UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

REGION IX AIR DIVISION

Technical Support Document 

For

EPA's Direct Final Rulemaking

for the

California State Implementation Plan

Antelope Valley Air Quality Management District, 

Rule 218.1 Continuous Emission Monitoring Performance Specifications

Prepared by: Stanley Tong

 May 1, 2013
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RULE IDENTIFICATION

Agency: Antelope Valley Air Quality Management District (AVAQMD)

SIP Approved Rule: There is no prior version of this rule in the SIP

Subject of this TSD: Rule 218.1 - Continuous Emission Monitoring Performance 

Specifications 

Adopted July 17, 2012; 

Submitted February 6, 2013

RULE SUMMARY - Requirements from the 2005 SIP approved version of Rule 218

were updated and divided into an administrative portion (Rule 218) and a technical 

portion (Rule 218.1). Rule 218.1 is a new rule and contains requirements for the 

certification of continuous emission monitoring systems (CEMS), the performance 

specifications of CEMS, and the operation and maintenance of CEMS.

The rule applies to all sources that require a certified CEMS pursuant to AVAQMD Rule 

218, Continuous Emission Monitoring.

 

Rule 218.1 contains:

1. Technical standards for new or modified CEMS

This section includes pre-certification requirements such as: the location of the 

CEMS; locations for the sampling probe and reference method sampling port; full 

span range of the CEMS; strip chart recorder requirements; and requirements for 

the data acquisition system.

To demonstrate the acceptability of a new or modified CEMS, Rule 218 requires 

a series of certification tests be performed using the technical criteria in Rule 

218.1. These criteria include: testing to determine calibration error; testing for 

relative accuracy; and verifying analyzer enclosure environmental control and 

alarm requirements are met.

Rule 218.1 also requires CEMS to be properly operated and maintained which 

includes conducting calibration error tests each operating day, quarterly cylinder 

gas audits, and annual system bias and relative accuracy tests. Rule 218.1 

allows the District to require recertification of the CEMS if its annual availability 

falls below 95 percent.

2. Standards for existing CEMS

Existing gaseous air contaminant CEMS must meet certain performance 

specifications such as: the minimum time a CEMS must operate continuously 

according to the manufacturer’s specifications without unscheduled 

maintenance, repair, or adjustment; and requirements for the allowable 
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calibration error, response time, zero drift, calibration drift, and relative accuracy. 

Rule 218.1 contains similar performance specifications for diluent gas CEMS. 

3. Standards, specifications and requirements for new, modified and existing CEMS

This section contains specifications for the manufacture, analysis and 

certification of calibration and zero gases, requirements to record the magnitude 

of automatic calibration adjustments, and a requirement to perform NO2 to NO 

conversion efficiency testing using SCAQMD Method 100.1.

4. Time-shared CEMS

Time-shared CEMS are monitoring systems where the analyzer and possibly the 

sample conditioning systems are used on more than one source. Rule 218.1 

requires time-shared CEMS to meet all performance specifications in the rule,

data-reading periods at least three times the longest response time of the 

system, and capable of performing zero and span calibrations at each source.

5. Minor changes were also made to update Rule 218.1’s list of reference test 

methods.

6. Rule 218.1 also includes alternative requirements for CEMS operators who elect 

or may be required to measure concentrations that fall below 10 percent of the 

lowest vendor guaranteed full scale span range.

EPA EVALUATION - The following documents were used to evaluate the submitted 

rule. 

1. 40 CFR 60 Appendix B – Performance Specifications

2. 40 CFR 60 Appendix F – Quality Assurance Procedures

3. Enforceability - The Bluebook (Issues Relating to VOC Regulation Cutpoints, 

Deficiencies, and Deviations, EPA, May 25, 1988) and the Little Bluebook 

(Guidance Document for Correcting Common VOC & Other Rule Deficiencies,

EPA Region 9, August 21, 2001) were used to help evaluate compliance with the 

CAA §110(a)(2)(A) requirement for enforceability. 

4. SIP Relaxation - Where previous versions of rules have been SIP approved, new 

submittals must comply with CAA §110(l) and §193 regarding SIP relaxations.

The submitted rule provides performance specifications standards for new or modified 

CEMS, and standards for existing CEMS. Technical standards that originally appeared 

in Rule 218 for existing CEMS were moved to Rule 218.1 and were generally unchanged 

except for minor technical clarifications. 

The standards for new or modified CEMS include specifications and requirements for 

installation and sample location, certification tests, relative accuracy tests, and 
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performance specifications for the operation and maintenance of the CEMS after they 

have been certified by the District.

Daily calibration error tests, quarterly cylinder gas audits, and annual system bias and 

relative accuracy test audits are also required for quality assurance/quality control under 

Rule 218.1.

AVAQMD incorporated EPA’s recommendation on a similar South Coast rule to remove

the relative accuracy de minimus criteria for NOx and CO. 

EPA ACTION –

The submitted Rule 218.1 strengthens the SIP. There are no expected emission 

reductions from this rule as it primarily updates technical performance specifications for 

continuous emission monitoring systems. The rule largely fulfills the relevant CAA §110 

and part D requirements. EPA staff recommends approval of Rule 218.1 pursuant to 

CAA §110(k)(3) and §301(a).

REFERENCES -

1. "Issues Relating to VOC Regulation Cutpoints, Deficiencies, and Deviations," 

(a.k.a., Bluebook) EPA OAQPS, May 25, 1988.

(http://www.epa.gov/ttn/naaqs/ozone/ozonetech/voc_bluebook.pdf).

2. "Guidance Document for Correcting Common VOC & Other Rule Deficiencies," 

(a.k.a., Little Bluebook), EPA Region 9, August 21, 2001 

(http://www.epa.gov/region09/air/sips/littlebluebook2001.pdf).

3. AVAQMD Rule 218.1, Continuous Emission Monitoring Performance 

Specifications, amended July 17, 2012, submitted on February 6, 2013.

4. AVAQMD Rule 218, Continuous Emission Monitoring, adopted July 17, 2012, 

submitted on February 6, 2013.

5. SCAQMD Rule 218.1, Continuous Emission Monitoring Performance 

Specifications, adopted May 14, 1999.

6. SCAQMD Rule 218, Stack Monitoring, amended May 14, 1999.

7. Comment letter dated March 31, 1999, Review of Proposed Amended Rule 218 

(PAR 218 – December 11, 1998) and proposed Rule 218.1 (PR 218.1 – no date) 

from EPA Region IX (Andrew Steckel) to SCAQMD (Elaine Chang).