

29. Koch, R.C. and H.E. Rector. Optimum

Network Design and Site Exposure Criteria

for Particulate Matter, GEOMET Technologies, Inc., Rockville, MD. Prepared for

U.S. Environmental Protection Agency, Research Triangle Park, NC. EPA Contract No.

68-02-3584. EPA 450/4-87-009. May 1987.

30. Burton, R.M. and J.C. Suggs. Philadelphia Roadway Study. Environmental Monitoring Systems Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, N.C. EPA-600/4-84-070 September

1984.

31. Technical Assistance Document For

Sampling and Analysis of Ozone Precursors.

Atmospheric Research and Exposure Assessment Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC

27711. EPA 600/8-91-215. October 1991.

32. Quality Assurance Handbook for Air

Pollution Measurement Systems: Volume IV.

Meteorological Measurements. Atmospheric

301
Pt. 58, App. G

Research and Exposure Assessment Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711. EPA

600/4-90-0003. August 1989.

33. On-Site Meteorological Program Guidance for Regulatory Modeling Applications.

Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711. EPA

450/4-87-013. June 1987F.

[71 FR 61323, Oct. 17, 2006, as amended at 75

FR 6535, Feb. 9, 2010; 76 FR 54342, Aug. 31,

2011]

APPENDIX F TO PART 58 [RESERVED]

APPENDIX G TO PART 58--UNIFORM AIR

QUALITY INDEX (AQI) AND DAILY REPORTING

GENERAL REQUIREMENTS

1. What is the AQI?

2. Why report the AQI?

3. Must I report the AQI?

4. What goes into my AQI report?

5. Is my AQI report for my MSA only?

6. How do I get my AQI report to the public?

7. How often must I report the AQI?

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. Do I have to forecast the AQI?

12. How Do I Calculate the AQI?

BACKGROUND AND REFERENCE MATERIALS

13. What Additional Information Should I

Know?

GENERAL REQUIREMENTS

1. What Is the AQI?

The AQI is a tool that simplifies reporting

air quality to the general public. The AQI incorporates into a single index concentrations

of 5 criteria pollutants: ozone (03), particulate matter (PM), carbon monoxide (CO), sulfur dioxide (SO2), and nitrogen dioxide (NO2)- The scale of the index is divided into general

categories that are associated with health

messages.

2. Why Report the AQI?

The AQI offers various advantages: a. It is simple to create and understand.

b. It conveys the health implications of air

quality.

c. It promotes uniform use throughout the

country.

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

3. Must I Report the AQI?

You must report the AQI daily if yours is a metropolitan statistical area (MSA) with a population over 350,000.

4. What Goes Into My AQI Report?

i. Your AQI report must contain the following:

a. The reporting area(s) (the MSA or subdivision of the MSA).

b. The reporting period (the day for which

the AQI is reported).

c. The critical pollutant (the pollutant

with the highest index value).

d. The AQI (the highest index value).

e. The category descriptor and index value

associated with the AQI and, 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-AQI CATEGORIES

For this AQI Use this descriptor And this color1

0 to 50 ............ "Good" ....................... Green.

51 to 100 ......... "Moderate" ................. Yellow.

101 to 150 .................. "Unhealthy for Sen- Orange.

sitive Groups".

151 to 200 .................. "Unhealthy" ................ Red.

201 to 300 .................. "Very Unhealthy" Purple.

301 and above ........... "Hazardous" .............. Maroon.'

1 Specific colors can be found in the most recent reporting guidance (Guideline for Public Reporting of Daily Air Quality- ir Quality Index (AQl)).

f. The pollutant specific sensitive groups

for any reported index value greater than

100. Use the following sensitive groups for

each pollutant:

When this

pollutant

has an index Report these sensitive groups* value

above 100

Ozone Children and people with asthma are the groups

most at risk.

PM2.

5 People with respiratory or heart disease, the elderly and children are the groups most at risk.

PMo ........ People with respiratory disease are the group

most at risk.

CO ........... People with heart disease are the group most at

risk.

SO .......... People with asthma are the group most at risk.

NO2 . Children and people with respiratory. disease are

the groups most at risk.

302
Environmental Protection Agency

ii. When appropriate, your AQI report may

also contain the following: a. Appropriate health and cautionary

statements.

b. The name and index value for other pollutants, particularly those with an index

value greater than 100. c. The index values for sub-areas of your

MSA.

d. Causes for unusual AQI values. e. Actual pollutant concentrations.

5. Is My AQI Report for My 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

but not in it (for example, 03 concentrations are often highest downwind and outside an urban area), you should identify these areas and report the AQI for these areas as well.

6. How Do I Get My AQI Report to the Public?

You must furnish the daily report to the

appropriate news media (radio, television,

and newspapers). You must make the daily

report publicly available at one or more places of public access, or by any other

means, including a recorded phone message, a public Internet site, or facsimile transmission. When the AQI value is greater than

100, it is particularly critical that the reporting to the various news media be as extensive as possible. At a minimum, it should include notification to the media with the

largest market coverages for the area in

question.

7. How Often Must I Report the AQI?

You must report the AQI at least 5 days

per week. Exceptions to this requirement are in section 8 of this appendix.

8. May I Make Exceptions to These Reporting

Requirements?

i. If the index value for a particular pollutant remains below 50 for a season or year,

then you may exclude the pollutant from

your calculation of the 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 the AQI must be reported as required

in sections 3, 4, 6, and 7 of this appendix.

CALCULATION

9. How Does the AQI Relate to 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 index value of 100 is associated with the

Pt. 58, App. G

numerical level of the short-term (i.e., aver- aging time of 24-hours or less) standard for

each pollutant. The index value of 50 is associated with one of the following: the numerical level of the annual standard for a pollutant, if there is one; one-half the level of the

short-term standard for the pollutant; or the

level at which it is appropriate to begin to

provide guidance on cautionary language.

Higher categories of the index are based on

increasingly serious health effects that affect increasing proportions of the population. An index value is calculated each day

for each pollutant (as described in section 12

of this appendix), unless that pollutant is

specifically excluded (see section 8 of this appendix). The pollutant with the highest

index value for the day is the "critical" pollutant, and must be included in the daily

AQI report. As a result, the AQI for any

given day is equal to the index value of the

critical pollutant for that day. For the purposes of reporting the AQI, the indexes for

PM0 and PM2 .

5 are to be considered separately.

10. What Monitors Should I Use To Get the Pollutant Concentrations for Calculating the

AQI?

You must use concentration data from

population-oriented State/Local Air Monitoring Station (SLAMS) or parts of the

SLAMS required by 40 CFR 58.10 for each

pollutant except PM. For PM, calculate and

report the AQI on days for which you have

measured air quality data (e.g., from continuous PM2.

5 monitors required in Appendix D

to this part). You may use PM measurements from monitors that are not reference

or equivalent methods (for example, contin- uous PMio or PM2.

5 monitors). Detailed guid- ance for relating non-approved measurements to approved methods by statistical

linear regression is referenced in section 13

below.

11. Do I Have to Forecast the AQI?

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 the AQI at least 24-hours in

advance using the most accurate and reasonable procedures considering meteorology, topography, availability of data, and forecasting expertise. The document "Guideline

for Developing an Ozone Forecasting Program" (the Forecasting Guidance) will help

you start a forecasting program. You can

also issue short-term forecasts by predicting

8-hour ozone values from 1-hour ozone values

using methods suggested in the Reporting

Guidance, "Guideline for Public Reporting of

Daily Air Quality."

303
Pt. 58, App. G

12. How Do I Calculate the AQI?

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 the pollutant concentration to one more than the significant

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

digits used to express the level of the NAAQS

for that pollutant. This is equivalent to the

rounding conventions used in the NAAQS.

b. Using Table 2, find the two breakpoints

that contain the concentration.

c. Using Equation 1, calculate the index.

d. Round the index to the nearest integer.

TABLE 2-BREAKPOINTS FOR THE AQI

These breakpoints Equal these AQI's

03 (ppm) 03 (ppm) PM2.5 PM1o CO (ppm) SO2 (ppm) NO2 (ppm) AQl Category 8-hour 1-hourI (pg/m 3

) (pg/m 3) 1-hour 1-hour

0.000-0.059 0.0-15.4 0-54 0.0-4.4 0-0.035 0-0.053 0-50 Good.

0.060-0.075 15.5-40.4 55-154 4.5-9.4 0.036-0.075 0.054-0.100 51-100 Moderate.

0.076-0.095 0.125-0.164 40.5-65.4 155-254 9.5-12.4 0.076-0.185 0.101-0.360 101-150 Unhealthy for

Sensitive

Groups.

0.096-0.115 0.165-0.204 365.5-150.4 255-354 12.5-15.4 40.186-0.304 0.361-0.64 151-200 Unhealthy.

0.116-0.374 0.205-0.404 3150.5-250.4 355-424 15.5-30.4 40.305-0.604 0.65-1.24 201-300 Very

Unhealthy. (2) ................ 0.4050.504 3250.5-350.4 425-504 30.5-40.4 40.605-0.804 1.25-1.64 301-400

(2) ................ 0.505-0.604 3350.5-500.4 505-604 40.5-50.4 40.805-1.004 1.65-2.04 401-500 Hazardous.

' Areas are generally required to report the A0l based on 8-hour ozone values. However, there are a small number of areas where an AQl based on 1-hour ozone values would be more precautionary. In these cases, in addition to calculating the 8-hour ozone 2 index value, the 1-hour ozone index value may be calculated, and the maximum of the two values reported. 8-hour 03 values do not define higher AOI values ( 301). AQl values of 301 or greater are calculated with 1-hour 03 con- centrations.

31f a different SHL for PM2

., is promulgated, these numbers will change accordingly. 4 1-hr SO2 values do not detine higher AGl values ( 200). AQl values of 200 or greater are calculated with 24-hour SO2 concentrations.

ii. If the concentration is equal to a break- note that in some areas, the AQI based on 1-

point, then the index is equal to the cor- hour 03 will be more precautionary than

responding index value in Table 2. However, uaing 8-hour values (see footnote 1 to Table

Equation 1 can still be used. The results will 2). In these cases, you may use 1-hour values

be equal. If the concentration is between two as well as 8-hour values to calculate index

breakpoints, then calculate the index of that values and then use the maximum index

pollutant with Equation 1. You must also value as the AQI for 03.

BP8h -s - BPvl a + wLe rC 1 (Equation 1) c a 

Where: measured and select the one that produces

Ip = the index value for pollutant, the highest index value for the AQI. For exC,, = the truncated concentration of pollut- ample, if you observe a PM1o value of 210 g

antp i 3

, a 1-hour 03 value of 0.156 ppm, and an 8-

BPi = the breakpoint that is greater than or hour 03 value of 0.130 ppm, then do this:

equal to C, a. Find the breakpoints for PMe at 210 pg/

BPu = the breakpoint that is less than or M3 as 155 pg/i 3 and 254 pg/i 3

, corresponding

equal to C, to index values 101 and 150;

Ii = the AQI value corresponding to BPw b. Find the breakpoints for 1-hour 03 at

I1o = the AQI value corresponding to BP. 0.156 ppm as 0.125 ppm and 0.164 ppm, coriii. If the concentration is larger than the responding to index values 101 and 150;

highest breakpoint in Table 2 then you may c. Find the breakpoints for 8-hour 03 at

use the last two breakpoints in Table 2 when 0.130 ppm as 0.116 ppm and 0.374 ppm, coryou apply Equation 1. responding to index values 201 and 300;

Example d. Apply Equation 1 for 210 pg/in', FMIO:

iv. Using Table 2 and Equation 1, calculate

the index value for each of the pollutants

304
Environmental Protection Agency

150 - 101

540- 155 (210 - 155) + 101 = 128

254 - 155

Pt. 59

e. Apply Equation 1 for 0.156 ppm, 1-hour

03:

150 - 101

0 (0.156 - 0.125) + 101 = 140

0.164 - 0.125

f. Apply Equation 1 for 0.130 ppm, 8-hour

03:

300 - 201

04- 01 (0.130 - 0.116) +201 = 206

0.374 - 0.116

g. Find the maximum, 206. This is the AQI.

The minimal AQI report would 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

at risk.

13. What Additional Information Should I

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 EPA has also prepared a brochure on the

AQI that explains the index in detail (The

Air Quality Index), Reporting Guidance

(Guideline for Public Reporting of Daily Air

Quality) 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 PM25. Measurements to Report an Air Quality Index

(AQI). U.S. Environmental Protection Agency, research Triangle Park, NC. EPA-454/B02-002, November 2002) can be found on the

Ambient Monitoring Technology Information Center (AMTIC)

www.epa.gov/ttnamtil/.

Web site, http://

[64 FR 42547, Aug. 4, 1999, as amended at 73

FR 16513, Mar. 27, 2008; 75 FR 6537, Feb. 9,

2010; 75 FR 35602, June 22, 2010]

PART 59-NATIONAL VOLATILE ORGANIC COMPOUND EMISSION

STANDARDS FOR CONSUMER

AND COMMERCIAL PRODUCTS

Sec.

Subpart A-General

59.1 Final determinations under Section

183(e)(3)(C) of the CAA.

Subpart B-National Volatile Organic Compound Emission Standards for

Automobile Refinish Coatings

59.100 Applicability and designation of regulated entity.

59.101 Definitions.

59.102 Standards.

59.103 Container labeling requirements.

59.104 Compliance provisions.

59.105 Reporting requirements.

59.106 Variance.

59.107 Addresses of EPA Regional offices.

59.108 State authority.

59.109 Circumvention.

59.110 Incorporations by reference.

59.111 Availability of information and confidentiality.

305