04/22/86
Guidance: Enforcement Applications of Continuous Emission
Monitoring System Data
MEMORANDUM
SUBJECT: Guidance: Enforcement Applications of Continuous Emission
Monitoring System Data
FROM: /s/ Edward E. Reich, Director
Stationary Source Compliance Division
Office of Air Quality Planning and Standards
/s/ Michael S. Alushin
Associate Enforcement Counsel
Air Enforcement Division
TO: Addressees
I. Purpose and Application
The purpose of this guidance is to increase the use of continuous
emission monitoring system ( "CEMS" ) data in the Agency's compliance and
enforcement program. 1/
1/ "CEMS" as used in this guidance principally means instrumental or
manual continuous emission monitoring systems. Furthermore, as with any
other data, "CEMS" as used in this guidance assumes that EPA confirms
that the specific data, normally available from the source, are
reasonably accurate and precise. This information includes data such as
those acquired during Performance Tests, Performance Specification
Tests, and periodic calibrations of the CEMS. For additional
information, see 6/.
EPA intends in this way to strengthen its efforts to ensure that sources
comply with applicable law on a continuous basis and to enforce against
those that do not.
This document addresses the following three enforcement applications for
CEMS data:
1) the governing regulation specifies CEMS as the official compliance
test method ( "Compliance Method" ), e.g., the Reference Method for
the Standards of Performance for New Stationary Sources ( NSPS );
2) the governing regulation specifies some method other than CEMS as
the Compliance Method; and
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3) the governing regulation concerns proper operation and maintenance,
recordkeeping, and other requirements where no test method would be
specified.
This guidance applies to any Federally-enforceable regulation or other
requirement governing emissions, operations and maintenance ( "O&M" ), and
monitoring and reporting procedures for stationary sources of air pollution.
It should be read together with the attached document entitled "Guidance
Concerning EPA's Use of Continuous Emission Monitoring Data" ( August 12,
1982 ). 2/
2/ The 1982 guidance clarifies, among other things, the circumstances
under which CEMS constitutes the applicable Compliance Method and the
role played by CEMS under State Implementation Plans ( "SIPs" ) which do
not identify any Compliance Method.
II. Conclusion
EPA can put CEMS data to a variety of important enforcement uses,
irrespective of whether the legal requirement being enforced specifies CEMS
as the Compliance Method. For example, EPA can rely on CEMS data alone to
issue Findings of Violation ( "FOVs" ) and Notices of Violation ( "NOVs" ).
However, the legal requirement must specify CEMS as the Compliance
Method in order for EPA to rely on CEMS data alone to refer a case to the
Department of Justice ( "DOJ" ), to prove a violation of an emission
limitation in Federal District court, or to issue a Notice of Noncompliance
( "NON" ) under Section 120. The same is true if EPA is to rely on CEMS
data alone to issue an administrative order respecting emissions violations
under Section 113(a).
On technical grounds, CEMS data typically are at least comparable to
Compliance Method and inspection data derived from equally well-executed and
quality-assured monitoring. CEMS data certainly are more representative of
actual continuous emissions than are some traditional sources of compliance
data, such as emission factors and engineering calculations.
III. Discussion
A. Where the Governing Regulation Specifies CEMS as the Compliance
Method
CEMS is the Compliance Method in NSPS Subparts Da ( covering new
electric steam generators ), P, Q and R ( covering new nonferrous
smelters ), and in certain SIP provisions, Federally-
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enforceable compliance orders and permits. For sources covered by these
provisions, EPA can rely on CEMS data alone to take all of the following
enforcement actions:
1. Devise a priority list for inspections and other investigative
activities;
2. Issue NOVs to SIP sources, or FOVs to non-SIP sources; 3/
3. Document that a violation has continued 30 days beyond the
date of the NOV in SIP cases;
4. Quantify the severity of violations for penalty calculation
purposes, in negotiation or litigation;
5. Issue an administrative order under Section 113(a);
6. Issue a Section 120 NON;
7. Formally refer a case to the DOJ for filing as a civil or
criminal action; and
8. Prove a violation in civil or criminal litigation in Federal
district court.
3/ While some Regional Offices do issue FOVs, it should be noted that EPA
has no legal obligation to do so.
B. Where the Governing Regulation Specifies Some Method Other Than CEMS
as the Compliance Method
Here, CEMS data still can be very useful in initiating and supporting
cases alleging emission violations. The Agency can rely on CEMS data alone
to take any of the first four enforcement actions listed at Section III(A)
above.
For example, EPA can use CEMS data standing alone as the basis for
issuing an NOV or FOV for violation of an emission limitation. 4/
4/ The Clean Air Act expressly permits the Administrator to issue an NOV
"on the basis of any information available to him . . . that any person
is in violation of any requirement of an applicable implementation plan"
42 USC Section 7413(a)(1).
Proof of the existence of a violation of an emission limit for purposes of a
compliance order or litigation virtually always must be based on Compliance
Method data. However, issuance of an NOV or FOV requires a less rigorous
evidentiary showing.
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If after issuance, the source fails to come into compliance with the
emission regulation, EPA normally must acquire Compliance Method evidence
before it takes any of the last four enforcement actions listed at Section
III(A) above. 5/
5/ However, in most circumstances a Regional Office may rely on non-
Compliance Method CEMS data alone to support a referral where it
constitutes a pre-negotiated settlement agreement, referred for the
single purpose of lodging with the court. The exception would be in
situations where adverse public comments on the decree may be expected,
and that could lead the government not to request the court to enter the
decree. In such exceptional circumstances, the referral must be based
upon Compliance Method data.
However, a second NOV is not necessary under these circumstances, assuming
that there is evidence that a sufficient relationship exists between the
CEMS data and the Compliance Method data.
In addition, CEMS data also can be used in support of emission violation
cases to quantify emission levels and to document that a violation continued
30 days beyond the NOV issuance data. While EPA is frequently prepared to
argue that any particular day should be considered a day of violation in the
absence of emission data per se, CEMS data should serve to strengthen the
government's case.
We believe that courts will generally accept non-Compliance Method CEMS
data as an indicator of the magnitude and duration of emission violations
because they represent emissions comparably to Compliance Method data. 6/
6/ We assume that CEMS and Compliance Method data will be reliable and
comparable to each other. This assumption is based principally upon
three facts. First, the Agency requires sources to acquire and report
reliable data ( whether CEMS or Compliance Method ). With respect to
CEMS, this is accomplished by requiring sources to: (a) purchase,
install and operate the CEMS in accordance with specific location
criteria and performance standards; (b) demonstrate achievement of the
Performance Specifications by comparing the CEMS and the Compliance
Method results; (c) implement ( at least daily ) calibrations and O&M
procedures; and (d) operate the CEMS during all Performance Tests. ( If
doubts remain, EPA can require additional comparative tests using
Section 114. )
Second, the Agency has acquired data from numerous sources. Such
data document the fact that sources are able to, and generally do report
reliable and comparable data to agencies. Such documentation includes
data acquired: (a) during the development of the CEMS Performance
Specifications and ( Proposed ) Appendix F of Part 60 ( Quality
Assurance Requirements for SO2 CEMS ); (b) by receipt of hundreds of
Performance Specification Test Results; and (c) while performing quality
assurance and compliance audits of CEMS. ( See, e.g., EPA publications
entitled "Summary of Opacity and Gas CEMS Audit Programs" ( EPA-340/1-
84-016, September 1984 ); and "A Compilation of SO2 and NOx Continuous
Emission Monitor Reliability Information" ( EPA-340/1-83-012, January
1983 ). )
Third, all certifications of visible emission observers are based
upon quantitative comparisons between observers and "smoke schools'"
opacity CEMS.
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Finally, of course, CEMS data provide an altogether appropriate basis
upon which to issue a Section 114 request for Compliance Method data.
C. Where No Compliance Method Is Specified by the Governing Regulation
This Section applies exclusively to requirements which govern violations
of other than emission regulations. Here, the Agency may rely upon CEMS
data alone to enforce directly various O&M, monitoring, recordkeeping and
reporting requirements set out in NSPS regulations, SIPS, and Federally-
enforceable orders and permits.
For example, Section 60.11(d) of the NSPS regulations establishes a
general "good practices" O&M requirement. This requirement identifies no
specific compliance method. Rather, it states that the "determination of
whether acceptable . . . procedures are being used will be based on
information . . . which may include, but is not limited to, monitoring
results, opacity observations, review of operating and maintenance
procedures, and inspection of the source." ( Emphasis added. ) Similar
language is contained in many SIPs. CEMS data alone are sufficient to prove
violations of such O&M requirements.
IV. Recommendations
CEMS provides a very useful and versatile source of enforcement data.
EPA can use such data to take many traditional enforcement actions, often
even when CEMS is not specified as the Compliance Method. Therefore, we
encourage Regional Offices to use CEMS data consistent with the
aforementioned paragraphs.
In addition, we encourage Regional Offices to:
A. Make CEMS data acquisition and evaluation a standard operating
procedure;
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B. Cite CEMS data as supplementary evidence of violations in each NOV
or Section 113(a) administrative order issued whenever the CEMS data
substantiate the primary evidence; and
C. Incorporate CEMS into ongoing enforcement actions ( e.g., (1)
consider requiring chronic violators to install and use CEMS; (2)
cite CEMS procedural violations whenever they exist; and (3) cite
the source for failure to properly operate and maintain its
facility, based upon CEMS data ).
Attachment
Addressees
Regional Counsels
Region I-X
Air Management Division Directors
Region I, III, V and IX
Air and Waste Management Division Director,
Region II
Air, Pesticides, and Toxics Management Division Directors,
Region IV and VI
Air and Toxics Division Directors
Region VII, VIII and X
Air Branch Chiefs
Regions I-X
Air Compliance Branch Chiefs
Region II, III, IV, V, VI and IX
CEMS Enforcement Workgroup
Jerry Emison, OAQPS
Jack Farmer, ESED
George Walsh, ESED
Roger Shigehara, ESED
Darryl Tyler, CPDD
Rodney Midgett, EMSL/RTP
Darryl von Lehmden, EMSL/RTP
Earl Salo, OGC
Joseph Lees, DOJ
Reed Neuman, DOJ
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