[Federal Register: October 9, 2008 (Volume 73, Number 197)]
[Proposed Rules]
[Page 59955-60005]
[DOCID:fr09oc08-44]

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Part III

Environmental Protection Agency

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40 CFR Parts 60, 61, and 63

Standards of Performance for New Stationary Sources; National Emission
Standards for Hazardous Air Pollutants; and National Emission Standards
for Hazardous Air Pollutants for Source Categories; Proposed Rule

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 60, 61, and 63

[EPA-HQ-OAR-2006-0640; FRL-8721-4]
RIN 2060-AJ86

Performance Specification and Quality Assurance Requirements for
Continuous Parameter Monitoring Systems and Amendments to Standards of
Performance for New Stationary Sources; National Emission Standards for
Hazardous Air Pollutants; and National Emission Standards for Hazardous
Air Pollutants for Source Categories

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: This action proposes Performance Specification 17,
``Specifications and Test Procedures for Continuous Parameter
Monitoring Systems at Stationary Sources'' and Procedure 4, ``Quality
Assurance Requirements for Continuous Parameter Monitoring Systems at
Stationary Sources.'' The proposed performance specification and
quality assurance requirements establish procedures and other
requirements to ensure that the systems are properly selected,
installed, and placed into operation. This action also proposes minor
amendments to Procedure 1 of the ``Quality Assurance Requirements for
Gas Continuous Emission Monitoring Systems Used for Compliance
Determinations'' to address continuous emissions monitoring systems
that are used for monitoring multiple pollutants. Minor changes to the
General Provisions for the Standards of Performance for New Stationary
Sources, the National Emission Standards for Hazardous Air Pollutants,
and the National Emission Standards for Hazardous Air Pollutants for
Source Categories are also proposed to ensure consistency between the
proposed Performance Specification 17, Procedure 4, and the General
Provisions and to clarify that Performance Specification 17 and
Procedure 4 apply instead of requirements that pertain specifically to
continuous parameter monitoring systems. Finally, this action proposes
amendments to the current national emission standards for closed vent
systems, control devices and recovery systems to ensure consistency
with Performance Specification 17 and Procedure 4. These actions are
needed to establish consistent requirements for ensuring and assessing
the quality of data measured by continuous parameter monitoring systems
and to provide quality assurance procedures for continuous emission
monitoring systems used to monitor multiple pollutants.

DATES: Comments must be received on or before December 8, 2008. Under
the Paperwork Reduction Act, comments on the information collection
provisions must be received by the Office of Management and Budget
(OMB) on or before November 10, 2008.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2006-0640, by one of the following methods:
     http://www.regulations.gov: Follow the on-line
instructions for submitting comments.
     E-mail<EMAIL_ADDRESS>     Fax:<PHONE_NUMBER>.
     Mail: Performance Specification 17 and Procedure 4 for
Continuous Parameter Monitoring Systems Docket, Docket No. EPA-HQ-OAR-
2006-0640, Environmental Protection Agency, EPA Docket Center,
Mailcode: 6102T, 1200 Pennsylvania Ave., NW., Washington, DC 20460.
Please include a total of two copies. In addition, please mail a copy
of your comments on the information collection provisions to the Office
of Information and Regulatory Affairs, Office of Management and Budget
(OMB), Attn: Desk Officer for EPA, 725 17th St., NW., Washington, DC
20503.
     Hand Delivery: EPA Docket Center, Public Reading Room, EPA
West, Room 3334, 1301 Constitution Avenue, NW., Washington, DC 20460.
Such deliveries are only accepted during the Docket's normal hours of
operation, and special arrangements should be made for deliveries of
boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2006-0640. EPA's policy is that all comments received will be included
in the public docket without change and may be made available online at
http://www.regulations.gov, including any personal information
provided, unless the comment includes information claimed to be
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Do not submit information that you
consider to be CBI or otherwise protected through http://
www.regulations.gov or e-mail. The http://www.regulations.gov Web site
is an ``anonymous access'' system, which means EPA will not know your
identity or contact information unless you provide it in the body of
your comment. If you send an e-mail comment directly to EPA without
going through http://www.regulations.gov your e-mail address will be
automatically captured and included as part of the comment that is
placed in the public docket and made available on the Internet. If you
submit an electronic comment, EPA recommends that you include your name
and other contact information in the body of your comment and with any
disk or CD-ROM you submit. If EPA cannot read your comment due to
technical difficulties and cannot contact you for clarification, EPA
may not be able to consider your comment. Electronic files should avoid
the use of special characters, any form of encryption, and be free of
any defects or viruses.
    Docket: All documents in the docket are listed in the http://
www.regulations.gov index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy.
Publicly available docket materials are available either electronically
in http://www.regulations.gov or in hard copy at the EPA Air Docket,
EPA/DC, EPA West, Room 3334, 1301 Constitution Ave., NW., Washington,
DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday
through Friday, excluding legal holidays. The telephone number for the
Public Reading Room is<PHONE_NUMBER>, and the telephone number for the
Air Docket is<PHONE_NUMBER>.

FOR FURTHER INFORMATION CONTACT: Mr. Barrett Parker, Sector Policies
and Programs Division, Office of Air Quality Planning and Standards
(D243-05), Environmental Protection Agency, Research Triangle Park,
North Carolina 27711, telephone number:<PHONE_NUMBER>; e-mail address:
<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:
    Outline. The information presented in this preamble is organized as
follows:

I. General Information
    A. Does this action apply to you?
    B. What should you consider as you prepare your comments to EPA?
    C. Where can you get a copy of this document and other related
information?
    D. Will there be a public hearing?
II. Background
    A. What is the regulatory history of the proposed PS-17 and
Procedure 4?
    B. What is the regulatory history of the proposed amendments to
Procedure 1?
    C. What is the regulatory history of the proposed amendments to
the General Provisions to parts 60, 61, and 63?
    D. What is the regulatory history of the proposed amendments to
40 CFR part 63, subpart SS?

III. Summary of Proposed Performance Specification 17
    A. What is the purpose of PS-17?
    B. Who must comply with PS-17?
    C. When must owners or operators of affected CPMS comply with
PS-17?
    D. What are the basic requirements of PS-17?
    E. What initial performance criteria must be demonstrated to
comply with PS-17?
    F. What are the reporting and recordkeeping requirements for PS-
17?
IV. Summary of Proposed Procedure 4
    A. What is the purpose of Procedure 4?
    B. Who must comply with Procedure 4?
    C. When must owners or operators of affected CPMS comply with
Procedure 4?
    D. What are the basic requirements of Procedure 4?
    E. How often must accuracy audits and other QA/QC procedures be
performed?
    F. What are the reporting and recordkeeping requirements for
Procedure 4?
V. Summary of Proposed Amendments to Procedure 1
    A. What is the purpose of the amendments?
    B. To whom do the amendments apply?
    C. How do the amendments address CEMS that are subject to PS-9?
    D. How do the amendments address CEMS that are subject to PS-15?
VI. Summary of Proposed Amendments to the General Provisions to
Parts 60, 61, and 63
    A. What is the purpose of the amendments to the General
Provisions to parts 60, 61, and 63?
    B. What specific changes are we proposing to the General
Provisions to parts 60, 61, and 63?
VII. Summary of the Proposed Amendments to 40 CFR Part 63, Subpart
SS
    A. What is the purpose of the amendments to subpart SS?
    B. What specific changes are we proposing to subpart SS?
VIII. Rationale for Selecting the Proposed Requirements of
Performance Specification 17
    A. What information did we use to develop PS-17?
    B. How did we select the applicability criteria for PS-17?
    C. How did we select the parameters that are addressed by PS-17?
    D. Why did we include requirements for flow CPMS in PS-17 if PS-
6 already specifies requirements for flow sensors?
    E. How did we select the equipment requirements?
    F. How did we select the installation and location requirements?
    G. How did we select the initial QA measures?
    H. How did we select the methods for performing the initial
validation check?
    I. How did we select the performance criteria for the initial
validation check?
    J. How did we select the recordkeeping requirements?
IX. Rationale for Selecting the Proposed Requirements of Procedure 4
    A. What information did we use to develop Procedure 4?
    B. Why did we decide to apply Procedure 4 to all CPMS that are
subject to PS-17?
    C. How did we select the accuracy audit procedures?
    D. How did we select the accuracy audit frequencies?
    E. How did we select the performance criteria for accuracy
audits?
    F. How did we select the recordkeeping requirements?
X. Rationale for Selecting the Proposed Amendments to Procedure 1
    A. How did we select the amendments to Procedure 1 that apply to
PS-9?
    B. How did we select the amendments to Procedure 1 that apply to
PS-15?
XI. Rationale for Selecting the Proposed Amendments to the General
Provisions to Parts 60, 61, and 63
    A. How did we select the amendments to the General Provisions to
parts 60, 61, and 63?
XII. Rationale for Selecting the Proposed Amendments to 40 CFR Part
63, Subpart SS
    A. How did we select the amendments to subpart SS?
XIII. Summary of Environmental, Energy, and Economic Impacts
    A. What are the impacts of PS-17 and Procedure 4?
    B. What are the impacts of the amendments to Procedure 1?
    C. What are the impacts of the amendments to the General
Provisions to parts 60, 61, and 63?
    D. What are the impacts of the amendments to subpart SS?
XIV. Solicitation of Comments and Public Participation
XV. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
    G. Executive Order 13045, Protection of Children From
Environmental Health Risks & Safety Risks
    H. Executive Order 13211: Actions That Significantly Affect
Energy Supply, Distribution, or Use
    I. National Technology Transfer Advancement Act
    J. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Populations

I. General Information

A. Does this action apply to you?

    The proposed Performance Specification 17 (PS-17) and Procedure 4
would apply to any facility that is required to install a new
continuous parameter monitoring system (CPMS), relocate an existing
CPMS, or replace an existing CPMS under any applicable subpart of 40
CFR parts 60, 61, or 63, with certain exceptions. Moreover, the
proposed PS-17 and Procedure 4 would become effective upon permit
renewal (or within 5 years for area sources that are exempt from title
V permitting) for any affected facility subject to an applicable
subpart of 40 CFR parts 60, 61, or 63, with certain exceptions. Table 1
of this preamble lists the applicable rules by subpart and the
corresponding source categories to which the proposed PS-17 and
Procedure 4 would apply.

                    Table 1--Source Categories That Would Be Subject to PS-17 and Procedure 4
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             Subpart(s)                                             Source category
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                                                 40 CFR part 63
¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
O...................................  Commercial Ethylene Oxide Sterilization/Fumigation Facilities.
R...................................  Gasoline Distribution Facilities (Bulk Gasoline Terminals and Pipeline
                                       Breakout Stations).
S...................................  Pulp and Paper--Process Operations.
X...................................  Secondary Lead Smelters.
EE..................................  Magnetic Tape Manufacturing Operations.
GG..................................  Aerospace Manufacturing and Rework.
HH..................................  Oil and Natural Gas Production Facilities.
JJ..................................  Wood Furniture Manufacturing Operations.
KK..................................  Printing and Publishing.
MM..................................  Combustion Sources at Kraft, Soda & Sulfite Pulp & Paper Mills.

YY..................................  Spandex.
YY..................................  Cyanide Chemical Manufacture.
YY..................................  Carbon Black Production.
CCC.................................  Steel Pickling--HCl Process Facilities and Hydrochloric Acid Regeneration
                                       Plants.
EEE.................................  Hazardous Waste Combustors.
GGG.................................  Pharmaceuticals Production.
HHH.................................  Natural Gas Transmission and Storage Facilities.
MMM.................................  Pesticide Active Ingredient Production.
NNN.................................  Wool Fiberglass Manufacturing.
RRR.................................  Secondary Aluminum Production.
UUU.................................  Petroleum Refineries: Catalytic Cracking Units, Catalytic Reforming Units,
                                       and Sulfur Recovery Units.
DDDD................................  Plywood & Composite Wood Products.
EEEE................................  Organic Liquids Distribution (non-gasoline).
FFFF................................  Miscellaneous Organic Chemical Manufacturing.
HHHH................................  Wet-Formed Fiberglass Mat Production.
IIII................................  Surface Coating of Automobiles and Light Duty Trucks.
JJJJ................................  Paper & Other Web (surface coating).
KKKK................................  Surface Coating of Metal Cans.
PPPP................................  Surface Coating of Plastic Parts & Products.
QQQQ................................  Surface Coating of Wood Building Products.
RRRR................................  Surface Coating of Metal Furniture.
SSSS................................  Surface Coating of Metal Coil.
UUUU................................  Cellulose Products Manufacturing.
VVVV................................  Boat Manufacturing.
WWWW................................  Reinforced Plastics Composites Production.
XXXX................................  Rubber Tire Manufacturing.
YYYY................................  Stationary Combustion Turbines.
ZZZZ................................  Reciprocating Internal Combustion Engines.
CCCCC...............................  Coke Ovens: Pushing, Quenching, & Battery Stacks.
DDDDD...............................  Industrial/Commercial/Institutional Boilers and Process Heaters.
EEEEE...............................  Iron and Steel Foundries.
FFFFF...............................  Integrated Iron and Steel Manufacturing Facilities.
GGGGG...............................  Site Remediation.
HHHHH...............................  Miscellaneous Coating Manufacturing.
MMMMM...............................  Flexible Polyurethane Foam Fabrication Operations.
NNNNN...............................  Hydrochloric Acid Production.
PPPPP...............................  Engine Test Cells/Stands.
QQQQQ...............................  Friction Materials.
RRRRR...............................  Taconite Iron Ore Processing.
TTTTT...............................  Primary Magnesium Refining.
ZZZZZ...............................  Iron and Steel Foundries Area Sources.
LLLLLL..............................  Acrylic and Modacrylic Fibers Production Area Sources.
OOOOOO..............................  Flexible Polyurethane Foam Production and Fabrication Area Sources.
PPPPPP..............................  Lead Acid Battery Manufacturing Area Sources.
SSSSSS..............................  Glass Manufacturing Area Sources.
¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
                                                 40 CFR part 60
¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
Ea..................................  Municipal Waste Combustors after December 20, 1989 and on or before
                                       September 20, 1994.
Ec..................................  Hospital, Medical, and Infectious Waste Incinerators.
J...................................  Petroleum Refineries.
O...................................  Sewage Treatment Plants.
T, U, V, W, X.......................  Phosphate Fertilizer Industry.
Y...................................  Coal Preparation Plants (>200 tons per day).
Z...................................  Ferroalloy Production Facilities.
AA..................................  Steel Plants: EAF's and Oxygen Decarburization Vessels after October 21,
                                       1974 and on or before August 17, 1983.
BB..................................  Kraft Pulp Mills.
HH..................................  Lime Manufacturing Plants.
LL..................................  Metallic Mineral Processing Plants.
NN..................................  Phosphate rock plants (with prod. capacity >4 ton/hr).
PP..................................  Ammonium Sulfate Manufacture.
RR..................................  Pressure Sensitive Tape and Label Surface Coating Operations.
FFF.................................  Flexible Vinyl and Urethane Coating and Printing.
LLL.................................  Onshore Natural Gas Processing: SO2 Emissions.

UUU.................................  Calciners and Dryers in Mineral Industries.
VVV.................................  Polymeric Coating of Supporting Substrates Facilities.
AAAA................................  Small Municipal Waste Combustion Units Constructed after August 30, 1999.
¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
                                                 40 CFR part 61
¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤¤
K...................................  Radionuclide Emissions from Elemental Phosphorus Plants.
L...................................  Benzene from Coke By-Product Recovery Plants.
BB..................................  Benzene Emissions from Benzene Transfer Operations.
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    The requirements of the proposed PS-17 and Procedure 4 may also
apply to stationary sources located in a State, District, Reservation,
or Territory that adopts PS-17 or Procedure 4 in its implementation
plan. The exceptions to the applicability criteria for PS-17 and
Procedure 4 are those source categories that are subject to part 63
rules that specify that Sec.  63.8(a)(2) of the General Provisions for
the National Emission Standards for Hazardous Air Pollutants (NESHAP)
for Source Categories in 40 CFR part 63, subpart A does not apply to
the source category. Section 63.8(a)(2) specifies that rules
promulgated under part 63 are subject to the monitoring provisions of
Sec.  63.8 upon promulgation of performance specifications (i.e., the
proposed PS-17). Consequently, rules which specify that Sec.
63.8(a)(2) does not apply, are not subject to PS-17 or Procedure 4.
Table 2 of this preamble lists the part 63 rules that require CPMS but
would not be subject to PS-17 or Procedure 4 for this reason.

                           Table 2--Part 63 Rules Not Subject to PS-17 or Procedure 4
                                       [Sec.   63.8(a)(2) does not apply]
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                   Subpart(s)                                            Source category
----------------------------------------------------------------------------------------------------------------
F, G, H, I.....................................  Hazardous Organic NESHAP.
U..............................................  Polymers and Resins (Group I).
AA.............................................  Phosphoric Acid Plants.
BB.............................................  Phosphate Fertilizer Production.
CC.............................................  Petroleum Refineries.
DD.............................................  Offsite Waste and Recovery Operations.
DDD............................................  Mineral Wool.
III............................................  Flexible Polyurethane Foam Production.
JJJ............................................  Polymers and Resins (Group IV).
LLL............................................  Portland Cement Manufacturing.
OOO............................................  Amino/Phenolic Resins Production.
PPP............................................  Polyether Polyols Production.
AAAA...........................................  Municipal Solid Waste Landfills.
TTTT...........................................  Leather Tanning and Finishing Operations.
IIIII..........................................  Mercury Cell Chlor-Alkali Plants.
LLLLL..........................................  Asphalt Roofing and Processing.
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    The standard industrial classification (SIC) codes and North
American Industry Classification System (NAICS) codes that correspond
to potentially regulated entities are listed in Tables 3 and 4 of this
preamble, respectively. To determine the specific types of industry
referenced by the SIC or NAICS codes, go to http://www.osha.gov/pls/
imis/sic_manual.html or http://www.osha.gov/oshstats/naics-
manual.html, respectively.

          Table 3--SIC Codes for Potentially Regulated Entities
------------------------------------------------------------------------
                                SIC code
-------------------------------------------------------------------------
12, 42, 44, 47, 109, 279, 281, 282, 283, 284, 285, 286, 287, 289, 386,
 1011, 1021, 1031, 1041, 1044, 1051, 1061, 1099, 1311, 1321, 1411, 1422,
 1423, 1429, 1442, 1445, 1446, 1454, 1455, 1459, 1474, 1475, 1479, 1492,
 1496, 1499, 2034, 2035, 2046, 2099, 2211, 2241, 2295, 2296, 2392, 2394,
 2396, 2399, 2421, 2426, 2429, 2431, 2435, 2436, 2439, 2441, 2448, 2449,
 2451, 2452, 2491, 2493, 2499, 2514, 2522, 2531, 2542, 2599, 2611, 2621,
 2631, 2652, 2653, 2655, 2656, 2657, 2671, 2672, 2673, 2674, 2675, 2676,
 2677, 2678, 2679, 2711, 2721, 2741, 2754, 2759, 2761, 2771, 2812, 2813,
 2816, 2819, 2821, 2822, 2823, 2824, 2832, 2833, 2834, 2835, 2836, 2841,
 2842, 2843, 2844, 2851, 2861, 2865, 2869, 2873, 2874, 2875, 2879, 2891,
 2892, 2893, 2895, 2899, 2911, 2951, 2952, 2992, 2999, 3011, 3021, 3052,
 3053, 3061, 3069, 3074, 3079, 3081, 3082, 3083, 3084, 3085, 3086, 3087,
 3088, 3089, 3111, 3131, 3142, 3143, 3144, 3149, 3161, 3171, 3172, 3199,
 3211, 3221, 3229, 3274, 3281, 3291, 3292, 3295, 3296, 3299, 3312, 3313,
 3315, 3316, 3317, 3321, 3322, 3324, 3325, 3329, 3331, 3334, 3339, 3341,
 3351, 3353, 3354, 3355, 3356, 3357, 3363, 3364, 3365, 3366, 3369, 3398,
 3399, 3411, 3412, 3421, 3423, 3425, 3429, 3431, 3432, 3441, 3442, 3443,
 3444, 3446, 3448, 3449, 3451, 3452, 3462, 3463, 3465, 3466, 3469, 3471,
 3479, 3482, 3483, 3484, 3489, 3491, 3492, 3493, 3494, 3495, 3497, 3499,
 3511, 3519, 3523, 3524, 3531, 3537, 3543, 3545, 3559, 3562, 3566, 3568,
 3569, 3579, 3585, 3592, 3599, 3621, 3634, 3639, 3644, 3645, 3646, 3647,
 3663, 3677, 3691, 3693, 3694, 3695, 3711, 3713, 3714, 3715, 3716, 3720,
 3721, 3724, 3726, 3728, 3731, 3732, 3743, 3751, 3760, 3761, 3764, 3765,
 3769, 3792, 3795, 3799, 3821, 3829, 3841, 3842, 3843, 3851, 3861, 3911,
 3914, 3915, 3931, 3942, 3944, 3949, 3951, 3952, 3953, 3955, 3961, 3965,
 3991, 3993, 3995, 3996, 3999, 4225, 4226, 4512, 4581, 4612, 4911, 4922,
 4923, 4924, 4925, 4931, 4932, 4939, 4941, 4952, 4953, 4961, 4971, 5086,
 5122, 5149, 5169, 5171, 5172, 5541, 5995, 7218, 7231, 7241, 7391, 7397,
 7399, 7534, 7538, 7539, 7641, 7699, 7911, 7999, 8062, 8063, 8069, 8071,
 8072, 8091, 8211, 8221, 8222, 8231, 8243, 8244, 8249, 8299, 8411, 8711,
 8731, 8734, 8741, 8748, 8922, 9511, 9661, 9711
------------------------------------------------------------------------

         Table 4--NAICS Codes for Potentially Regulated Entities
------------------------------------------------------------------------
                               NAICS code
-------------------------------------------------------------------------
211, 221, 316, 321, 322, 324, 325, 326, 331, 332, 336, 339, 611, 622,
 2123, 2211, 3231, 3241, 3251, 3252, 3253, 3254, 3255, 3256, 3259, 3271,
 3273, 3274, 3279, 3327, 3328, 3329, 3332, 3335, 3339, 3341, 3342, 3343,
 3344, 3361, 3362, 3363, 4227, 5622, 5629, 21221, 22121, 22132, 31332,
 32211, 32222, 32411, 32613, 32614, 32615, 32791, 33422, 33634, 33992,
 33995, 42269, 42271, 45431, 48611, 48621, 49311, 49319, 51113, 51114,
 51223, 54171, 56220, 56221, 56292, 81142, 92411, 92711, 92811, 111998,
 112519, 112910, 112990, 211111, 211112, 212111, 212112, 212113, 212210,
 212221, 212222, 212231, 212234, 212299, 212319, 212322, 212324, 212325,
 212393, 212399, 213113, 221112, 221320, 238910, 311211, 311212, 311221,
 311225, 311340, 311421, 311423, 311823, 311830, 311911, 311920, 311941,
 311942, 311991, 311999, 313210, 313320, 314911, 314992, 315299, 315999,
 321211, 321212, 321213, 321214, 321219, 321911, 321918, 321999, 322110,
 322121, 322122, 322130, 322211, 322212, 322213, 322215, 322221, 322222,
 322223, 322224, 322225, 322226, 322231, 322291, 322299, 323111, 323112,
 323116, 323119, 324121, 324199, 325131, 325181, 325182, 325188, 325192,
 325199, 325211, 325221, 325222, 325311, 325312, 325320, 325411, 325412,
 325991, 326111, 326113, 326121, 326122, 326150, 326191, 326192, 326199,
 326211, 326212, 326299, 327211, 327212, 327213, 327410, 327991, 327992,
 327993, 327999, 331111, 331112, 331210, 331221, 331222, 331312, 331315,
 331316, 331319, 331419, 331492, 331511, 331512, 331513, 331521, 331524,
 332115, 332116, 332212, 332431, 332612, 332618, 332812, 332912, 332951,
 332999, 333111, 333112, 333120, 333313, 333319, 333611, 333612, 333613,
 333618, 334613, 335121, 335122, 335312, 335911, 336111, 336112, 336120,
 336211, 336213, 336214, 336312, 336350, 336399, 336411, 336412, 336413,
 336414, 336415, 336419, 336612, 336992, 336999, 337124, 337127, 337214,
 337215, 339111, 339112, 339114, 339911, 339912, 339914, 339999, 424690,
 424720, 425110, 425120, 481111, 483111, 483112, 483113, 483114, 483211,
 483212, 484110, 484121, 484122, 484210, 484220, 484230, 487210, 488111,
 488119, 488190, 488310, 488320, 488330, 488390, 488490, 492110, 492210,
 493110, 493120, 493130, 493190, 511199, 531130, 532411, 541380, 541710,
 541990, 561720, 562111, 562112, 562119, 562213, 562219, 611310, 611692,
 622110, 622310, 713930, 811111, 811118, 811310, 811411, 811420, 924110,
 928110
------------------------------------------------------------------------

    The proposed amendments to Procedure 1 (40 CFR part 60, appendix F)
would apply to any facility that operates a continuous emission
monitoring system (CEMS) that is subject to PS-9 or PS-15 (40 CFR part
60, appendix B) and also must comply with 40 CFR part 60, appendix F.
The proposed amendments to the General Provisions to 40 CFR parts 60,
61, and 63 would apply to the same facilities that the proposed PS-17
and Procedure 4 would apply. The proposed amendments to 40 CFR part 63,
subpart SS, would apply to producers and coproducers of hydrogen
cyanide; sodium cyanide; carbon black by thermal-oxidative
decomposition in a closed system, thermal decomposition in a cyclic
process, or thermal decomposition in a continuous process; ethylene
from refined petroleum or liquid hydrocarbons; and spandex by reaction
spinning.
    To determine whether your facility would be regulated by this
action, you should examine the applicability criteria in section 1.2 of
proposed PS-17 and the applicability criteria in the part 60, 61, or 63
standard to which your facility is subject. If you have any questions
regarding the applicability of this action to a particular entity,
consult either the air permit authority for the entity or your EPA
regional representative as listed in Sec.  63.13 of the General
Provisions to part 63 (40 CFR part 63, subpart A).

B. What should you consider as you prepare your comments for EPA?

    Do not submit information containing CBI to EPA through http://
www.regulations.gov or e-mail. Send or deliver information identified
as CBI only to the following address: Roberto Morales, OAQPS Document
Control Officer (C404-02), U.S. EPA, Office of Air Quality Planning and
Standards, Research Triangle Park, North Carolina 27711, Attention
Docket ID EPA-HQ-OAR-2006-0640. Clearly mark the part or all of the
information that you claim to be CBI. For CBI information in a disk or
CD-ROM that you mail to EPA, mark the outside of the disk or CD-ROM as
CBI and then identify electronically within the disk or CD-ROM the
specific information that is claimed as CBI. In addition to one
complete version of the comment that includes information claimed as
CBI, a copy of the comment that does not contain the information
claimed as CBI must be submitted for inclusion in the public docket.
Information so marked will not be disclosed except in accordance with
procedures set forth in 40 CFR part 2.

C. Where can you get a copy of this document and other related
information?

    In addition to being available in the docket, an electronic copy of
these proposed actions will also be available on the Worldwide Web
(WWW) through the Technology Transfer Network (TTN). A copy of this
proposed action will be posted on the TTN's policy and guidance page
for newly proposed or promulgated rules at the following address:
http://www.epa.gov/ttn/oarpg/. The TTN provides information and
technology exchange in various areas of air pollution control.

D. Will there be a public hearing?

    The EPA will hold a public hearing on this proposed rule only if
requested by November 10, 2008. The request for a public hearing should
be made in writing and addressed to Mr. Barrett Parker, Sector Policies
and Programs Division, Office of Air Quality Planning and Standards
(D243-05), U.S. Environmental Protection Agency, Research Triangle
Park, North Carolina 27711. The hearing, if requested, will be held on
a date and at a place published in a separate Federal Register notice.

II. Background

A. What is the regulatory history of the proposed PS-17 and Procedure
4?

    Monitoring of emissions, control device operating parameters, and
process operations has been a requirement of many of the emission
standards that we have promulgated under the authority of the Clean Air
Act (CAA). Recognizing the need for good quality data, we initially
developed performance specifications for CEMS. These performance
specifications stipulate CEMS equipment design, location, and
installation requirements and focus on the initial performance of CEMS.
To address the ongoing performance of CEMS, we developed quality
assurance (QA) procedures.
    The basis for performance specifications for CPMS was initially
established by the General Provisions for Standards of Performance for
New Stationary Sources in 40 CFR part 60, subpart A. Section 60.13(a),
which addresses monitoring requirements, states that ``* * * all
continuous monitoring systems required under applicable subparts shall
be subject to the provisions of this section upon promulgation of
performance specifications for continuous monitoring systems under
appendix B to this part * * *'' As defined in Sec.  60.2, these
``continuous monitoring systems'' include those systems that are used
to measure and record process parameters. Section 60.13 specifies basic
requirements for the installation, validation, and operation of
continuous monitoring systems, including CPMS. General recordkeeping
requirements for CPMS required under part 60 are specified in Sec.
60.7(f).
    Section 61.14 of the NESHAP General Provisions in 40 CFR part 61,
subpart A also addresses CPMS, although in less detail than does Sec.
60.13. Included in the requirements for CPMS under part 61 are
provisions for the general operation and maintenance of continuous
monitoring systems, monitoring system performance evaluations, and
recordkeeping.
    With the enactment of the Clean Air Act Amendments of 1990 (1990
Amendments), we have placed increased emphasis on the collection and
use of monitoring data as a means of ensuring continuous compliance
with emission standards. In response to the mandates of the 1990
Amendments, we incorporated into the General Provisions to part 63,
basic requirements for all continuous monitoring systems (CMS). Section
63.2 broadly defines CMS to include CPMS, as well as CEMS and other
forms of monitoring that are used to demonstrate compliance with
applicable regulations. In Sec.  63.8(a)(2), the General Provisions
specify that, ``* * * all CMS required under relevant standards shall
be subject to the provisions of this section upon promulgation of
performance specifications for CMS as specified in the relevant
standard or otherwise by the Administrator.'' As is the case for part
60, the General Provisions to part 63 establish the need for
performance specifications for CPMS.
    Rules promulgated under parts 60, 61, and 63 generally require
owners or operators of affected sources to use CPMS to monitor the
performance of emission control devices associated with those sources.
Although many of these standards specify general design, installation,
and calibration requirements for CPMS, these rules do not include
specific performance requirements for CPMS. In addition, neither the
General Provisions nor the subparts to parts 60, 61, and 63 fully
specify procedures and criteria for ensuring that CPMS provide good
quality data initially and on an ongoing basis. By proposing a new
performance specification and QA procedure specifically for CPMS, we
would be establishing standards for the design, installation,
operation, and maintenance of CPMS that will help to ensure the
generation of good quality data on a consistent basis.
    The proposed requirements for CPMS also reflect EPA's commitment to
improving the quality of data collected and disseminated by the Agency.
Although we have always recognized its importance, there has been
increased emphasis on ensuring data quality in response to section 515
of the Treasury and General Government Appropriations Act for Fiscal
Year 2001 (Pub. L. 106-554), which directs the OMB to issue guidelines
that ``provide policy and procedural guidance to Federal agencies for
ensuring and maximizing the quality, objectivity, utility, and
integrity of information * * * disseminated by Federal agencies.'' On
September 28, 2001, OMB issued final Guidelines for Ensuring and
Maximizing the Quality, Objectivity, Utility, and Integrity of
Information Disseminated by Federal Agencies (66 FR 49718). These
guidelines require Federal agencies to adopt ``* * * a basic standard
of quality (including objectivity, utility, and integrity) as a
performance goal and should take appropriate steps to incorporate
information quality criteria into agency dissemination practices.'' The
guidelines also require agencies to ``* * * develop a process for
reviewing the quality (including objectivity, utility, and integrity)
of information before it is disseminated * * *'' and that the process
must ``* * * enable the agency to substantiate the quality of the
information it has disseminated through documentation or other means
appropriate to the information.''
    In response to the OMB guidelines, we developed ``Guidelines for
Ensuring and Maximizing the Quality, Objectivity, Utility, and
Integrity of Information Disseminated by the Environmental Protection
Agency'' (EPA/260R-02-008, October 2002). As noted in these guidelines,
we are committed to ensuring the quality control of information
collected through regulatory requirements, such as this proposed rule,
by specifying analytical procedures for data collection and sample
analysis that will produce good quality data. We believe the procedures
specified in the proposed PS-17 and Procedure 4 will help to ensure the
quality of data measured and recorded by affected CPMS, which may
subsequently be collected and disseminated by EPA.
    This proposed rule also represents an important part of our efforts
to implement the recommendations developed by the Air Quality
Management Work Group in response to the National Research Council
(NRC) report on Air Quality Management in the United States.
Specifically, the

recommendations developed by the Work Group call for improving
emissions factors and other emissions estimation methods and reducing
the uncertainty in emissions inventories and air quality modeling
applications. When emissions factors and other methods are used to
estimate emissions from controlled sources, the assumption is that the
control device is operating properly. The improved monitoring of air
pollution control device parameters that would be achieved by the
proposed PS-17 and Procedure 4 would help to ensure that affected
control devices are operated properly, and, when problems arise,
corrective action is taken in a timely manner. Furthermore, the
improved monitoring will help to reduce the uncertainty and improve the
reliability of emission estimates that typically are based on the
assumptions that emission controls are being operated properly and are
performing as designed.

B. What is the regulatory history of the proposed amendments to
Procedure 1?

    Quality Assurance Procedure 1 of 40 CFR part 60, appendix F,
specifies QA procedures for CEMS. At the time that Procedure 1 was
promulgated, affected CEMS were designed to monitor a single gaseous
pollutant. Since that time, emission standards have been promulgated
under parts 60, 61, and 63 that require the installation and operation
of CEMS that monitor multiple pollutants. Although most of the
provisions of Procedure 1 can be applied directly to multiple pollutant
CEMS, there are differences in how multiple pollutant CEMS operate and
how their performance should be assessed. We are proposing amendments
to Procedure 1 to address those differences.

C. What is the regulatory history of the proposed amendments to the
General Provisions to parts 60, 61, and 63?

    The only purpose of these proposed amendments to the General
Provisions to parts 60 and 61 is to ensure consistency between those
provisions, the applicable subparts to parts 60 and 61 that require the
use of CPMS, and the requirements of the proposed PS-17 and Procedure
4. As this is the initial proposal of PS-17 and Procedure 4, there is
no regulatory history to these proposed amendments to the General
Provisions to parts 60 and 61.
    We proposed amendments to the monitoring requirements of the
General Provisions to part 63 on March 23, 2001 (66 FR 16318) and
promulgated those amendments on April 5, 2002 (67 FR 16582). At the
time we proposed those amendments, we had not yet developed PS-17 or
Procedure 4. As a result, the amendments to the General Provisions,
which were incorporated into Sec.  63.8, are not consistent with the
requirements of PS-17 and Procedure 4 that we are now proposing. With
this proposal of PS-17 and Procedure 4, we decided that additional
amendments to the General Provisions to part 63 were needed to ensure
consistency between subpart A of part 63, PS-17, Procedure 4, and the
applicable subparts to part 63 that require CPMS.

D. What is the regulatory history of the proposed amendments to 40 CFR
part 63, subpart SS?

    On June 29, 1999, we promulgated the consolidated rulemaking
proposal for the ``generic MACT standards'' program (64 FR 34866). The
generic MACT program established an alternative methodology for making
maximum achievable control technology (MACT) determinations for
appropriate small categories by referring to previous MACT standards
that have been promulgated for similar sources in other categories.
Initially, the generic MACT standards applied to four source
categories: Acetal Resins Production, Acrylic and Modacrylic Fibers
Production, Hydrogen Fluoride Production, and Polycarbonate Production.
We included in the consolidated rulemaking package general control
requirements for certain types of hazardous air pollutant (HAP)
emissions from storage vessels containing organic materials, process
vents emitting organic vapors, and leaks from equipment components. We
also established a separate subpart SS, which specifies requirements
for closed vent systems, control devices, recovery devices and routing
emissions to fuel gas systems or a process. We included in Sec.  63.996
of subpart SS general monitoring requirements for control and recovery
devices. On December 6, 2000, we proposed revisions to the monitoring
requirements of subpart SS (65 FR 76444). Those proposed revisions
specified in greater detail the requirements for CPMS that are used to
monitor temperature, pressure, or pH. At the time these revisions to
subpart SS were proposed, we were in the early stages of developing PS-
17 and Procedure 4 and had not yet refined many of the requirements for
CPMS that we are proposing today. However, with this proposal of PS-17
and Procedure 4, we concluded that it would be appropriate to propose
further amendments to subpart SS to ensure consistency with PS-17 and
Procedure 4.

III. Summary of Proposed Performance Specification 17

A. What is the purpose of PS-17?

    The purpose of PS-17 is to establish the initial installation and
performance procedures that are required for evaluating the
acceptability of a CPMS that is used to monitor specific process or
control device parameters. The specific parameters that would be
addressed by the proposed PS-17 are temperature, pressure, liquid flow
rate, gas flow rate, mass flow rate, pH, and conductivity. Mass flow
rate includes the mass flow of liquids as well as solids, such as the
flow of powders or dry solid material into a processing unit. As
proposed, the requirements for the selection, installation, and
validation of CPMS specified in PS-17 would apply instead of the
corresponding requirements in an applicable subpart to parts 60, 61, or
63 that requires the use of CPMS for monitoring temperature, pressure,
flow rate, pH, or conductivity.

B. Who must comply with PS-17?

    The proposed PS-17 would apply to CPMS that are used to monitor
temperature, pressure, liquid flow rate, gas flow rate, mass flow rate,
pH, or conductivity as indicators of good control device performance or
emission source operation. If adopted as a final rule, owners and
operators of emission sources that would be required to install and
operate any such CPMS under any subpart of parts 60, 61, or 63 (listed
in Table 1 of this preamble) would be required to comply with PS-17,
with the exception of facilities that are subject to the part 63 rules
that are listed in Table 2 of this preamble. In addition to new CPMS
that are installed after the proposed effective date of PS-17, existing
CPMS that are required under parts 60, 61, or 63 also would be required
to comply with PS-17.

C. When must owners or operators of affected CPMS comply with PS-17?

    Owners and operators of affected existing CPMS that were installed
prior to the effective date of this rule and are located at facilities
that are required to obtain a title V operating permit would be
required to comply with PS-17 when they renew their title V permit, or
when they replace any key components of an affected CPMS. The key
components of a CPMS are the sensors, data recorders, and any other
parts of the CPMS that affect overall system accuracy, measurement
range, or measurement resolution. Owners and operators of affected
existing CPMS that were installed prior to the effective date of this
rulemaking and are located at area

source facilities that are exempt from obtaining a title V operating
permit would be required to comply with PS-17 within 5 years of the
effective date of this rule, or when they replace any key components of
an affected CPMS. Owners and operators of new affected CPMS would have
to comply with the proposed PS-17 when they install and place into
operation the affected CPMS.

D. What are the basic requirements of PS-17?

    The proposed PS-17 would require owners and operators of affected
CPMS to: (1) Select a CPMS that satisfies basic equipment design
criteria; (2) install their CPMS according to standard procedures; (3)
validate their CPMS prior to placing it into operation; and (4) record
and maintain information on their CPMS and its operation. The technical
rationales for proposed criteria, specifications, and other related
requirements of PS-17 are described in section VIII of this document.
1. Equipment Selection
    Two types of equipment would be needed for complying with PS-17:
(1) the components that comprise the CPMS, and (2) the equipment that
is used to validate the CPMS. For CPMS components, PS-17 would require
the selection of equipment that can satisfy basic criteria for
measurement range, resolution, and overall system accuracy.
    For CPMS components, PS-17 does not specify sensor design criteria,
allowing affected owners and operators to select any equipment,
provided the CPMS meets the accuracy requirements for the initial
validation. However, PS-17 would identify voluntary consensus standards
that can be used as guidelines for selecting specific types of sensors.
    For a temperature CPMS, PS-17 would require a sensor that is
consistent with one of the following standards: (1) ASTM E235-06,
``Specification for Thermocouples, Sheathed, Type K, for Nuclear or
Other High-Reliability Applications''; (2) ASTM E585/E585M-04,
``Specification for Compacted Mineral-Insulated, Metal-Sheathed Base
Metal Thermocouple Cables''; (3) ASTM E608/E608M-06, ``Specification
for Mineral-Insulated, Metal-Sheathed Base Metal Thermocouples''; (4)
ASTM E696-07, ``Specification for Tungsten-Rhenium Alloy Thermocouple
Wire''; (5) ASTM E1129/E1129M-98 (2002), ``Standard Specification for
Thermocouple Connectors''; (6) ASTM E 1159-98 (2003), ``Specification
for Thermocouple Materials, Platinum-Rhodium Alloys, and Platinum'';
(7) ISA-MC96.1-1982, ``Temperature Measurement Thermocouples''; or (8)
ASTM E 1137/E 1137M-04, ``Standard Specification for Industrial
Platinum Resistance Thermometers'' (incorporated by reference-see Sec.
60.17)
    For a pressure CPMS that uses a pressure gauge as the sensor, PS-17
would require a gauge that conforms to the design requirements of ASME
B40.100-2005, ``Pressure Gauges and Gauge Attachments'' (incorporated
by reference-see Sec.  60.17).
2. Range
    With respect to measurement range, this proposed rule would require
that temperature, pressure, flow rate, and conductivity CPMS be capable
of measuring the appropriate parameter over a range that extends at
least 20 percent beyond the normal expected operating range of values
for that parameter. For example, if the pressure drop measurement
across a scrubber typically ranges from 5.0 to 7.5 kilopascals (kPa)
(20 to 30 inches of water column (in. wc)), the range of the data
recorder for a CPMS that monitors that pressure drop would have to
extend from at least 4.0 to 9.0 kPa (16 to 36 in. wc). For pH CPMS, the
proposed PS-17 would require that the CPMS data recorder range covers
the entire pH scale from 0 to 14.
3. Resolution
    The data recording system associated with affected CPMS would
require a resolution that is equal to or better than one-half of the
required system accuracy. For example, if a temperature CPMS is
required to have an accuracy of 1 [deg]C, the required resolution for
the CPMS would be 0.5 [deg]C, or better.
4. Accuracy
    The accuracy criteria for CPMS, which are a function of the
parameter that is measured by the CPMS, are described in detail in
section II.E of this document.
    For devices or instruments that are used to validate or check the
initial accuracy of a temperature, pressure, or flow CPMS, PS-17
generally would require an accuracy hierarchy of three. In other words,
the ratio of the required accuracy of the CPMS to the accuracy of the
calibrated validation device would have to be at least three. For
example, if the required accuracy of a temperature CPMS is 1.0 percent, to satisfy the accuracy hierarchy of three
criterion, the calibrated validation device would need an accuracy of
0.33 percent or better (1.0 / 0.33 = 3). A CPMS with an
accuracy of 0.25 percent would satisfy the accuracy hierarchy
criterion, but a CPMS with an accuracy of 0.5 percent would not satisfy
the accuracy hierarchy criterion in this example. The accuracy of the
equipment used to validate the CPMS also would have to be traceable to
National Institute of Standards and Technology (NIST) standards. We
have incorporated into the proposed PS-17 two exceptions to the
accuracy requirements for instruments that are used to validate CPMS.
First, a mercury-in-glass or water-in-glass U-tube manometer could be
used instead of a calibrated pressure measurement device with NIST-
traceable accuracy when validating a pressure CPMS or a flow CPMS that
uses a differential pressure flow meter. Secondly, for instruments and
reagents that are used to validate a pH CPMS, the performance
specification would require NIST-traceable accuracy of 0.02 pH units or
better, rather than an accuracy hierarchy of three.
5. Installation
    The PS-17 would require each CPMS sensor to be located so as to
provide representative measurements of the appropriate parameter. The
proposed PS-17 also lists voluntary consensus standards that could
serve as guidelines for installing specific types of sensors. Voluntary
consensus standards are technical standards that are developed or
adopted by one or more voluntary consensus standards bodies, such as
the American Society for Testing and Materials (ASTM) or the American
Society of Mechanical Engineers (ASME).
    If required to install a flow CPMS and the sensor of the flow CPMS
is a differential pressure device, turbine flow meter, rotameter,
vortex formation flow meter or Coriolis mass flow meter, PS-17 would
allow one of the following standards to be used as guidance: (1) ASME
MFC-3M-2004, ``Measurement of Fluid Flow in Pipes Using Orifice,
Nozzle, and Venturi''; (2) ANSI/ASME MFC-7M-1987 (R2001), ``Measurement
of Gas Flow by Means of Critical Flow Venturi Nozzles''; (3) ANSI/ISA
RP 31.1-1977, ``Recommended Practice: Specification, Installation, and
Calibration of Turbine Flowmeters''; (4) ANSI/ASME MFC 4M-1986 (R2003),
``Measurement of Gas Flow by Turbine Meters'' (if used for gas flow
measurement); (5) ISA RP 16.5-1961, ``Installation, Operation, and
Maintenance Instructions for Glass Tube Variable Area Meters
(Rotameters)''; (6) ISO 10790:1999(E), ``Measurement of Fluid Flow in
Closed Conduits-Guidance to the Selection, Installation and Use of
Coriolis Meters (Mass Flow, Density and Volume Flow Measurements); or
(7) ANSI/ASME MFC-6M-1998 (R2005) ``Measurement

of Fluid Flow in Pipes Using Vortex Flow Meters'' (incorporated by
reference--see Sec.  60.17).
    There are also several voluntary consensus standards that can be
used as alternative methods for checking the accuracy of specific types
of CPMS sensors. Prior to validating the performance of a CPMS, owners
and operators would be required to install work platforms, test ports,
taps, valves, or any other equipment needed to perform the initial
validation check.
6. CPMS Validation
    Under this proposed rule, we would require owners and operators of
affected CPMS to demonstrate that affected CPMS meet a minimum overall
system accuracy. Several methods are specified for checking CPMS
accuracy, and owners and operators of affected CPMS could choose among
the methods specified for each type of CPMS. These validation methods
generally would involve either: (1) Comparing measurements made by the
affected CPMS to measurements made by a calibrated measurement device,
or (2) simulating the signal generated by the CPMS sensor using a
calibrated simulation device. Table 5 of this preamble lists the CPMS
validation methods specified in the proposed PS-17 and their
applicability. As part of specific validation methods, the proposed PS-
17 specifies several voluntary consensus standards as alternative
methods for checking sensor accuracy.

                Table 5--CPMS Initial Validation Methods
------------------------------------------------------------------------
                                You can validate      If the sensor of
 If your CPMS measures . . .   your CPMS by . . .    your CPMS is . . .
------------------------------------------------------------------------
1. Temperature..............  a. Comparison to a    Thermocouple, RTD,
                               calibrated            or any other type
                               temperature           of temperature
                               measurement device.   sensor.
                              b. Temperature        Thermocouple, RTD,
                               simulation.           or any other type
                                                     of sensor that
                                                     generates an
                                                     electronic signal
                                                     that can be related
                                                     to temperature
                                                     magnitude.
------------------------------------------------------------------------
2. Pressure.................  a. Comparison to a    Pressure transducer,
                               calibrated pressure   pressure gauge, or
                               measurement device.   any other type of
                                                     pressure sensor.
                              b. Pressure           Pressure transducer,
                               simulation            pressure gauge, or
                               procedure using a     any other type of
                               calibrated pressure   pressure sensor.
                               source.
                              c. Pressure           Pressure transducer,
                               simulation using a    pressure gauge, or
                               pressure source and   any other type of
                               a calibrated          pressure sensor.
                               pressure
                               measurement device.
------------------------------------------------------------------------
3. Liquid flow rate.........  a. Volumetric method  Any type of liquid
                                                     flow meter.
                              b. Gravimetric        Any type of liquid
                               method.               flow meter.
                              c. Differential       Orifice plate, flow
                               pressure              nozzle, or other
                               measurement method.   type of
                                                     differential
                                                     pressure liquid
                                                     flow meter.
                              d. Pressure source    Orifice plate, flow
                               flow simulation       nozzle, or other
                               method.               type of
                                                     differential
                                                     pressure liquid
                                                     flow meter.
                              e. Electronic signal  Turbine flow meter,
                               simulation method.    vortex shedding
                                                     flow meter, or any
                                                     other type of
                                                     liquid flow meter
                                                     that generates an
                                                     electronic signal
                                                     that can be related
                                                     to flow rate
                                                     magnitude.
------------------------------------------------------------------------
4. Gas flow rate............  a. Differential       Orifice plate, flow
                               pressure              nozzle, or any
                               measurement method.   other type of
                                                     differential
                                                     pressure gas flow
                                                     meter other than a
                                                     differential
                                                     pressure tube.
                              b. Pressure source    Orifice plate, flow
                               flow simulation       nozzle, or any
                               method.               other type of
                                                     differential
                                                     pressure gas flow
                                                     meter other than a
                                                     differential
                                                     pressure tube.
                              c. Electronic signal  Any type of gas flow
                               simulation method.    meter that
                                                     generates an
                                                     electronic signal
                                                     that can be related
                                                     to flow rate
                                                     magnitude.
                              d. Relative accuracy  Any type of gas flow
                               test.                 meter.
------------------------------------------------------------------------
5. Liquid mass flow rate....  Gravimetric method..  Any type of liquid
                                                     flow meter.
------------------------------------------------------------------------
6. Solid mass flow rate.....  a. Gravimetric        Any type of solid
                               method.               mass flow meter.
                              b. Material weight    Belt conveyor with
                               comparison method.    weigh scale,
                                                     equipped with a
                                                     totalizer.
------------------------------------------------------------------------
7. pH.......................  a. Comparison to      Any type of pH
                               calibrated pH meter.  meter.
                              b. Single point       Any type of pH
                               calibration.          meter.
------------------------------------------------------------------------
8. Conductivity.............  a. Comparison to      Any type of
                               calibrated            conductivity meter.
                               conductivity meter.
                              b. Single point       Any type of
                               calibration.          conductivity meter.
------------------------------------------------------------------------

7. Temperature CPMS Validation
    Under this proposed rule, the performance of a temperature CPMS
could be validated by comparing measured values to a calibrated
temperature measurement device or by simulating a typical operating
temperature using a calibrated temperature simulation device. When the
calibrated temperature measurement device method is used, the sensor of
the calibrated device would have to be located adjacent to the CPMS
sensor and must be subjected to the same

environmental conditions as the CPMS sensor. In addition, the
measurements made using the CPMS and calibrated temperature measurement
device would have to be concurrent. The method is based on ASTM E 220-
07e1, ``Standard Test Methods for Calibration of Thermocouples by
Comparison Techniques'' (incorporated by reference--see Sec.  60.17).
    An alternative method for thermocouples is ASTM E 452-02 (2007),
``Standard Test Method for Calibration of Refractory Metal
Thermocouples Using an Optical Pyrometer'' and an alternative method
for resistance temperature detectors is ASTM E 644-06, ``Standard Test
Methods for Testing Industrial Resistance Thermometers'' (incorporated
by reference--see Sec.  60.17).
8. Pressure CPMS Validation
    To validate the performance of a pressure CPMS, owners and
operators could choose from one of three methods: (1) Comparison to a
calibrated pressure measurement device, (2) pressure simulation using a
calibrated pressure source, or (3) pressure simulation using a pressure
source and calibrated pressure measurement device. Prior to performing
the initial validation check of a pressure CPMS, PS-17 would require a
leak test on all connections between the process line that is
monitored, the CPMS, and the calibrated device that is used as the
basis for comparison. If the calibrated pressure measurement device
comparison were used, the measurements by the CPMS and calibrated
device would have to be concurrent.
    As an alternative to the initial validation check, PS-17 would
allow the user to check the accuracy of the pressure sensor associated
with the pressure CPMS using one of the following methods: (1) ASME
B40.100-2005, ``Pressure Gauges and Gauge Attachments'' or (2) ASTM E
251-92 (2003), ``Standard Test Methods for Performance Characteristics
of Metallic Bonded Resistance Strain Gages'' (incorporated by
reference--see Sec.  60.17). Users would also be required to check the
accuracy of the overall CPMS.
9. Flow CPMS Validation
    Under the proposed PS-17, the performance of a flow CPMS could be
validated using one of seven methods. However, none of the methods
could be applied universally to all types of flow CPMS; there would be
limitations on the use of each specific method. The volumetric method,
which could be used to validate any liquid flow rate measurement
device, would entail collecting a volume of liquid for a timed period,
then calculating the flow rate based on the volume collected and the
length of the time period over which the liquid was collected. The
gravimetric method is similar to the volumetric method except that the
material collected would be weighed. The gravimetric method could be
used to validate any liquid flow CPMS, liquid mass flow CPMS, and solid
mass flow CPMS. Liquid mass flow rates and solid mass flow rates would
be calculated based on the weight of the liquid or solid and the length
of the time period over which the liquid or solid was collected. Liquid
flow rate would be calculated based on the weight and density of the
liquid and the length of the time period over which the liquid was
collected.
    The volumetric and gravimetric methods are based on voluntary
consensus standards and could be used to validate liquid flow CPMS.
Both methods are described in the following standards: (1) ISA RP 16.6-
1961, ``Methods and Equipment for Calibration of Variable Area Meters
(Rotameters)''; (2) ISA RP 31.1-1977, ``Specification, Installation,
and Calibration of Turbine Flow Meters''; and (3) ISO 8316:1987,
``Measurement of Liquid Flow in Closed Conduits-Method by Collection of
Liquid in a Volumetric Tank'' (incorporated by reference-see Sec.
60.17). The gravimetric method also is described in the following
standards: (1) ANSI/ASME MFC-9M-1988, ``Measurement of Liquid Flow in
Closed Conduits by Weighing Method''; and (2) ASHRAE 41.8-1989,
``Standard Methods of Measurement of Flow of Liquids in Pipes Using
Orifice Flow Meters'' (incorporated by reference-see Sec.  60.17). The
gravimetric method also could be used to validate liquid mass flow or
solid mass flow CPMS.
    The differential pressure measurement method and the pressure
source flow simulation method could be used to validate any flow CPMS
that uses a differential pressure measurement flow device, such as an
orifice plate, flow nozzle, or venturi tube. Both methods would entail
measuring the differential pressure across a flow constriction, then
calculating the corresponding flow rate based on the measured
differential pressure using the manufacturer's literature or the
procedures specified in ASME MFC-3M-2004, ``Measurement of Fluid Flow
in Pipes Using Orifice, Nozzle, and Venturi'' (incorporated by
reference--see Sec.  60.17), the characteristics of the liquid, and the
dimensions and design of the flow constriction. For CPMS that use an
orifice flow meter, the flow rate can be calculated using procedures
specified in ASHRAE 41.8-1989, ``Standard Methods of Measurement of
Flow of Liquids in Pipes Using Orifice Flowmeters'' (incorporated by
reference--see Sec.  60.17).
    In addition, prior to the validation check, both methods would
require a leak test on all connections associated with the process
line, CPMS, and pressure connections. Neither the differential pressure
measurement method nor the pressure source flow simulation method could
be used to validate a gas flow CPMS that uses one or more differential
pressure tubes as the flow sensor. A differential pressure tube is
defined as a device, such as a pitot tube, that consists of one or more
pairs of tubes that are oriented to measure the velocity pressure and
static pressure at one of more fixed points within a duct for the
purpose of determining gas velocity.
    The electronic signal simulation method could be used to validate
any flow CPMS that operates with a sensor that generates an electronic
signal, provided the electronic signal can be simulated and is related
to the magnitude of the flow rate. Examples of this type of flow sensor
are turbine meters and vortex shedding flow meters. The electronic
signal simulation method would entail simulating an electronic signal
using a calibrated signal simulator, then calculating the flow rate
that corresponds to the value of the simulated signal.
    Owners or operators of flow CPMS that are used for monitoring gas
flow rate could validate their CPMS by performing a relative accuracy
(RA) test using Reference Methods 2, 2A, 2B, 2C, 2D, or 2F (40 CFR part
60, appendix A-1), or 2G (40 CFR part 60, appendix A-2). The RA test is
the only method specified in the proposed PS-17 for validating a gas
flow CPMS that incorporates a differential pressure tube.
    Finally, the material weight comparison method could be used to
validate a solid mass flow CPMS that uses a combination belt conveyor
and weigh scale equipped with a totalizer. The method is based on the
Belt-Conveyor Scale Systems Method, which is described in NIST Handbook
44--2002 Edition, ``Specifications, Tolerances, And Other Technical
Requirements for Weighing and Measuring Devices'' (incorporated by
reference--see Sec.  60.17) as adopted by the 86th National Conference
on Weights and Measures in 2001.

10. pH CPMS Validation
    To validate the performance of a pH CPMS, two methods are specified
in the proposed PS-17. In the first method, the pH measured by the CPMS
would be compared to the pH measured by a calibrated pH meter. In the
second method, the single point calibration method, the value measured
by the CPMS would be compared to the pH measurement of a certified
buffer solution. If the CPMS did not satisfy the accuracy requirement,
a two-point calibration method, based on ASTM D 1293-99 (2005),
``Standard Test Methods for pH of Water'' (incorporated by reference--
see Sec.  60.17), would be suggested.
11. Conductivity CPMS Validation
    The proposed PS-17 would specify two methods for validating
conductivity CPMS. The two methods parallel the methods for validating
pH CPMS: comparison to a calibrated conductivity meter and the single
point calibration method using a standard conductivity solution.
    If the conductivity CPMS did not satisfy the accuracy requirement,
calibration based on the procedures specified in the manufacturer's
owner's manual would be suggested. If the manufacturer's owner's manual
does not specify a calibration procedure, calibration should be
performed based on one of the following standards: (1) ASTM D 1125-95
(2005), ``Standard Test Methods for Electrical Conductivity and
Resistivity of Water''; or (2) ASTM D 5391-99 (2005), ``Standard Test
Method for Electrical conductivity and Resistivity of a Flowing High
Purity Water Sample'' (incorporated by reference--see Sec.  60.17).
12. Alternative Methods of CPMS Validation
    Owners and operators of affected CPMS could have the option of
using alternative methods for validating their CPMS, provided the
alternative method has been approved by us or by a delegated authority.
In all cases, owners and operators of affected CPMS would be required
to take corrective action if the initial validation check indicates
that the CPMS does not satisfy the accuracy requirement. Alternative
monitoring methods are addressed under the General Provisions to parts
60, 61, and 63 in Sec. Sec.  60.13(i), 61.14(g), and 63.8(f),
respectively. Alternative monitoring methods also are addressed in the
applicable subparts for each rule.

E. What initial performance criteria must be demonstrated to comply
with PS-17?

    Owners or operators of affected CPMS would be required to
demonstrate that their CPMS meet a minimum system accuracy. Table 6 of
this preamble summarizes the required accuracies. These minimum
accuracies would pertain to the overall CPMS and not simply the sensor.

         Table 6--Accuracy Criteria for Initial Validation Check
------------------------------------------------------------------------
                                 The accuracy criteria for the initial
  If the CPMS measures . . .           validation check are . . .
------------------------------------------------------------------------
1. Temperature (in a non-      System accuracy of 1.0
 cryogenic environment).        percent of the temperature or 2.8 [deg]C
                                (5 [deg]F), whichever is greater.
2. Temperature (in a           System accuracy of 2.5
 cryogenic environment).        percent of the temperature or 2.8 [deg]C
                                (5 [deg]F), whichever is greater.
3. Pressure..................  System accuracy of 5 percent
                                or 0.12 kPa (0.5 in. wc), whichever is
                                greater.
4. Liquid flow rate..........  System accuracy of 5 percent
                                or 1.9 L/min (0.5 gal/min), whichever is
                                greater.
5. Gas flow rate.............  a. Relative accuracy of 20
                                percent, if the relative accuracy test
                                is used to demonstrate compliance, OR.
                               b. System accuracy of 10
                                percent, if the CPMS measures steam flow
                                rate, OR.
                               c. System accuracy of 5
                                percent or 280 L/min (10 ft\3\/min),
                                whichever is greater, for all other
                                gases and validation test methods.
6. Mass flow rate............  System accuracy of 5 percent.
7. pH........................  System accuracy of 0.2 pH units.
8. Conductivity..............  System accuracy percentage of 5 percent.
------------------------------------------------------------------------

    In most cases, the required accuracies are expressed both as
accuracy percentages and as accuracy values; for a specific parameter
value, the accuracy criterion that results in the greater value would
apply (i.e., the less stringent criterion would apply). For example,
for liquid flow rate, the accuracy percentage would be 5
percent, and the accuracy value would be 1.9 liters per minute (L/min)
(0.5 gallons per minute (gal/min)). If the actual flow rate were 30 L/
min (7.9 gal/min), the accuracy percentage criterion would result in a
value of 1.5 L/min (0.4 gal/min). Therefore, the accuracy value
criterion of 1.9 L/min (0.5 gal/min) would apply because 1.9 L/min is
greater than 1.5 L/min.
    For temperature CPMS, the proposed PS-17 would make a distinction
between cryogenic and non-cryogenic environments; cryogenic
environments are those characterized by a temperature less than 0
[deg]C (32 [deg]F), and non-cryogenic environments are those with a
temperature of at least 0 [deg]C (32 [deg]F). The minimum accuracy for
a temperature CPMS used in a non-cryogenic application would be the
greater of 1.0 percent of the temperature measured on the
Celsius scale ([deg]C) and 2.8 [deg]C (5 [deg]F). For
example, for a temperature CPMS that is used to monitor a thermal
oxidizer operating at 760 [deg]C (1400 [deg]F), the 1 percent accuracy
criterion would require the CPMS to be accurate to within 7.6 [deg]C (14 [deg]F). Because 7.6 [deg]C (14 [deg]F) is greater than 2.8 [deg]C (5 [deg]F), the 1 percent
accuracy criterion would apply. The minimum accuracy of a temperature
CPMS used in a cryogenic application would be 2.8 [deg]C (5
[deg]F) or 2.5 percent of the temperature measured on the
Celsius scale, whichever is greater. For a temperature CPMS that is
used to monitor a condenser operating with an outlet temperature of -12
[deg]C (10 [deg]F), the temperature value criterion would apply; the
CPMS would have to be accurate to 2.8 [deg]C (5
[deg]F) because 2.8 [deg]C (5 [deg]F) is greater than 2.5 percent of -
12 [deg]C (10 [deg]F), which is 0.3 [deg]C (0.5
[deg]F). These criteria translate to the accuracies listed in Table 7
of this preamble.

       Table 7--Summary of Temperature CPMS Accuracy Requirements
------------------------------------------------------------------------
 For temperatures that are . .   The required temperature CPMS accuracy
               .                                is . . .
------------------------------------------------------------------------
1. Greater than 280 [deg]C       1 percent of temperature.
 (540 [deg]F).
2. Between -112 and 280 [deg]C  2.8 [deg]C (5 [deg]F).
 (-170 and 540 [deg]F).
3. Less than -112 [deg]C (-170  2.5 percent of temperature.
 [deg]F).
------------------------------------------------------------------------

    The proposed PS-17 would require pressure CPMS to be accurate to
within 5 percent or 0.12 kPa (0.5 in. wc), whichever is
greater. For example, a CPMS that is used to monitor a venturi scrubber
with a pressure drop of 7.5 kPa (30 in. wc) would have to be accurate
to 0.37 kPa (1.5 in. wc) or better, based on the 5 percent
criterion because 0.37 kPa (1.5 in. wc) is greater than 0.12 kPa (0.5
in. wc). On the other hand, the required accuracy for a CPMS that
monitored a pressure drop of 1.0 kPa (4 in. wc) across a fabric filter
would be 0.12 kPa (0.5 in. wc), or better, because the 5
percent criterion would result in an accuracy of 0.05 kPa (0.2 in. wc).
    The required accuracy for flow CPMS would depend on the material
that is being monitored. For liquid flow rate CPMS, the minimum
accuracy would be 1.9 L/min (0.5 gal/min) or 5 percent,
whichever is greater. For example, to monitor a scrubber liquid flow
rate of 300 L/min (80 gal/min), the required CPMS accuracy would be 15
L/min (4 gal/min) or better. For gas flow rate CPMS, PS-17 would
require a minimum accuracy of 280 L/min (10 cubic feet per minute
(ft\3\/min)) or 5 percent, whichever is greater. Therefore,
a fuel flow meter on a natural gas-fired 8 MMBtu/hr incinerator with a
gas flow rate of 3,700 L/min (130 ft\3\/min) would have to be accurate
to 280 L/min (10 ft\3\/min) or better. An exception to these accuracy
requirements for flow meters would apply if an RA test is used to
validate a gas flow CPMS. In such cases, the required RA would be 20
percent of the mean value of the reference method test data, or better.
An exception to the gas flow CPMS accuracy requirements would also
apply for steam flow rate CPMS. The proposed PS-17 stipulates the
minimum accuracy for a CPMS that is used for monitoring steam flow rate
would have to be 10 percent or better. The minimum accuracy
specified in the proposed PS-17 for mass flow CPMS would be 5 percent. We would require pH CPMS to be accurate to within
0.2 pH units. Finally, conductivity CPMS would have to be
accurate to 5 percent.

F. What are the reporting and recordkeeping requirements for PS-17?

    The proposed PS-17 does not specify reporting requirements but
would require owners and operators of affected CPMS to record and
maintain information that identifies the CPMS, including the location
of the CPMS, identification number assigned by the owner or operator,
the manufacturer's name and model number, and the typical operating
range for each parameter that is monitored. In addition, owners and
operators of affected CPMS would be required to document performance
demonstrations.

IV. Summary of Proposed Procedure 4

A. What is the purpose of Procedure 4?

    The proposed Procedure 4 would have two primary purposes. First,
the procedure would be used for evaluating the quality of data produced
by CPMS on an ongoing basis. Second, the procedure would help evaluate
the effectiveness of the QA and quality control (QC) programs that
owners and operators develop for CPMS. As proposed, Procedure 4 would
apply instead of the requirements for evaluating the operation and
quality of the data produced by CPMS specified in an applicable subpart
to parts 60, 61, or 63 that requires the use of CPMS for monitoring
temperature, pressure, flow rate, pH, or conductivity.

B. Who must comply with Procedure 4?

    This procedure would apply to any CPMS that is subject to PS-17.
That is, any owner or operator who would be required under an
applicable subpart to parts 60, 61, or 63 to install and operate a CPMS
that is used to monitor temperature, pressure, flow rate, pH, or
conductivity would be subject to both PS-17 and Procedure 4.

C. When must owners or operators of affected CPMS comply with Procedure
4?

    Owners and operators of affected CPMS would have to comply with
Procedure 4 when they install and place into operation a CPMS that is
subject to PS-17 or when an existing CPMS becomes subject to PS-17.

D. What are the basic requirements of Procedure 4?

    The proposed Procedure 4 would require owners or operators to
perform periodic accuracy audits, perform visual inspections and other
operational checks, and develop and implement a QA/QC program for each
affected CPMS. The technical rationales for specific proposed
requirements of Procedure 4 are described in section IX of this
document.
1. Accuracy Audits
    The requirements for periodic accuracy audits would consist of
equipment requirements and procedural requirements. As is the case for
equipment used to perform initial validations under the proposed PS-17,
the specific equipment required to perform an accuracy audit would
depend on the type of CPMS and the method selected for evaluating the
accuracy of the CPMS. However, all such equipment would have to be
calibrated and would have to meet the same two general requirements for
accuracy: (1) An accuracy hierarchy of at least three, and (2) an
accuracy that is NIST-traceable.
    We have incorporated into the proposed Procedure 4 three exceptions
to the accuracy requirements for instruments that are used to audit the
accuracy of CPMS: (1) When performing an accuracy audit using a
redundant sensor, the redundant sensor would have to have an accuracy
equal to or better than the accuracy of your primary sensor; (2) a
mercury-in-glass or water-in-glass U-tube manometer could be used
instead of a calibrated pressure measurement device with NIST-traceable
accuracy when auditing the accuracy of a pressure CPMS or a flow CPMS
that uses a differential pressure flow meter; and (3) when performing
an accuracy audit of a flow CPMS using the volumetric or gravimetric
methods, the container that is used to collect the liquid or solid
material would not be required to have NIST-traceable accuracy.
    The procedural requirements for performing accuracy audits of a
CPMS would depend on the type of CPMS. Owners or operators of affected
CPMS generally could choose among several methods for performing CPMS
accuracy audits. Many of these methods are identical to the methods for
performing the initial validation check of CPMS, as specified in the
proposed PS-17 and

described in section III.D of this document. However, one significant
difference between the initial validation methods specified in the
proposed PS-17 and the accuracy audit methods specified in the proposed
Procedure 4 is that the accuracy audit methods would require you to
check the accuracy of each primary sensor, either separately or as part
of the overall system accuracy audit. For PS-17, we assumed that newly
installed sensors are calibrated, and a separate check of sensor
accuracy would be unnecessary. However, for assessing ongoing QA,
affected owners and operators would be required to perform accuracy
audits on CPMS that have been in service, and the audit procedure would
have to verify that the entire system, including the sensor, meets the
accuracy criteria. Table 8 of this document lists the CPMS accuracy
audit methods specified in the proposed Procedure 4 and the associated
applicability.

                     Table 8--Accuracy Audit Methods
------------------------------------------------------------------------
                               You can perform the
 If your CPMS measures . . .    accuracy audit of     If the sensor of
                               your CPMS by . . .    your CPMS is . . .
------------------------------------------------------------------------
1. Temperature..............  a. Comparison to      Any type of
                               redundant             temperature sensor.
                               temperature CPMS.
                              b. Comparison to      Thermocouple, RTD,
                               calibrated            or any other type
                               temperature           of temperature
                               measurement device.   sensor.
                              c. Separate sensor    Thermocouple or RTD.
                               check and system
                               check by
                               temperature
                               simulation.
------------------------------------------------------------------------
2. Pressure.................  a. Comparison to      Any type of pressure
                               redundant pressure    sensor.
                               sensor..
                              b. Comparison to      Pressure transducer,
                               calibrated pressure   pressure gauge, or
                               measurement device.   any other type of
                                                     pressure sensor.
                              c. Separate sensor    Pressure gauge or
                               check and system      metallic-bonded
                               check by pressure     resistance strain
                               simulation using a    gauge.
                               calibrated pressure
                               source.
                              d. Separate sensor    Pressure gauge or
                               check and system      metallic-bonded
                               check by pressure     resistance strain
                               simulation using a    gauge.
                               pressure source and
                               a calibrated
                               pressure
                               measurement device.
------------------------------------------------------------------------
3. Liquid flow rate.........  a. Comparison to      Any type of liquid
                               redundant flow        flow meter.
                               sensor.
                              b. Volumetric method  Any type of liquid
                                                     flow meter.
                              c. Gravimetric        Any type of liquid
                               method.               flow meter.
                              d. Separate sensor    Orifice plate, flow
                               check and system      nozzle, or other
                               check by              type of
                               differential          differential
                               pressure              pressure liquid
                               measurement method.   flow meter.
                              e. Separate sensor    Orifice plate, flow
                               check and system      nozzle, or other
                               check by pressure     type of
                               source flow           differential
                               simulation method.    pressure liquid
                                                     flow meter.
------------------------------------------------------------------------
4. Gas flow rate............  a. Comparison to      Any type of gas flow
                               redundant flow        meter.
                               sensor.
                              b. Separate sensor    Orifice plate, flow
                               check and system      nozzle, or any
                               check by              other type of
                               differential          differential
                               pressure              pressure gas flow
                               measurement method.   meter other than a
                                                     differential
                                                     pressure tube.
                              c. Separate sensor    Orifice plate, flow
                               check and system      nozzle, or any
                               check by pressure     other type of
                               source flow           differential
                               simulation method.    pressure gas flow
                                                     meter.
                              d. Relative accuracy  Any type of gas flow
                               test.                 meter.
------------------------------------------------------------------------
5. Liquid mass flow rate....  a. Comparison to      Any type of liquid
                               redundant flow        mass flow meter.
                               sensor.
                              b. Gravimetric        Any type of liquid
                               method.               mass flow meter.
------------------------------------------------------------------------
6. Solid mass flow rate.....  a. Comparison to      Any type of liquid
                               redundant flow        mass flow meter.
                               sensor.
                              b. Gravimetric        Any type of solid
                               method.               mass flow meter.
                              c. Material weight    Combination belt
                               comparison method.    conveyor, weigh
                                                     scale, and
                                                     totalizer.
------------------------------------------------------------------------
7. pH.......................  a. Comparison to      Any type of pH
                               redundant pH meter.   meter.
                              b. Comparison to      Any type of pH
                               calibrated pH meter.  meter.
                              c. Single point       Any type of pH
                               calibration.          meter.
------------------------------------------------------------------------
8. Conductivity.............  a. Comparison to      Any type of
                               redundant             conductivity meter.
                               conductivity meter.
                              b. Comparison to      Any type of
                               calibrated            conductivity meter.
                               conductivity meter.
                              c. Single point       Any type of
                               calibration.          conductivity meter.
------------------------------------------------------------------------

2. Temperature CPMS Accuracy Audit Methods
    To perform an accuracy audit of a temperature CPMS, owners and
operators of affected CPMS could choose from three methods. The first
method would apply to CPMS with redundant temperature sensors and would
entail comparing the temperature measured by the primary sensor of your
CPMS to that of the redundant temperature sensor. The second method
would consist of comparing the temperature measured by the CPMS to

a separate calibrated temperature measurement device. The third method
would require checking the temperature sensor independent of the other
components of the CPMS. The temperature sensor could be checked using
methods specified in any of the following voluntary consensus
standards: (1) ASTM E 220-07e1, ``Standard Test Methods for Calibration
of Thermocouples by Comparison Techniques'' (for thermocouples); (2)
ASTM E 452-02 (2007), ``Standard Test Method for Calibration of
Refractory Metal Thermocouples Using an Optical Pyrometer'' (for
thermocouples); or (3) ASTM E 644-06, ``Standard Test Methods for
Testing Industrial Resistance Thermometers'' (for resistance
temperature detectors) (incorporated by reference--see Sec.  60.17).
The other components of the CPMS could be checked by simulating a
temperature, then comparing the temperature recorded by the CPMS to the
simulated temperature. Because the voluntary consensus standards
specified in the proposed Procedure 4 would apply only to thermocouples
and resistance temperature detectors (RTDs), this accuracy audit method
would apply only to CPMS that use those types of temperature sensors.
3. Pressure CPMS Accuracy Audit Methods
    For an accuracy audit of a pressure CPMS, the proposed Procedure 4
would specify four methods. The first method would apply to CPMS with
redundant pressure sensors and would entail comparing the pressure
measured by the primary pressure sensor of your CPMS to the pressure
measured by the redundant pressure sensor. The second method would
consist of comparing the pressure measured by your CPMS to the pressure
measured by a separate calibrated pressure measurement device. The
other two methods would involve checking the accuracies of the pressure
sensor independent of the other components of the CPMS. For checking
sensor accuracy, the proposed Procedure 4 would reference voluntary
consensus standards. Because we were able to identify voluntary
consensus standards only for pressure gauges (ASME B40.100-2005,
``Pressure Gauges and Gauge Attachments'') and metallic-bonded
resistance strain gauges (ASTM E 251-92 (2003), ``Standard Test Methods
for Performance Characteristics of Metallic Bonded Resistance Strain
Gages'') (incorporated by reference--see Sec.  60.17), these other two
pressure CPMS accuracy audit methods would apply only to CPMS that use
pressure gauge or metallic-bonded resistance strain gauge sensors.
    After checking sensor accuracy, the accuracy of the other
components of the CPMS could be checked by either: (1) Pressure
simulation using a calibrated pressure source, or (2) pressure
simulation using a pressure source and a calibrated pressure
measurement device. In either method, a simulated pressure would be
compared to a calibrated pressure to determine accuracy.
4. Liquid Flow CPMS Accuracy Audit Methods
    To perform an accuracy audit of a liquid flow CPMS, five methods
are specified in the proposed Procedure 4. As is the case with other
types of CPMS, owners and operators of affected CPMS could choose among
the methods specified. The first method would apply to CPMS with
redundant flow sensors and would entail comparing the flow rate
measured by the primary flow sensor of your CPMS to the flow rate
measured by the redundant flow sensor. The next two methods--the
volumetric and gravimetric methods--are the same methods as specified
for the initial CPMS validation in the proposed PS-17 and described in
section III.D of this document. The volumetric and gravimetric methods
are based on voluntary consensus standards and could be used to
validate liquid flow CPMS. Both methods are described in the following
standards: (1) ISA RP 16.6-1961, ``Methods and Equipment for
Calibration of Variable Area Meters (Rotameters)''; (2) ISA RP 31.1-
1977, ``Specification, Installation, and Calibration of Turbine Flow
Meters''; (3) ISO 10790:1999, ``Measurement of Fluid Flow in Closed
Conduits--Guidance to the Selection, Installation and Use of Coriolis
Meters (Mass Flow, Density and Volume Flow Measurements)''; and (4) ISO
8316:1987, ``Measurement of Liquid Flow in Closed Conduits--Method by
Collection of Liquid in a Volumetric Tank'' (incorporated by
reference--see Sec.  60.17). The gravimetric method also is described
in the following standards: (1) ANSI/ASME MFC-9M-1988, ``Measurement of
Liquid Flow in Closed Conduits by Weighing Method''; and (2) ASHRAE
41.8-1989, ``Standard Methods of Measurement of Flow of Liquids in
Pipes Using Orifice Flowmeters'' (incorporated by reference--see Sec.
60.17). The gravimetric method also could be used to validate liquid
mass flow or solid mass flow CPMS.
    For liquid flow CPMS that use a differential pressure meter, such
as an orifice plate, venturi tube, or flow nozzle, two accuracy audit
methods are specified in the proposed Procedure 4. Both of these
methods would require a separate visual inspection of the flow
constriction and a check of the accuracy of the other components of the
system. The accuracy of the other components would have to be checked
by pressure simulation, using either a calibrated differential pressure
source or a differential pressure source in combination with a
calibrated differential pressure measurement device. The required
pressure drop that corresponds to the normal operating flow rate
expected for the flow CPMS can be calculated using ASME MFC-3M-2004,
``Measurement of Fluid Flow in Pipes Using Orifice, Nozzle, and
Venturi'' (incorporated by reference, see Sec.  60.17). For CPMS that
use an orifice flow meter, the pressure drop can be calculated using
ASHRAE 41.8-1989, ``Standard Methods of Measurement of Flow of Liquids
in Pipes Using Orifice Flowmeters'' (incorporated by reference--see
Sec.  60.17).
5. Gas Flow CPMS Accuracy Audit Methods
    The proposed Procedure 4 specifies four methods for checking the
accuracy of a gas flow CPMS. One method would entail comparison to a
redundant flow sensor and could be used with any gas flow CPMS. Two
methods would apply only to gas flow CPMS that incorporate differential
pressure meters. These are the same two methods that would apply to
differential pressure liquid flow meter systems described in the
previous paragraph. The final method specified in the proposed
Procedure 4 for checking the accuracy of a gas flow CPMS is the RA test
using Reference Methods 2, 2A, 2B, 2C, 2D, or 2F (40 CFR part 60,
appendix A-1), or 2G (40 CFR part 60, appendix A-2). This is the only
method specified in Procedure 4 that could be used to check the
accuracy of gas flow CPMS that use differential flow tubes.
6. Mass Flow CPMS Accuracy Audit Methods
    The accuracy of CPMS that measure either liquid mass flow or solid
mass flow could be checked using the redundant sensor method and the
gravimetric method, both of which are described in the previous section
for liquid flow CPMS. The same two methods could be used for checking
the accuracy of solid mass flow CPMS. The accuracy of solid mass flow
CPMS also could be evaluated using the material weight comparison
method, which is based on the Belt-Conveyor Scale Systems Method,
described in NIST

Handbook 44--2002 Edition, ``Specifications, Tolerances, and Other
Technical Requirements for Weighing and Measuring Devices''
(incorporated by reference--see Sec.  60.17), as adopted by the 86th
National Conference on Weights and Measures in 2001.
7. pH CPMS Accuracy Audit Methods
    To check the accuracy of pH CPMS, owners and operators of affected
CPMS could choose between three methods: (1) Comparison to a redundant
pH sensor, (2) comparison to a calibrated pH meter calibrated according
to ASTM D1293-99 (2005), ``Standard Test Methods for pH of Water''
(incorporated by reference--see Sec.  60.17), and (3) single point
calibration. The redundant sensor method would require you to compare
the pH measured by the primary pH sensor of your pH CPMS to that of a
redundant pH sensor. The other two methods are the same as specified in
the proposed PS-17 for the initial validation check.
8. Conductivity CPMS Accuracy Audit Methods
    The proposed Procedure 4 specifies three methods for checking the
accuracy of a conductivity CPMS. These methods (comparison to redundant
conductivity sensor, comparison to calibrated conductivity meter, and
single point calibration) are based on the same principles as the
methods specified for pH CPMS accuracy audits in this proposed rule.
    Calibration of the conductivity CPMS should be performed according
to the manufacturer's owner's manual. If not specified, calibration
must be performed based on one of the following standards: (1) ASTM D
1125-95 (2005), ``Standard Test Methods for Electrical Conductivity and
Resistivity of Water''; or (2) ASTM D 5391-99 (2005), ``Standard Test
Method for Electrical Conductivity and Resistivity of a Flowing High
Purity Water Sample'' (incorporated by reference--see Sec.  60.17).
9. Other Operational Checks
    In addition to accuracy audits, owners or operators of affected
CPMS that do not use redundant sensors would be required to perform
visual inspections and other checks of the operation of each affected
CPMS. These checks would include such activities as inspecting the
physical appearance of the CPMS for damage or wear and checking the
electrical components for corrosion.
10. QA/QC Program
    The Procedure 4 would require CPMS owners or operators to develop
QA/QC programs for each affected CPMS. The QA/QC programs would have to
address procedures for accuracy audits, system calibration, preventive
maintenance, recordkeeping, and corrective action.

E. How often must accuracy audits and other QA/QC procedures be
performed?

    Table 9 of this document summarizes the required frequencies for
accuracy audits and other QA/QC procedures that would be required under
the proposed Procedure 4.

      Table 9--Frequency of Accuracy Audits and Other QC Procedures
------------------------------------------------------------------------
                              You must perform . .
 If your CPMS measures . . .            .              At least . . .
------------------------------------------------------------------------
 1. Temperature.............   a. Accuracy audits.   i. Quarterly; AND
                                                    ii. Following any
                                                     period of more than
                                                     24 hours throughout
                                                     which the
                                                     temperature
                                                     exceeded the
                                                     maximum rated
                                                     temperature of the
                                                     sensor, or the data
                                                     recorder was off
                                                     scale.
                               b. Visual             Quarterly, unless
                               inspections and       the CPMS has a
                               checks of CPMS        redundant
                               operation.            temperature sensor.
------------------------------------------------------------------------
 2. Pressure................   a. Accuracy audits.   i. Quarterly; AND
                                                    ii. Following any
                                                     period of more than
                                                     24 hours throughout
                                                     which the pressure
                                                     exceeded the
                                                     maximum rated
                                                     pressure of the
                                                     sensor, or the data
                                                     recorder was off
                                                     scale.
                               b. Checks of all      Monthly.
                               mechanical
                               connections for
                               leakage.
                               c. Visual             Quarterly, unless
                               inspections and       the CPMS has a
                               checks of CPMS        redundant pressure
                               operation.            sensor.
------------------------------------------------------------------------
 3. Flow rate (liquid, gas,    a. Accuracy audits.   i. Quarterly; AND
 mass).                                             ii. Following any
                                                     period of more than
                                                     24 hours throughout
                                                     which the flow rate
                                                     exceeded the
                                                     maximum rated flow
                                                     rate of the sensor,
                                                     or the data
                                                     recorder was off
                                                     scale.
                               b. Checks of all      Monthly.
                               mechanical
                               connections for
                               leakage.
                               c. Visual             Quarterly, unless
                               inspections and       the CPMS has a
                               checks of CPMS        redundant flow
                               operation.            sensor.
------------------------------------------------------------------------
 4. pH......................   a. Accuracy audits.   Weekly.
                               b. Visual             Monthly, unless the
                               inspections and       CPMS has a
                               checks of CPMS        redundant pH
                               operation.            sensor.
------------------------------------------------------------------------
 5. Conductivity............   a. Accuracy audits.   Quarterly.
                               b. Visual             Quarterly, unless
                               inspections and       the CPMS has a
                               checks of CPMS        redundant
                               operation.            conductivity
                                                     sensor.
------------------------------------------------------------------------

    For affected CPMS that are used to monitor temperature, pressure,
or flow rate, owners and operators would be required to perform
accuracy audits on a quarterly basis. For pH CPMS, accuracy audits
would have to be performed weekly, and, for conductivity CPMS, monthly
accuracy audits would be required. In addition, for temperature,
pressure, and flow CPMS, an accuracy audit would be required following
any periods of 24 hours or more, throughout which either: (1) The
measured value exceeded the operating limit for the sensor, based on
the manufacturer's recommendations, or (2) the parameter value remained
off the scale of the CPMS data recorder. As an example of the first
condition, consider a Type J thermocouple with a rated operating
temperature limit of 760 [deg]C (1400 [deg]F). If a temperature CPMS
that uses a Type J thermocouple records a temperature in excess of 760
[deg]C (1400 [deg]F) for more than 24 hours, an accuracy audit of the
CPMS would have to be performed within 48 hours.
    Visual inspections and other operational checks of temperature,
pressure, and flow CPMS would be required quarterly, unless the CPMS is
equipped with a redundant sensor. In addition, mechanical connections
associated with pressure or flow CPMS would have to be checked monthly
for leakage. For pH and conductivity CPMS that are not equipped with
redundant sensors, owners or operators of affected units would have to
visually inspect and perform operational checks of the affected CPMS on
a monthly basis.

F. What are the reporting and recordkeeping requirements for Procedure
4?

    The proposed Procedure 4 does not specify reporting requirements
but would require owners and operators of affected CPMS to maintain
records of all accuracy audits and corrective actions taken to return
the CPMS to normal operation. These records would have to be maintained
for a period of at least 5 years. For the first 2 years, the records
would have to be kept onsite.

V. Summary of Proposed Amendments to Procedure 1

A. What is the purpose of the amendments?

    The purpose of the amendments to Procedure 1 of 40 CFR part 60,
appendix F is to revise the procedure to address CEMS that must comply
with PS-9 or PS-15 (40 CFR part 60, appendix B). Procedure 1 was
developed for CEMS that are used to monitor a single pollutant or
diluent. As a result, there may be some questions on how to apply
Procedure 1 to CEMS subject to PS-9 or PS-15 that measure more than one
pollutant. In addition, both PS-9 and PS-15 partially specify ongoing
QA procedures. By amending the QA procedure, we are clarifying what
owners or operators of CEMS subject to PS-9 or PS-15 must do to comply
with Procedure 1 to ensure the quality of the data produced by these
CEMS. The technical rationale for proposed changes to Procedure 1 is
discussed further in section X of this document.

B. To whom do the amendments apply?

    The amendments to Procedure 1 (40 CFR part 60, appendix F) would
apply to owners or operators of CEMS that are subject to PS-9 or PS-15
(40 CFR part 60, appendix B) and are used to demonstrate compliance on
a continuous basis. Several subparts to parts 60, 61, and 63 require
that owners and operators of affected sources demonstrate that those
sources are in continuous compliance with the applicable emission
standard. Any such standard that requires the use of gas
chromatographic CEMS subject to PS-9 or extractive Fourier Transfer
Infrared (FTIR) CEMS subject to PS-15 would also require compliance
with Procedure 1, and these proposed amendments to Procedure 1 would
apply specifically to such sources.

C. How do the amendments address CEMS that are subject to PS-9?

    These proposed amendments would address CEMS that are subject to
PS-9 (40 CFR part 60, appendix B) by clarifying that the procedure can
be used for multiple-pollutant CEMS and by modifying the requirements
for daily calibration drift (CD) and data accuracy assessments so that
the procedure can be applied specifically to CEMS that are subject to
PS-9. The proposed amendments to section 4.1.1 of Procedure 1 specify
that the daily CD can be performed using any of the target pollutants
that are monitored by the CEMS. For example, if a CEMS is subject to
PS-9 and is used to monitor benzene and toluene, the CD check could be
performed using either benzene or toluene.
    The PS-9 requires neither relative accuracy test audits (RATA's)
nor relative accuracy assessments (RAA's). Instead, PS-9 requires
cylinder gas audits (CGA's) every calendar quarter. To address data
accuracy assessments for CEMS subject to PS-9, the amendments would add
section 5.1.5 to Procedure 1. The new section would specify that the
requirements for RATA's and RAA's do not apply to CEMS subject to PS-9.
Instead, quarterly CGA's of each target pollutant would be required.
The amendments further would specify that the quarterly CGA's are to be
performed according to the procedure described in PS-9, except that the
CGA's would have to be performed at two points rather than the single
point requirement of PS-9. Finally, the amendments would clarify that
the CGA's performed under the revised Procedure 1 satisfy the quarterly
performance audit requirement of PS-9.

D. How do the amendments address CEMS that are subject to PS-15?

    These proposed amendments would address extractive FTIR CEMS that
are subject to PS-15 (40 CFR part 60, appendix B) by modifying the
requirements for checking daily CD, data recording, and data accuracy
assessments so that the procedure could be applied specifically to CEMS
that are subject to PS-15. The amendments also would clarify what
constitutes excessive CD for CEMS subject to PS-15 and the criteria for
determining when the CEMS is ``out of control.'' These modifications
would be addressed in the amendments by adding sections 4.1.2, 4.3.3,
4.4.1, and 5.1.6 to Procedure 1. Proposed section 4.1.2 of Procedure 1
would specify that the daily CD requirement must be satisfied by
performing a daily Calibration Transfer Standards (CTS) Check, Analyte
Spike Check, and Background Deviation Check. For the specific
procedures to be followed, the amendments would reference the
appropriate sections of PS-15, which describe how to perform these
system assessments.
    Proposed section 4.3.3 of Procedure 1 would specify the criteria
for determining when a CEMS subject to PS-15 is out of control. The
CEMS would be out of control under either of two conditions. The first
condition would occur when the CTS Check, Analyte Spike Check, or
Background Deviation Check exceeds twice the drift specification of
5 percent for five consecutive daily periods. The second
condition would occur when the CTS Check, Analyte Spike Check, or
Background Deviation Check exceeds four times the drift specification
of 5 percent during any daily check.
    Proposed section 4.4.1 of Procedure 1 would specify data storage
criteria for CEMS subject to PS-15. In addition to the recordkeeping
requirements specified in section 4.4 of Procedure 1, the proposed
amended procedure would require owners or operators of affected CEMS to
satisfy the data storage requirements of section 6.3 of PS-15. That is,
the data storage system would

have to have capacity sufficient to store all data collected over the
course of one week. The data would have to be stored on either a write-
protected medium or to a password-protected remote storage location.
    Proposed section 5.1.6 of Procedure 1 would specify the criteria
for data accuracy assessments of CEMS subject to PS-15. Instead of
requiring data accuracy assessments by RATA's, CGA's, or RAA's, as
required for other types of CEMS, the amended Procedure 1 would require
quarterly data accuracy assessments according to the three audit
procedures specified in section 9 of PS-15. The Audit Sample Check,
which is specified in section 9.1 of PS-15, would be required at least
once every four calendar quarters. The Audit Spectra Check, which is
specified in section 9.2 of PS-15, could be used to satisfy the data
accuracy assessment requirement no more than once every four calendar
quarters. The Submit Audit for Independent Analysis, which is specified
in section 9.3 of PS-15, could be used to satisfy the data accuracy
assessment in no more than three of every four consecutive calendar
quarters. Proposed section 5.1.6(3) of Procedure 1 also would stipulate
that the data accuracy audits performed under the QA procedure satisfy
the PS-15 requirement for quarterly or semiannual QA/QC checks on the
operation of the CEMS.

VI. Summary of Proposed Amendments to the General Provisions to Parts
60, 61, and 63

A. What is the purpose of the amendments to the General Provisions to
parts 60, 61, and 63?

    The purpose of the proposed amendments to the General Provisions to
parts 60, 61, and 63 is to ensure that the monitoring requirements
specified in the General Provisions that apply to CPMS are consistent
with the requirements in the proposed PS-17 and Procedure 4 and the
requirements specified in the applicable subparts that require the use
of the CPMS that are affected by this proposed rule.

B. What specific changes are we proposing to the General Provisions to
parts 60, 61, and 63?

    These proposed amendments to the General Provisions to part 60
would redesignate Sec.  60.13(a) as Sec.  60.13(a)(1) and would add
Sec.  60.13(a)(2). The new paragraph would state that performance
specifications and QA procedures for CPMS, promulgated under part 60,
appendices B and F, respectively, apply instead of requirements for
CPMS specified in applicable subparts to part 60.
    These proposed amendments to the General Provisions to part 61
would redesignate Sec.  61.14(a) as Sec.  61.14(a)(1) and would add
Sec.  61.14(a)(2). The new paragraph would state that performance
specifications and QA procedures for CPMS, promulgated under part 60,
appendices B and F, respectively, apply instead of requirements for
CPMS specified in applicable subparts to part 61.
    These proposed amendments to the General Provisions to part 63
would make several changes to Sec.  63.8(c). Section 63.8(a)(2) would
be revised to include new paragraph Sec.  63.8(a)(2)(ii). The new
paragraph would state that performance specifications and QA procedures
for CPMS, promulgated under part 60, appendices B and F, respectively,
apply instead of the requirements for CPMS specified in applicable
subparts to part 63.
    Under these proposed amendments, the installation requirements of
Sec.  63.8(c)(2) would apply to all CMS, including CPMS.
    Section 63.8(c)(4) addresses continuous operation and cycle time
for CEMS and COMS. These proposed amendments would expand the
requirement of Sec.  63.8(c)(4) to require that all CPMS also must be
in continuous operation. These proposed amendments also would add
paragraph Sec.  63.8(c)(4)(iii) to require that all CPMS complete one
cycle of operation within the time period specified in the applicable
rule.
    Section 63.8(c)(6) addresses daily drift checks. In this proposal,
we would delete the last three sentences of paragraph (c)(6) that apply
specifically to CPMS because the proposed PS-17 and Procedure 4 would
specify the applicable criteria.
    Section 63.8(c)(7) defines when a CMS is out of control. The
proposed amendments would clarify in Sec.  63.8(c)(7)(i)(A) that the
term ``out of control'', when defined in terms of excessive calibration
drift, applies to CEMS and COMS and not to CPMS. We also would revise
Sec.  63.8(c)(7)(i)(B), which relates out of control to failed
performance test audits, relative accuracy audits, relative accuracy
test audits, and linearity test audits. In these proposed amendments,
Sec.  63.8(c)(7)(i)(A) and (B) would apply only to CEMS and COMS. These
proposed amendments would add Sec.  63.8(c)(7)(i)(D) to clarify that a
CPMS is out of control when the system fails an accuracy audit.
    Quality control programs for CMS are addressed in Sec.  63.8(d). We
are proposing to revise Sec.  63.8(d)(2)(ii) to clarify that written
protocols for calibration drift determinations and adjustments would
not necessarily apply to CPMS.
    Finally, we are proposing changes to Sec.  63.8(e), which address
CMS performance evaluations. We are proposing to amend Sec.  63.8(e)(2)
and (3)(i) to clarify that prior written notice of performance
evaluations and performance evaluation test plans are required for CEMS
or COMS only. In addition, we are proposing to revise Sec.  63.8(e)(4)
to clarify that CPMS performance evaluations must be performed in
accordance with the applicable QA procedure (i.e., Procedure 4).

VII. Summary of the Proposed Amendments to 40 CFR Part 63, Subpart SS.

A. What is the purpose of the amendments to subpart SS?

    We are proposing to amend subpart SS to ensure that the monitoring
requirements for CPMS specified in subpart SS are consistent with the
proposed PS-17 and Procedure 4.

B. What specific changes are we proposing to subpart SS?

    We are proposing several changes to the general monitoring
requirements for control and recovery devices specified in Sec.
63.996. The purpose of these changes is to clarify CPMS monitoring
requirements and ensure that the requirements of subpart SS are
consistent with the proposed PS-17 and Procedure 4.
    Under Sec.  63.996(c)(7), we are proposing to require that you
satisfy the requirements of applicable performance specifications and
QA procedures established under 40 CFR part 60. In addition, the
amended subpart SS would require a CPMS cycle time of no longer than 15
minutes and at least four equally-spaced measurements for each valid
hour of data for all CPMS. Any device that is used to perform an
initial validation or an accuracy audit of a CPMS would have to have
NIST-traceable accuracy and an accuracy hierarchy of at least three.
    Section 63.996(c)(8), (9), and (10) of the amended subpart SS would
specify requirements for temperature, pressure, and pH CPMS,
respectively. Specific requirements would include the same minimum
accuracies and data recording system resolution specified in the
proposed PS-17 for the same type of CPMS. The proposed amendments to
subpart SS would require owners or operators of affected CPMS to
perform initial calibrations and initial validations of each CPMS. The
initial

validation of a temperature or pressure CPMS could be performed by
comparison to a calibrated measurement device or by any other method
specified in applicable performance specifications for CPMS established
under 40 CFR part 60, appendix B. The initial validation of a pH CPMS
could be performed using a single point calibration or by any other
method specified in applicable performance specifications for CPMS
established under 40 CFR part 60, appendix B.
    The proposed amendments to subpart SS also would require accuracy
audits at the same frequencies that would be required by proposed
Procedure 4: quarterly for temperature and pressure CPMS, and weekly
for pH CPMS. Accuracy audits also would be required for temperature and
pressure CPMS following any period of 24 hours throughout which the
measured value (temperature or pressure) exceeded the manufacturer's
recommended maximum operating value. Owners or operators of affected
temperature or pressure CPMS could perform accuracy audits by the
redundant sensor method, by comparison to a calibrated measurement
device, or by any other accuracy audit method specified in applicable
QA procedures established under 40 CFR part 60, appendix F. For pH
CPMS, owners or operators could perform accuracy audits by the
redundant sensor method, single point calibration method, or by any
other accuracy audit method specified in applicable QA procedures
established under 40 CFR part 60, appendix F. In addition, quarterly
visual inspections would be required for any temperature or pressure
CPMS not equipped with a redundant sensor; for pH CPMS not equipped
with a redundant sensor, monthly visual inspections would be required.

VIII. Rationale for Selecting the Proposed Requirements of Performance
Specification 17

A. What information did we use to develop PS-17?

    To develop proposed PS-17, we considered the requirements of
emission standards promulgated under 40 CFR parts 60, 61, and 63; State
agency requirements for CPMS; manufacturer and vendor recommendations;
and current operational and design practices in industry. To the extent
possible, we also considered voluntary consensus standards for CPMS
specifications and requirements, and this proposed rule lists several
voluntary consensus standards that can be used as alternative methods
for checking instrument sensor accuracies. Our review of voluntary
consensus standards that apply to parameter monitoring devices is
summarized in section XV.I of this document.
    To obtain information on current practices and recommendations
regarding CPMS design, installation and operation, we developed three
separate surveys (hereafter referred to as the CPMS surveys). We sent
one survey to nine State agencies, one survey to nine CPMS
manufacturers and vendors, and the third survey to nine companies with
facilities that currently are subject to emission standards. Although
the responses to the CPMS survey were far from complete, the surveys
did provide useful information on equipment accuracies, operation and
maintenance procedures, and calibration frequencies. To the extent
possible, we used the information presented in the CPMS survey
responses in the selection of the requirements for PS-17.

B. How did we select the applicability criteria for PS-17?

    To select the applicability criteria for PS-17, we considered the
current parameter monitoring requirements that are now in effect under
40 CFR parts 60, 61, and 63. The General Provisions to parts 60 and 63
clearly establish the need for performance specifications for CPMS.
Although the monitoring provisions of the part 61 General Provisions
are not as detailed as the General Provisions requirements of parts 60
and 63, we believe that the need for performance specifications for
part 61 is also warranted. The need for CPMS performance specifications
is most evident for part 63 in that standards promulgated under part 63
establish enforceable operating limits for parameter monitoring
systems. As stated in Sec.  63.6(e)(iii), operation and maintenance
requirements, which include parameter monitor operating limits, ``* * *
are enforceable independent of emissions limitations or other
requirements in relevant standards.'' As a result, there is a need for
additional QA and QC for part 63 rules to ensure that the equipment
used to comply with those operating limits is properly designed,
installed, operated, and maintained.
    We recognize that parameter monitoring data for sources subject to
part 60 and 61 rules are not in themselves the basis for compliance
determinations with the applicable rules, as is the case for sources
subject to part 63 rules. Despite that, we believe that there still is
a strong need for performance specifications to help ensure the quality
of those monitoring system data. In addition, many of the sources
regulated under parts 60 and 61 are also regulated under part 63. For
these reasons, and to achieve consistency among the requirements for
all of our emission standards, we have decided to require PS-17 to
apply uniformly to all sources for which CPMS are required under parts
60, 61, or 63. It should be noted that the proposed requirements for
CPMS would not be retroactive, but would apply only to the operation,
use, and maintenance of CPMS following promulgation of the final PS-17
and Procedure 4 for CPMS.

C. How did we select the parameters that are addressed by PS-17?

    The parameters that currently are addressed by proposed PS-17
(temperature, pressure, flow rate, pH, and conductivity) were selected
primarily for two reasons: (1) These parameters are generally accepted