SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT 

Staff Report for 

Proposed Amended Rule 218 - Continuous Emission Monitoring 

and 

Proposed Rule 218.1 - Continuous Emission Monitoring Performance Specifications 

Deputy Executive Officer 

Science & Technology Advancement 

Chung Liu, D.Env. 

Asst. Deputy Executive Officer 

Science & Technology Advancement 

Melvin D. Zeldin 

Manager 

Monitoring & Source Testing Engineering 

John Higuchi 

Supervising Engineer 

Monitoring & Source Testing Engineering 

Steve Marinoff 

Author: Rarniro Gonzalez, Jr. 

Senior Air Quality Engineer 

Monitoring & Source Testing Engineering 

Date: April 9, 1999 
SOUTH COAST AIR QUALITY MANAGEMENT DISTRICT 

GOVERNING BOARD 

Chairman: WILLIAM A. BURKE, Ed.D. 

Speaker of the Assembly Appointee 

Vice Chairman: NORMA J. GLOVER 

Cities Representative, Orange County 

Members: 

MICHAEL D. ANTONOVICH 

Los Angeles County Representative 

HAL BERNSON 

Cities Representative, Los Angeles CountyIWestern Region . 

CYNTHIA P. COAD 

Orange County Representative 

BEATRICE J.S.LAPIST0-KIRTLEY 

Cities Representative, Los Angeles CountyiEastern Region 

MEE HAE LEE 

Senate Rules Committee Appointee 

RONALD 0. LOVERIDGE 

Cities ~epresentative, Riverside County 

JON D. MIKELS 

San Bernardino County Representative 

LEONARD PAULITZ 

Cities Representative, San Bernardino County 

S. ROY WILSON, Ed.D. 

Riverside County Representative 

VACANT 

Governor's Appointee 

Executive Officer 

BARRY R. WALLERSTEM, D.Env. 
TABLE OF CONTENTS 

I. EXECUTIVE SUMMARY 

I1 BACKGROUND 

m. SUMMARY OF PROPOSED AMENDMENTS TO RULE 218 

IV. SUMMARY OF PROPOSED RULE 218.1 

V. IMPACTS 

VI. COMMENTS 

VII. ATTACHMENTS 

Attachment A - Summary of Public Comments 

Attachment B - List of Public Comment Letters Received 

Attachment C - Socioeconomic Assessment Report 

VIII. APPENDICES 

Appendix A - Technical Guidance Documents 

Appendix B - Guidelines to Rule 218 CEMS Quality Assurance and 

Quality Control Plan 

Appendix C - Sample CEMS QAIQC Plan 
- I. EXECUTIVE SUMMARY 

The South Coast Air Quality Management District (AQMD) has various rules, 

regulations and permit conditions that require the installation and use of continuous 

emission monitoring systems (CEMS) as a means to determine source compliance. 

One of these is Rule 2 18 - Stack Monitoring (R2 18) which provides administrative 

guidelines and technical specifications for the approval of stack monitoring systems 

that are required for specified sources of oxides of nitrogen (Nod, sulfur dioxide 

(SO,), carbon dioxide (CO,) and carbon monoxide (CO). Currently, this rule covers 

twenty-four (24) existing certified CEMS and thirty-five (35) CEMS that are in the 

process of obtaining final approval by AQMD. The practical applicability of 

CEMS technology for regulatory compliance is increasingly being recognized by 

AQMD as well as by other regulatory agencies in the federal, state and local levels. 

Staff proposes to divide the administrative and technical provisions of the current 

Rule 218 into two separate rules, Proposed Amended Rule 21 8 - Continuous 

Emission Monitoring (PAR21 8) and Proposed Rule 21 8.1 1 - Continuous Emission 

Monitoring Performance Specifications (PR2 18.1). PAR2 1 8 defines the 

applicability and specifies the administrative requirements for continuous emission 

monitoring including the application and approval process for CEMS, the option to 

choose alternative performance specifications, compliance dates, and record 

retention and reporting. PR218.1 specifies CEMS certification, performance 

specifications, and technical requiremehts for CEMS operation and maintenance. 

PAR21 8 and PR218.1 will apply to all sources for which CEMS are required in 

AQMD regulations or permit conditions, except as stated below. Examples where 

PAR2 18 and PR2 18.1 apply are CEMS that are required under Rule 1 1 10.2 - 

Emissions from Gaseous- and Liquid-Fueled Internal Combustion Engines, Rule 

11 34 - Emissions of Oxides of Nitrogen from Stationary Gas Turbines, Rule 1 135 - 

Emissions of Oxides of Nitrogen from Electric Power Generating Systems, and 

Rule 1146 - Emissions of Oxides of Nitrogen from Industrial Institutional, 

Commercial Boilers, Steam Generators and Process Heaters. 

Proposed amended Rule 2 18 will delete obsolete language, clarify administrative 

requirements, and delete the CEMS performance specifications in the rule. 

Proposed Rule 218.1 will revise and identify these CEMS performance 

specifications to meet AQMD requirements for approval. Both PAR21 8 and 
PR218.1 would not apply to CEMS under Regulation XX - Regional Clean Air 

Incentives Market (RECLAIM), Regulation XX - New Source Performance 

Standards (NSPS), Regulation X - National Emission Standards for Hazardous Air 

Pollutants (NESHAP), and Regulation XXI - Acid Rain Permit Program (Acid 

Rain). 

At the direction of the Stationary Source Committee, staff requested EPA Region 

XX to review the proposed amendments to Rule 218 and newly proposed Rule 

218.1, with respect to conformity with Title V. The specific issues were theinclusion of the absolute de minirnus values for Relative Accuracy (RA) 

performance specifications and alternative quality assurance requirements, and their 

impact on stringency relative to federal requirements under 40CFR60, Appendices 

B and F. 

EPA Region IX expressed concern over how emission limits in the lower ranges 

would be enforced and originally agreed to the use of a de-minimus absolute 

performance specification provided that the AQMD commit to developing written 

guidelines on how enforcement would be handled where low emission limits are an 

issue. However, upon concurring with the efficacy of addressing measurements at 

or near the lower limits of current technology, the availability and accuracy of low 

concentration of calibration gases, and the degree of precision of the reference 

methods at low concentrations, EPA subsequently eliminated the written guideline 

requirement and approved the use of PR218.1 absolute de minimus relative 

accuracy specifications. 

Staff has reviewed PAR2 18 and PR2 18.1 and has determined that the proposals are 

exempt fiom the requirements of California Environmental Quality Act (CEQA). 

Staff has concluded with certainty that the proposals will not have a significant 

adverse impact on the environment and has prepared a Notice of Exemption (NOE) 

pursuant to state CEQA Guidelines Section 15061(b)(3) - Review for Exemption 

(AQMD Guidelines Section 5.1) and Section 15308 - Actions by the Regulatory 

Agencies for Protection of the Environment (AQMD Guidelines Section 19.12) 

The NOE will be filed with the local county clerks inirnediately following the 

adoption of the PAR2 18 and PR2 18.1. Staff has prepared an assessment of the 

socioeconomic and cost impacts that are associated with PAR2 18 and PR218.1, and 

this is provided in Attachment C. 
11. BACKGROUND 

The AQMD Governing Board adopted Rule 218 - Stack Monitoring, on January 9, 

1976 which requires continuous stack emission monitoring of NO,, SO,, CO, andlor 

CO discharged fiom sources such as power plants, refineries, sulfuric acid plants 

and nitric acid plants. The rule has been amended four times to provide procedural 

clarity and facilitate enforcement. The most recent amendments to Rule 2 18 were 

adopted in August 7, 1981. These amendments were purely administrative in nature 

and did not affect any increase or decrease in contaminant emissions. 

Since the last amendments, the development and progress in source specific rules, 

the recent adoption of RECLAIM and the advancement in continuous emissions 

monitoring technology have made most of Rule 218 administrative provisions and 

many of the technical requirements obsolete and outdated. Proper CEMS 

installation, testing and certification, subsequent operation and maintenance, 

advances in calibration gas integrity, and the computerization of data acquisition, 

recording and reporting are just some of the issues that warrant delineation of 

requirements to provide CEMS with better operational and output reliability. Also, 

through the implementation CEMS quality assurance and quality control programs 

(QNQC), the CEMS is adequately managed to produce good quality assured data 

and achieve high system availability. 

AQMD staff, recognizing the deficiency or inapplicability of several R218 

provisions, is proposing amendments that will provide specific administrative and 

technical guidelines to provide clarity for review, certification, approval and 

operation of CEMS. In essence, the proposals identify the requirements, intent and 

standards in CEMS certification and performance by providing well-defined 

specifications and guidelines to eliminate ambiguity in both the technical and 

administrative provisions of the rule. The deficiencies in guidelines have led to 

varying rule interpretations by the regulated industry with staff implementation of 

Rule 218 CEMS requirements. The proposed administrative requirements and 

performance specifications are more consistent with current CEMS standards 

contained in other regulations with similar requirements. 
Public comments and clarifying questions were raised at the initial public workshop 

on March 25, 1 998. A consultation meeting on June 1 1, 1998 followed to provide 

feedback to key contacts and interested parties regarding staff responses to the 

public comments. A second public workshop was held on August 26, 1998 to 

discuss the revisions and changes to the proposals following the consultation 

meeting. Another cosultation meeting was held on April 2, 1999 to discuss and 

receive comments on the changes made in response to EPA Region M co'mments 

and recommendations. Attachment A to this staff report lists and summarizes the 

public comments and staff responses. 

111. SLMMARY OF PROPOSED AMENDED RULE 218 

The basic intent of amending Rule 218 is to clarify and revise both the 

administrative and technical provisions. PAR2 1 8 contains administrative 

provisions and PR218.1 contains the performance specifications and technical 

requirements. Some provisions of Rule 21 8 have been deleted or revised, as 

appropriate. PAR218 include the foIlowing major sections: Definitions, 

Applicability and Requirements, Application qnd Approval for New or Modified 

CEMS and SCEMS, Requirements for existing CEMS and SCEMS, Quality 

AssuranceIQuality Control Plan, Retention of Records, Reporting, and Posting of 

Written -4pproval. 

A. Rule Title - Continuous Emission Monitoring 

The proposal amends the rule title from "Stack Monitoring" to "Continuous 

Emission Monitoring". The proposed titIe is more appropriate with the 

applicability of the provisions of PAR218 and more consistent with other 

regulations of similar requirements and intent. The requirements for monitoring 

of emissions to enforce source compliance with emission standards are no 

longer limited to the monitoring of contaminant concentration in the stack. As 

in the case of Rule 43 1 .l, sulh content of gaseous fuels are measured before 

burning. 

B. Definitions 

All the definitions in Rule 21 8 have either been deleted or revised while several 

new terms have been defined. All terms related to the performance 
specifications and technical requirements have been deleted and incorporated in 

PR218.1. The new defmed terms include: certified CEMS, continuous 

monitoring, CEMS, data acquisition system (DAS), Laboratory Approval 

Program (LAP), modification requiring recertification, quality assurance/quality 

control (QAIQC) plan, semi-continuous emission monitoring (SCEMS), and 

working day. The definition for CEMS has been expanded to include the total 

combined equipment required for the continuous determination of contaminant 

and diluent emissions, mass emission, fuel flow and/or stack gas flow rates as 

applicable. CEMS consists of three major subsystems: sampling interface, 

analyzer and DAS. 

A major component of the proposed amendment is the definition for 

"continuous monitoring". Continuous monitoring is defined as a minimum of 

one measurement taken and recorded each minute and where 15 or 60 minute 

averages may be required. Semi-continuous emission monitoring is a 

monitoring technique in which a minimum of one measurement is taken and 

recorded every 15 minutes. One measurement may be of concentration, mass 

-- emission rate, stack gas flow rate and/or fuel flow rate. As further discussed 

( below, an application for SCEMS may be submitted in lieu of CEMS. It is 

important to note in the duration of this report that, unless otherwise stipulated, 

the requirements, specifications and standards for CEMS shall al'so apply to 

SCEMS. 

C. Applicability 

PAR2 18 applies to all CEMS that are required or specified in AQMD rules and 

regulations including permit conditions. Examples are CEMS that are required 

under Rule 11 10.1 - Emissions fiom Stationary Combustion Engines, Rule 

1 1 10.2 - Emissions fiom Gaseous- and Liquid-Fueled Internal Combustion 

Engines, Rule 1134 - Emissions of Oxides of Nitrogen from Stationary Gas 

Turbines, Rule 1135 - Emissions of Oxides of Nitrogen from Electric Power 

Generating Systems, and Rule 1146 - Emissions of Oxides of Nitrogen from 

Industrial Institutional, Commercial Boilers, Steam Generators and Process 

Heaters. 

PAR218 does not apply to CEMS under RECLAIM, NSPS, NESHAP, Acid 

Rain, and permit conditions where the CEMS is mainly to monitor the 
performance of the equipment (basic or control) being served and not to 

determine compliance with any applicable limit or standard. The rule does not 

apply to CEMS where alternative performance specifications are stipulated. 

It is not the intent of PAR218 to expand its applicability to include any 

equipment which are not currently covered by the Rule 218, nor to mandate 

additional monitoring devices other than those required by a rule or a permit 

condition. Similarly, the rule does not apply to systems where .only a flow 

meter or a continuous oxygen analyzer (not a contaminant analyzer) is required 

by a permit under which contaminant emissions are calculated fiom emission 

factors or test data. PAR21 8 will not supercede the permit condition to require a 

contaminant analyzer. 

D. CEMS Application and Approval for CEMS and SCEMS 

PAR218 requires the owner or operator of any CEMS subject to the rule to 

submit an "Application for new CEMS or CEMS Modifications". An initial 

approval from the Executive Officer is required before the installation of the 

new CEMS or performing any modification to an existing CEMS, as applicable. 

The Executive Officer will notify the applicant within 60 calendar days (for new 

CEMS) or 30 calendar days (for modified CEMS) from the receipt of the 

application that is deemed complete. Should the Executive Officer require 

additional information to complete the application, a new 30-day period from 

the receipt of any resubmittal or additional information requested shall begin. - 

During this period, the Executive Officer will notify the applicant regarding the 

completeness of the application. 

Upon submission of an "Application for new or Modified CEMS", the owner or 

operator is provided an option to choose the set of performance specifications 

and requirements for the technical review, approval, certification, and 

operational requirements the new or modified CEMS will be subject to. The 

applicant may choose either the standards and specifications that are provided 

according to the provisions of PR 218.1 - Continuous Emission Monitoring 

Performance Specifications, or, according to the applicable provisions of the 

Code of Federal Regulations, Title 40 - "Protection of Environment", Part 60 - 

"Standards of Performance for New Stationary Sources" (40CFR60), Appendix 

B - "Performance Specifications" (Appendix B) and the requirements of 
40CFR60, Appendix F - "Quality Assurance Procedures" (Appendix F). Table 

1 of this report provides a comparison of the administrative and technical 

requirements of the current Rule 2 18, PR2 18.1 and 40CFR60 Appendices B and 

F. The table also compares the stringency of each rule against PR2 18.1. 

Notwithstanding these requirements, any alternative test methods for 40CFR60, 

Appendices B and F will be .those that are listed in PR218.1, Table 1 - 

Reference Methods. 

The standards, requirements and performance specifications of PR218.1 or 

40CFR60 Appendices B and F, as applicable, will be referred to as "New 

Standards" for the duration of this report. "New CEMS or SCEMS" includes 

those CEMS with applications that were submitted to the Executive Officer on 

or after May 14, 1999. "Modified CEMS or SCEMS" include all CEMS or 

SCEMS, after certification and approval, is subjected to modifications requiring 

recertifications. Modification requiring recertification is further discussed 

below. 

The CEMS owner or operator is required to notify the District at least 14 days 

before the scheduled certification tests. The test report must be submitted to the 

Executive Officer no later than 45 days upon completion of the tests. Only 

those testing laboratories or fms that are approved under the AQMD 

Laboratory Approval Program (LAP) are authorized to perform CEMS 

certification and other performance tests. LAP is a program administered by 

AQMD that grants test method-specific approvals to private testing laboratories 

or hs to perform tests to determine source compliance with AQMD rules and 

regulations. The certification tests are to be performed no later than 90 days 

after the CEMS installation. If the equipment being served by the CEMS is not 

operating at the end of the 90-day period, the certification tests must be 

performed no later than 60 days from the start-up of the equipment. 

After certification and final approval, any CEMS that is subjected to a 

modification requiring recertification will require approval from the Executive 

Officer. Modification requiring a recertification is any change to the basic 

equipment, control equipment, contaminant concentration, interfering 

substances, or CEMS, that has a potential for adversely affecting the ability of 
the CEMS to provide accurate, precise and timely data representative of the 

emissions for which the CEMS is required. Examples of modification requiring 

a recertification are as follows: 

a) Modification of basic equipment or basic process that results in the need to 

change a CEMS range. 

b) Modification of basic equipment or basic process that results in a change 

in the gas matrix that could interfere with the detection and quantification 

of the species of interest. 

c) Replacement of a complete monitor. 

The Executive Officer will review and approve modifications made to the 

CEMS and, depending on the assessment, may require all or a portion of the 

performance tests to be conducted. The Executive Officer will assess how the 

modification to the CEMS will affect its intesty to generate quality assured 

data. Any modifications following the AQMD Technical Guidance Document 

#ROO2 - Quality Assurance Requirements for CEMS Modification (see 

Appendix A) will not require recertification. This guidance document provides 

specifics regarding the changes or modifications to CEMS technology, 

equipment, parts, design, model, etc., and the corresponding required tests to 

assess the CEMS ability to generate good, quality assured data. It also includes 

both identical (such as same model, temperature setting, operation and 

maintenance requirements) and non-identical replacements. This document is 

the prevailing reference for CEMS modification at this time. Staff anticipates 

that, as CEMS technologies progress, revisions to this document are inevitable 

such that the most recent version of the guidance document will be the 

prevailing reference at that time. 

An application for a semi-continuous emission monitoring system (SCEMS) 

may be submitted in-lieu of an application for CEMS. An owner may submit an 

application for SCEMS if: 

a) the averaging time for the applicable limit(s) for which the CEMS is 

required is 24 hours or greater; or, 

b) if the owner or operator of the equipment for which the CEMS is required, 

demonstrates that no CEMS technology is commercially available for the 

applicable contaminant and the applicable limits. 
If the conditions in (a) andlor (b) above do not apply, the owner or operator may 

still choose to submit an application for SCEMS subject to the following: 

a) the owner or operator demonstrates that the concentration andlor 

emissions required to be monitored would be equivalent to those 

monitored by a CEMS for the applicable averaging period; 

b) the SCEMS is capable to take and record a minimum of one measurement 

of the pararneter(s) of interest every fifteen minutes with data points as 

equally spaced as practical; 

c) the owner or operator provides in the QAIQC plan the method of 

calculation to be used in determining the 15 minute averages for 

compliance to the applicable limit(s); 

d) the owner of operator accepts the condition that if the allowable limit(s) is 

exceeded using fewer than 100% valid data points, the AQMD will use 

any relevant operational or process data to verify the calculated 

exceedance; 

e) if a time-shared CEMS is proposed, it must meet the standards for timeshared CEMS in accordance with PR218.1. 

E. Requirements for Existing CEMS and SCEMS 

Existing CEMS and SCEMS include previously certified CEMS and SCEMS, 

and also those for which applications for initial approval were submitted to the 

Executive Officer before May 14, 1999. Existing CEMS and SCEMS will 

continue to be subject to the performance specification standards of the current 

R218, now incorporated in PR218.1 sections (c) & (d), as referenced in 

PAR218. The standards to which existing CEMS and SCEMS are subject to 

will be referred to as "Old Standards" for the duration of this report. And, as 

mentioned in an earlier section of this report, all requirements for CEMS will 

also apply to SCEMS, unless otherwise stated. 

The proposals require that existing CEMS must comply with the "New 

Standards" no later than May 14, 2006, which is seven years from the adoption 

of the proposed amended rule. The proposals provide several means for the 

CEMS to meet or waive the requirements by the compliance date. The owner or 

operator may choose to replace, unreliable existing CEMS with a new system, 

or modify the existing CEMS, to meet the "New Standards". The owner or 

operator of a CEMS that meets the "New Standards" without requiring a 
modification may submit a certification, signed by an authorized representative 

of the source, to that effect. Another option is to submit an application for a 

waiver. These options are further discussed below. 

Upon recommendation from the U.S. Environmental Protection Agency (EPA), 

the proposal includes a requirement for existing CEMS to have a written CEMS 

Quality Assurance Plan on record and implemented on or before May 14,2000. 

The plan must be available to the Executive Officer for inspection upon request. 

When a modification requiring a recertification is made to an existing CEMS 

before the compliance date, an "Application for Modified CEMS" must be 

submitted with the corresponding fee as required in Rule 301 at least one year 

before the compliance date. This will allow sufficient time for staff to review 

the application, address changes or request for additional information, as 

appropriate. The application will be evaluated and approved based on the "New 

Standards" (e.g., 40CFR60 App. B & F or PR218.1 performance specifications 

as opted by the applicant). The AQMD will consider each existing CEMS 

modification on a case-by-case basis and may require all or only a portion of the 

performance tests to be conducted. 

For existing CEMS that meets the "New Standards" without modification 

requiring recertification, the owner or operator must submit a certification to 

that effect, signed by an authorized representative of the facility, one year before 

the date on which the existing CEMS must comply with the "New Standards". 

When a modification(s) is made in accordance with AQMD's Technical 

Guidance Document #R002, recertification is not required. However, the owner 

must submit to the Executive Officer a "Notification of Pre-Approved 

Modification" and a report of results of the prescribed quality assurance checks, 

in-lieu of an "Application for CEMS Modification". 

For existing CEMS that provides proven good quality, consistent data that is 

commensurate with the original performance specifications inchding other data 

quality factors, the owner may elect to submit an application for waiver to the 

compliance date requirements every three years after May 14, 2006. In this 

regard, AQMD will consider the following data quality factors to evaluate 

CEMS performance: 
a) Relative accuracy 

b) Calibration error 

c) Calibration drift 

d) Zero drift 

e) Valid data return percentage 

f) Availability or up-time percentage 

g) Breakdown frequency and duration, and 

h) Excursions beyond quality control limits. 

This waiver provision of the PAR2 18 will not apply to existing CEMS that are 

made to comply with the "New Standards" as a result of CEMS modification 

requiring recertification, rule implementation or compliance with a permit 

condition. 

F. Existing Time-Shared CEMS 

PAR21 8 allows existing time-shared CEMS to comply with the "Old Standards" 

indefinitely until a modification requiring a recertification occurs. 

Modifications may be necessary as a result of a new monitoring range for one or 

more of the sources served by the CEMS, or, a source specific rule is amended 

or the operating permit is modified such that the continuous monitoring 

requirement must be satisfied. If a modification occurs, then it will be required 

to meet the "New Standards". In order that time-shared CEMS will satis6 the 

definition of continuous monitoring, a new CEMS or a replacement of a portion 

of the CEMS (i.e., analyzer) may be required in most situations. Otherwise, a 

SCEMS requirement may apply. Each situation will be evaluated on a case-bycase basis. 

G. Quality AssuranceIQuality Control (QNQC) Plan 

QNQC programs will ensure the reliability of the data generated by the CEMS 

to meet regulatory requirements. The current Rule 218 does not implicitly 

provide for CEMS QNQC. Basically, QNQC programs are not new 

requirements. The AQMD, in implementing CEMS, has put the responsibility 

on the source for CEM performance and has recommended a minimum QNQC 

program to achieve the specified levels of performance. Some source specific 

rules (e.g., Rule 1 1 10.2, Rule 1 134, and Rule 1 135) speci6 that CEMS must 
comply with the QA requirements of 40CFR60 Appendix F. Owners or 

operators of new or modified CEMS electing the performance specifications of 

40CFR60, the quality assurance requirements of Appendix F will apply. If the 

owner or operator of the CEMS elects the performance specifications of 

PR218.1, PAR2 18 will require CEMS owners or operators of new or modified 

CEMS to submit a QNQC Plan within 90 days after the CEMS installation (or 

modification) and no later than 30 days before the certification test. The 

QNQC Plan will be reviewed for approval according to the "Guidelines for 

Rule 218 CEMS Quality Assurance/Quality Control Plan" (see appendix B), 

before a CEMS certification is granted. After approval, any changes or 

revisions to the QNQC shall be submitted to and approved by the Executive 

Officer before implementation. 

CEMS owners or operators may be able to expand and develop existing CEMS 

QNQC (i.e., RECLAIM) to include the requirements of PR218.1, or, may 

develop their specific alternative quality assurance practices to assure data of 

equivalent or better quality. These alternative QNQC procedures must be 

- submitted with the facility CEMS QNQC procedures and are subject to the 

( approval of the Executive Officer. 

H. Reporting Requirements for Existing, New or Modified CEMS and SCEMS 

CEMS owners or operators are required to submit a CEMS semiannd- report 

within 30 days of the end of the six-month period being reported. The report is 

a summary of the concentration or emission rate data, as applicable, as well as 

other pertinent information as specified by the Executive Officer. It is also 

required that the report shall be maintained on-site to be made available to the 

Executive Officer upon request, in a retrievable and readable form. Should an 

applicable rule or permit condition require or specify data reporting and 

frequency other than that of PAR218, the requirements of the applicable rule or 

permit condition shall prevail regardless of stringency. If the applicable rule or 

permit condition does not specify reporting requirements, the reporting 

provisions in PAR218 will apply. 

I. CEMS Failure or Shutdown Reporting for Existing, New or Modified CEMS 

and SCEMS 
The proposals require the owner or operator to report to the AQMD any 

exeedance fiom the regulated concentration andlor mass emission rate limits, or 

any system failure or shutdown, which exceeds 24 hours, within 24 hours or the 

next working day. An interim variance must be filed according to AQMD 

Regulation V if CEMS shutdown or failure exceeds the 96-hour-period waiver. 

Next working day is defined as any Monday through Friday excluding holidays. 

The definition fits practically those facilities, operating on a 24-hour-7-day-aweek schedule, that experience a CEMS failure or limit exeedance during 

weekend operations. 

Staff has also incorporated in PAR21 8 Section (f)(3)(B) - Reports of CEMS 

Failure and Shutdown, a reference to Rule 51 8.2 - Federal Alternative Operating 

Conditions to provide for Regulation XXX facilities to obtain ~e&n~ Board 

approval of alternative operating condition in the event of CEMS failures in 

excess of 96 hours. 

J. Notice of Approval 

As an alternative to the current requirement of affixing the District written 

notice of CEMS approval (or a legible facsimile) on the equipment, the proposal 

allows the notice to be placed within 26 feet (AQMD Rule 206) from the 

equipment as long as it is visible, legible and safely accessible. Should either 

requirement becomes impractical, the notice may be placed on a location 

approved by the Executive Officer. 
IV. SUMMARY OF PROPOSED RULE 218.1 

PR218.1 provides for the performance specification standards for new, modified 

and existing CEMS that are under the requirements of PAR.218. The standards for 

existing CEMS, which are deleted fiom the current R218 and incorporated in 

PR218.1; are basically unchanged with minor revisions for technical clax$3cation. 

To provide technical clarity and applicability, the definitions for the following have 

been deleted fiom R218 definitions, revised and incorporated in PR2 18.1 : CEMS, 

analyzer, data recorder, sampling interface, calibration drift (CD), calibration error 

(CE), certified gas mixture, confidence coefficient (CC), full span range (FSR), 

relative accuracy (RA), relative accuracy audit (RAA), relative accuracy test audit 

(RATA) and zero drift (ZD). Furthermore, R218.1 provides additional definitions of 

new terms as follows: CEMS availability percentage, continuous monitoring, 

operational period, quality assurancelquality control plan (QNQC), modification 

requiring recertification, and linearity error. The proposal also includes each 

equation(s) necessary to calculate for CEMS performance that corresponds to each 

standard specification. 

PAR2 1 8.1 also provides for the standards for certification, operational requirements 

and performance specifications for new, modified and existing CEMS, including the 

requirements for time-sharing operations. The "Old Standards" are deleted fiom 

Rule 2 1 8 and incorporated in PR2 1 8.1 without revisions to specifications. 

Therefore, PR2 18.1 provides different sets of performance specifications and 

technical requirements: standards that apply to new or modified CEMS, which is 

referred to as the "New Standards", and those that apply to existing CEMS which is 

referred to as the "Old Standards". 

A. Standards for New or Modified CEMS 

Standards that apply to new or modified CEMS, referred to as "New Standards" 

include specifications and requirements for installation and sample location, 

certification tests, relative accuracy tests and the performance specifications for 

the subsequent operation and maintenance of the installed CEMS after AQMD 

certification. A CEMS meeting these standards is considered capable of 

providing quality assured data for compliance purposes. 
a) Pre-Certification Testing Standards 

Before any certification tests are performed, the CEMS must conform to 

the requirements for sampling probe location, reference sampling ports, full 

span range (FSR), strip chart recorder, Data Acquisition System (DAS) and 

operational period. The basic criteria for sampling location is at a point 

where the measurements of the parameters of interest are made which are 

representative of the stack emissions of the source. The location of the 

CEMS sampling probe and the reference sampling ports are determined 

according to Method 1.1 where the two probes do not interfere with each 

other when in use. However, there is no guarantee that at these locations, 

the flue gas concentrations are not stratified such that the absence of 

stratification must be verified, as discussed below. 

1) Sample Location 

The overall representativeness of the sample to the emissions of the 

source is as dependent on the sampling location as it is to the accuracy 

of the CEMS subsystems. The monitoring sampling probe must be 

located where a sample may be obtained which is representative of the 

source emissions. The monitoring system sampling probe tip and the 

reference method sampling port locations must be determined 

according to District Method 1.1. Each probe shall not interfere with 

the other when in use. Other locations may be chosen subject to a 

written approval of the Executive Officer. If an alternate location is 

chosen which does not conform with District Method 1.1, the absence 

of flow disturbance must be demonstrated using the District method in 

the source Test Manual, Chapter X, Section 1.4 - "Alternative Site 

Selection Method", or 40 CFR, Part 60, Appendix A, Method 1, 

Section 2.5 - "Alternative Measurement Site Selection Procedure", 

and, the absence of stratification must be demonstrated using the 

District method in the source Test Manual, Chapter X, Section I3 - 

"Determination of Gaseous Constituent Stratification". PR2 18.1 

21 S.l(b)(;)(C)(ii) also provides alternatives to sampling site selection 

where testing demonstrates the presence of stratification. The 

alternatives are subject to the approval of the Executive Officer. The 

overall goal is to select a sampling site that will obtain a sample which 

is representative of the source emissions. 
Full Span Range 

PAR218.1 provides that the FSR is set such that all data points fall 

within 10 to 95 percent of the span range for the measurement to be 

valid. Furthermore, the FSR for contaminant monitors must be able to 

measure between 150 to 200 percent of the allowed concentration 

limit, or at a value approved by the Executive Officer. At this range, 

exeedance to the applicable limits may be quantified. For normally 

low contaminant concentration, a dual-span-range may be required if 

the owner or operator needs to quantify, at low-concentration range, 

the emissions for Emission Fee Billing (EFB) and reporting. 

Otherwise, concentrations (or other parameters of interest) may be 

reported at the 10% of the span range. Alternate FSR may be 

approved by the Executive Officer provided that the CEMS owner or 

operator could demonstrate, through historical data and operational or 

process stability, that the proposed FSR will not be exceeded. 

Alternate FSR may not be lower than 120% of the allowed 

concentration limit. 

Additionally, PR218.1 stipulates the following DAS requirements: 

a) DAS must maintain all the required data as stipulated in Rule 2 18, 

Section (e) as follows: CEMS generated data, calculations of 

emissions and all parameters used in the calculations, start-up and 

shutdown information, calibration and adjustments made, and 

CEMS repair and maintenance information. 

b) CEMS data acquisition of monitored parameters must be at least 

once per minute. 

c) SCEMS data acquisition of monitored parameters must be at least 

once every fifteen minutes. 

d) The acquisition rate of monitored parameters must be set at a 

constant rate such that the time span between data points are 

equally spaced as practical. 

e) All valid points will be used for determining compliance with 

applicable standards. 
f) The DAS sample acquisition rate during certification must be the 

same as DAS sample acquisition rate during the normal operating 

mode of the CEMS or SCEMS. 

3) Operational Period 

The operational period is a minimum of 168 hours of continuous 

CEMS operation without unscheduled maintenance, repair or 

adjustments before any certification test is conducted. During this 

period, the source and the CEMS must be operating. 

b) Certification Testing 

Certification is the final approval of a CEMS demonstrating its acceptability 

to conform to all the technical requirements for operation. To be a certified 

CEMS, a CEMS must meet all the specifications and pass a series of 

certification tests, such as the 24-hour CE test, linearity error (LE), and 

RATA. 

1) 24-Hour CE 

The 24-hour CE test is comprised of a series of eight (8) tests during a 

seven-day period performed once each day with as close to 24-hour 

interval as practicable. During this seven-day period test, the CE 

specifications may not be exceeded on any of the tests. 

2-Hour CE and Analyzer Enclosure 

Diurnal temperature variations may. affect the analyzer performance 

should it exceed the manufacturer specifications for temperature drift. 

PR218.1 requires that analyzers be contained in an environmentally 

controlled enclosure, supplied with an alarm device to alert the 

operator for any corrective action if the analyzer exceeds 

recommended temperature specifications. However, the CEMS owner 

may waive the above requirement if he demonstrates to the Executive 

Officer that the analyzer is located in a geographical area where the 

seasonal temperatures do not exceed the analyzer temperature 

specifications, and where the averaged monthly diurnal temperature 

variation is less than 30 degrees F for all months the year. 
If the above enclosure requirement is not met, the operator may 

perform the 2-Hr CE test in lieu of meeting the requirement, The 2- 

hour CE test is a series of thirteen (13) tests over a 24-hour period 

performed once every two (2) hours. The CE must be less than or 

equal to 2.5% of the FSR for all analyzers and 3.0 % of FSR for flow 

monitors when an electronic calibration is applicable. 

3) Relative Accuracy Test Audit 

RATA is the relative accuracy statistical test that is performed during 

certification testing to determine CEMS accuracy in generating data 

within specified limits, that can be compared with the reference 

methods or other applicable standards data. RATA is performed for 

raw pollutant concentrations (for corrected concentrations, if 

applicable), emission rates, diluent concentrations, stack flow 

monitors, and/or fuel flow monitors, as applicable. RATA consists of 

nine sets (minimum) of RM tests to determine the degree of accuracy 

between the CEMS generate data as compared to the value generated 

by the reference method (RM). RATA may include data from 

concentrations and flow monitors to perform calculation in terms of 

units of applicable standards. A minimum of 9 sets of tests will be 

used for RATA calculations. If more than 9 sets of tests are collected, 

no data may be rejected without a valid reason and all data collected 

must be submitted and reported to the Executive Officer. Appendix A 

includes AQMD's Technical Guidance Document #002 - Relative 

Accuracy Test Audit Outliers. The procedure in this document may be 

used if the tester elects to discard any RATA test data after the 

minimm number of tests (nine) have been performed. This document 

may be revised in the future, in which case, the most recent version of 

the guidance document will be the prevailing reference at that time. 

Any documents revisions will go through a public review process. 

PR218.1 (b)(2)(C) provides for the RATA specifications for 

pollutants, dilluents, flow and emission rates.' It also provides for 

alternative specifications for low pollutant and diluent concentrations, 

low flowrates, and low emission rates. 
c) Other test requirements during RATA 

PAR218 requires specific tests during certification and other relative 

accuracy tests. These tests must be satisfied within 14 days or during all 

relative accuracy tests and are as follows: 

Response Time 

The response time specification for CO CEMS, if there is no technical 

limitation, is no more than 1.5 minutes. Otherwise, it will be the same 

as all other CEMS and flow monitors- which is not to exceed 5 

minutes. Response is determined by injecting calibration gas (at a 

value between 50 and 90% of FSR) at the probe of the CEMS. The 

average time interval between injecting a known concentration and 

reaching 95% of the concentration value must be no more than 5 

minutes. 

Stratification, Cyclonic Flow & Interference 

The absence of stratification, cyclonic flow and sampling, analytical 

and flow interference must all be verified. Cyclonic flow check is 

specifically required for emission rate measurements. Cyclonic flow 

and stratification tests must be performed according to AQMD method 

in the Source Test Manual, Chapter X: Non- Standard Methods and 

Techniques at one load if the equipment served by the CEMS operates 

within 20% load range at least 80% of the time or at two loads if it 

operates at 50% load range for at least 80% of the time, or, at three 

loads it operates outside the above criteria. 

Testing under cyclonic flow profiles and stratified concentrations may 

require additional preparation, relocation of sampling ports or process 

modification to obtain a representative velocity/flow and concentration 

data, as applicable. PR2 18.1 Section (b)(2)(C) also provides other 

alternatives if the testing proves that stratification exists. 

Previous tests or historical data that will support the absence of 

cyclonic flow, stratification or interference may be submitted for 

approval by the Executive Officer to satisfy the requirements for 

periodic relative accuracy tests. 
3) Linearity Error 

Linearity Error (LE) will be required for all certification tests and 

RATA's. LE is performed by introducing a known gas concentration 

at the low (10 to 30%), middle (40 to 60%) and high ranges (75 to 

95%) of concentration. The CEMS is challenged with the calibration 

gas three times at each range. The same gas may not be used twice in 

succession. The specification for LE tests is less than or equal to 5.0 

% of the calibration gas concentration. 

B. Quality Assurance/Quality Control Requirements 

The above test procedures and performance specifications have been established 

to certify CEMS (as installed) as capable of generating data that are of adequate 

quality and representative of the stack emissions. However, certification does 

not assure the long-term operation of the CEMS in such a manner as to provide 

the same level of data quality as certified. Continued adequate data quality relies 

on the QNQC program that is developed for the CEMS. A well-thought out 

and implemented QNQC program will result in CEMS good quality data. 

AQMD has prepared a Technical Guidance Document for Rule 218 CEMS 

QNQC Plan, and is provided in Appendix B. PAR21 8.1 provides at a 

minimum the following requirements and specifications for a continuing CEMS 

operations. 

a) Daily 24-hour CE tests to be performed as close to 24-hour intervals as 

practicable at the low (0 to 20%) and high (80 to 100%) ranges of 

concentration. CE's greater that 2.5% but less than 5.0% will be addressed 

by QNQC plan remediation. The CEMS is considered out-of-control when 

CE's exceeds 5.0% of FSR until brought down to specifications. 

b) System bias tests are required once a year during relative accuracy tests 

audits or at a time of replacement of specific parts of CEMS as specified in 

the technical guidance document for modifications. The CEMS bias must 

not exceed 5.0% of FSR for contaminant analyzers. The criteria for 

excessive drift, such as the control limits on cumulative drift, and 

appropriate diagnostic techniques must be included in the QAQC program to 

identify sources of analyzer drift and system bias when QC limit infractions 
occur. Since sample system bias can be a cause of drift aside from many 

other possibilities, CEMS operators are allowed to choose the appropriate 

diagnostic techniques to prevent and resolve sampling bias problems. 

c) RATA must be performed annually and be completed by the end of the 

calendar quarter in which the CEMS was originally certified. 

d) A quarterly Cylinder Gas Audit (CGA) must be performed for three of the 

four calendar quarters, with no more than three quarters in succession. The 

CGA must be performed according to the requirements of 40 CFR, Part 60, 

Appendix F, Section 5.1.2. 

e) The CEMS availability may not be lower than 95%, otherwise, the 

Executive Officer may require a recertification of the CEMS. The 95% 

CEMS availability percentage does not include periods of calibration, 

maintenance, repair, or audit, up to a maximum of 40 hours per month. This 

in essence is in the 90% data availability requirement when these exclusions 

are considered. The basic concern is more for the accumulation of many 

short term CEMS "unexplainable" outages that add up to a large number at 

the end of the year. Staff will take into account mitigating factors 

(appropriately documented) that contribute to CEMS downtime such as a 

broken part that cannot be replaced immediately. 

The CEMS QNQC Plan directs the facility in establishing the implementation 

of procedures for QC activities. These procedures incorporated into a written 

document, the QA manual, provide at a minimum, the CEMS system 

description, detailed operation checks (daily checks, observations, adjustments), 

routine periodic and preventive maintenance, audit procedures and standard 

operating procedures. The QNQC requirements are discussed extensively in the 

"Guidelines for Rule 218 CEMS Quality Assurance and Quality Control Plan". 

This guidance document is subject to revisions as often as necessary, to reflect 

the CEMS state-of-the-science, particularly in the operation and maintenance 

affecting quality control and quality assurance activities. The most recent 

revisions to this document will serve as the prevailing technical guidance for 

QNQC for Rule 218 CEMS. Any future changes to this guidance document 

will go through a public review process. 
V. IMPACTS 

A. Environmental Impacts 

Staff has reviewed PAR21 8 and PR2 18.1 and has determined that they are 

exempt fiom the requirements of California Environmental Quality Act 

(CEQA). Staff has conducted with certainty that the proposals will not have a 

significant adverse impact on the environment. Therefore, staff has prepared a 

Notice of Exemption WOE) pursuant to state CEQA Guidelines Section 

15061(b)(3) - Review for Exemption (AQMD Guidelines Section 5.1) and 

Section 15308 - Actions by the Regulatory Agencies for Protection of the 

Environment (AQMD Guidelines Section 19.12). The NOE will be filed with 

the local county clerks immediately following the adoption of the PAR21 8 and 

PR218.1. 

B. Cost Impacts 

The AQMD staff has prepared a Socioeconomic Assessment Report to address 

the potential cost impacts associated with PAR2 18 and PR2 18.1. The report is 

in Attachment C. 

C. AQMD Impacts 

No significant additional resources will be required to implement PAR21 8 and 

PR218.1. The clarification and delineation of the CEMS specifications and 

requirements will allow staff to evaluate, review and approve CEMS more 

efficiently and consistently. 

VI. COMMENTS 

A. California Air Resources Board (ARB) Comments 

In consultation with ARB regarding the proposed relative accuracy 

specifications as provided in PR2 1 8.1, ARB recognized that the proposed 
standards may in many cases be more restrictive than the federal standards 

addressed and supported by 40CFR60, Appendix B. The District's approach 

"seem reasonable provided the de minimus differential concentration standards 

are as restrictive as the concentrations which would be found by converting the 

percentages given in 40CFR60 Appendix B to differential concentration based 

on values of the federal standards for a comparable facility." 

B. U.S. Environmental Agency (EPA) Comments 

AQMD staff consulted with EPA and requested the review of PAR218 and 

PR218.1, particularly on the equivalency of the requirements of PR2 18.1 to 

40CFR60 requirements for Title V purposes and federal enforceability. EPA 

accepted the proposed de minimus specifications of PR2 1 8.1. EPA considered 

that at medium to high emission limits, PR218.11s relative accuracy criteria are 

equivalent to, or more stringent than, the federal standards. At low 

concentrations, however, where the de minimus criteria apply (e.g., at less than 

5 ppm NOX limits), PR2 1 8.1's relative accuracy de minimus specifications 

become less stringent than the federal limits. EPA recognized that the intent of 

the de minimus criteria is to compensate for the limitations of current 

technology in obtaining a meaningfid relative accuracy at low emission levels 

including the availability and accuracy of low concentration protocol calibration 

gases. 

Additional comments and recommendations from EPA are summarized as 

follows: 

a) Add language to the full span range provisions of PR218.1 on how to 

handle spikes and specifL acceptable conditions that would allow alternate 

full span range to be approved by the Executive Officer. 

b) ClarifL in PR2 18.1 the hierarchy that will be used to evaluate and approve 

alternate sampling locations. 

c) ClarifL in PR2 18.1 the hierarchy that will be used to evaluate and approve 

alternative certification methods for low concentration gases such as 10 

ppm NOx or CO. 

d) UnIess there is a technical limitation, incIude the 1.5 minutes response 

time for CO monitors per 40CFR60, Appendix A, Performance Spec 4A. 
e) Provide in PAR2 18 to require existing CEMS to have the written QAQC 

Plan available and implementation within one year fiom adoption of the 

rule. 

f) Provide a five year record retention period rather than the two year period 

to make record retention consistent with the statute of limitations. 

g) Provide a quarterly cylinder gas audit requirement as part of the QAQC 

similar to 40CFR60, Appendix F. 

EPA Regions IX and district staff discussed the above issues extensively. 

District staff has revised the proposed language to incorporate changes as agreed 

upon with EPA Region IX. Table 2 is a summary of EPA comments and 

recommendations and the corresponding staff responses. 

C. Public Comments 

Staff received public comments and inputs during and after the public 

workshops held on March 25, 1998 and August 26, 1998. Consultation 

meetings were also held on June 1 1, 1998 and April 2, 1999. Staff provided 

responses and actions to the comments received, and incorporated suggestions, 

as appropriate. A summarized tabulation of verbal and written comments and 

staff responses and actions is in Attachment A. A list of public comment letters 

received is in Attachment B and copies of the written comments are on file and 

available upon request. 

VII. ATTACHMENTS 

Attachment A - Summary of Public Comments 

Attachment B - List of Public Comment Letters Received 

Attachment C - Socioeconomic Assessment Report 

VIII. APPENDICES 

Appendix A - Technical Guidance Documents 

Appendix B - Guidelines to Rule 2 18 CEMS Quality Assurance and 

Quality Control Plan 

Appendix C - Sample CEMS QNQC Plan 

Table 1 - Comparison of 

REQUIREMENTS & PERFORMANCE SPECIFICATIONS 

Rule 218 vs. Proposed Rule 2181218.1 vs. 40CFR60, App. B & P 

I I ADMINISTMTIVE REQUIREMENTS 

A CEMS Application Required before installation; initial approval = Required before installation; initial 

by Exec. Off~cer approval by Exec. Officer 

Standards, Tests 

or Parameters 

A I Certification Test 

I 

- 

Proposed Rule 2 1812 18.1 

(New or Modified CEMS) 

Upon completion of installation 

Current Rule 2 18 

(Existing CEMS) 

I I Within 90 days of installation 

s1*+ S2** 

A Test Notification None specified + 

A QNQC Plan None provided + 

40CFR60, Appendices B & F 

(Non- Acid Rain) 

FailureIShutdown Duration Exceeds 60 consecutive minutes 

for Reoortine 

14 davs before tests 

Written plan submitted 45 days afler 

CEMS installation and 30 days before 

certification test, for approval 

More than 24 hours in duration 

A Failure/Sl~utdow~i Reporting Wilhin 96 hours + Within 24 hours or the next working day 

A FailureIShutdown Waiver Not to exceed 96 hours, extended through = Not to exceed 96 hours, extended through 

Hearing Board variance Hearing Board variance 

A Exeedance Reporting Within 96 hours + Within 24 liours or the next working day 

A Data Summary Reporting Monthly - Quarterly 

A Records Retention 2 years = 2 years 

A Posting of Written Approval Affix on equipment or other approved = Affix on equipment, or within 26 feet, or 

location other approved location 

In a form of written notification and plan 

for review & initial approval by Exec. 

Officer (Administrator) 

Within 60 days after the maximum 

production rate but no later than 180 days 

from start-up. 

30 days before test 

Written QC procedures maintained in the 

facility, not required to be submitted for 

approval.. 

Every incident 

+ Included in quarterly sumnlary report 

+ None specified 

None specified 

1 ) PRE - CERTIFICATION REQUIREMENTS 

-Table 1 page i - 

A 

A 

A 

Operational Period 

CEMS Location 

Sampling Location 

- - 

+ 

= 

2 168 hours 

lnstalled where measurements are 

representative of stack emissions or can 

be adjusted to be representative 

Accessible location where the 

concentration or emission rate 

1 168 hours 

Installed where measurements are 

representative of stack emissions 

Located where measurements are 

representative of stack emissions 

- 

= 

= 

1 168 hours 

Installed where measurements are 

representative of stack emissions 

Locations shall be determined per 

SCAQMD Method 1.1 ' 
i- -> - 

1 B i 

Table 1 - Comparison of 

REQUIREMENTS & PERFORMANCE SPECIFICATIONS 

Rule 218 vs. Proposed Rule 2181218.1 vs. 40CFR60, App. B & F 

or Parameters (Existing GEMS) 

measurements are directly representative 

or can be corrected so as to be 

representative of the total emissions or 

at a location. Suggested measurement 

location is greater than I meter from 

stack or duct wall, or, centrally located 

over the centroidal area of the stack or 

duct. 

1.25 to 2 times of the average emission 

contaminant monitors. percent of the span range. FSR between for uncontrolled emissions 

150 and 200 % of the concentration limit. 1.5 times of standard limit for 

controlled emissions 

00% of the c 1.25 to 2 times of the average emrsslori 

contaminant monitors. for uncontrolled emissions 

150 and 200 % of the concentration limit. 1.5 times of standard limit for 

controlled emissions 

normal concentration range 

Multiple - span range may be required 

concentrations can be can be measured for 

diluent monitors. diluent monitors, with maximum setting 

at 25.0% 0, and a minimum setting of 

Revised: 04/07/99 KG -Table I page 2 - 
i' 

Table 1 - Comparison of 

REQUIREMENTS & PERFORMANCE SPECIFICATIONS 

Rule 218 vs. Proposed Rule 2181218.1 vs. 40CFR60, App. B & F 

or Parameters (Existing CEMS) (New or Modified CEMS) (NOD- Acid Rain) 

II CERTIFICATION TEST REQUIREMENTS 

Verification of non-existence 

Verification of non-existence 

Verification of non-existence 

Verification of non-existence 

Stratification '$' 

Stratification 's' 

Cvclonic Flow 's3 

None specified 

None specified 

None specified 

None soecified 

Verification of non-existence 

Verification of non-existence 

Verification of ~OII-existence 

Interference ' Verification of non-existence 

Response Time 

Response Time 

Response Time 

Response Time 

I 10 minutes 5 5 minutes None specified 

None specified 

None specified 

5 1.5 min. to achieve 95% of stable 

value 

I 10 minutes 

5 10 minutes 

I 10 minutes 

< 5 minutes 

I 5 minutes 

I 1.5 minutes or 5 5 minutes if 

technical limitations exists 

Calibration Error (CE) 5 5% of the cal. gas value < 5% of the cal. gas value < 5% of the cal. gas value 

Calibration Error (CE) I 5% of the cal. gas value 

I 20% of the mean value of the RM or 

10% of the allowed concentration, 

whichever is greater 

< 5% of the cal. gas value 5 5% of the cal. gas value 

< 20% of the mean value of the .RM 

concentrations, or, the de-minimus 

concentration of 1.0 ppm NOx, 

whichever is greater 

< 20% of the mean value of the RM 

concentratio~~s, or, I0 % of 

applicable standard, whichever is 

greater 

520% of the mean value of the Rh4 

concentrations, or, I0 % of 

applicable stkdard, whichever is 

greater 

< 15% of applicable standard if standard 

is bet. 0.20-0.30 Ib per MMBTU, 

or, 

< 20% of applicable standard if 

standard is 

< 0.20 Ib per MMBTU. 

I 10% of the mean value of the RM 

concentrations, or, 5 % of 

applicable standard, whichever is 

Relative Accuracy 

20% of the mean value of the Rh4 

concentrations or, the de-minimus 

concentration of 2.0 ppm S02, 

whichever is greater 

lielative Accuracy I 20% of the mean value of the Rh4 or 

10% of the allowed concentration, 

whichever is greater 

. 5 20% of the mean value of the RM 

concentrations or, the de-minimus 

concentration of 2.0 ppm CO, 

whichever is ereater 

Relative Accuracy 5 20% of the mean value of the RM or 

10% of the allowed concentration, 

whichever is greater 

Revised: 04/07/99 RG -Table 1 page 3 - 
t 

Table 1 - Comparison of 

REQUIREMENTS & PERFORMANCE SPECIFICATIONS 

Rule 218 vs. Proposed Rule 2181218.1 vs. 40CFR60, App. B & F 

I greater 

Relative Accuracy 5 20% of the mean value of the RM , or 

'Code* 

10% of the allowed concentration, 

whichever is greater 

or Paranleters (Existing CEMS) (New or Modified CEMS) (Non- Acid Rain) I 

I 

S2** 

concentrations or, the de-minimus 

concentration of 4.0 ppm Total 

Reduced Sulfur (TRS), whichever is 

' ' 40CFR60, Appendices B & P 

10% of the applicable standard, 

whichever is greater 

-.. 

Standards, Tests. Propwed Rule 21 8/21 8.1 

greater. 

5 10% of the mean value of the RM for 

diluent concentrations, or 1 .O% O,, 

- - 5 20% of the mean value of the Rh4 for 

diluent concentrations, or 1 .O% 0,; 

or C 0, whichever is greater 

None; included in RA for Inass 

emission rate (CERMS) 

Current Rule 2 18 

Relative Accuracy 

Sl** 

None specified 

whichever is greater 

5 15% of the mean value of the RM for 

flow monitors, or the equivalent 

flow rate based on 2.0 fps stack gas 

velocity, whichever is greater 

Relative Accuracy None provided 

I 20% of the mean value of the RM 

concentrations, or.10 % of 

applicable standard, whichever is 

greater 

None provided + 5 20% of the mean value of the RM for 

mass emission rates, or the 

equivalent mass emission rate based 

on 2.0 fps stack gas velocity, 

whichever is greater 

5 2.5 % of the FSR, or, analyzer 

environmental enclosure 

5 2.5 % of the FSR, or, analyzer 

Relative Accuracy 

2-hour Zero Drift + ( none specified (ZD) 5 2% of the FSR for contaminant monitors - I 

2-hour Zero Drift (ZD) 5 0.4% CO, or 0, I - + I none specified 

environmental enclosure 

< 2% of the FSR for contaminant monitors 5 2.5 % of the FSR, - - -5 2.5 % of the FSR 

5 0.5% CO, or 0, < 2.5 % of the FSR, - - -5 2.5 % of the FSR 

5 2% of the FSIC for contaminant mo~iitors - 5 2.5 % of tlie FSR, or, analyzer + none specified 

environmental enclosure 

5 0.4% CO, or 0, < 2.5 % of the FSR, or, analyzer + none specified 

24-hour ZD 

2-liour Calibratio~i Dri 

(CD) ( or CE)5 

2-hour CI))( or CE) 

environmental enclosure 

5 2.5% of the FSR - - r 2.5 % of the FSR - 5 2,5 % ol the FSR - 

5 2.5% of the FSR - - 5 2.5 % of the FSR - 5 2.5 % of the FSR - 

5 0.5% CO, or 0, 5 2.5 % of the FSR - 5 0.5% CO, or 0, - 

24-liour CD ( or CE) ' 

24-hour CD ( or CE)5 

24-hour CD f or CE)' 

24-hour CD ( or CE)' 

24-hour CD ( or CE) 

5 2.5% of the FSR I - 5 2.5 % of the FSR I + I - 5 5.0 %of FSR, 6 of 7 test 

None provided + < 3.0 % of the FSR for flow monitors 1 - -< 3.0 % of 1.25 times the average - 

I I Revised: 04/07/99 RG - Table 1 page 4 - 
- Table 1 page 5 - 

7-, 

i 

Table 1 - Co~nparison of 

REQUIREMENTS & PEWORhANCE SPECIFICATIONS 

Rule 218 vs. Proposed Rule 2181218.1 vs. 40CFR60, App. B & F 

%ode* Standards, Tests 

or Parameters 

I: 

N 

vsp*, 

- ~ 

Current Rule 2 18 '" 

(Existing CEMS) 

A 40CFR60, Appendices B & F 

(Non- Acid Rain) 

F-factors 

NOx Conversion Efficiency 

MINIMUM QUALITY ASSUMNCE /CONTROL REQUIREMENTS 

S1** 

- - 

+ 

Proposed Rule 21 812 18.1 

te 7 -, (New or Modified CEMS) ' 

potential absolute value for that 

measurement. 

Fd factors listed in 40CFR60, App. A, 

Method 19, Table 19- 1 

None provided 

None provided 

None provided 

Once every four calendar quarters 

Daily CD check 

Conducted in 3 of 4 calendar quarters, 

but no more than three quarters in 

succession 

------ 

EPA Protocol Gases 

EPA Protocol Gases 

EPA Protocol Gases 

EPA Protocol Gases 

Revised: 04/07/99 RG 

= 

- - 

= 

+ 

= 

= 

= 

, = 

A 

A 

A 

A 

P 

D 

P 

C , 

+ 

+ 

Fd factors listed in 40CFR60, App. A, 

Method 19, Table 19- 1 

According to Method 100.1.- 

RATA 

CD (or CE) 

Cylinder Gas Audit (CGA) 

System Bias 

Calibration Gas 

Calibration Gas 

Zero Gas 

Zero Gas 

None provided 

Daily CD checks 

None specified 

None specified 

5 2.0% of stated value, 

I 0.2% of stated value, ambient air ' maybe used for oxygen monitors if 

span is 

> 21 % 02. 

< 1 ppm of contaminant for contaminant 

monitors 

< 10 ppm CO for CO monitors 

+ 

= 

+ 

+ 

= 

= 

= 

- 

Performed annually 

Daily CE check 

Conducted in 3 of 4 calendar quarters, 

but no more than three quarters in 

succession 

f 5.0 percent of the FSR performed 

every 7 days or every 3 months6 

According to EPA Traceability Protocol 

for Assay and Certification of Gaseous 

Calibration Standards, EPA-600/R93/22 

According to EPA Traceability Protocol 

for Assay and Certification of Gaseous 

Calibration Standards. Instrument air 

may be used if filteredprocessed and 

included in QNQC Plan. 

According to EPA Traceability Protocol 

for Assay and Certification of Gaseous 

Calibration Standards 

< 1.0 % of FSR of contaminant 

monitors 

Instrument air may be used if 

filteredprocessed and included in 

the QNQC Plan. 

According to EPA Traceability Protocol 
t 

Table 1 - Comparison of 

REQUIREMENTS & PERFORMANCE SPECIFICATIONS 

Rule 218 vs. Proposed Rule 2181218.1 vs. 40CFR60, App. B & F 

Standards, Tests 

-- Every 6 months by NBS procedures 

I 

! 

i 

for Assay and Certification of Gaseous 

Calibration Standards. 

Instrument air may be used if 

filteredprocessed and included in 

QNQC Plan . 

According to EPA Traceability Protocol 

for Assay and Certification of Gaseous 

Calibration Standards. 

* Code: A - applies to all CEMS 

C - applies to CO CEMS 

D - applies to diluent CEMS 

According to EPA Traceability Protocol 

for Assay and Certification of Gaseous 

calibration Standards. 

I 

Current Rule 21 8 

F - applies to flow monitors P - applies to pollutant CEMS 

N - applies to NOx CEMS S - applies to SO2 CEMS 

M - applies to mass emissions T - applies to TSR CEMS 

or Parameters 

Proposed Rule 21 812 18.1 ' * St** 

* * S I - Stringency comparison of PR2 18.1 to current Rule 2 18 (e., "+ " in S 1 means PR2 18.1 is more stringent than current Rule 2 18) 

S2 - Stringency comparison of PR218.1 to 40CFR60, Appendices B & F (i.e., "+" in S2 means PR218.1 is more stringent than 40CFR60) ,I _ ,, - denotes equally stringent " + " denotes more stringent " - " denotes less stringent 

EPA Protocol Gases 

EPA Protocol Gases 

(Existing CEMS) 

S2** 

The CEMS and the RM sampling probes shall not interfere with each other. If not applicable, other locations may be chosen with approval of the Executive Officer following specific provisions. 

The stratification and cyclonic flow tests are performed according to the method in the Source Test Manual Chapter X: Non-Standard Methods and Techniques tested as follows: at one (1) load 

if the equipment operates within a 20% load range for at least 80% of the time; at two (2) loads if the equipment operates within a 50% load range for at least 80% of the time; or at three loads if 

the equipment operates other than the two above criteria. 

Docu~nentation of previous tests or historical data may satisfy the stratification, cyclonic flow and interference requirements. 

Linearity Error (LE) test at low and high range of concentration. 

The CD for the current Rule 21 8 is the same term and is used in the same context as that for the CE in PR2 18.1 that applies to new or modified CEMS. 

May be tested once every quarter with a documented procedure in QAiQC to assure and record that no cumulative adjustments > 5.0 %. If the cumulative adjustments exceed 5 %, a system bias 

check shall be performed within 24 hours. 

Recertification periods of certified gas mixtures shall be in accordance with EPA Traceability Protocol, Procedure GI or EPA Procedure G2, if EPA Procedure GI is not available. If EPA 

protocols do not apply, the gas manufacturer may submit a recertification protocol for approval. 

' 40CFRb0, Appendices B & F 

-Table 1 page 6 - 

(New or Modified CE;MS) ' s (Non- Acid Rain) I 

Table 2 

SUMMARY OF 

EPA COMMENTS & RECOMMENDATIONS 

EPA CO~IMENTS / RECOMMENDATIONS I PRQPOSED RULE LANGUAGE REVISED PROPOSED RULE LANGUAGE 

I) Relative Accuracy: 

Because of current technical limitations in 

obtaining meaningful relative accuracy 

(RA) at low concentration levels, EPA does 

not object to PR218.l'~ use of an absolute 

de-minimus value subject to the following 

condition: 

3) Record Retention: 

Provide a five-year record retention 

requirement rather than a two-year 

period. 

4) Cylinder Gas Audit (CGA) 

The rule is silent on CGA; strongly 

recomniends that CGA be required. 

PR2 18.1 (b)(2)(C) - Relative Accuracy 

The CEMS shall meet the following RA 

performance specifications: 

Less than or equal to 20.0 percent of the 

mean value of .the reference method for 

pollutant concentrations, or the de-minimus 

concentration as follows, whichever is 

greater: 

Pollutant De-minimus 

Concentration 

NOx 1.0 ppm 

so2 2.0 ppm 

CO 2.0 ppm 

Reduced Sulfur Compounds 4.0 ppm 

(QAQC required within three years after 

adoption) 

PAR21 8(D)(l)(E) - The owner or operator 

of existing CEMS shall submit to the 

Executive Officer for approval, a Quality 

Assurance/ Quality Control (QNQC) Plan 

no later than May 14,2002. 

PAR2 18(e)(l) - The records ......... , shall be 

maintained by the CEMS owner or operator 

for a minimum period of two years or as 

specified by the applicable rule or 

regulation . . . . . . . . . None required . 

No change in proposed rule language; 

(revised to one year after adoption) 

PAR2 18(D)(l)(E) - The owner or operator 

of existing CEMS shall develop and 

implement a writtell Quality Assurance/ 

Quality Control (QAIQC) Plan no later than 

May 14, 2000. The written QA/QC Plan 

shall be kept on record and available for 

inspection upon request by the Executive 

Officer. 

No revisions made on the proposed 

language to be consistent with recent 

federal rulemaking activities (February 12, 

1999) pertaining to 40CFR59, 60 & 61 on 

recordkeeping and reporting. 

PR2 18.l(b)(4)(D) - Cylinder Gas Audit 

(CGA) 

A CGA shall be performed every calendar 

auarter but in no more than three auarters in 

! Table 2 - page 2 
I 

'Table 2 

SUMMARY OF 

EPA COMMENTS & RECOMMENDATIONS 

1 5) Response Time: 

Unless there is a technical limitation, 

include the shorter response time of 1.5 

minutes for CO CEMS, per 40CFR60, 

App. B, I'erformance Spec 4A 

6) Full Span Range (FSR) : 

Add language to the rule on how to 

handle spikes, indicating that if a value 

falls outside the acceptable range, it 

shall be invalid but must be reported. 

7) Full Span Range (FSR): 

Specify acceptable conditions which 

would warrant alternate FSR which is 

outside of the FSR specification. 

PAR2 18.1 (b)(3)(A) - Response Time 

The response time for all analyzers and 

flow monitors, as applicable, shall not 

exceed 5 minutes. 

PR2 1 8.1 (b)(l)(C)(i) - Full Span Range 

The FSR for mass emission rate, air 

contaminant, diluent and flow analyzers 

shall be set such that all data points are 

within I0 to 95 percent of the range. 

PR2 18.1 (b)( l)(C)(ii) - Full Span Range 

For air contaminant monitors, the FSR shall 

be set between 150 and 200 percent of the 

concentration limit as specified in the 

applicable rule or permit condition. 

Table 2 - page 3 

succession. The CGA shall be conducted 

according to the provisions of 40 CFR 60, 

Appendix F. The audit gases shall be 

according to the certification requirements 

ofRule218.1. 

PAR2 18,l(b)(3)(A) - Response Time 

The response time for CO analyzers shall 

not exceed 1.5 minutes except where there 

is a technical limitation, in which case the 

response time shall be 5 minutes. The 

response time for all other analyzers and 

flow monitors, as applicable, shall not 

exceed 5 minutes. 

PR2 18.1(b)(l)(C)(ii) - Full Span Range 

The FSR for mass emission rate, air 

contaminant, diluent and flow analyzers 

shall be set such that all data points are 

within 10 to 95 percent of the range. 

Pm 1 8. l (b)(l)(C)(vi) - Should any data 

points fall above 95 percent of FSR, the 

value shall be invalid for quantification and 

the CEMS shall be considered unavailable 

for the purposes of determining CEMS 

availability percentage. All excursions 

above 95 percent of FSR and the duration 

of these excursions shall be reported in the 

CEMS summary report as prescribed under 

Rule 2 18(f). 

For air contaminant monitors, the FSR shall 

be set between 150 and 200 percent of the 

concentration limit as specified in the 
Table 2 

SUMMARY OF 

EPA COMMENTS & RECOMMENDATIONS 

-A CO~IMENTS / RECOL~MENDATIONS ORIGINAL PROPOSED RULE LANGUAGE REVISED PROPOSED RULE LANGUAGE I 

provide hierarchy that will be used to 

evaluate and approve alternate 

certification and recertificatiom methods 

for calibratio~i gases. 

- 

PR218.l(d)(l) - Calibration Gas 

(A) Calibration gas mixtures shall be 

certified in accordance with the EPA 

Traceability Protocol for Assay and 

Certification of Gaseous Calibration 

Standards. Alternative certification 

methods for low concentration calibration 

gases, such as 10 ppm NOx or CO, may 

be submitted to the Executive Officer for 

approval. 

(B) Recertification periods of certified 

gas mixtures shall be in accordance with 

EPA Traceability Protocol, Procedure G 1 

or EPA Procedure G2, if EPA Procedure 

G1 is unavailable. If EPA protocols are 

not applicable, the gas manufacturer may 

submit an alternative recertification 

protocol for District approval. Ally 

FSR may be set at a value other than that 

specified, but no lower than 120 percent, 

provided that the CEMS owner or operator 

demonstrates to the satisfaction of the 

Executive Officer that the FSR will not be 

exceeded. Such demonstrations may 

include, but not limited to, historical 

emissions data, historical process 

information, and historical operational 

information. A written approval from the 

Executive Officer shall be obtained before 

the FSR may be modified outside of the 

150 to 200 percent of the concentration 

limit. 

PR218.1 (d)(l) - Calibration Gas 

(A) Calibration gas mixtures, as defined in 

Rule2 1 8.1 (a)@), shall be manufactured, 

analyzed and certified in accorda~ice with 

the "EPA Traceability Protocol for Assay 

and Certification of Gaseous Calibration 

Standards9'-EPA-6001R9711 2 1, September 

1997 Revision (EPA Protocol). The 

certification period and recertification 

requirements, as applicable, shall be 

according to the EPA Protocol. 

(B) For gas calibration standards not 

explicitly covered by the EPA I'rotocol, 

the CEMS owner or operator shall submit 

the gas manufacturer's alternative 

certification protocol for the specific 

compound or dompounds. 

(i) The procedures of the EPA Protocol 

shall be used for gas calibration 

Table 2 - page 4 
tecnnical aara also proviaea oy me 

manufacturer. This alternative shall be 

subject to the approval of Executive 

Officer. 

(ii) If there is no existing National 

Institute of Standards and Technology 

(NIST) standard for the measured 

parameter, the gas manufacturer may 

submit an alternative reference standard 

and the supporting technical data that 

define the stability, accuracy, and 

precision of the alternative reference 

standard. This alternative shall be 

subject to the approval of Executive 

Officer. 

(iii) The CEMS owner or operator may 

submit an alternative protocol to the 

EPA. Protocol, provided that the CEMS 

owner or operator demonstrates through 

supporting technical data that the 

procedures therein are not applicable to 

the constituent in the calibration gas 

standard being certified. This alternative 

shall be subject to the approval of 

Executive Officer. 

Table 2 - page 5 
SUMMARY OF' 

EPA COMMENTS & RECOMMENDATIONS 

9) Alternate Sampling Locations: 

provide hierarchy that will be used to 

evaluate and approve alternate sampling 

I locations. 

I 

PR2 18.l(b)(l)(B) - Sampling Location 

The monitoring system sampling probe tip 

and the reference method sampling port 

locations shall be determined according to 

District Method 1.1. The monitoring 

sampling probe shall be located where a 

sample may be obtained which is 

representative of the source emissions. 

Each probe shall not interfere with the other 

when in use. Other locations may be 

chosen subject to a written approval of the 

Executive Officer. 

PR2 18.l(b)(l)(B) - Sampling Location 

The monitoring system sampling probe tip 

and the reference method sampling port 

locations shall be determined according to 

District Method 1.1. The monitoring 

sampling probe shall be located where a 

sample may be obtained which is 

representative of the source emissions. 

Each probe shall not interfere with the other 

when in use. Other locations may be 

chosen subject to a written approval of the 

Executive Officer. If an alternate location 

is chosen which does not conform with 

District Method 1.1, the absence of flow 

disturbance shall be demonstrated using the 

District method in the source Test Manual, 

Chapter X, Section 1.4 - "Alternative Site 

Selection Method", or 40 CFR, Part 60, 

Appendix A, Method 1, Section 2.5 - 

"Alternative Measurement Site Selection 

Procedure", and, the absence of 

stratification shall be demonstrated using 

the District method in the source Test 

Manual, Chapter X, Section 13 - 

"Determination of Gaseous Constituent 

Stratification". Alternatives to sampling 

site selection in the presence of 

stratification are presented in Rule 

2 18.1 (b)(3)(C)(ii). 

EPA COMMENTS 1 RECOMMENDATIONS REVISED PROPOSED RULE LANGUAGE 

Table 2 - page 6 

ORIGINAL PROPOSED RULE LANGUAGE