UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                          WASHINGTON, D.C. 20460


                                APR 22  1986
   MEMORANDUM
   SUBJECT!
   FROM:
          Transmittal of National Program Guidance -
          Enforcement Applications of Continuous Emission
          Monitoring System Data

          Edward E. Reich, Director
          Stationary Source Compliance Division
          Office of Air Quality Planning and Standards
   TO:
          Michael S. Alushin
          Associate Enforcement Counsel
          Air Enforcement Division

          Addressees
 en
     Attached is final enforcement guidance advocating increased
use of continuous emission monitoring system (CEHS) data for
direct Federal enforcement of stationary source air pollution
requirements.  This guidance directly supports EPA's Continuous
Compliance Strategy.
 DL     The guidance points out many important uses to which EPA
 — can put CEMS data, both where CEMS is, and is not, the official
 T compliance test method ("Compliance Method").  Since the
   guidance may be helpful to State and local agencies, the
•&  Regional Offices may forward it to them at their discretion.

   Issues Raised by Commenters

        On January 31, 1986, Headquarters sent out for comment  a
   draft document entitled "Program Guidance on Enforcement
   Application of Continuous Emission Monitoring System Data".
   Six Regional Offices, ESED, CPDD and OGC commented on the
   draft of the guidance.  In general, the commenters supported
   the draft.  Some commenters sought clarifications or disagreed
   with certain elements of the draft.  Commenters raised the
   following key issues:

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                            - 2 -

       0  Can CEMS data stand alone as the basis for issuing
          a Notice of Violation ("NOV") or Finding of Violation
          ("FOV")?  Yes.  Section 113(a)(l) of the Clean Air
          Act expressly permits the Administrator to issue an
          NOV "on the basis of any information available to
          him..." See Section III(B) and footnote 4 at page 3
          of the Guidance.

       0  If an NOV does not spur compliance,  must EPA issue
          a second NOV based on Compliance Method data to sup-
          port further enforcement actions? A second NOV is
          not necessarily required.  If a litigation referral
          is developed, however, it should include proof of
          violation based on Compliance Method data.  See
          Section III(B) at page 4.

       0  Can EPA rely on CEMS data alone to issue a §113(a)
          administrative order where CEMS is not the Compliance
          Method?  No.  EPA should not issue an order for
          violation of an emission limit without having at
          least some Compliance Method data showing a violation
          of that limit.

       0  Are CEMS Data as Reliable as Compliance Method Data?
          CEMS data are likely to be as reliable and credi-
          ble as Compliance Method data.  See  Section III(B)
          and footnote number 6 at pages 4 and 5.

     Please direct any comments or questions about the guidance
to Louis Paley (SSCD) or Laurence Groner (AED) at 382-2835 or
382-2820, respectively.

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
Region I - X

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                            - 3 -

Air Compliance Branch Chiefs
Region II, III, IV, V, VI and IX

CEMS Enforcement Workgroup
Jerry Emison, OAQPS
Jack Fanner, 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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           UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

                       WASHINGTON, D.C. 20460
                           APR 2 2 1986
MEMORANDUM                     *
SUBJECT:  Guidance:  Enforcement Applications of Continuous
          Emission Monitoring System Data

FROM:     Edward E. Reich, Director
          Stationary Source Compliance Division
          Office of Air Quality Planning and Standards
          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. IV  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
I/ "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/.

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                            - 2 -

      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 pro-
cedures 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/

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
§120.  The same is true if EPA is to rely on CEMS data alone
to issue an administrative order respecting emissions violations
under §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 non-
ferrous smelters), and in certain SIP provisions, Federally-
2_/ The 1982 guidance clarifies, among other things, the cir-
cumstances 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.

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                            - 3 -

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 §113(a);

          6.  Issue a §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.

     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_/  Proof of the existance 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.
3_/ While some Regional Offices do issue FOVs, it should be
noted that EPA has no legal obligation to do so.

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 §7413(a)(l).

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                            - 4 -

     If after issuance, the source fails to come into compliance
with the emission regulation, EPA normally must acquire Com-
pliance Method evidence before it takes any of the last four
enforcement actions listed at Section III(A) above.Jj/  However,
a second NOV is not necessary under these circumstances,
assuming that there is evidence that a sufficient relationship
exists between the CENS 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 date.  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/
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.

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 Com-
pliance 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 §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
(footnote 6/ continued on page  5)

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                            - 5 -

     Finally, of course, CEMS data provide an altogether appro-
priate basis upon which to issue a §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 u'sed 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.  Recommendat ions

     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;
(continuation of footnote
development of the CEMS Performance Specifications and
(Proposed) Appendix F of Part 60 (Quality Assurance Require-
ments for S02 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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                            - 6 -

     B.  Cite CEMS data as supplementary evidence of violations
         in each NOV or §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
Region 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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             UUI FED STA its EN VIKOMMENTAL PROTECTION AGENCY

                         WASHINGTON. D.C. *0*«0
                               I A ~~                    OFFICBOF
                               I 2 BG2               *"*• NO'86 AND RADIATION
MEMORANDUM
SUBJECT:  Guidance Concerning EPA's Use of Continuous
          Enission Monitoring Data
     i   -4i-~

'"'    ,|**"«~ -
FROM:     Kathleen M. Bennett
          Assistant Administrator for Air, Noise and Radiation

TO:       Directors, Air and Haste Management Divisions,
            Regions II-IV, VI -VIII, and X

          Directors, Air Management Divisions,
            Regions I, V and IX


     This memorandum addresses EPA's use of Continuous Emission
Monitoring  (CEM) data in enforcement of NSPS and SIP emission and
operating and maintenance  (O&M) provisions and in other general EPA
activities.  It provides guidance as to when, as a legal matter,
continuous  emission monitoring constitutes the test method  associated
with an emission limitation.  It is not intended to preclude the
exercise of reasoned discretion by an enforcing agency based on a
review of the representativeness of the data and the circumstances
giving rise to the excess  emissions.

Use of CEMs that are Specified as the Source Compliance Test Method

     In each instance where CEMs have been promulgated or approved by
the Agency  as an official  method to determine source compliance with
the applicable emission limitations, the Agency can rely upon CEM data
when making compliance determinations.  CEMs have been specifically
prescribed  as the method to establish emission violations for one or
more pollutants in the following instances:

     0  NSPS electric utility steam generating units,
        regulated by 40 CFR Part 60 Subpart Da;

     •  NSPS primary n on ferrous smelters, regulated by
        40  CFR Part 60 Subparts P, Q and R;

     •  NSPS stationary gas turbines, regulated by 40
        CFR Part 60 Subpart GG;

     0  various sources regulated by permits, orders, or consent
        decrees in which CEM has been specifically designated as
        the test method;

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                                 - 2 -


     0  various types of sources which are regulated by 6JPs
        (e.g., Nevada SIP, 40 CFR $52.1475(d)) where the fetate
        has specified CEM as the test method.

     ;Spme  sources object to EPA's reliance upon CEM data to enforce SIP
emission provisions for source categories for which EPA has not
specified  the use of CEMs in comparable NSPS regulations.  Such an
objection  is not legally supportable, since States have the right to
specify their own methods in their SIPs, even if they are different
from those imposed by EPA for NSPS sources.  Section 1.0 of Appendix P
to 40 CFR Part 51 delineates that SIPs may specify that CEM data be
used "directly or indirectly for compliance determinations or any other
purpose deemed appropriate fcy the state."  The Agency can rely upon CEM
data for compliance determinations whenever such methods are specified
in the EPA-approved SIP.

Use of CEMs in SIPs where an Emission Compliance Test Method is Not
Specified

     There are some instances when SIPs do not specify a compliance
test method.  When that occurs, the applicable regulation, 40 CFR
S52.12(c)(1), states that for the purpose of Federal enforcement:

           •sources subject to plan provisions which do not
          specify a test procedure... will be tested by means
          of the appropriate procedures and methods prescribed
           in part 60 of this chapter; unless otherwise specified
           in this part.*

Generally, Part €0 does not specify CEM as the compliance test method
and therefore EPA cannot use CEM data to determine source compliance
with a SIP emission limitation.  However, in accordance with
S52.12(c)(1), CEM data would be the applicable test method for the two
categories of sources for which it is the NSPS performance test method,
nonferrous smelters (as in Subparts P, Q and R); and stationary gas
turbines (as in Subpart GG).

     The Agency shall rely upon CEM data to determine a source's
compliance status with a SIP emission limit for smelters (for 502)
and for stationary gas turbines (for NOX).  Since CEM is the only
compliance test method specified in Part 60 for these source
categories, CEM is clearly the "appropriate" method under Part 60 for
purposes of $52.12(0(1).

     In addition, there is some ambiguity regarding the appropriate
procedures for fossil-fuel-fired steam generators prescribed in Part 60
because Part 60 contains two significantly different types of 502 and
NOX performance test methods.  Specifically, Subpart D specifies

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                                - 3 -


Reference (stack test) Methods 6 and 7 as the performance test methods
for'-SOo and NOX emissions, respectively.  However, Subpart Da
specifies use of CEH data to determine compliance with the S02 and
NOX.emission standards.

     The Agency shall rely upon the performance test methods specified
in Subpart D (Reference Methods 6 and 7) to determine a source's com-
pliance status with SIP SO2 and NOX emission limits for fossil-
fuel-fired steam generators.  For this category of sources, it is more
consistent with the development of the SIPs to use these methods since
they are the traditional compliance test methods for this source
category.  (For new sources actually subject to Subpart Da, we would
not expect this issue to arise since new source permits should specify
the applicable test method.)

Use of CEM's where State Regulations Contain Discretionary Authority as
to Compliance Test Methods

     A problem in interpreting the SIP continually arises because most
SIPs specify test methods (often adopting EPA methods by reference) but
also allow for discretionary acceptance of an "equivalent" or an
appropriate "alternative* by the State.  Relying on such language, many
States have accepted CEM data as an adequate demonstration of com-
pliance and have used such data to determine the existence of a
violation.

     Since EPA1 a enforcement authority is guided by State regulations
specifically approved in the SIP, questions have been raised as to
whether EPA will independently apply State discretionary authority and
interpret what is reasonable as an "equivalent" or "alternative*
compliance test method, or, if not, whether EPA may follow the State's
lead, if the State chooses to allow CEM as the test method.

     The answer is that EPA will not independently exercise such
authority.  Only when the State has exercised such authority to adopt
CEM as a test method and when the exercise of that authority has been
reflected in the SIP,~wIll EPA use CEM as the test method.
Use of CEM Data for Determining Potential Operations and Maintenance
(O&M) Violations

     NSPS regulations (40 CFR 60.11(d)) specify that "at all times,
including periods of startup, shutdown, and malfunction, owners and
operators shall, to the extent practicable, maintain and operate any
affected facility including associated air pollution control equipment
in a manner consistent with good air pollution control practice for
minimizing emissions.  Determination of whether acceptable operating
and maintenance procedures are being used will be based on information

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                                - 4 -


•vailable to the Administrator which may include, but is sot limited
to, Monitoring results, opacity observations, review of operating and
maintenance procedures, and inspection of the source.*  Kany SIP's have
similar provisions requiring proper operation and maintenance.  Use of
CEM data, while not necessarily conclusive, is a valid indicator of
compliance with requirements such as S60.11(d) and can be used as such.

Use of CEMs as a General Compliance Monitoring Tool

     CEMs can provide the Agency with useful data for circumstances
other than those delineated above.  For instance, CEK data can be used
tos  (1) screen a source*s compliance status (with both emission
limitations and O*M requirements); (2) select which sources should be
inspected or compliance (stack) tested; (3) document the severity
(e.g., duration* magnitude and frequency) of a source's excess
emissions} and (4) document that a compliance test was performed during
•non-representative* operating conditions.

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