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Part II

Environmental

Protection Agency

40 CFR Part 58

Ambient Air Quality Surveillance; Final

Rule
8452 Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations

ENVIRONMENTAL PROTECTION

AGENCY

40 CFR Part 58

[AD-FRL-4099-61

RIN 2060-AD18

Ambient Air Quality Surveillance

AGENCY: Environmental Protection

Agency (EPA).

ACTION: Final rule.

SUMMARY: This final rule revises the

ambient air quality surveillance

regulations to include provisions for the

enhanced monitoring of ozone and its

precursors including oxides of nitrogen,

volatile organic compounds (including

carbonyls) and meteorological

parameters. These revisions satisfy the

requirements of title I, section 182 of the

1990 Clean Air Act Amendments. These

revisions require States to establish

photochemical assessment monitoring

stations (PAMS) as part of their State

Implementation Plan (SIP) monitoring

network in ozone nonattainment areas

classified as serious, severe, or extreme.

Included in these revisions are

minimum criteria for network design,

monitor siting, monitoring methods,

operating schedules, quality assurance,

and data submittal.

EFFECTIVE DATE: These regulations take

effect on February 12, 1993.

ADDRESSES: Docket Statement: All

comments received relative to this rule

have been placed in Docket No. A-91-

22, located in the Central Docket

Section, Room M1500 (First Floor,

Waterside Mall), U.S. Environmental

Protection Agency, 401 M Street SW.,

Washington, DC 20460. This docket is

available for public inspection and

copying from 8:30-12 a.m. and from

1:30-3:30 p.m., Monday through Friday.

A reasonable fee may be charged for.

copying.

FOR FURTHER INFORMATION CONTACT: Geri

Dorosz-Stargardt, Technical Support

Division (MD-14), Office of Air Quality

Planning and Standards, U.S.

Environmental Protection Agency,

Research Triangle Park, NC 27711,

phone: (919) 541-5492.

SUPPLEMENTARY INFORMATION:

Background

Section 110(a)(2)(C) of the Clean Air

Act requires ambient air quality

monitoring for purposes of the State

Implementation Plan (SIP) and reporting

of the data to EPA. Uniform criteria for

measuring air quality and provisions for

the reporting of a daily air pollution

index are required by section 319 of the

Act. To satisfy these requirements, on

May 10, 1979 (44 FR 27571), EPA

established 40 CFR part 58 which

provided detailed requirements for air

quality surveillance and data reporting

for all the pollutants except lead for

which ambient air quality standards

(criteria pollutants) had been

established. On September 3, 1981 (46

FR 44164) similar rules were

promulgated for lead and on July 1,

1987 (52 FR 24740) for particulate

matter (PMlo).

On March 4, 1992, these rules were

proposed in the Federal Register as

amendments to 40 CFR part 58. These

regulations address the minimum

requirements for the monitoring of

speciated volatile organic compounds

(VOC), oxides of nitrogen (NOx), and

meteorological parameters as well as

additional ambient air monitoring for

ozone (03). Title I, section 182 of the

1990 Clean Air Act Amendments

requires EPA to promulgate regulations

for the enhanced monitoring of 03 and

its precursors and for the affected States

to incorporate the requirements as a part

of their State Implementation Plans.

Also, section 184(d) requires that the

best available air quality monitoring and

modeling techniques be used in making

determinations concerning the

contribution of sources in one area to

concentrations of 03 in another area

which is a nonattainment area for

ozone. Additionally, these enhanced

ozone and ozone precursor monitoring

rules adhere to the fundamental

recommendations, regarding ambient

monitoring, of the National Academy of

Sciences (NAS) in the report entitled,

Rethinking the Ozone Problem in Urban

and Regional Air Pollution, which was

prepared pursuant-to section 185B of

the 1990 Clean Air Act Amendments. In

that report, the NAS noted the need for

additional feedback mechanisms for

evaluating the effectiveness of ozone

control strategies. The intent of these enhanced ozone

and ozone precursor monitoring

regulations is to require air pollution

control agencies to obtain an air quality

database that will assist in evaluating,

tracking the progress of, and, if

necessary, refining control strategies for

attaining the ozone National Ambient

Air Quality Standards (NAAQS).

Photochemical assessment monitoring

stations (PAMS) will be established to

collect ambient concentrations of ozone

(03), oxides of nitrogen (NOx), nitrogen

dioxide (NO2), nitrogen oxide (NO), and

speciated VOC.including carbonyls, and

meteorological data to better

characterize the nature and extent of the

03 problem, aid in tracking VOC and

NOx emission inventory reductions,

assess air quality trends, and make

attainment/nonattainment decisions. In

addition, the PAMS will provide a more

definitive database for evaluating

photochemical model performance,

especially for future control strategy

mid-course corrections as part of the

continuing air quality management

process. The data will be particularly

useful to States in ensuring the

implementation of the most costeffective regulatory controls.

In the process of developing these

regulations, EPA sought the assistance

of the Standing Air Monitoring Work

Group (SAMWG). SAMWG was

established by EPA in 1975 to assist in

developing air monitoring strategies,

correcting identified monitoring

problems, and improving overall

national monitoring operations.

SAMWG members represent State and

local air pollution control agencies and

EPA program and Regional Offices.

SAMWG members were active partners

in developing and reviewing the 1979

part 58 rulemaking package which

formally established the existing

framework of the ambient air quality

surveillance and data reporting

regulations. The group also played a

prominent role In all subsequent

revisions to part 58.

Public Comments

The object of Federal Register

proposals is to allow comments on new

regulations prior to their promulgation,

thereby providing an opportunity for the

public to participate in the rulemaking

process. On March 4, 1992, these rules

were proposed in the Federal Register

with a 30-day comment period. In

response to requests from the public,

especially from the regulated

community of State and local air

pollution control agencies on April 3,

1992, EPA extended the public

comment period on the enhanced 03

and 03 precursor monitoring regulations

until May 4, 1992.

EPA received 40 written comment

letters on the proposal of March 4, 1992.

All of the written comments submitted

to EPA are contained in EPA's Docket

No. A-91-22. Of the letters reviewed, 16

come from State agencies, 10 from

industry, 2 from institutes and

universities, 6 from State/local

associations, 5 from local agencies, and

1 from a federal agency. A list of all

commenters writing to the public docket

is provided in Docket A-91-22.

The following discussion covers the

substantive comments. A detailed

discussion of the basic concepts of the

regulations can be found in the

preamble to the March 4, 1992 proposal.
Federal Register / Vol.- 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations

A. General Comments

The comments discussed under this

heading were not specific to any rule or

appendix, but were general comments

on some aspect of the proposed

monitoring program.

One commenter noted that the

Muskegon nonattainment area had been

reclassified from a serious to a moderate

classification and therefore should be

withdrawn from consideration in the

final rules. Since this area and the

Sheyboygan area have been reclassified

and are no longer serious, severe, or

extreme 03 nonattainment areas, EPA

agrees that these rules would not apply

to either Muskegon or Sheyboygan.

Accordingly, Muskegon and

Sheyboygan are not included in EPA's

estimated requirements for PAMS. Note

that applicability of these enhanced 03

and 03 precursor monitoring rules is

determined by the classification of the

03 nonattainment area and not by the

fact that an area is listed specifically in

or omitted from this notice.

One commenter observed that

Ventura County, California, was created

as a separate 03 nonattainment area

from the Los Angeles Consolidated

Metropolitan Statistical Area (CMSA)

and requested clarification as to this

area's status with regard to the

enhanced 03 and 03 precursor

monitoring requirements. EPA notes

that since Ventura County was classified

as a severe 03 nonattainment area, the

county is subject to these rules.

One commenter agreed with the basic

concepts proposed on March 4, but

suggested that the final promulgation

not add additional requirements. A

second commenter expressed a similar

opinion that EPA not kill the effort with

additional mandates unless the Agency

is willing to proceed slowly and absorb

the costs. EPA evaluated the substantive

comments on their individual and

collective merits and has incorporated a

number of modifications to the original

proposal. Only those additional

activities addressed, in the March 4

proposal, were added. Regarding

resources, EPA has demonstrated its

willingness to participate in the funding

process; a further discussion of resource

needs and funffling follows under

Resources and Costs.

One commenter indicated that

although the regulation is reasonably

specific concerning network design, it

lacks specificity for the submittal of SIP

revisions. Given the complexity of the

rules, EPA believed that it was

necessary to provide extensive detail

concerning the design of the new PAMS

networks. The wide variability, inherent

in SIPs, precludes such specificity when

requiring SIP revisions. Each currentlyapproved SIP contains appropriate

provisions for establishing and

operating the network of State and Local

Air Monitoring Stations (SLAMS)

including those stations identified as

National Air Monitoring Stations

(NAMS). The SIPs generally provide

that SLAMS and NAMS will measure

ambient concentrations of those criteria

pollutants for which standards have

been established in 40 CFR part 50. The

SIP revisions submitted to comply with

these revisions to 40 CFR part 58.20 will

additionally provide for the monitoring

of ambient concentrations of noncriteria pollutants such as speciated

VOC including carbonyls, NO and NOx,

as well as meteorological parameters in

the same manner that the criteria

pollutants were addressed. Note that the

reference to aldehydes has been

changed to carbonyls to more accurately

reflect the requirements of the technical

assistance document (Reference 2 of

Appendix C). The guidance currently

stipulates sampling and analysis for the

following carbonyls: Formaldehyde,

acetaldehyde, and acetone.

The same commenter contends that

the rules indicate virtually no need for

new 03 sites and a modest expansion of

the NO2 monitoring effort and believes

that these conclusions are based in great

part on the assumption that PAMS

monitors could be located at existing 03

and/or NO2 monitoring sites. The

commenter was concerned that if this

assumption is in error, the expansion

needs of the networks may be

underestimated. In fact, EPA did assume

that some of the PAMS stations could be

located at existing SLAMS or NAMS

sites. For example, the PAMS type (3)

site is located at the downwind site

where maximum 03 concentrations are

expected to occur. This description

corresponds to the category (a) NAMS

03 site specified in appendix D of 40

CFR part 58. Such a site is required for

all urban areas having a population of

greater than 200,000. Because most of

the nonattainment areas classified as

severe, serious, or extreme for 03 are

located in urbanized areas which exceed

this population threshold, each area

would currently be expected to be

operating a category (a) NAMS 03 site.

Assuming that these sites are properly

located, it would therefore be common

to find the PAMS type (3) site and the

NAMS category (a) site coincident. In

siting NAMS NO 2 sites in urban areas

with populations greater than 1,000,000,

the monitoring sites could potentially be

collocated with one of the two PAMS

type (2) sites. Generally, EPA believes

that some collocation of PAMS and

SLAMS/NAMS sites is highly likely. In

addition, in areas where a substantial

number of SLAMS 03 and NO2 sites

currently exist, it is not unreasonable,

for purposes of estimating costs, to

assume that the State air pollution

control agency will relocate ambient

monitors and appurtenances rather than

purchase only new monitors to develop

the PAMS network. For example, in one

nonattainment area, 26 03 monitors and

15 NO2 monitors were in operation

during the 1991 fiscal year compared to

a PAMS requirement of only 5 sites,

some of which could obviously be

located coincident with existing sites. In

response to the concerns expressed by

the commenters, however, EPA has

adjusted its cost estimates to reflect the

collocation of PAMS with existing

monitors at only two sites in a five-site

network.

One commenter was doubtful that the

potential-benefits to be received from

the program would be justified given the

estimated implementation costs and the

unaddressed technical questions. A

slower, more cautious schedule was

recommended. In designing the

requirements for the PAMS network,

EPA considered the potential benefits of

the data and weighed those against the

projected costs and uncertainties. In

ight of the Agency's estimate for future

03 control costs of $8 to 12 billion per

year (Ozone Nonattainment AnalysisClean Air Amendments of 1990. Office

of Air Quality Planning and Standards,

U.S. Environmental Protection Agency,

Research Triangle Park, NC 27711.

DRAFT. September 1991), the potential

return in benefits for a cost of $5 to 12

million per year provides an

exceptionally prudent investment.

Nevertheless, the Agency made every

effort to craft a minimum requirement

which would in great part satisfy a

number of important objectives, yet not

become a financial burden either upon

the air pollution control agencies or the

States (note further discussions'of

financial burden in this preamble under

Resources and Costs). Modifications to

the proposed five-year transitional

period address the commenter's concern

and should provide ample flexibility. This commenter also indicated that

computer model sensitivity analyses

should be conducted for all parameters

to be measured and that the rule should

acknowledge the need for measuring

pollutant concentrations aloft. EPA

notes that although the PAMS network

design is not the direct result of

sensitivity analyses for each affected

area, it nevertheless reflects the current

expectations of the photochemical

models. Heretofore, the national

program has not had the benefit of the

8453
8454 Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations

availability of comprehensive 03

precursor data as a tool to evaluate,

calibrate, or otherwise adjust and

conduct reality checks on the operation

of the Urban Airshed Model (UAM).

EPA views the PAMS networks as a

vital step forward in complementing

grid model applications and control

strategy assessments and refinements.

Although the sampling of pollutant

concentrations aloft may also be a

highly valuable activity, EPA does not

agree that such activities should be

included in the specifications for

minimum routine measurements. These

rules, however, do not preclude a State

agency from proposing such pollutant

measurements (made either on a routine

basis or at periodic intervals during

more Intensive sampling efforts),

including them in their EPA-approved

comprehensive network description.

and subsequently utilizing Clean Air

Act Section 105 Grant monies, in part,

to support these monitoring efforts. In

fact, EPA has encouraged affected air

pollution control agencies to view these

rules as a base upon which to tailor and

expand the precursor monitoring

program to meet the States' individual

needs. Monitoring pollutant

concentrations aloft has therefore been

assigned to the category of desirable, yet

optional activities.

Two commenters suggested that EPA

adjust its program to reflect information

from previous field studies (i.e., base the

rules on actual field-verified techniques

rather than on good technical

assumptions alone). EPA recognizes the

value of quality measurements and

field-proven techniques. In fact, the

fundamental tenets of the proposal were

based on the demonstration of emerging

measurement technology and data

obtained during a number of field

studies, particularly the Atlanta O3

Precursor Study conducted during the

summer of 1990 (Reference 32 of

Appendix D). Although technical

assumptions were necessary to some

extent due to the emerging nature and

complexity of the measurement

technology, EPA believes that these

assumptions were warranted

considering the need for more definitive

03 precursor data to develop improved

03 control strategies. States are

encouraged to take full advantage of

experience and data obtained in past

studies and routine monitoring efforts,

and use that experience to refine and

focus their individual PAMS network

designs.

One commenter noted that the

requirements for intensive daily

sampling will engender major database

management activities. EPA agrees that

the measurement of numerous

compounds during multiple hours of

the day will create a very large database.

Consequently, the Agency is proceeding

to revise the capabilities of its

computer-based Aerometric Information

and Retrieval System (AIRS) to allow

these data to be securely stored,

retrieved, and adequately analyzed via

the existing national system. The AIRS

is currently utilized by all States for the

storage and/or retrieval of NAMS and

SLAMS data. The data required to be

submitted by § 58.45 will be deposited

in this same data bank. Further

information on AIRS and its capabilities

may be obtained by contacting any of

the 10 EPA Regional Offices or the

National Air Data Branch, Technical

Support Division (MD-14), Office of Air

Quality Planning and Standards, U.S.

Environmental Protection Agency,

Research Triangle Park, North Carolina

27711. The Agency is also revising its

technical assistance document

(Reference 2 of Appendix C) to include

additional guidance regarding the

processing of data at the State and local

agency level, i.e., generic procedures for

data processing and validation.

In a related topic, another commenter

estimated that the proposed rules will

result in a workload increase of 60

percent, predominantly in data

reporting burden. This commenter

advocates the development by EPA of

expert software for use with the VOC

analyzers. The Agency notes this

concern and has therefore undertaken

the aforesaid modifications to the AIRS

system and to its technical assistance

document.

One commenter was concerned that a

bias in 03 measurements often occurs

on design-value days, in part due to

differences in measurement techniques.

While the Agency cannot substantiate a

particular problem occurring on 03

design value days, the Agency notes that

data which is gathered in accordance

with 40 CFR part 58 and the quality

assurance procedures of appendix A, are

acceptable for use in computing design

values and for conducting attainment/

nonattainment determinations.

The same commenter believes that

EPA should examine the following four

areas more carefully before finalizing

the rule: (1) The linking of monitoring

specifications with monitoring objectives, (2) the consequences for an

urban area adhering to the minimum

stipulated monitoring requirements, (3)

the rationale for recommended

averaging times and frequencies for

sampling of VOC, and (4) the rationale

for air quality and meteorological siting

requirements. The Agency considered

these suggestions, recognized their

value, and subsequently incorporated

these considerations into the final rules.

Specific recommendations made by this

commenter are addressed elsewhere in

this preamble.

Two commenters expressed concern

that EPA had not adequately addressed

critical issues relating to the role of NOx

in the photochemical process. These

commenters assert that EPA must

ensure that the data gathered will be

appropriate for NOx sensitivity

modeling and will facilitate

discrimination and impact of various

sources of NOx. EPA is concerned about

the function of nitrogenous compounds

in 03 formation, particularly in the

southeastern United States. Special

studies are being initiated as joint

projects with EPA in the Southeast

employing research monitoring

concepts to derive the most effective

strategies for NOx monitoring and

control. These integrated projects are

expected to have a significant impact on

future 03 control actions. Modeling

predictions of various nitrogen species

[e.g., total reactive oxides of nitrogen

(NOy), NOx, NO, NO 2, peroxyacetyl

nitrate (PAN), and nitric acid (HNO3},

etc.] can then be examined by the

research community to determine the

performance of chemical mechanisms in

predicting non-03 oxidants. This will

help ensure that chemistry, leading to

03 formation in urban and rural areas,

is properly characterized and may lead

to further modeling improvements. Note

that the measurement of more highly

oxidized forms of nitrogen requires a

high degree of skill/training using

nonstandard techniques to measure

pollutants at very low concentrations.

EPA has determined that it is premature

to require such efforts in a routinely

operated network, but encourages and

recommends that States consider the

option of deploying more sensitive NOx

instruments when establishing future

PAMS sites. For the near term, the

current NOx monitoring methodology (Federal Reference Method for NO2) will

be acceptable. The Agency will develop

future guidance for more sensitive and

definitive NOx methods and

measurements.

One commenter expressed concarn

that many technical, logistical, and

fiscal issues remain to be resolved to

ensure the success of the PAMS

monitoring program. This respondent

asserted that its comments, analyses and

suggestions were, for the most part,

ignored. On the contrary, however, the

Agency has considered all comments

and suggestions received by the Agency.

This commenter's suggestions, being

rather comprehensive, complicated, and

unique, received careful scrutiny by

EPA. In a number of cases, these
Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations

suggestions were incorporated both in

the previous draft proposals as well as

in this final promulgation. In fact, the

final regulation has been revised to

allow alternative monitoring schemes

and intermittent sampling frequencies

in section 4 of appendix D, in part in

direct response to this commenter. The

fact that EPA did not radically change

its approach to identically match the

suggestions of this particular respondent

in no way diminishes the importance of

the suggestions, nor does it equate to

ignoring the recommendations. Each

specific recommendation has been

addressed elsewhere in this preamble.

B. Public Comments-Resources and

Costs

Several commenters were concerned

with the statement in the proposal

which says that the primary

responsibility for Implementing the

program with its associated costs rests

with the States. The commenters feel

strongly that EPA needs to make a much

larger financial commitment to the

program to ensure its success. EPA

understands that this unique program

will require a strong federal presence

both as a partner in system management

and in providing appropriate technical

and financial assistance. EPA has

provided funds during FY-92 to initiate

monitoring for air toxics in 10 areas.

These sites, which are generally located

consistent with the requirements for

PAMS type (2) sites, will be continued

as part of the PAMS program in 1993.

Additionally, the Agency has earmarked

approximately $4,000,000 in § 105 Grant

monies for distribution to the States in

FY-93 and has provided technical

support via contract and direct EPA

involvement and participation. Overall,

EPA will have home the burden of

financing a significant portion of the

costs of initiating sampling during FY92 and FY-93. The Agency has plans for

subsequent years which will ensure a

major financial role in this partnership

for EPA.

Eighteen commenters submitted other

observations related to funding and

resource needs to properly implement

the PAMS program. Ten of those

commenters believed that the proposed

levels of federal funding (discussed

above) are generally inadequate to

support the PAMS program. Three

commenters noted that the potential

benefits of the program outweigh the

projected costs, that serious

consideration should be given to

utilizing permit fees collected under

title V of the Clean Air Act

Amendments for this program, and/or

'that the monitoring costs are only a

fraction of the costs incurred by society

in attaining the air quality standards.

Two commenters expressed strong

objections to the use of reprogramming

of existing funds to support the PAMS

rogram. As previously discussed, EPA

as provided substantial section 105

Grant funds to support both FY-92 and

FY-93 monitoring activities. The

Agency expects to continue to provide

significant support through section 105

grants in subsequent years.

Reprogramming of existing monies is an

action which historically has been used

by the Agency to designate certain

portions of section 105 Grant funds,

provided annually to the States for

support of air pollution planning and

control programs. EPA believes that this

mechanism is a legitimate tool to focus

its limited grant funds in part on

particular air pollution problems having

high national priorities. Rarely does the

Agency suggest using this mechanism

unless the priority of a competing

program or project is significantly

greater than the currently-funded

activity. EPA has determined that the

potential benefits of the PAMS program

are significant enough to justify taking

this unilateral action.

One commenter suggested that the

distribution of section 105 Grant funds

be based on the number of sites and

monitors operated regardless of the

location of the nonattainment areas.

Perennially, it has been EPA's practice

to develop reasonable allocation

schemes for the available grant dollars

based on defensible parameters such as

activity levels, numbers of sources, etc.

In the case of the monies set aside for

the photochemical assessment

monitoring program, EPA concluded

that an appropriate mechanism for the

distribution of funds was to consider the

number of required PAMS sites. Each

affected Regional Office receives an

allocation of funds based on a national

prorata scheme; the final allocation to

State or local grantees is computed by

the Region. During FY-93, the primary

allocation criteria was essentially the

minimum number of PAMS sites that

would be required in each area by the

regulation. By FY-94, the Agency will

have received more information on

individual network designs from each

affected State and will therefore be able

to consider the actual number of sites to

be operated during the year as one of the

criteria for the distribution of grant

funds.

Another commenter suggested that if

States are unable to hire additional

personnel, they could return grant

monies in exchange for EPA contracted

services or perhaps pool analytical

support among a group of States. Given

the continuing nature of much of the

federal funding for photochemical

assessment monitoring, EPA asserts that

it would not be inappropriate for a State

agency to utilize the monies to hire new

personnel. Further, due to economies of

scale and within permissible

limitations, States may take advantage

of EPA contracts which are designed to

provide support to State agencies.

Additionally, the EPA Regions may at

the urging of a group of States, reserve

certain monies for a particular State

who would agree to, in turn, provide

services to the others.

One commenter was concerned that

the design of the enhanced 03 and 03

precursor monitoring program was

influenced more by financial constraints

than by scientific constraints. EPA

disagrees with this contention, and

instead has attempted to provide a

sensible balance between the costs of

the program and degree to which the

program objectives are satisfied. In any

case, EPA has only provided the

framework for a minimum required

monitoring strategy. States are

encouraged to implement larger, more

comprehensive networks if those

networks will provide a superior

database for the fulfillment of the data

objectives.

Five commenters expressed concern

that EPA's estimates for the costs of

implementing this monitoring program

were too low. EPA's costs estimates

were prepared from data gathered

during 1990 and 1991, and therefore are

generally expressed as 1990 and 1991

dollars. It is not surprising that

estimates prepared in 1992 should be

somewhat higher. In many cases it was

difficult to compare estimates prepared

by the commenters, since they often

utilized different wage scales, different

quoted equipment costs, and different

operating scenarios. In most cases,

recognizing that these figures are only

estimates of the true implementation

costs, the Agency believes that its

original estimates reflected a reasonable

appraisal of the resources needed to

implement a minimally-acceptable

program at that time. EPA has, however,

incorporated many of the suggestions of

the commenters for computing costs and

has compiled an updated version of its

cost estimates. These estimates reflect

the changes in the boundaries of several

nonattainment areas, changes in

classification of others, higher

equipment and labor costs, revised

sampling frequencies, additional

allocations for data processing, upper

air measurements, 03 and NOx

monitors, security concerns, and larger

monitoring shelters. For information,

the Agency's updated cost estimates for

each affected area may be found in

Table 1.

8455
8456 Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations

TABLE 1.-ESTIMATED REQUIREMENTS FOR PAMS

Ares name Po ion r Claslflcatlon of nonattailn- Number of re- Estimated liveManeayear cumulative

Beaumont-Port Arthur, TX ............................. Less Than Serious ................................ 2 $2,323,820

500,000. Porsmouth-Dover-Rochester NH-ME ........... ...... do................ Serious ............................. 2 2,227,130 Southeast Desert Modified AOMA, CA ................................. do. ..... Severe ............................... 2 2,280,860 Baton Rouge, LA ................................................................................. 500.000 to Serlous ...................... a 3,199,135

1,000,000.

El Paso, TX ........................................................................................... ...... do .......... S........ serious ............................... 3 3,199,135 Springfield, MA ...................... .......... ................................. O.................... Serious ................................ 3 3,127,495 Ventura County CA ..................................................................................... do ... . .. Severe ............................ 3 3,199,135 Milwaukee-Racine, WI .................................................................................... 100,000 to Severe...... .. 4 3,789,490

2,000,000.

Provldence-Pawtucket-Fa River, RI-MA ..................................................... d .................. se4ous ............................. 4 3,789,490 Sacramento, CA .............................. ..................................................... ...... o .................. Serious ............................... 4 3.873,070 Atlanta, GA ........................................................................................ More than Serious ........ .. ... 5 4,031,150

2,000,000. Baltimore, MD . . ...-. .... . . . do d ................. Severe ....................... 5 3,995,300

Boston-Lawrence-Worcester, MA-NH . ..... do......... .......... Serious ................................ 5 3,995300 Chicago-Gary-Lake County (IL), IL-IN-Wi ....... .. do......... Severe ................................. 5 3,995.300 Greater Connecticut CT ............................................................................... ...... do ................. Serlou ...................... 5 3,995,300 Houston-Galveto-Brzore. TX ................................................................ ...... do .................. Severe ................................ 5 4,084.850 Los Angeles-South Coast Air Basin, CA ........................................................ .... do ..... .... .... Extreme ............................... 5 4,084,850 New York-New Jersey-Long Island, NY-NJ-CT ..... ... ... do.. Severe ........................ 5 3,995,300 Philadelphla-Wilmlngton-Trenton. PA-NJ-DE-MD ................................. do............" .Severe ................................. 5 3,995,300 San Diego. CA ......................................................................................... . ... do . Severe ................................. 5 4,0 4,850 San Joaquln Valley, CA ......... ..... ....... ............ ............do . . ......... Serious . ............. ..... 5 4,084,850

Washington, DC-MD-VA . ...... .............. . . . ... Serious ........................... 6 3,995,300

Totals ................................................................................................ ................... ...... ...................................... 90 79,.346410

'1992 Dollars.

Additionally, several commenters

were concerned that EPA only

computed costs for the three-month

period of June, July, and August, while

the draft rule implies that monitoring

should be conducted during the entire

03 season, which can be much longer. EPA indeed states that monitoring for

precursors should be conducted during

the entire 03 season, but recognizes that

monitoring for only 3 months is an

acceptable minimum. The preamble

from the March 4, 1992 proposal clearly

stated that because of the relatively large

resource requirements to conduct PAMS

monitoring, 3 months was proposed as

the minimum annual precursor

monitoring period for the PAMS. EPA

did encourage, however, the

establishment of a monitoring period for

the entire 03 season in order to provide

a more comprehensive air quality

database and increase the possibility of

actually conducting monitoring during

most of the Worst 03 episodes. EPA goes

further, however, in the revised section

4.3 of appendix D, stating that alternate

precursor monitoring periods may be

submitted for approval as a part of the

PAMS network description. This action,

therefore, allows a State to propose a

monitoring season which will best meet

its particular needs as long as the

proposal will capture those worst 03

events. The length of any particular

PAMS monitoring season may therefore

vary from area to area.

Two commenters asserted that the

data collection requirements of the rule

were excessive for some of the stated

purposes and inadequate for others.

EPA has continually maintained that in

formulating the data requirements for

the PAMS program, it was necessary to

achieve some compromises, (i.e., some

more crucial objectives would be better

satisfied than other less important

objectives). Regardless, the Agency has

reconsidered the requirements for data

collection, and has modified the

specifications to better reflect a balance

of the needs of the data users.

One commenter alleged that EPA

committed to provide full funding for

all efforts required under the

Photochemical Assessment Monitoring

Program and further alleged that EPA

committed that it would not require

state or local agencies to perform the

specified monitoring if full funding of

all materials, equipment and labor is not

provided by EPA. That commenter also

requested that EPA clearly articulate

this assertion in the rules promulgated

today. Another commenter asserts that

EPA indicated this intent in the

proposed regulation. It is common

practice for State agencies to share

substantially in the costs of

implementing and operating all air

pollution monitoring and control

programs. In fact, the Clean Air Act

Amendments of 1990, section 802,

revise section 105 of the Act to require

that States provide an overall minimum

of 40 percent of the costs of

implementing programs for the

prevention and control of air pollution

or implementation of national primary

and secondary ambient air quality

standards. EPA is therefore unable to

commit that it would provide 100

percent of the funding for such a

substantial program. Evidently, some

confusion has resulted from EPA's

attempts to provide maximum monetary

support for the implementation of the

enhanced 03 and 03 precursor

monitoring regulations.

One commenter believed that

although the proposed funding for this

program may be adequate to encompass

capital expenses, provisions for skilled

labor costs will be a problem. EPA notes

that provisions for the hiring of highly

skilled chemists and statisticians were

included in its cost estimates and

planning for PAMS. Further, these

estimates were reviewed by the Agency

and revised upward to reflect changes in

the national labor burden and the

expressed needs of the State and local

air pollution control agencies.

One commenter believed that the

comprehensive sampling and analysis

schedule stipulatedby the proposed

rules is the primary contributor to the

high costs of the program. As previously

stated, EPA is committed to only

requiring a minimum program which

will comprise the best technical-fiscal

balance to satisfy a variety of data

objectives. Since the proposal was
Federal Register / Vol. 58, No. 28 / Friday, February 12, 19931 Rules and Regulations

published, EPA has refined its sampling

and analysis requirements to better

reflect the data needs.

In an effort to focus resources and

reduce the costs of implementation,

several commenters have recommended

totally different strategies that they

believe will also achieve the data

objectives of the PAMS program. The

Agency has reviewed these different

proposals and believes that they do not

constitute appropriate national

minimum requirements, but may be

considered as alternative networks for

particular nonattainment areas if they

are submitted pursuant to the

requirements of § 58.40 and appendix D

as promulgated. EPA has determined

that the suggestions were too closely tailored to particular geographic areas to

be applied nationally.

One commenter was concerned that

the costs of measuring air toxics was a

substantial addition to the price of the

PAMS program. EPA has noted that the

PAMS stations would be available as

platforms for the additional monitoring

of air toxics compounds if necessary.

Specifically, it is noted by the Agency

that by measuring the VOC targeted in

reference 2 appendix C, a number of

toxic air pollutants will also be

measured. Although compliance with

title I, section 182 of the Clean Air Act

Amendments does.not require the

measurement and analysis of additional

toxic air pollutants, the Agency believes

that the PAMS stations can serve as

cost-effective platforms for an enhanced

air toxics monitoring program. The

adjunct use of PAMS for air toxics

monitoring will allow the consideration

of air toxics impacts in the development

of future 03 control strategies. The

establishment of a second PAMS type

(2) site will prvide an even better data

base for such uses. The Agency,

however, takes note of the concerns of

several respondents that the PAMS

network is not ideal as a source of

primary air toxics data and further,

regards the collection of air toxics data

as an incidental and secondary, though

important, objective of the PAMS

system.

In overall response to concerns over

the estimates of costs previously

provided by the Agency, EPA has

recomputed its estimates including such

additions noted previously as inflation

factors, additional capital equipment,

etc.; the new computations are

summarized in Table 1.

C. Public Comments--Regulations

The following discussions address the

Lomments received on specific

provisions of the enhanced 03 and 03

precursor monitoring regulations:

1. Public Comments-Section 58.1-

Definitions

Four commenters suggested adding

definitions for the term NOy, a relatively

new term for total reactive oxides of

nitrogen including NO, NO2, PAN,

HNO3, and organic nitrite compounds

which all participate in the

photochemical process. Current

research has revealed that these other

compounds may indeed play a

significant.role in 03 formation. EPA

does not disagree with the commenters.

Since no readily-available monitoring

method has been designated for these

species, however, and most information

on the role of NO, or other such

compounds, still lies within the

research community, EPA has

determined that inclusion of any

definition and/or regulatory

requirements fQr monitoring for NOy is

premature. Future revisions to 40 CFR

part 58 will reexamine the state of the

research and reconsider this Issue.

Nevertheless, EPA encourages the

deployment of this emerging technology

at PAMS sites to further augment the

value of the 03 and 03 precursor

measurements.

Additionally, two commenters

recommended that the definition of

VOC be clarified and perhaps focused to

indicate a reference to reactive organic

gases. Further, one commenter

suggested that an acronym be included

for toxic air pollutants. Inasmuch as

EPA has specifically named the

compounds (VOC) targeted for

monitoring and analysis by this

program, see reference 2 appendix C,

and expects that list to evolve as the

monitoring program matures, the

Agency believes that a more focused

regulatory definition is not needed at

this time. Such a move, made

prematurely, might unnecessarily

constrain development of the program

in future years and inadvertently limit

the data available to the States to craft

the most effective 03 control strategies.

Since the foci of this monitoring

program are clearly 03 precursors and

03, these rules are not the most

appropriate vehicle to define or name

air toxics compounds. Such actions will

be subsequently considered by the

Agency's air toxics control programs.

2. Public Comments--Section 58.2-

Purpose

One commenter felt that it is an

oversight not to consider application of

this regulation to moderate 03

nonattainment areas. EPA notes that

enhanced information on 03, 03

precursors, and meteorology would be

beneficial to any State government

wrestling with the enigma of any level

of 03 nonattainment. Section 182(c)(1)

of the Clean Air Act Amendments of

1990, however, authorized the Agency

to develop rules only for those areas

classified as serious or above for 03

nonattainment. The fact that States with

moderate areas will not be required to

institute these specifications, should not

impede those State agencies from

configuring monitoring strategies which

are similar to the photochemical

assessment monitoring program.

3. Public Comments--Section 58.13-

Operating Schedule

One commenter recommended that

this section be amended to restate the

monitoring period requirements of

section 4.3 of appendix D. EPA notes

that it would be beneficial to include a

reference to section 4.3 in § 58.13, and

has amended the final rule accordingly.,

4. Public Comments-Section 58.20-

Air Quality Surveillance Plan Content

Your commenters expressed concern

that the requirements for VOC and/or

meteorological parameters were.too

comprehensive and constituted

excessive collection of data.

Additionally, several commenters

believed that the substitution of

measurements for total VOC, nonmethane organic compounds (NMOC),

or total non-methane hydrocarbons

(NMHC) (note that these acronyms

essentially represent the same group of

species) would be adequate to fulfill the

PAMS data objectives, at least at some

of the designated sites. EPA has

reexamined its position regarding

requirements for the speciation of VOC

analyses and has concluded that

continuation of the speciated

requirement is both appropriate and

necessary. This conclusion is based on

the need for more definitive information

regarding VOC at the specific

geographic locations where 03 exceeds

the National Ambient Air Quality

Standard (NAAQS), in order to address

the multi-faceted PAMS objectives. The

sampling for speciated VOC data allows

the verification of NMOC measurements

and provides a better understanding of

the biogenic contribution to the 03

problem. The corroboration of progress

in the reduction of 03 precursor

emissions inventories would necessitate

the quantification of the biogenic and.

anthropogenic fractions for those areas

where biogenics represent a significant

component of the ambient air.

Additionally, the Agency has modified

t'e sampling and analysis requirements

to reflect the acceptance of event

sampling at 3 of the 5 minimallyrequired sites. Such a modification has

8457
8458 Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations

the potential to reduce the data

handling requirements, costs, and level

of technology needed. The amended

sampling and analysis requirements are

specified in section 4.4 of appendix D.

Alterations to the requirements for the

measurement of meteorological

parameters are discussed in section 4.6

of appendix D. Note, however, that the

promulgated sampling requirements for

speciated VOC do not preclude the

submittal of alternative sampling

schemes as a part of the network design reqirdby § 58.40. ecommenters felt that 6 months

is too short a time frame for SIP

development, processing, and approval.

Note the brief discussion of SIPs under

General Comments, EPA believes that

the required SIP revision to empower

States to implement the enhanced 03

and 03 precursor monitoring regulationi

will be a relatively uncomplicated

procedure. Given the intrinsic need for

the data required in this promulgation,

the Agency recommends that all States,

including those which are not affected

by these rules, develop such SIP

revisions. Based on a review of common

SIP procedures, EPA has subsequently

modified § 58.20 to allow 9 months for

the submittal of a revision to the SIP for

the establishment and maintenance of

PAMS.

5. Public Comments--Section 58.40-

PAMS Network Establishment

Seven commenters asserted that 6

months is insufficient time for a State to

develop and submit a PAMS network

description. Inter- and intra-State

cooperation, data needs, and complexity

issues were cited as reasons for the

demand for more time. EPA

Headquarters and the EPA Regional

Offices have been working with affected

State and local air pollution control

agencies as well as cooperative bodies

such as the Northeast States for

Coordinated Air Use Management

(NESCAUM) and the Mid-Atlantic

Regional Air Management Association

(MARAMA), to develop the basics of

individual and regional PAMS network

descriptions. Additionally, EPA has

provided funding during FY-92 to begin

the establishment of monitoring sites,

many of which will eventually

constitute the first PAMS type (2) sites.

Given the extensive preparatory work

conducted since 1990 by both the

Agency and the States, EPA believes

that a 6-month requirement for the

submittal of a network design is both

achievable and appropriate. In response

to the concerns of the commenters,

however, EPA has clarified, in § 58.41,

its need for detail in the initial network

design submittal and has indicated that

specific details on the first PAMS type

(2) site plus general information on

other sites, would constitute a complete

submittal for fulfillment of the

requirements of § 58.40. Note, however,

that since the network design must

receive the approval of the

Administrator as stipulated by § 58,42,

EPA will require the submittal of

subsequent phases of detailed network

design by January I of each year of

implementation. In this way, a State

may focus its resources on an annual

basis toward the establishment of one

site per area. For groups of States

planning to submit coordinated network

designs, the process will also be

simplified somewhat. Sections 58.40,

58.41, and 58.42 have been amended

accordingly.

Four commenters felt that the

language of § 58.40, which allows the

joint submittal of network descriptions

and implementation schedules by disparate States (and further discussed

in section 4.2 of appendix D), should be

strengthened to make such inter/intraState cooperation mandatory to ensure

consistency and coordination,

especially in 03 transport regions. In

general, EPA believes that cooperation

among State and local air pollution

control agencies should be encouraged,

but not required. The Agency has

demonstrated its preference for

cooperation by its technical,

administrative, and financial support of

such multi-State cooperative agencies as

the State and Territorial Air Pollution

Program Administrators and the

Association of Local Air Pollution

Control Officials (STAPPA/ALAPCO),

NESCAUM and permanent FederalState-local work groups such as the

Standing Air Monitoring Work Group

(SAMWG), the Standing Air Emissions

Work Group (SAEWG), and the

Standing Air Simulation Work Group

(SASWG), affiliated with STAPPA/

ALAPCO. This particular provision of

the rule is designed to enable the

exercise of cooperative efforts, but does

not serve as the tool to require States to

plan and implement programs jointly.

Note, however, that section 182(j) of the

Clean Air Act Amendments of 1990

does stipulate that each State in which

there is located a portion of a single 03

nonattainment area which covers more

than one State should take all

reasonable steps to coordinate,

substantially and procedurally, the

revisions and implementation of State

implementation plans applicable to the

nonattainment area concerned. Also,

interstate transport regions established

pursuant to section 176A of the Clean

Air Act Amendments should be guided

in multi-State coordination and

consistency via the establishment of

transport commissions. Further, section

184 of the Act indicates that such

procedures are requisite for those

northeastern States included in an 03

transport region. These premises have

been articulated in an advance notice of

how EPA generally intends to take

action on SIP submissions and to

interpret various title I provisions in the

Federal Register on April 16, 1992, as

amendments to 40 CFR part 52. It is

therefore inappropriate for EPA to

separately require such cooperation as a

part of these enhanced 03 and 03

precursor monitoring rules. The Agency

has, however, modified the rules to

Indicate this preference for cooperation

and joint network design submittal,

where appropriate. One commenter suggested that EPA

support joint submittals, but not joint

implementation schedules. In § 58.40,

EPA indicates a preference for

coordination, but does not necessarily

require identical designs and

implementation schedules for

cooperating States. Differences in

designs and schedules would be

evaluated on a case-by-case basis.

One commenter recommended that

regional plans be given favorable if not

at least equal attention as is given to

State-by-State plans within the same

regional area. EPA has previously

expressed its preference for regionally

coordinated network designs, but must

provide equal consideration to both

types of descriptions allowed by these

rules.

Two commenters suggested that the

approval of the PAMS program be

relegated to the Regional Offices in lieu

of requiring approval by the

Administrator. In considering this

comment, EPA agrees with the

contention of the commenter that the

Regions are more familiar with the

idiosyncrasies of each 03 nonattainment

area and, as a result, Regional Office

concurrence on each network design is

required. In several cases, however, the

areas subject to these rules, cross both

State and EPA Regional boundaries. The

Agency is convinced that a program of

this magnitude requires intensive

national oversight and a high degree of

consistency and coordination; final

approval must therefore rest with a

central reviewing authority.

Two commenters suggested that

flexibility be included to allow each

network to be designed on a case-bycase basis because each area has unique

features such as irregular terrain or

distinct meteorology, such as sea/lake

breezes, which should be addressed

separately. EPA also believes that each
Federal Register I VoL 58, No. 28 / Friday, February. 12, 1993 / Rules and Regulations

ares's network design should be

specifically tailored to fit that particular

area or region, The network design

parameters promulgated today are those

considered by the Agency as a

minimum and/or a default network for

those State agencies wishing to omit

.comprehensive, area-specific planning

exercises. Although EPA does not

recommend minimizing planning, the

Agency recognizes that State resources

and technical- epertise often demand a - fallback position in lieu of extensive

investments in the planning process.

Note that the Agency is revising the

siting criteria guidance document

(Reference 19 of Appendix D) to provide

guidance on siting and network design

for areas with complex terrain or unique

meteorology.

One commenter recommended that a

working group be established to deal

with the coordination of monitoring

strategies and network designs in the

Northeast Ozone Transport Region. The

commenter recommended two specific

groups associated with electric utilities,

as technical resources for such a

working group. EPA maintains that the

responsibility for the implementation,

and therefore the coordination, of SIP

strategies lies-with the States. The

Agency is therefore cooperating with

NESCAUM, MARAMA, and the

Regional Ozone Modeling for Northeast

Transport (ROMNET) committees to

form a working group of State, local,

and EPA officials to provide guidance in

the development of a coordinated

monitoring network for the Northeast.

Another commenter encouraged EPA

to perform quantitative statistical

analyses to ensure that the minimumrequired network is sufficient to

corroborate emission inventories and

determine precursor trends. Due to the

emerging nature of the technology for

corroborating emission inventories and

procedures for determining precursor

trends, it is not feasible at this time to

perform quantitative statistical analyses

for this purpose. EPA believes, however,

that these analyses can be performed effectively once the PAMS networks are

in place and producing data.

Adjustments based on these analyses

will be appropriate when the

procedures are more mature and the

data bases are more complete. To shed

light on these comments, EPA has

.prepared a Data Quality Objectives (DQO) document which was used to

evaluate the original network proposal

of March 4, 1992, and this modified

final rule. That document is identified

as'reference 24 of appendix D.

Additionally, EPA supported and/or

noted other analyses concerning data for

emissions inventory applications and

trends. Those studies are noted as

references 26, 27, 28, 29, and 30 of

appendix D.

Several commenters pointed out the

need for EPA to better articulate

guidance on the submittal of

information for network approval and

any criteria EPA would utilize for

approval of these and any alternative

network submittals. Further information

concerning network design is included

in section 4 of appendix D. EPA has also

incorporated additional information and

criteria regarding the approval of

alternative networks in section 4 of

appendix D as a part of this

promulgation. During the comment period, several

agencies submitted proposals for their

areas which are considered to be

alternativenetwork descriptions. EPA

will review those designs individually

and respond directly to the particular

agency. Those designs are not

considered germane to the requirements

of the regulation and so are not

specifically reviewed in this notice of

rulemaking. One commenter urged EPA to

eliminate the public notice

rum irements of alternative plans and

subject them to the same process as

other network designs. EPA realizes that

although it is today promulgating

minimum criteria for PAMS networks,

many designs will have peculiarities

which may qualify them as alternative

networks and subject them to the

proposed public notice requirements of

§ 58.40 and further, sections 4.3 of

appendix C and 4.2 of appendix D. To

facilitate the submittal of network

descriptions and to expedite their

processing by the Agency, EPA is today

removing the proposed requirements for

public notice for alternative network

descriptions and will instead focus

resources on improving the quality of

the negotiation, review and approval

process.

One commenter noted that it may be

necessary to site PAMS monitoring

stations near major roadways and

certain large stationary sources because

of the possibility of their direct

influence on local concentrations of 03.

The regulations promulgated today

require the siting of certain monitors at

the location of the maximum impact of

emissions from sources of 03

precursors. EPA recognizes that in some

instances this site may be substantially

affected by one or more very large major

stationary sources which constitute a

principal source of 3 precursors for the

nonattainment area. Additionally, if the

major impact on 03 in a particular area

originates from mobile sources, It would

be logical to place a PAMS site -

downwind of a major roadway. In any

case, it is crucial to consider and

account for local NOx sources including

roadways which may act as local • depressors for 03 when designing a

network as described in section 10 of

appendix E.

6. Public Comments-Section 5&42-

PAMS Approval

Note that comments submitted

recommending approval of network

designs at the EPA Regional Office level

were previously addressed under

§ 58.40.

One commenter in voicing support of

the flexibility of allowing alternative

plans noted that their agency does not

feel that national consistency and

uniformity of methods are essential,

given that different areas are at different

levels of learning with respect to their

area's 3 precursor composition and

concentrations. EPA notes that each air

pollution control agency program is

subjected to its own particular set of

problems, strategies, limitations, and

coverage; in many cases some of these

factors are quite unique. EPA, on the

other hand, must deal with national

databases and national problems under

an entirely dissimilarset of limitations

than any particular air pollution control

agency. To that end, EPA is charged

with ensuring some reasonable degree of

national consistency so that national

trends, comparisons, and strategies can

be devised. Further, the Agency is

convinced that during the phase-in

period specified in section 4.5 of

appendix 1, most agencies will be

capable of rising to the challenge of

developing the necessary expertise to 'operate PAMS.

Concerning the approval of network

designs, one commenter recommended

that this section (and specifically

section 4.2 of appendix D) be revised to

require an EPA approval or disapproval

within 60 days of the receipt of an

alternative plan. Although EPA notes

this commenter's sense of urgency with

regard to the approval and

'implementation of the PAMS

monitoring program, the Agency has

determined that instituting artificial

approval deadlines would not prove

beneficial to improving the quality of

alternatives, nor would the public be

served by imposing restrictions which

could result in lowering the quality of

the review and approval process. EPA

has therefore not incorporated this 60-

day deadline.

7. Public Comments-Section 58.43-

PAMS Methodology

One commenter suggested that

additional language be added to the

8459
8460 Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations

rules to establish a process by which

EPA could streamline the review and

approval of innovative monitoring and

analytical techniques. Further, this

commenter recommended the use at

PAMS of a particular new type of

monitor which continuously tracks key

photochemical oxidant components.

The Agency believes that the new

requirements provide sufficient

flexibility for the incorporation of

innovative monitoring and analytical

techniques. The Atmospheric Research

and Exposure Assessment Laboratory

(AREAL) is currently responsible for the

development, evolution, review and

testing of new methodology to ensure its

applicability and appropriateness for

emerging national air monitoring needs.

Regarding the use of this new

measurement technology for

photochemical oxidant tracking,

AREAL, in conjunction with other

interested parties, is engaged in an

evaluation study of the proposed

instrumentation to determine its utility

in depicting the photochemical process.

Additionally, research is underway to

ascertain the usefulness of the data

gathered by this instrument and others

in meeting necessary 03 control

objectives such as those described in

this rule. The results of these

investigations will likely have a

significant bearing on the future uses of

the proposed instrumentation. In any

case, neither the current research status

of the procedures nor the innovative

nature of the methods preclude their use

at PAMS stations. A State air pollution

control agency may, at its own

initiative, implement this monitoring

strategy as an adjunct to the minimum

PAMS requirements; or, may submit a

sampling scheme utilizing this

technology exclusively, for

consideration by EPA as an alternative

pursuant to § 58.40 of this regulation.

8. Public Comments--Section 58.44-

PAMS Network Completion

Ten commenters provided

observations regarding the 5-year

transition (phase-in) period further

delineated in section 4.5 of appendix D.

Four of those respondents indicated that

total implementation of the program

was not only possible, but also desirable

in a 2- to 3-year period. One commenter,

however, in supporting a 3-year

transition, indicated that the reporting

of VOC data should be deferred for 5

years due in great part to the technical,

financial,. and technology issues

associated with VOC monitoring. Four

of the ten commenters also

characterized the urgency of expediting

the implementation of PAMS to provide

data support to the 1994 SIP

photochemical grid modeling process.

Five commenters indicated that the 5-

year schedule is reasonable or at least

ambitious, although two of these

respondents suggested that the initial

phases of the transition be either

deferred or prolonged, essentially to

allow for testing and evaluation of the

new monitoring technologies and for

training of professional staff. One

commenter suggested that due to

technology issues, the implementation

simply be delayed one year. Five of the

ten commenters reiterated their

concerns with funding and urged EPA

to provide substantial, adequate

resources to complete the PAMS

transition. One additional commenter

urged EPA to allow sufficient flexibility

for States to phase-in the program over

time in a manner consistent with the

level of available resources.

Due to expected near-term changes to

the atmospheric mix of 03 precursors

and the need to begin monitoring as

soon as practicable to provide a measure

of support to SIP strategy development

and emission inventory corroboration

efforts, EPA believes that deferral of

implementation is not a preferred

option. Accordingly, the Agency is

continuing efforts to support FY-92 and

FY-93 PAMS-type monitoring

initiatives via the Section 105 Grant

process. Noting, however, the real

concerns of State and local air pollution

control agencies regarding the phase-in

details, EPA is, in this promulgation,

reconfirming the transition

requirements, previously proposed, of

one station per year and modifying the

requirements to include provisions for

flexibility.

9. Public Comments-Section 58.45-

PAMS Data Submittal

Seven respondents expressed the opinion that the 6-month time period

allowed by § 58.45 is reasonable and

adequate for the submittal of VOC data.

Three of these commenters indicated

that allowing a reporting deadline of 9

months to a year for the first 2 years or

so of the program would be preferable.

This data phase-in would then allow

added time for training in the

implementation and interpretation of

data and the data acquisition system.

The final rules stipulate that the VOC

data must be reported within 6 months

following the end of each quarterly

reporting period. Since the PAMS

minimum monitoring season runs from

June through August and encompasses

two quarterly reporting periods, the

June data would not be due until

January I of the following year, and the

remainder of July and August data

would not be due until the following

April 1. The'Agency believes that when

the systems of data analysis, handling,

and reporting are routinized, these time

periods will be more than adequate for

VOC data reporting. The Agency

understands, however, as States begin to

wrestle With new personnel and

technology, that even such a reasonable

reporting deadline may be difficult to

meet during the initial years of

implementation. One commenter questioned the need

to delay submittal of the meteorological

data past the time period. required for

submittal of the NOx and 03 data. EPA

agrees that the measurement and data

handling technology for meteorological

parameters is currently sufficient for

States to be capable of submitting such

information on a more expedited

schedule. The Agency recognizes,

however, that the uses for such data in

photochemical modeling, receptor

analysis, and emissions inventory

functions, generally requires integration

with the VOC data. Since the utility of

expediting this data submittal would be

only marginal, EPA has required that

the meteorological measurements be

submitted on the same time schedule as

the VOC data.

Concurrent with the development of

the photochemical assessment

monitoring proposal of March 4, 1992,

EPA was considering a modification to

the data reporting requirements for

SLAMS and NAMS monitoring as

iterated in §§ 58.26 and 58.35. The

stipulation for 60-day reporting for 03,

NO, NO2, and NOx, outlined in

§ 58.45(c), was patterned after the

changes to the draft requirements for

NAMS, since at that time it was

expected that these other revisions

would be complete. Since the revisions

to NAMS and SLAMS requirements

have not yet been proposed and

subjected to public comment, EPA today

is promulgating a modification to

§ 58.45(c) which would cause these

pollutants to be reported on an identical

schedule to that stipulated in § 58.35 for

NAMS. Changes to the reporting

schedule for all monitors will thus be

considered in a separate Federal

Register notice at a later date. This

modification would also be consistent

with the comments from two of the

respondents. Two commenters expressed the belief

that EPA should make a greater

commitment to assist the States in

developing and implementing VOC data

acquisition and processing systems to

ensure timely compliance with the 6-

month requirement for VOC data

submittal. An additional commenter

expressed a similar concern, that given

the large data handling requirements,
Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations 4

the 6-month limitation would be

difficult to meet. EPA has sponsored parallel projects involving the

acquisition, processing, analysis, and

interpretation of VOC data which may provide needed assistance to States in

the handling of the massive VOC data

base. Further, the Agency has revised'its

PAMS cost estimates upwards to

consider the necessary costs of VOC

data acquisition and processing and is

considering the inclusion of additional

guidance in the technical assistance

document (Reference 2 of Appendix C).

One respondent suggested that a

target list of VOC species should be

developed and augmented with a

shorter priority list for reporting. EPA

notes that such a target list has been

published by the Agency in reference 2

of appendix C, but believes that placing

limits on reporting via a priority list is

premature and would in no case be

universally applicable.

Two commenters pointed out the

immediate need to make appropriate

changes to the Aerometric Information

Retrieval System tAIRS), the national

ambient air monitoring database, to

accommodate the new PAMS data

elements. EPA has incorporated such

changes to AIRS.

One commenter suggested that

§ 58.45(d) be reworded to allow the

monitoring and reporting of NMHC

(non-methane hydrocarbons) in lieu of

VOC. Note that this issue has been

previously addressed in comments

pertaining to § 58.20'.

10. Public Comments--Section 58.46-

System Modification

One commenter stated that they

believe that changes in attainment status

should not reduce the requirements of

the PAMS and that monitoring should

continue to be funded by EPA. A second

commenter suggested that once an area

demonstrates attainment of the 03

NAAQS, EPA should either reduce the

PAMS monitoring requirements or

assume responsibility for the PAMS

funding in that area. EPA believes that

continued PAMS monitoring, even after

a demonstration of attainment is

performed, will be crucial to

maintaining the 03 NAAQS over time.

Nevertheless, if a State can demonstrate

that it can properly track unexpected

changes in the ambient VOC mix and

emission inventories, while maintaining

the NAAQS, it may propose changes,

even reductions, in its PAMS

monitoring network as stipulated by

§ 58.46(b). EPA-is not authorized to

accept a cessation of PAMS monitoring,

however, until an area is redesignated to

attainment.

EPA has demonstrated its willingness

to provide substantial funding to States

for ambient air monitoring activities via

the section 105 Grant process. Although

the Agency is predisposed to continue

to contribute to ambient air monitoring

programs such as PAMS, it is of course

subject to the limitations of section 105,

in part described in the Resources and

Costs section of this Preamble.

One commenter felt that the annual

network review should be conducted

and approved by the Regional

Administrator. EPA notes that the

network review for ambient air

monitoring systems described in § 58.20

is currently conducted and approved

annually by the appropriate EPA

Regional Office. Section 58.46

articulates a national approval process

for changes to PAMS networks similar

to that required for NAMS and

referenced in §§ 58.32 and 58.36.

National data needs and consistency

dictate Headquarters EPA approval for

changes in both cases.

11. Public Comments-Appendix AQuality Assurance

All five commenters on this section

p'ointed out the explicit need for a

specific, uniform, improved system of

quality assurance (QA) for the VOC

sampling and analysis requirements

(especially) mandated by PAMS. One

respondent added the following three

recommendations for a national QA

program: (1) The establishment of

uniform QA criteria including

calibration schedules, duplicates

schedules, blanks schedules, (2) the

establishment of standardized audit

procedures, and (3) the establishment of

laboratory audit samples and an

interlaboratory exchange program

between States and EPA laboratories.

EPA is aware that the PAMS sites will

require a QA program similar to the one

now used for SLAMS criteria pollutants.

EPA is currently developing the audit

materials and QA guidance required to

establish such a system for the pollutant

monitoring systems that will be located

at the PAMS sites. These materials for

the VOC measurement systems are being developed in conjunction with the

evaluation study EPA is now

conducting on the candidate VOC

instrumentation for use at PAMS sites.

This study is briefly described in the

public comments on 8 58.43-PAMS

Methodology. Additionally, EPA plans

to provide VOC samples to the State and

local agencies operating PAMS sites to

assist them in validating their VOC

monitoring systems and the

performance of the personnel operating

these systems.

12. Public Comments-Appendix CMonitoring Methodology

Five commenters recommended that

equivalency of methodology must be

established at least on a regional level

and perhaps even nationally. Several

commenters went so far as to

recommend that EPA develop federal

reference and equivalent methods for

VOC. Further, several commenters

reiterated their perception of the need

for routine inter-State, inter-area quality

assurance procedures. Given that the

complexity of the technology for VOC

sampling and analysis and its rapid rate

of development and change, EPA has

chosen to publish specific guidance for

monitoring methodology in lieu of

publishing federal reference or

equivalent methods. Such guidance has

been published and is available as

reference 2 of appendix C. The Agency

will track the progress of the

development of new methods and will

reconsider the specificity of methods in

the future. EPA agrees that common and

continuing, or at least comparable,

methodologies are desirable on a regionwide basis. Comparability of data will

be one factor used by the Agency in

approving coordinated, region-wide

network designs.

One commenter pointed out that the

rules should not preclude the expansion

of the monitoring period to longer than

3 months, noting also that the length of

the monitoring season is not necessarily

proportional to the total network

operational costs. EPA notes that

provisions for changing the monitoring

period are promulgated today In section

4.3 of appendix D. EPA agrees with this

respondent that monitoring periods

should be consistent across a regional

network. This factor would also be

scrutinized when approving joint

networks. EPA recognizes the role that

the length of the monitoring period

plays in the computations of total costs

and has weighted that role accordingly.

One commenter felt that EPA should

specify a particular chromatographic

column for use on gas chromatographs

(GCs) analyzing for the various VOC.

Reference 2 of appendix C specifies

those column characteristics which

AREAL believes are necessary to

produce meaningful data on the target

VOC compounds. The laboratory even

goes so far as to provide specifications

on several acceptable columns, but falls

short of requiring a chromatographer to

choose any one particular design. EPA

reiterates its position that the

technology for VOC sampling is simply

evolving too quickly to allow such

specificity at this time.

8461,
8462 Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations

One commenter believed that the

VOC monitoring technology is not yet

advanced enough for State and local

agencies to economically operate a

speciated VOC monitoring program. As

previously stated, the Agency believes

that States are capable of competency in

utilizing new monitoring methods, and

in fact a number of State agencies are

currently employing such emerging

techniques with success. Per this

commenter's suggestion, EPA is

providing significant financial and

technical assistance for implementation

of this technologi.

In a related issue, a commenter

suggested that the rules should tighten

the equipment design and performance

standards for VOC in order to drive the

technology. Noting the progress made to

date by the researchers, designers, and

fabricators of VOC sampling equipment,

EPA believes that the existing technical

specificity and market pressures are

sufficient to spark development in new

and emerging sampling and analysis

methods. One other respondent

encourages the development of less

labor-intensive methodologies to

counter the specter of future resource

constraints. AREAL has continued to

articulate its support for such efforts

and will continue to exercise flexibility

in investigating new, more economical,

and uncomplicated procedures as

recommended by yet another

commenter.

One commenter felt that EPA should

append the provisions of the rules (and

particularly appendix C) to facilitate

and encourage the use of innovative

analytical technologies which are useful

for 03 control strategies. Although EPA

is investigating the use of such

innovative monitoring technology, and

specifically the technology

recommended by this commenter the

Agency has not yet determined how the

use of these sampling methods will fit

into the current SIP process.

Nevertheless, EPA does not wish to

preclude the use nor discourage the

development of new monitoring

technologies and so has amended the

language of appendix C accordingly. In

a related issue, a second commenter was

concerned that the stipulations of

section 4.2 of appendix C required the

use of reference or equivalent methods

for the monitoring of NO and NOx at

PAMS. This respondent recommends

the use of more advanced and sensitive

methods for such monitoring. EPA notes

that in great part, the use of the NOx

data measured at PAMS is dictated by

the need for precursor information

rather than for comparison with the NO2

NAAQS. Since the Agency does not

wish to preclude the use of potential

innovations or more sensitive

monitoring devices for either VOC or

NOx, It has therefore added additional

language to sections 4.2 and 4.3 of

appendix C to indicate that such other

methodology may be proposed by the

State as alternatives. Further, although

the Agency has determined that such

new technologies may be proposed and

even encourages and recommends their

use, It is premature to make their use a

requirement.

One commenter specifically raised a

number of technical questions for

consideration by EPA. In response, EPA

has determined that pressurized and

nonpressurized canister samples are

equivalent and that drying of samples

prior to analysis to reduce water content

is an acceptable procedure.

Additionally, the Agency notes that an

03 scrubber is required on the carbonyl

samplers, and C-18 cartridges are

equivalent to silica gel cartridges for

such analyses. Guidance on

standardization protocols (what gas,

how many points, what concentrations?)

will be addressed in future revisions to

the Technical Assistance Document for

Sampling and Analysis of 03 Precursors

(EPA 600/8-91-215). Further detail

concerning such information may be

found in reference 2 of appendix C.

13. Public Comments-Appendix DNetwork Design for SLAMS, NAMS, and

PAMS

The following discussions address the

comments received on specific

provisions to appendix D:

14. Public Comments-Section 4.1 of

Appendix D-PAMS Data Uses

Five commenters expressed concern

that the PAMS program might be

insufficient for the purpose of verifying

emissions inventories. One suggested

that further flexibility be built into the

regulation since techniques for

inventory verification are still in the

developmental stages. Further, two

commenters expressed conflicting views

in the use of air quality data and/or

emissions inventory data for the

tracking of emissions reductions over

time. The use of air quality data, and

especially that of photochemically

reactive species, is admittedly an

evolving science. EPA does believe,

however, that such data have been

demonstrated to be a constructive

adjunct tool to emissions inventories in

qualitatively verifying their accuracy

and serving as a corroborative

instrument to calculations of reasonable

further progress (RFP) in reductions of

emissions (See References 26-30 of

Appendix D). Note that the Clean Air

Act clearly stipulates that RFP is

defined via reductions of emissions

rather than progress in air quality

measurements for precursors or fox 03.

Emissions inventory reduction

calculations must therefore persist as

the primary tool for evaluating both

progress and reductions. These facts do

not lessen the importance, however, of

ensuring that those calculated values are

corroborated by actual air quality

measurements. EPA would be remiss if

it allowed the disregard of air quality

information in judging the adequacy of

State Implementation Plan performance.

The Agency notes that since the

inventory corroboration techniques are

not specified or limited by this section,

adequate flexibility is incorporated in

the rule.

In a related matter, one commenter

suggested that EPA has not shown the

correlation of target list compounds to

actual emissions inventories and

proposes that continuous NMOC

monitoring in conjunction with

integrated canister samples would be a

better indicator of emissions

inventories. As previously iterated, EPA

is promulgating rules which can be

applied nationally as a minimum

requirement. The Agency recognizes

and clearly articulates that the PAMS

network requirements are designed to

provide information which can be used

in maximizing the utility of a number of

data objectives. Were a commenter to

demonstrate that their particular

method of monitoring is superior to

PAMS for one data use, it is possible

that further scrutiny would reveal that

it is not ideal for the remainder. Air

pollution agencies are not precluded by

the rule from instituting monitoring

strategies additional to the PAMS

minimums or proposing alternatives

more tailored to their particular

geographic area. Similarly, one

commenter was concerned that the

program may not fulfill the needs for

SIP control strategy evaluation and

suggests that modeling is the preferable

tool for this purpose. The Agency agrees

that modeling is the more appropriate

tool to determine the potential for the

success of a proposed SP strategy;

however, the Agency asserts that

knowing what changes actually

occurred in the ambient air is an

extremely useful measure of the true

effectiveness of any control program. Two commenters indicated the need

for the Agency to publish a data uses

guidance document. They imply that

such a document should expound on

the details of how the data generated by

PAMS can be used to meet the data

objectives. One respondent complained

that It currently does not have a

program that can use the data provided
Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations

by the PAMS. EPA has prepared documents dealing with the data quality

objectives (DQOs) for the PAMS

program. Additionally, other

demonstrations of the continuing use of

such data are noted as references 26-31

of appendix D. Further, in response to

these comments, minor revisions have

been made to clarify section 4.1 of

appendix D. Those State agencies which

have recognized their lack of ability to

use these important data may employ

the additional section 105 Grant monies

made available for PAMS toward

enhancing their data processing and

analysis capabilities.

Four respondents noted that although

some of the stated objectives for PAMS

support application of photochemical

grid modeling techniques, the network

design does not seem to effectively

accomplish this feat. Further, three

commenters protest that the network

specifically does not meet the data

requirements of their State's

photochemical modeling protocol. EPA

has reexamined the overall data needs

of the photochemical modeling

-community and has modified the

network to be more responsive. Since

the Agency is attempting to ensure that

PAMS is compatible with national

needs, particular States may find that

the requirements provide better data

than needed to execute a minimal

modeling run or that their particular

model application demands other

information not measured by PAMS. In

the latter case or as one commenter

noted, when more intensive data is

needed, the State is free to measure

those additional parameters which they

feel are necessary to drive and/or

evaluate future model applications. . One commenter questioned why the

methodology to determine air quality

trends is not specified in the rules. This

respondent joined with another to point

out the need to address and eliminate

the variability of air quality data due to

meteorology. EPA maintains that a rule

which specifies monitoring

requirements and network design, is not

an appropriate vehicle to promulgate

particular statistical techniques for

calculating or presenting trends

analyses. Given the variety of such

techniques available to the State and

local air pollution agencies today, it

would be nearly presumptuous or EPA

to attempt to limit their ability to

analyze their own data via rulemaking.

The absence of specific trends

requirements allows the States to retain

the maximum flexibility and employ the

most appropriate state-of-the-art

analysis techniques. Clearly, there are

two basic concepts which may be

employed in preparing trends analyses:

(1) Displaying unadjusted

measurements which portray the quality

of the air actually breathed by the

public, or (2) calculating adjusted trends

to infer progress towards attainment of

standards due to the influences of

pollutant control programs. In either

case, the cornerstone of the analyses are

the actual air quality and meteorological

measurements such as those required by

PAMS. Particularly, for evaluating the

effectiveness of control programs, it may

be appropriate to integrate such factors

as meteorology and emissions inventory

data. EPA simply disagrees that this rule

is the correct forum to expound on

specific procedures for the analysis of

pollutant trends. Trends techniques

utilized by EPA for criteria pollutants

have appeared perennially in the

Agency's National Air Quality and

Emissions Trends Report. Frther, EPA

is currently evaluating techniques for

improving the effectiveness of 03

control strategies including indicators

for assessing progress. This work will

address techniques for integrating

meteorology, emissions, and ambient

data.

The second commenter concerning

trends went further to question whether

or not the 5-site PAMS network is

sufficient to conduct 03 and 03

precursor trends analyses. Since PAMS

sites are located to detect particular

characteristics of the air quality, such as

maximum 03 or upwind transport, the

5 sites have been determined by EPA to

be the minimum network necessary for

larger areas to encompass specific

situations of interest. Experience with

the NAMS network requirements has

shown that some areas may choose to

supplement this minimum network to

meet their own objectives. EPA has

decided that the 5-site network

represents a minimum core requirement which will provide a consistent and

stable database to be used for trends.

Additionally, the Agency notes that for

areas which submit coordinated, joint

network designs, it is expected that

more than 5 sites will be established

and become available for trends

analyses. One commenter noted that sampling

sites located to measure either VOC or

air toxics impacts may not be an optimal location for the other. EPA has

previously articulated its view on this

matterin this preamble's discussion of

Resources and Costs.

One commenter vociferously

criticized the basic tenets of the PAMS

program and professes that a successful

PAMS program can be cultivated via a

program of less-frequent focused

sampling for generalized precursor data

(e.g., NMOC) with a minimum of

speciation information. They believe

that their experience with this type of

program has been largely ignored in

designing the PAMS program. EPA

again observes that a program which has

been simplified or merely focused to

meet the specific data needs of a

particular locale, may not be

approiiate to fulfill the data uses for a

national program which is generally

routine 03 precursor data-poor.

Nevertheless, the opportunity is

provided by section 4 of appendix C and

section 4 of appendix D for the approval

of such focused alternative networks in

accordance with § 58.40, especially

where significant historical precursor

monitoring data are available. The

adoption of different or more

comprehensive requirements, as

discussed further in the Agency's

response to comments on § 58.42, does

not imply deficiencies in an existing

monitoring program. EPA's program

simply highlights that national needs

are often different and more inclusive

than local needs.

15. Public Comments--Section 4.2 of

Appendix D-PAMS Monitoring

Objectives

Four respondents revived the issue

that the sites chosen for PAMS would

not necessarily constitute appropriate

locations for the monitoring of air

toxics. Further, these commenters seem

to support a separate and expanded air

toxics monitoring effort. As noted by

EPA in the discussion of resources and

costs in this preamble, the Clean Air Act

Amendments call for a network which

is geared toward the monitoring of

photochemical parameters. The Agency

agrees that PAMS may not be the ideal

platform for monitoring air toxics, but

eels that the establishment of

additional air toxics monitoring at these

sites is a valuable adjunct to the PAMS

program. Separate national air toxics

monitoring networks are not currently a

highly-ranked, nationally mandated

priority.

Two additional commenters requested

that the Agency continue its efforts to

define and monitor NO,. EPA

previously expressed, in addressing

comments to § 58.1, its reluctance to

rush the regulatory and monitoring

program for NOy. EPA will continue its

investigations of this concept and will

propose future revisions to 40 CFR part

58 if appropriate.

One commenter espoused the

importance of measuring VOC aloft.

EPA has previously indicated its

reluctance to require this monitoring in

the discussions of the general

comments.

8463
8464 Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations

The same commenter felt that rural

sites for the collection of boundary

condition carbon monoxide (CO) and

NOx data should be added to the PAMS

program. EPA also has recognized the

importance of including sites that will

better define boundary conditions.

Consequently, section 4.2 of appendix D

and its associated Figures have been

modified to better reflect the

measurement of boundary conditions.

Note that since CO was not addressed in

section 182 of the Clean Air Act

Amendments as a required pollutant for

PAMS, no monitoring requirements for

CO were included. This omission does

not preclude a State from adding CO

monitoring to its network design.' One commenter believes that due to

the effects of complex meteorology, the

placement of PAMS sites should be

ased more on studies of past 03

episodes rather than the generic model

proposed by EPA. The Agency agrees in

principal with this comment and has

alteredthe location of the PAMS sites to

correspond more closely with the wind

conditions associated with 03 events.

One commenter requested that EPA

provide more specificity for locating

PAMS type (2) sites, the sites where

maximum emissions are expected to

impact. In response, EPA has clarified

and added additional detail for this

site's location.

One commenter was concerned that

many of their current NAMS and

SLAMS monitors are not located at

potential PAMS sites. EPA notes this

concern and considered that some, but

not all PAMS sites might be coincident

with SLAMS or NAMS in its

recomputation of cost estimates.

Reference is made to a similar

discussion under General Comments

and Resources and Costs in this

preamble.

One commenter also requested that

existing data be allowed to be used as

a part of alternative PAMS monitoring schemes. Note as discussed in § 58.40

that EPA has amended section 4.2 of

appendix D to include broad criteria for

the approval of alternative networks.

The use of existing information and

existing monitoring networks is not

precluded by these changes to the rule.

16. Public Comments--Section 4.3 of

Appendix D-Monitoring Period

Ten commenters expressed opinions regarding the length and specificity of

the monitoring period for the PAMS.

Three of those respondents supported

the proposed requirement of 3 months,

especially June, July. and August,

although they indicated that more

sampling would obviously be better,

that consistency across regions is

crucial, and that more specificity would

be useful. Three others indicated that

they felt that the 3 month period was

too short and would create staffing

problems for affected State governments

with a minimal cost savings over

sampling for longer periods such as the

entire 03 season. One of these

commenters asserted that 5 months

would be a better choice, especially in

the State of California. Five commenters

believed that employing 03 level

forecasting and episode monitoring

would be a more efficient use of

resources and provide a more intensive

database for the critical periods and

could make better use of manual

sampling methods. One commenter felt

that the length of the sampling period

should best be specified on a regional

basis and that while a 3-month period

would likely capture the majority of

episodes in the Northeast, such a period

would be insufficient for the South and

West.

EPA agrees that more than 3-months

would be preferable and has articulated

this opinion in section 4.3. The Agency

has recognized, however, that other

particular months rather than June, July,

and August may, on a case-by-case basis

be more appropriate. Accordingly, EPA

has expressed its intent to allow other

monitoring periods if submitted and

approved as a part of the network

description required by § 58.40. in the

discussion concerning comments to

§ 58.40 in this preamble, EPA has

clearly espoused its support for

coordination and consistency among

States and across regions and noted that

other requirements of the Clean Air Act

Amendments may require such

coordination, in this case in establishing

'the monitoring period for PAMS. The

Agency's goal in choosing the 3-month

period was to attempt to capture the

highest 03 evetts for the year. The

Agency has established only a minimum

sampling period; any affected State or

region may expand this period to a"

longer time to meet its particular needs.

Flexibility has been included in the rule

to allow the use of either manual or

continuous sampling technologies.

Given that the Agency recognizes the

utility and efficiency of focussing its

efforts on 03 events, section 4.4

sampling requirements have been

amended in this promulgation to allow

the sampling for such events and as an

option make the use of manual methods

more feasible. A discussion of those

changes follow under section 4.4. EPA

has included a stipulation in section 4.3

that intermittent sampling must follow

the previously-established national

schedule for intermittent sampling such

as the one-in-six-day schedule used for

particulate matter.

17. Public Comments--Section 4.4 of

Appendix D--Minimum Network

Requirements

Twenty-four commenters responded

to this section of the proposed rule

concerning the details of PAMS network

sampling and design. Eleven of those

respondents specifically indicated their

concern that the proposed requirements for VOC sampling were excessive and

the rule should be amended to allow

less intensive sampling. Many suggested

that such a less-intensive sampling

program would save funds which could

be better allocated for other purposes,

upper atmospheric monitoring for

example. Several commenters included

suggested sampling plans for

implementation in lieu of the proposed

schedule. Six commenters believed that

a better use of limited resources would

be to focus VOC monitoring on days

when high 03 levels would be expected

or forecast. EPA has examined the

proposed optional sampling schedules,

considered the economic impact of the

schedule, revisited the current state of

the monitoring technology and has

concluded that it is appropriate to make

a number of changes to the minimum

sampling schedule for VOC. To respond

to the data needs of the Agency and the

State and local air pollution control

agencies, EPA has decided the

following: Sampling schedules for NO,

NO2, NOx, 03 and surface

meteorological parameters remain

unchanged. EPA has determined that

the minimum requirements for pollutant

sampling will continue to mirror those

for gaseous criteria pollutants, (i.e.,

continuous measurements). The

minimum sampling period for

precursors is designated as three

months, specifically June, July, and

August unless a different 3-month

period is proposed by the State and

approved by EPA. The minimum

sampling period for ozone remains for

the entire ozone season. The Agency has

added an option for VOC monitoring at

sites other than PAMS type (2) sites. In

lieu of one in 3-day sampling (as

stipulated by Frequency A-in section 4.4

of appendix D), a State may substitute

monitoring before and during 03 events

as specified by section 4.4 of appendix

D plus one in 6-day sampling. Since the

Agency is not promulgating a preferred

event forecasting method, each State

choosing this option (identified as

sampling Frequency C by section 4.4 of

appendix D), must submit an 03 event

forecasting scheme as a part of the

PAMS network description as

delineated in § 58.41. States or areas
Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations -8465

proposing the joint submittal of network

descriptions and choosing this option

should include a strategy for ensuring a

coordinated, network-wide -esponse to

O3 event monitoring. Such a change in

focus to event monitoring will also

increase the feasibility of utilizing

manual sampling methods as requested

by several commenters.

Also in response to these concerns

and in order to ensure the collection of

data sufficient to conduct emission

inventory verification and reconciliation

exercises, establish source-receptor

relationships, corroborate reasonable

further progress (RFP) calculations, and

produce meaningful precursor trends

analyses, the proposed PAMS type (3)

site has been changed to an additional

PAMS type (2) site. To respond to other

photochemical modeling concerns, the

proposed PAMS type (5) site has been

moved downwind of the new type (3)

site and renumbered PAMS type (4).

Responding to observations by six

commenters that sampling schedules

should be standardized to promote data

comparability among parameters,

carbonyl sampling requirements have

been amended to more closely coincide

with the required frequencies for VOC.

Eleven respondents suggested

alternative locations or numbers of

PAMS sampling stations. There was

considerable variation among the

suggested options, with several

commenting that more sites were

needed, others noting that specific local

terrain and meteorological effects

require different station placement. Five

respondents in particular recommended

that the collected data should be more

responsive to the needs of the

photochemical grid modeling process.

EPA has closely surveyed the specific

data needs engendered by the program

objectives, especially the necessity to

provide a measure of support for

photochemical grid modeling, and has

concluded that further clarification on

the location of the PAMS sites is

requisite. Accordingly, EPA has

provided detail regarding the use of

particular high 03 day wind data, rather

than general seasonally-predominant

winds, for the location of potential

PAMS monitoring sites. Further the

Agency has provided guidance in

reference 19 of appendix D to aid in

specifying the location of sites,

particularly sites type (2), when there

are no predominant high 03 day winds

which can be accurately identified.

Also, the Agency has relocated the

upwind and downwind sites to

correspond more appropriately to the

data needs for photochemical grid

models and has added guidance on the

location of monitors, especially site

types (3) or (4). in areas of complex

terrain, e.g., mountain-valley, coastal,

etc., to reference 19.

One-commenter inquired why there Is

no requirement for a site in the area of

greatest 03 concentration given that the

rule's objectives include making

attainment/nonattainment decisions and

characterizing the nature and extent of

the 03 problem. EPA notes that the

siting requirements for PAMS type (3)

sites and its monitoring objectives as

articulated in section 4.2 and secdon 4.4

of appendix D clearly require its

location to be the maximum 03

monitoring site for the area. . Several respondents suggested that

the requirement for each PAMS site to

monitor all parameters was not

necessary, i.e., that some PAMS sites

should be allowed to operate with

monitoring conducted for only some of

the specified pollutants. EPA has

revisited its PAMS data objectives and

has determined this monitoring I

requirement should remain unchanged.

Elimination of parameters at individual

sites would weaken an otherwise

comprehensive database and decrease

its utility for fulfillment of the PAMS

data objectives and future undiscovered

data needs.

One commenter, while recommending

alternate monitoring technologies for

the PAMS, stated that in lieu of

monitoring 1-hour averages for VOC

monitoring, the sampling of 10-minute

average for VOC equivalents or

surrogates should be allowed. The

technology recommended by this

commenter is currently being

scrutinized by the AREAL laboratory to

determine its utility in the SIP process

as noted in the discussion of § 58.43.

EPA has otherwise determined that VOC

monitoring at increments of 10 minutes

is not practical at this time.

Several other commenters suggested

the use of 24-hour and/or continuous

NMOC monitoring (with periodic

speciation) as an adjunct to or even as

a replacement for the PAMS speciated

VOC monitoring. They assert that the

technology for NMOC monitoring is

proven and that the subsequent data are

sufficient for the development and

tracking of control strategies. EPA has

considered these arguments and has

determined that although some ofthe

PAMS objectives may be fulfilled via

total NMOC data, the remainder require

the gathering of speciated VOC

measurements. The Agency has

therefore not adopted the use of NMOC

instead of speciated VOC as a national

requirement as discussed previously

under the public comments to § 58.20.

The PAMS requirements, however, do

not preclude the collection of additional

NMOC data as an adjunct or for the

submittal of alternative networks which

propose elements of NMOC monitoring. Two commenters questioned the

utility of gathering a 24-hour integrated

and speciated VOC sample to

supplement the 1-hour speciated VOC

samples. EPA notes that given the

variations inherent in continuous/Ihour VOC measurement technology, the

addition of a periodic 24-hour sample

for purposes of quality assurance is a

prudent and necessary reality check.

Additionally, the year-round 24-hour

periodic sample will provide

information on emissions inventories,

RFP, and long-term VOC trends and

data for exposure assessments.

One State commenter felt that the

guidance for regional network design.

provided by figure 2 of appendix D, is

too generic. This respondent suggests

specifically that EPA should develop

PAMS monitoring network

description for the Northeast 03

Transport Region. EPA recognizes the

unique nature of the 03 problem

occurring in the northeastern United

States. Further, the Agency agrees with

the principle that a strong federal

contribution to the development of a

region-wide monitoring network is

critical to develop the needed

consistency, cohesiveness, and

comparability of the PAMS in the

Northeast. Accordingly, the Agency has

offered and is supplying both technical

and financial assistance to coordinated

region-wide State and local efforts. EPA

does not agree, however, that the

Agency should, by rule, usurp the State

Implementation Plan process

established by section 110 of the Clean

Air Act, nor shortcut the requirements

for the submittal of a network

description for PAMS. Failure of a State

to comply with the requirements for

submittal of a SIP could, however,

ultimately require EPA to promulgate

and implement a Federal " . Implementation Plan for that State

pursuant to section 110.

Several agencies submitted a PAMS

monitoring plan which was

fundamentally different from the

proposed rule and requested that EPA

substitute those requirements as the

national requirements for PAMS

monitoring. EPA observes that these

agencies, being proximate to one

another, would benefit greatly by

submitting and implementing similar

monitoring strategies. In this respect,

EPA applauds those agencies' efforts

toward consistency across a

geographical region. On the contrary,

however, for the same reasons that the

requirements are specifically tailored to

the characteristics of that particular
8466 Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations

region, the Agency does not believe that

it would suffice as a national minimum

program.

18. Public Comments-Section 4.5 of

Appendix D-Transition Period

Six commenters responded to this

section, with varying points of view,

although most were discussed as part of

the debate outlined in § 58.44.

Additionally, however, two commenters

suggested that the early years of the

program requirements should not be

overly prescriptive and that areas be

allowed to build up their programs over

'time, intimating that technology

changes and resource needs could be

* phased in along with the monitoring

program. In response, EPA has

incorporated additional transition

period flexibility as iterated in the

discussion of § 58.44.

19. Public Comments---Section 4.6 of

Appendix D-Meteorological

Monitoring

Sixteen commenters provided

observations regarding the

meteorological monitoring requirements proposed by section 4.6 of appendix D

and further stipulated by reference 2 of

appendix C. Eleven of these respondents

indicated support for the collection of

upper air meteorological data in each

area, especially if high quality upper air

data are not currently available. Several

supported this suggestion with

notations that the photochemical grid

models demand such data. One

commenter, although recognizing the

need for upper air monitoring, advised

caution and deferral of such

requirements due to the current state of

atmospheric sounding technology. EPA

has investigated the merits and

projected costs of upper air

meteorological monitoring and has

concluded that the benefits of

incorporating a requirement for upper

air measurements are substantial. In

response, therefore, the Agency has

amended section 4.6 to reflect these

requirements and has further indicated

its predisposition to allow adequate

time for securing data from this

network. EPA also believes that States

should take advantage of existing upper air monitoring programs and where

possible, substitute these data for the

PAMS requirements. EPA will provide

guidance for the collection of these data.

Several respondents provided specific

recommendations concerning the

particular meteorological parameters which should be monitored and those

for which they believed monitoring

should be limited. EPA notes that with

the exception of dew point

measurements, the recommendations for

particular parameters are incorporated

into reference 2 of appendix C.

Concerning dew point, one commenter

stated that their meteorological staff find

dew point temperature measurements to

be much more useful than relative

humidity to the study and forecasting of

0 episodes. The measurement

technique for dewpoint is

straightforward; States are encouraged

to include such measurements at PAMS,

if they find them useful. The Agency

has not required the measurement of

this parameter since it may not be

essential for all locations and may be

derived from temperature and relative

humidity measurements. As observed

by one commenter, barometric pressure

generally does not vary widely within a

large area, except in areas with complex

terrain features. EPA therefore indicates

its predisposition to allow approved

network designs which offer limited

measurements of barometric pressure

(or other parameters) if the State can

demonstrate that the area's topography is not conducive to significant pressure

(or other) variations.

One respondent indicated that the

rule should allow measurements at a

minimum height, or a range, above

ground rather than specify 10 meters.

For consistency, EPA has retained the

10-meter requirement. The Agency has

determined that the lack of flexibility in

this requirement should not constitute

any hardship inasmuch as

measurements at 10 meters are

traditional as well as practical. States.

may institute additional monitoring at

other heights, at their own volition.

In the preamble to the March 4, 1992

proposal, EPA recognized the potential

difficulty in siting a 10-meter

meteorological monitoring tower at a

particular PAMS site. The Agency

therefore requested comments on

criteria to determine how such data

collected at a nearby site could be used

to represent the meteorology at a PAMS

site where the tower and air monitoring

equipment could not be collocated. One

respondent agreed with the premise that

nearby data (such as collected at

airports or National Weather Service

stations) should be accepted, but

provided no suggestions for criteria to

judge the representativeness of those

data. EPA has consequently decided to

consider requests to use nearby existing

meteorological data, both surface and

upper air, on a case-by-case basis. -

20. Public Comments-Appendix EProbe Siting Criteria for Ambient Air

Quality Monitoring

Four respondents provided specific

comments regarding the placement of

the probe and siting criteria for PAMS.

One was particularly concerned over the

description for the PAMS site to be

located downwind in the second-most

prevalent wind direction noting that the

probe siting criteria were based on the

primary wind direction. EPA recognizes

this deficiency, and notes that the rules

have been amended to eliminate this

PAMS type (5) site. Additional language

has been added to sections 10.2 and 12

of appendix E to correct this anomaly for the other sites.

One commenter, based on experience,

recommends that VOC samplers should

be located further from sources than

criteria pollutant monitors if they are to

measure area-emitted and regionallytransported VOC. EPA notes that the

minimum 'network detailed in section 4

of appendix D, stipulates 3 site types

which are located to adequately

measure incoming transported

emissions [type (1)], maximum 03

measurements [type (3)], and downwind

outgoing conditions [type (4)], all sited

as urban scale monitors.

Two agencies recommend the use of

a vertical manifold for the measurement

of ambient 03 precursor data rather than

a horizontal manifold. They further

recommend that a heated line from the

manifold to the GC be employed to

ensure the transmission of heavy

hydrocarbons through the line. EPA

notes no compelling reason to specify

the orientation of the sampling

manifold. The requirements published

in the technical assistance document

(Reference 2 of Appendix C) do not

preclude the use of a vertical sampling

manifold. Likewise, the Agency has not

specified nor prohibited the heating of

the manifold which may be necessary in

high humidity areas.

One commenter believes that the

specifications for separation distance

between PAMS and roadways, trees and

obstacles appear to be lenient and

should be more stringent. EPA believes

that the specifications are adequate

based on current best judgement. As

more information becomes available, the

Agency will revisit this issue.

D. Public Comments Concerning Impact

on Small Entities

The U.S. Small Business

Administration (SBA) requested further

detail regarding the impact of these

regulations on small entities which are

defined to include small businesses,

small organizations, and small

governmental jurisdictions (5 U.S.C. 601

et seq.). Since EPA is utilizing the State

Implementation Plan process as

outlined in section 110 of the Clean Air

Act, the provisions of these regulations

promulgated today, apply directly only

to State Governments, and particularly,
Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations

to the State air pollution control

agencies having jurisdiction over 03

nonattainment areas classified as severe,

serious, or extreme. EPA therefore has

concluded that no small entities would

be affected by the proposal. At the

request of the SBA's Chief Counsel for

Advocacy, this certification has been

clarified. Therefore, pursuant to 5 U.S.C.

605(b), the Administrator certifies that . these amendments would not-have a

significant economic impact on a

substantial number of small entities.

Classification

Since this revision Is classified as

minor, no additional reviews are

required. The rules were submitted to

the Office of Management and Budget*.

(OMB) for review (under Executive

Order 12291). This is not a major rule

under E.O. 12291 because it does not'

meet any of the criteria defined In the

Executive Order.

List of Subjects in 40 CFR Part 58

Air pollution control, air quality

surveillance and data reporting, ambient

air quality monitoring network design

and siting, intergovernmental relations,

pollutant standard index, quality

assurance program.

Effective Date of Regulation

These revisions to 40 CFR Part 58

incorporate a flexible, reasonable,

transition schedule for efficient phase-in

of the rules in lieu of a waiting period

for a rule effective date. This schedule

accounts for the anticipated delays

encountered by States in hiring

qualified personnel, obtaining

equipment, and providing training.

Given that States will need to begin as

soon as possible to prepare for 03

season sampling, a 30-day waiting period is not appropriate and an

effective date of immediately upon

promulgation is deemed necessary. This

explanation is provided pursuant to the

requirements of 5 U.S.C. 553.

Dated: January 19, 1993.

William K. Reilly,

' Administrator.

For the reasons set forth in the

preamble, part 58 of chapter I of title 40

of the Code of Federal Regulations is

amended as follows:

PART 58-AMBIENT AIR QUALITY

SURVEILLANCE

1. The authority citation for part 58 is

revised to read as follows:

Authority: 42 US.C. 7410, 7601(a)..7613,

and 7619.

2. Section 58.1 Is amended by revising

paragraph (f) and by adding paragraphs

(w), (x), and (y) to read as follows:

158.1 DefinitI.

(f) NO2 means nitrogen dioxide. NO

means nitrogen oxide. NOx means.

oxides of nitrogen and is defined as the

sum of the concentrations of N0 2 and

NO.

{w) PAMS means Photochemical

Assessment Monitoring Stations.

(x) VOC means volatile organic

compounds.

(y) Meteorological measurements

means measurements of wind speed,

wind direction, barometric pressure,

temperature, relative humidity, and

solar radiation.

3. Section 58.2 is amended by

redesignating paragraph (d) as

paragraph (e) and by adding a new

paragraph (d) to read as follows:

58.2 Purpos.

(d) This section also acts to establish

a Photochemical Assessment

Monitoring Stations (PAMS) network as

a subset of the State's SLAMS network

for the purpose of enhanced monitoring

in 03 nonattainment areas listed as

serious, severe, or extreme. The PAMS

network will be subject to the data

reporting and monitoring methodology

requirements as contained in subpart E

of this part.

4. Section 58.13 is amended by

revising paragraph (b), redesignating

paragraph (c) as paragraph (d), and

adding a new paragraph (c) to read as

follows:

558.13 Operating schedul.

Cb) For manual methods (excluding

PM10 samplers and PAMS VOC

samplers), at least one 24-hour sample

must be obtained every sixth day except

during periods or seasons exempted by

the Regional Administrator.

Cc) For PAMS VOC samplers, samples

must be obtained as specified in

sections 4.3 and 4.4 of appendix D to

this part. Area-specific PAMS operating

schedules must be, included as part of

the network description required by

§ 58.40 and must be approved by the

Administrator.

5. Section 58.20 is amended by

revising paragraphs (a) and (c) and

adding paragraph (f) to read as follows:

158.20 Air quality aurveillanwe: Plan content.

(a) Provide for the establishment of an

air quality surveillance system that

consists of a network of monitoring

stations designated as State and Local

Air Monitoring Stations (SLAMS) which

measure ambient concentrations of

those pollutants for which standards

have been established in part 50 of this

chapter. SLAMS (including NAMS)

designated as PAMS will also obtain

ambient concentrations of speciated

VOC and NOx, and meteorological

measurements. PAMS may therefore be

located at existing SLAMS or NAMS

sites when appropriate.

(c) Provide for the operation of at least

one SLAMS per criteria pollutant except

Pb during any stage of an air pollution

episode as defined in the plan.

(f) Within 9 months after;

(1) February 12, 1993; or

(2) Date of redesignation or

reclassification of any existing 03

nonattainment area to serious, severe, or

extreme; or

(3) The designation of a new area and

classification to serious, severe, or

extreme, affected States shall adopt and

submit a plan revision to the

Administrator.

The plan revision will provide for the

establishment and maintenance of

PAMS. Each PAMS site will provide for

the monitoring of ambient

concentrations of criteria pollutants (Os,

NO2), and non-criteria pollutants (NOx,

NO, and speciated VOC) as stipulated in

section 4.2 pf appendix D, and

meteorological measurements. The

PAMS network is part of the SLAMS

network, and the plan provisions in

paragraphs (a) through (f) of this section

will apply to the revision. Since NAMS

sites are also part of the SLAMS

network, some PAMS sites may be

coincident with NAMS sites and may be

designated as both PAMS and NAMS.

Subparts E and F-[Redesgnated as

Subparts F and G]

6. Subparts E (S 58.40) and F (§§ 58.50

and 58.51) are redesignated as subparts

F (§ 58.50) and G (§§ 58.60 and 58.61).

respectively. Subpart E is added to read

as follows:

Subpart E-Photochemical Assesament

Monitoring Stations (PAMS)

Sec.

58.40 PAMS network establishment

58.41 PAMS network description.

58.42 PAMS approval.

58.43 PAMS methodology

8467
8468 Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations

*Sec.

58.44 PAMS network completion. 58.45 PAMSdata submittal.

58.46 System modification.

Subpart E--Photochemlcal

Assessment Monitoring Stations

(PAMS)

§ 58.40 PAMS network establishmenL

(a) In addition to the plan revision,

the State shall submit a photochemical

assessment monitoring network

description including a schedule for

implementation to the Administrator

within 6 months after,

(1) February 12, 1993; or (2) Date of redesignation or

reclassification of any existing 03

nonattainment area to serious, severe, or

extreme; or (3) The designation of a new area and

classification to serious, severe, or

extreme 03 nonattainment.

The network description will apply to

all serious, severe, and extreme 03

nonattainment areas within the State.

Some 03 nonattainment areas may

extend beyond State or Regional

boundaries. In instances where PAMS

network design criteria as defined in

appendix D to this part require

monitoring stations located in different

States and/or Regions, the network

description and implementation

schedule should be submitted jointly by

the States involved. When appropriate,

such cooperation and joint network

design submittals are preferred. Network descriptions shall be submitted

through the appropriate Regional

Office(s). Alternative networks,

including different monitoring

schedules, periods, or methods, may be

submitted, but they must include a

demonstration that they satisfy the

monitoring data uses and fulfill the

PAMS monitoring objectives described

in sections 4.1 and 4.2 of appendix D to

this part.

(b) For purposes of plan development

and approval, the stations established or

designated as PAMS must be stations

from the SLAMS network or become

part of the SLAMS network required by

§ 58.20.

(c) The requirements of appendix D to

this part applicable to PAMS must be

met when designing the PAMS network.

§58.41 PAMS network description.

The PAMS network description

required by § 58.40 must contain the

following:

(a) Identification of the monitoring

area represented.

(b) The AIRS site identification form

for existing stations.

(c) The proposed location for

scheduled stations.

(d) Identification of the site type and

location within the PAMS network

design for each station as defined in

appendix D to this part except that

during any year, a State may choose to

submit detailed information for the site

scheduled to begin operation during

that year's PAMS monitoring season,

and defer submittal of detailed

information on the remaining sites until

succeeding years. Such deferred

network design phases should be

submitted to EPA for approval no later

than January I of the first year of

scheduled operation. As a minimum,

general information on each deferred

site should be submitted each year until

final approval of the complete network

is obtained from the Administrator.

(e) The sampling and analysis method

for each of the measurements.

(f) The operating schedule for each of

the measurements.

(g) An 03 event forecasting scheme, if

appropriate.

(h) A schedule for implementation.

This schedule should include the

following:

(1) A timetable for locating and

submitting the AIRS site identification

form for each scheduled PAMS that is

not located at the time of submittal of

the network description;

(2) A timetable for phasing-in

operation of the required number and

type of.sites as defined in appendix D

to this part; and

(3) A schedule for implementing the

quality assurance procedures of

appendix A to this part for each PAMS.

958.42 PAMS approval.

The PAMS network required by

§ 58.40 is subject to the approval of the

Administrator. Such approval will be

contingent upon completion of each

phase of the network description as

outlined in § 58.41 and upon

conformance to the PAMS network

design criteria contained in appendix D

to this part.

§ 58.43 PAMS methodology.

PAMS monitors must meet the

monitoring methodology requirements

of appendix C to this part applicable to

PAMS.

I 58.44 PAMS network completion.

- (a) The complete, operational PAMS

network will be phased in as described

in appendix D to this part over a period

of 5 years after;

(1) February 12, 1993; or

(2) Date of redesignation or

reclassification of any existing 03

nonattainment area to serious, severe, or

extreme; or

(3) The designation of a new area and

classification to serious, severe, or

extreme 03 nonattainment.

(b) The quality assurance criteria of

appendix A to this part must be

implemented for all PAMS.

958.45 PAMS data submittal.

(a) The requirements of this section

apply only to those stations designated

as PAMS by the network description

required by § 58.40.

(b) All data shall be submitted to the

Administrator in accordance with the

format, reporting periods, reporting

* deadlines, and other requirements as

specified for NAMS in § 58.35.

(c) The State shall report NO and NOx

data consistent with the requirements of

§ 58.35 for criteria pollutants.

(d) The State shall report VOC data

and meteorological data within 6

months following the end of each

quarterly reporting period.

§ 58.46 System modification.

(a) Any proposed changes to the

PAMS network description will be

evaluated during the annual SLAMS

Network Review specified in § 58.20.

Changes proposed by the State must be

approved by the Administrator. The

State will be allowed I year (until the

next annual evaluation) to implement

-the appropriate changes to the PAMS

network.

(b) PAMS network requirements are

mandatory only for serious, severe, and

extreme 03 nonattainment areas. When

any such area is redesignated to

attainment, the State may revise its

PAMS monitoring program subject to

approval by the Administrator.

7. Two new sentences are added

before the last sentence in the first

paragraph of section 2.2 of appendix A

to read as follows:

Appendix A to Part 58--Quality

Assurance Requirements for State and

Local Air Monitoring Stations (SLAMS) * * * * *

2.2 * * * Quality assurance

guidance for meteorological systems at

PAMS is contained in reference 3.

Qualityassurance procedures for VOC,

NOx (including NO and NO 2), 03, and

carbonyl measurements at PAMS must

be consistent with EPA guidance. * * * * *€ * * *

8. In the References section of

appendix A redesignate references 5, 6,

and 7 as references 6, 7, and 8,

respectively, and a new reference 5 is

added to read as follows:

References

* * *€ * *

5. Technical Assistance Document for

Sampling and Analysis of Ozone Precursors.
Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations

Atmospheric Research and Exposure

Assessment Laboratory, U.S. Environmental

Protection Agency, Research Triangle Park,

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

9. Sections 4.0, 5.0 and 5.1 of appendix C

are redesignated as sections 5.0, 6.0, and 6.1,

respectively (reference 5.1 will become

reference 6.1 of section 6.0), sections 4.0, 4.2,

and 4.3 are added, and newly redesignated

section 6.0 is revised to read as follows:

Appendix C-Ambient Air Quality

Methodology

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, N02 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, N02 or NOx monitoring methodologies

are proposed, such techniques must be

detailed in the network description required

by § 58.40 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. 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 § 58.40 and

subsequently approved by the Administrator.

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.

10. The heading of appendix D is

revised to read as follows:

Appendix D-Network Design for State

and Local Air Monitoring Stations

(SLAMS), National Air Monitoring Stations (NAMS), and Photochemical

Assessment Monitoring Stations

(PAMS)

11. The second sentence of the first

paragraph of section I of appendix D Is

revised to read as follows:

1. * " * It also describes criteria for

determining the number and location of

National Air Monitoring Stations (NAMS)

and Photochemical Assessment Monitoring Stations (PAMS). These criteria will also be

used by EPA in evaluating the adequacy of

the SLAMS/NAMS/PAMS networks.' ' "

Sections 4 and 5 of Appendix D

[Redesignated as Sections 5 and 6)

12. Section 4 and section 5 of

appendix D are redesignated as section

5 and section 6, respectively, and a new

section 4 is added to read as follows:

4. Network Design for Photochemical

Assessment Monitoring Stations (PAMS)

In order to obtain more comprehensive and

representative data on 03 air pollution, the

1990 Clean Air Act Amendments require

enhanced monitoring for ozone (03), oxides

of nitrogen (NO, NO2, and NOx), and

monitoring for VOC in 03 nonattainment areas classified as serious, severe, or extreme.

This will be accomplished through the

establishment of a network of Photochemical

Assessment Monitoring Stations (PAMS).

4.1 PAMS Data Uses. Data from the

PAMS are intended to satisfy several

coincident needs related to attainment of the

National Ambient Air Quality Standards

(NAAQS), SIP control strategy development

and evaluation, corroboration of emissions

tracking, preparation of trends appraisals,

and exposure assessment.

(a) NAAQS attainment and control strategy

development. Like SLAMS and NAMS data,

PAMS data will be used for monitoring 03

exceedances and providing input for

attainment/nonattainment decisions; In

addition, PAMS data will help resolve the

roles of transported and locally emitted 03

precursors in producing an observed

exceedance and may be utilized to identify

specific sources emitting excessive

concentrations of 03 precursors and

potentially contributing to observed

exceedances of the 03 NAAQS. The PAMS

data will enhance the characterization of 03

concentrations and provide critical

information on the precursors which cause 03, therefore extending the database available

for future attainment demonstrations. These

demonstrations will be based on photochemical grid modeling and other

approved analytical methods and will

provide a basis for prospective mid-course

control strategy corrections. PAMS data will

provide information concerning (1) which areas and episodes to model to develop

appropriate control strategies; (2) boundary

conditions required by the rnodels to produce

quantifiable estimates of needed emissions

reductions; and (3) the evaluation of the

predictive capability of the models used.

(b) SIP control strategy evaluation. The

PAMS will provide data for SIP control

strategy evaluation. Long-term PAMS data

will be used to evaluate the effectiveness of

these control strategies. Data may be used to

evaluate the impact of VOC and NOx

emission reductions on air quality levels for

03 If data is reviewed following the time

period during which control measures were implemented. Speciation of measured VOC

data will allow determination of which

organic species are most affected by the

emissions reductions and assist in

developing cost-effective, selective VOC

reductions and control strategies. A State or local air pollution control agency can therefore ensure that strategies which are implemented in their particular

nonattainment area are those which are best

suited for that area and achieve the most

effective emissions reductions (and therefore

largest impact) at the least cost.

(c) Emissions tracking. PAMS data will be

used to corroborate the quality of VOC and

NOx emission inventories. Although a perfect mathematical relationship between

emission inventories and ambient

measurements does not yet exist, a qualitative assessment of the relative

contributions of various compounds to the

ambient air can be roughly compared to

current emission inventory estimates to

evaluate the accuracy of the emission

inventories. In addition, PAMS data which are gathered year round will allow tracking

of VOC and NOx emission reductions,

provide additional information necessary to

support Reasonable Further Progress (RFP)

calculations, and corroborate emissions

trends analyses. While the regulatory

assessments of progress will be made in

terms of emission inventory estimates, the

ambient data can provide independent trends

analyses and corroboration of these

assessments which either verify or highlight

possible errors in emissions trends indicated

by inventories. The ambient assessments,

using speciated data, can gauge the accuracy

of estimated changes in emissions. The

speciated data can also be used to assess the

quality of the VOC speciated and NOx

emission inventories for input during

photochemical grid modeling exercises and

identify potential urban air toxic pollutant

problems which deserve closer scrutiny.

The speciated VOC data will be used to

determine changes in the species profile,

resulting from the emission control program,

particularly those resulting from the

reformulation of fuels.

(d) Trends. Long-term PAMS data will be

used to establish speciated VOC. NOx, and

limited toxic air pollutant trends, and

supplement the 03 trends database. Multiple

statistical indicators will be tracked,

including 03 and its precursors during the

events encompassing the days during each

year with the highest 03 concentrations, the

seasonal means for these pollutants, and the

annual means at representative locations.

The more PAMS that are established in and

near nonattainment areas, the more effective

the trends data will become. As the spatial

8469
.470 Federal Register / Vol. 58. No. 28 / Friday, February 12, 1993 / Rules and Regulations

distribution and number of 03 and 03

precursor monitors improves, trends analyses

will be less influenced by instrument or site

location anomalies. The requirement that

surface meteorological monitoring'be

established at each PAMS will help

maximize the utility of these trends analyses

by comparisons with metedrological trends,

and transport influences. The meteorological

data can also help interpret the ambient air

pollution trends by taking meteorological

factors into account

(a) Exposure assessment. PAMS data will

be used to better characterize 03 and toxic air

pollutant exposure to populations living in

serious, severe, or extreme areas. Annual mean toxic air pollutant concentrations will

be calculated to help estimate the average risk to the population associated with

individual VOC species, which are considered toxic, in urban environments.

4.2 PAMS Monitoring Objectives. Unlike

the SLAMS and NAMS design criteria which are pollutant specific, PAMS design criteria are site specific. Concurrent measurements of

0,. NOx, speciated VOC, and meteorology

are obtained at PAMS. Design criteria for the

PAMS network are based on selection of an array of site 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 into and out of the area. and

the photochemical processes related to 03

nonattainment, as well as developing an initial, though limited, urban air toxic

pollutant database. Specific objectives that

must be addressed include assessing ambient

trends in 03, NO, NO, NOx. VOC (including

carbonyls), and VOC species, determining

spatial and diurnal variability of 03. NO,

NO2, NOx. and VOC species and assessing

changes in the VOC species profiles that occur over time, particularly those occurring

due to the reformulation of fuels. A

maximum of five PAMS sites are required in an affected nonattainment area depending on the population of the Metropolitan Statistical

Area/Consolidated Metropolitan Statistical

Area (MSA/CMSA) or nonattainment area,

whichever is larger. Specific monitoring

objectives associated with each of these sites

result in four distinct site types. Note that

detailed guidance for the locating of these

sites may be found in reference 19.

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

overwhelming transport.Type 11) sites are located in the predominant morning upwind

direction from the local area of maximum

precursor emissions during the 03 season and at a distance sufficient to obtain urban

scale measurements as defined in section 1

of this appendix. Typically, type (1) sites will

be located near the edge of the

photochemical grid model domain in the

predominant morning upwind direction from

the city limits or fringe of the urbanized area. Depending on the boundaries and size of the

nonattainment area and the orientation of the

grid, this site may be located outside of the

nonattainment area. The appropriate

predominant morning wind direction should

be determined from historical wind data

occurring during the period 7 a.m. to 10 a.m. on high %3 days or on those days which

exhibit the potential for producing high 03

levels, i.e., %-conducive days as described in

reference 25. Alternate schemes for

specifying this morning wind direction may

be submitted as a part of the network

description required by 6§ 58.40 and 58.41.

Data measured at type (1) sites will be used

principally for the following purposes: .

* Future development and evaluation of

control strategies,

" Identification of incoming pollutants,

* Corroboration of NOx and VOC emission

inventories,

* Establishment of boundary conditions

for future photochemical grid modeling and

mid-course control strategy changes, and

* Development of incoming pollutant

trends.

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. Type (2) sites are located

immediately downwind of the area of

maximum precursor emissions and are typically placed near the downwind

boundary of the central business district to

obtain neighborhood scale measurements.

The appropriate downwind direction should

be obtained similarly to that for type (1) sites.

Additionally, a second type (2) site may be

required depending on the size of the area,

and should be placed in the second-most

predominant morning wind direction as noted previously. Data measured at type (2)

sites will be used principally for the

following purposes:

* Development and evaluation of

imiminent and future control strategies,

* Corroboration of NOx and VOC emission

inventories,

" Augmentation of RFP tracking.

* Verification of photochemical grid model

performance,

* Characterization of 03 and toxic air

pollutant exposures (appropriate site for

measuring toxic emissions impact), e Development of pollutant trends,

particularly toxic air pollutants and annual

ambient speciated VOC trends to compare

with trends in annual VOC emission

estimates, and

* Determination of attainment with the

NAAQS for NO2 and 03.

Type (3) sites are Intended to monitor

maximum 03 concentrations occurring

downwind from the area of maximum

precursor emissions. Locations for type (3)

sites should be chosen so that urban scale

measurements are obtained. Typically, type

(3) sites wiil be located 10 to 30 miles

downwind from the fringe of the urban area. The downwind direction should also be

determined from historical wind data. but

should be Identified as those afternbon winds

occurring during the period I p.m. to 4 p.m. on high 03 days or on those days which

exhibit the potential for producing high 03

levels. Alternate schemes for specifying this

afternoon wind direction may also be

submitted as a part of the network

description required by S§ 58.40 and 58.41.

Data measured at type (3) sites will be used

principally for the following purposes:

* Determination of attainment with the

NAAQS for O (this site may coincide with an existing maximum concentration 0,

monitoring site),

* Evaluation of future photochemical grid

modeling applications,

* Future development and evaluation of

control strategies,

" Development of pollutant trends, and

" Characterization of 03 pollutant

exposures.

Type (4) sites are established to

characterize the extreme 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. Type (4) sites are located in the

predominant afternoon downwind direction, as determined for the type (3) site, from the

local area of maximum precursor emissions

during the 03 season and at a distance

sufficient to obtain urban scale

measurements as defined elsewhere in this

appendix. Typically, type (4) sites will be

located near the downwind edge of the

photochemical grid model domain. Alternate

schemes for specifying the location of this

site may be submitted as a part of the

network description required by §§ 58.40 and

58.41. Data measured at type (4) sites will be

used principally for the following purposes: e Development and evaluation of 03

control strategies, • Identification of emissions and

photochemical products leaving the area,

* Establishment of boundary conditions

for photochemical grid modeling,

" Development of pollutant trends,

" Background and upwind information for

other downwind areas, and

* Evaluation of photochemical grid model

performance. States choosing to submit an individual

network description for each affected

nonattainment area, irrespective of its

proximity to other affected areas, must fulfill

the requirements for isolated areas as described in section 4 of appendix D, as an example, and illustrated by Figure 1. States

containing areas which experience

significant impact from long-range transport' or are proximate to other nonattainment areas (even in other States) should collectively

submit a network description which contains

alternative sites to those that would be

required for an isolated area. Such a submittal should, as a guide, be based on the

example provided in Figure 2, but must

include a demonstration that the design

satisfies the monitoring data uses and fulfills

the PAMS monitoring objectives described in

sections 4.1 and 4.2 of appendix D. EPA

recognizes that specific monitoring sites

identified for one area may serve to fulfill the

monitoring objectives for a different site in

another area; for example, a downwind site

for one areamay suffice as an upwind site

for another. These alternative network

designs must also be reviewed and approved

by the Administrator.

9ILUN0 CODE se- .
Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993. / Rules and Regulations

FIGURE 1- ISOLA TED AREA

NETWORK DESIGN 0

U2

0

4

Ul

URBANIZED FRINGE

U3

NOTE: U1 AND U2 REPRESENT THE FIRST AND SECOND MOST

PREDOMINANT HIGH OZONE DA Y MORNING WIND DIRECTION.

U3 REPRESENTS THE HIGH OZONE DAY AFTERNOON WIND DIRECTION.

8471
8472 Federal Register / Vol. 58, No. 28 / Friday., February 12, 1993 1 Rules and Regulations

FIGURE2 - MUL TI-A REA AND

TRANSPORT AREA

NETWORK DESIGN 0

~>'- CITY Z

C ITY Y (3

BUSINESS DI

CITY X

U2

FRINGE

U3

NOM-" LI? Ad U2 REPRESENT T FIRST SD SECOND MOST

PREDOMINANT tiNGH OZONE CA Y MOJWN WAJlD .IREC ffO

U3 REPRESENTS THE HIGH OZONE DAY AFTERNOON WIND DIREC77ON

113

BILUNG CODE 560-Co--

4

Ul

Alsop
Federal Register/ Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations 8473

Alternative PAMS network designs should, on a site-by-site basis, provide those data

necessary to enhance the attainment/

nonattainment database for criteria pollutants

end explain the origins of overwhelming 03

transport. The alternative PAMS data should

be usable for the corroboration and

verification of 03 precursor emissions

inventories and should comprise e

qualitative lf mnat quantitative) measure of

the accuracy of RFP calculations. The data

should be sufficient to evaluate the

effectiveness of the implemented 03 control

strategies and should provide data necessary

toestablish photochemical grid modeling

boundary conditions and necessary inputs

Including appropriate meteorological

parameters, and provide measurements

which can serve as model evaluation tools.

lFuther, utilizing its PAMS database

(alternative or not), a State should be able to

draw conclusions regarding population

exposure and conduct trends analyses for

both criteria and non-criteria pollutants.

Overall, the PAMS network should serve as one of several complementary means,

together with modeling and analysis of other

data bases (e.g., Inventories) and availability

oflcontrol technology, etc., for States to

justify the modification of existing control

programs, design new programs, and evaluate

future courses of actions for 03 control.

4.3 Monitoring Period. PAMS precursor

monitoring will be conducted annually

throughout the months of June, July and

August fas a -iminmum) when peak 03 values are expected in each area; however,'precursor

monitoring during the entire 03 season for

the area is preferred. Alternate precursor

monitoring periods may be submitted for

approval as apart of the PAMS network

description Tequired by § 58.40. Changes to

the PAMS monitoring period must be

identified during the annual SLAMS " Network Review specified in § 58.20. PAMS

03 onitors must adhere to the 03

monitoring season specified in section 2.5 of

appendix D. To ensure s degree of national

consistenc,, monitoring for the 1993 season

'should cimence as follows:

One in 3-day sarpling-me 3, 1993.

One in 6-day sampling-June 6, 1993.

These monitoring dates will therebybe

coincident with the previousty-established,

intermittent schedule for particulate matter.

States initiating sampling earlier (or later)

than June '3,1993 should adjust their

schedules to coincide with this national

schedule.

4.4 Minimum Monitoring Network

Requiments. The minimum required

number and type of monitoring sites and

sampling requirements are based on the

population of the affected MSA/CMSA or nonattainment area (whicheveris larger). The

MSAICMSA basis for monitoring network

requirements was chosen because it typically

is the most representative of the area which

encompasses the emissions sources contributing to assathlmament. The MSAI

CMSA emissions density can also be

effectively and conveniently portrayed by the

surrogate of population. Additionally, a

network which is adequate to characterize

the ambient air of an MSA/CMSA often must

extend beyond the boundaries of such an

area (especially for 03 and Its precursorsLtherefore, the use of smaller geographical

units Israch as counties or nonattainment areas which re smaller than the MSA/

CMSA) for monltoringnetwork design

purposes is inappropriate.'Various sampln requirements re imposed according to the

size of the area to accommodate the impact

of transport on the smaller MSAs/CMSAs, to

account for the spatial variations Inherent in

large areas, to satisfy the differing data needs

of large versus small areas due to the

intractability of the 03 nonattainment

problem, end to recognize the potential

economic impact-of implementation on State

and local government. Population figures

must reflect the most recent decennial U.S.

census population report. Specific guidance on determining network requirements is

provided in reference 19. Minimum network

requirements are outlined in'Table 2.

TA&E 2.--PAMS MINNIUM MONITORING

NETWORK REORREMENTS 1

mum Minispec- -mu

P lalon of USN Re- ated =atbony

or nonattain- qulred VOC sam- -merit area sam- pling e Sbp3 frr

"ape pling fe fre- quency'4 cy

Less than 500,000.. (1) AorC

(2) AorC OorF s

500,000 to () A or C

1,000,000. (2)

13) Aor C

I1000 00to (t AorC

2,00,000. (a) S E

12) 18 E

(' A orC

More ftantOO900 () A orC

(2) B E

(3) AorC

(4) A or C

1O and NOx (including NO and NO2) monitoring should be oontl kni measurements. t

Whichever area Is larger. 3Soe 4 Figure 1.

Ffequsrc1 Requiremlts are as follows: A-Eig,t 3-ho"W sa utles every third day aid one additional

24-hour sample evefy sixth day during the monitoring i , Bo- 3-bour samples, every day during monklt§ perid and one additional 24-hoar

sample samples every on the sbeth 5 pea dat yearround; 03 days u GE eacn previous %m

day, eight 3-hour samples every sixth day, and one additonal 244=r sample every sixth day, dung the

fmitoring peiod; D-EWIAh3-hotr e every third day during the monitoring period; E-9gh 3-

hour samples evey day during the monitoring period; F-Eight 341our samples onthe 5peak 03 days plus each previous day and *ight 34*or samles every ,clh day during the inatorig gerod. (NOTE: multiple samples taken on a dally basis must begn

at mridt and consist of sequent, on- oveplng sampn peiods.) 6Carbonyl .9sln frequency must meatch the wosen specisted VOC Irequency. Note that ft use of Frequencies C or F requires the submittal of an ozone event forecasting scheme.

For purposes of network implementation

and transition, EPA recommends the

following priority order for the establishment

of sites:

9 The type (2) site which provides the

most comprehensive data concerning 03

precursor emissions and toxic air pollutants,

a The type (3) site which provides a maximum 0. measurement and total

conversion of 03 precursors,

* The type (1) site which delineates the

effect of incoming precursor emissions and

ncenrations of Oa and provides upwind

boundary conditions,

o The type (4) site which provides extreme

downwind boundary conditions, and

* The second type 12) site which provides

comprehensive data concerning 03 precursor

emissions and toxic air pollutants in the

second-most predominant morning wind

direction on high 03 days.

Note also that 03 event (peak day)

monitoring will require the development of

a scheme for forecasting such bigh 03 days

or will necessitate the stipulation of what

meteorological conditions constitute a

potential high 03 day; monitoring could then

be triggered only via meteorological

projections. The 03 event forecasting and

monitoring scheme should be submitted as a

part of the network description required by

§ 58.40 and 58.41 and should be reviewed

during each annual SLAMS Network Review

.specified in § 58.20.

4.5 "bnsion Period. A variable period

of time is proposed for phasing in the

operation of al required PAMS. Within i

year after (1) February 12.1993, (2) or date

of redesignation or reclassification of any

existing 03 nonattainment area to serious,

severe, or extreme, or 13) the designation of

a new area and classification to serious.

severe, or extreme 03 nonattainment, a

minimum of one type J2) site must be

operating, Operation of the remaining sites

must, at a minimum, be phased inat the rate

of one site'per year during subsequent years

as outlined in the approved PAMS network

description provided by the State.

4.6 Meteoraloical Monitoring. In order to

support monitoring objectives associated

with the need for various air quality analyses,

model inputs and performance 'valuations,

meteorological monitoringincluding wind

measurements at 10 meters above ground is

required at each PAiS site. Monitoring

should begin with site establishment. in

addition, upper air meteorological

monitoring is required for each FAMS area.

Upper air monitoring should be Initiated as

soon as possible. but no later than 2 years

after (1) February 12. 1993. (2) or date of

redesignatloa or eclassification ofany

existing 0 nonattalnment area to serious.

severe, or extreme, or 13) the designation of

a new area and classification to serious.

severe, or extreme 03 nonattainment. The

upper air monitoring alte may be located

separately from the type (1) through [4) sites,

but the location should be representative of

the upper air data in the nonattainment area.

Upper air meteorological data must be

collected during those days specified for

monitoring by the sampling frequencies in

Table 2. of'section 4.4 ofthis appendixD In

accordance with current EPA guidance.

Section 6 of AppendixD [Amended]

13. References 19 through 32 are added to

section 6 of appendix D to read as follows:

6. References

* *
8474 Federal Register / Vol. 58, No. 28 / Friday, February i2, 1993 / Rules and Regulations

19. Enhanced Ozone Monitoring Network

Design and Siting Criteria Guideline

Document. Office of Air Quality Planning

and Standards, U.S. Environmental

Protection Agency, Research Triangle Park,

NC 27711. EPA 45/4-91-033. November

1991.

20. 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.

21. 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.

22. Criteria for Assessing the Role of

Transported Ozone/Precursors in Ozone

Non-attainment Areas. Office of Air Quality

'Planning and Standards, U.S. Environmental

Protection Agency, Research Triangle Park,

NC 27711. EPA-450/4-91-015. May 1991.

23. Guideline for Regulatory Application of

the Urban Airshed Model. Office of Air

Quality Planning and Standards, U.S.

Environmental Protection Agency, Research

Triangle Park, NC 27711. EPA-450/4-91-

013. July 1991.

24. Ambient Air Monitoring Data Quality

Objectives (DQOs) for the Photochemical

Assessment Monitoring Stations (PAMS)

Program. Guideline Document. Office of Air

Quality Planning and Standards, U.S.

Environmental Protection Agency, Research

Triangle Park, NC 27711. Draft Report. July

1992.

25. Shao-Hung Chu, "Using Windrose Data

to Site Monitors of Ozone and Its

Precursors", Office of Air Quality Planning

and Standards, U.S. Environmental

Protection Agency, Research Triangle Park,

NC 27711. Draft Report. June 1992.

26. Lewis, Charles W., and Teri L Conner,

"Source Reconciliation of Ambient Volatile

Organic Compounds Measured in the Atlanta

1990 Summer Study: The Mobile Source

Component", Atmospheric Research and

Exposure Assessment Laboratory, U.S.

Environmental Protection Agency, Research

Triangle Park, NC 27711. September 1991.

27. Fujita, Eric M., Bart E. Croes, Charles

L. Bennett, Douglas R. Lawson, Frederick W.

Lurmann, and Hilary H. Main, "Comparison

of Emission Inventory and Ambient

Concentration Ratios of CO, NMOG, and NOx

in California's South Coast Air Basin", J. Air

and Waste Management Association 42:264-

276. March 1992.

28. Nelson, P. F., S. M. Quigley and M. Y.

Smith, "Sources of Atmospheric

Hydrocarbons in Sydney: A quantitative

Determination Using a Source Reconciliation

Technique", Atmospheric Environment Vol

17, No. 3. 1983.

29. Mayrsohn, H. and J. H. Crabtree,

"Source Reconciliation of Atmospheric

Hydrocarbons", Atmospheric Environment

Vol 10. 1976.

30. Mayrsohn, Henry, James H. Crabtree,

Mutsuo Kuramoto, Ray D. Sothern, and

Henry Mano, "Source Reconciliation of

Atmospheric Hydrocarbons 1974",

Atmospheric Environment Vol 11. 1977.

31. Analysis of the Ambient VOC Data

Collected in the Southern California Air

Quality Study, State of California Air

Resources Board--Research Division, 1800

15th Street, Sacramento, CA 95814, Final

Report, Contract No. A832-130. February,

1992.

32. Purdue, Larry J., "Summer 1990

Atlanta Ozone Precursor Study", presented at

the 84th Annual Meeting and Exhibition of

the Air and Waste Management Association,

Vancouver, British Columbia, Canada. June

1991.

14. Appendix E is amended by adding a

new paragraph after the first paragraph in

section 9, redeslgnating sections 10, 11, and

12 as sections 11, 12, and 13, and adding a

new section 10, redesignating Table 5 as

Table 6 in newly redesignated section 12,

and adding a new Table 5 in new section 10,

amending the last sentence in newly

redesignated section 11 to add reference to

PAMS, and amending newly redesignated

section 12 by adding an entry to the bottom

of Table 6 for VOC to read as follows:

Appendix E-Probe Siting Criteria for

Ambient Air Quality Monitoring

9. * * *

For VOC monitoring at those SLAMS

designated as 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 20 seconds or

less.

10. Photochemical Assessment Monitoring

Stations (PAMS)

10.1 Horizontal and Vertical Probe

Placement. The height of the probe inlet

must be located 3 to 15 meters above ground

level. This range provides a practical

compromise for finding suitable sites for the

multipollutant PAMS. The probe inlet must

also be located more than 1 meter vertically

or horizontally away from any supporting

structure.

10.2 Spacingfrom Obstructions. The

probe must be located away from obstacles

and buildings such that the distance between

the obstacles and the robe inlet is at least

twice the height that te obstacle protrudes

above the sampler. There must be

unrestricted airflow in an arc of at least 2700

around the probe inlet. Additionally, the

predominant wind direction for the period of

greatest pollutant concentration (as described

for each site in section 4.2 of appendix D)

must be included in the 270* arc. If the probe

is located on the side of the building, 180°

clearance is required.

10.3 Spacing from Roads. It is Important

in the probe siting process to minimize

destructive interferences from sources of

nitrogen oxide.(NO) since NO readily reacts

with 03. Table 5 below provides the required

minimum separation distances between

roadways and PAMS (excluding upper air

measuring stations):

TABLE 5.-SEPARATION DISTANCE

BETWEEN PAMS AND ROADWAYS

(Edge of Nearest Traffic Lane]

Minimum separa- dion distance beRoadway average daily traffic tweenroadwa

vehicles per day and station

meters'

<10,000 ...................................

>10

15,000 ............................. ...... 20

20,000 .............................. ...... 30

40,000 ....................................... 50

70,000 ....................................... 100

>110,000 ................................... >250

I Distances should be Interpolated based on traffic

flow.I

Type (1), (3) and (4) sites are intended to be

regionally representative and should not be

unduly influenced by nearby roadways.

Similarly, a nearby roadway should not act

as a local depressor of 03 concentrations for

type (2) and (3) sites.

10.4 Spacing from Trees. Trees can provide surfaces for adsorption and/or

reactions to occur and can obstruct normal

wind flow patterns. To minimize these

effects at PAMS, the probe inlet should be

placed at least 20 meters from the drip line

of trees. Since the scavenging effect of trees

is greater for 03 than for the other criteria

pollutants, strong consideration of this effect

must be given in locating the PAMS probe

inlet to avoid this problem. Therefore, the

samplers must be at least 10 meters from the

drip line of trees that are located between the

urban city core area and the sampler along

the appropriate wind direction.

10.5 Meteorological Measurements. The

10-meter meteorological tower at each PAMS

site should be located so that measurements

can be obtained that are not immediately

influenced by surrounding structures and

trees. It is important that the meteorological

data reflect the origins of, and the conditions

within, the air mass containing the pollutants

collected at the probe. Specific guidance on

siting of meteorological towers is provided in

references 31 and 32.

11. Waiver Provisions

For those SLAMS also designated as

NAMS or PAMS, the request will be

forwarded to the Administrator.

12. Discussion and Summary
Federal Register / Vol. 58, No. 28 / Friday, February 12, 1993 / Rules and Regulations 8475

TABLE 6.-SUMMARY OF PROBE SITNG CRITERIA

Distance from supporting stnucPollutant ale Height above ture, motos Otter spacing citera

ground, meters

Vertical Horizontal

VOC 3-15 >1 >1 1. Should be >20 meters from the dripline and must be 10 meters from the driline when the

tree(s) act as an obstruction.

2. Distance from probe Inlet to obstacle must be at least twice the height the obstacle protniles above the Inlet probe. 3. Must hsve unrestricted sir flow In an arc of at least 270* around the probe Inlet and the prodominant wind direction for the period of greatest pollutant concentration (as described for

each site In section 4.2 of appendix D) must be Included In the 270r arc.'f probe located on the side of a building unrestricted air flow must be 1800.

4. Spacing from roadways (see Table 5).

,When probe Is located on rooftop, this separation distance Is In reference to walls, parapets, or penthouses located on the roof.

0t .it * * d

Section 13 ofAppendix [Amended]

15. References 31- 32, and 33 are added to

section 13 of appendix E to read as follows:

13. References

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

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. Ofce of Air Quality Planning

and Standards, U.S. Environmental

Protection Agency, Research Triangle Park,

NC 27711. EPA 450/4-87-013. June 1987.

[FR Doc. 93-3072 Filed 2-11-93; 8:45 am]

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