United States
          Environmental Protection
          Agency
Office of Air Quality
Planning and Standards
Research Triangle Park, NC 27711
EPA-454/R-94-033
September 1994
          Air
vvEPA
      PM-10 EMISSION INVENTORY
               REQUIREMENTS

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                                EPA-454/R-94-033
PM-10 EMISSION INVENTORY
         REQUIREMENTS
       Office Of Air Quality Planning And Standards
           Office Of Air And Radiation
        U. S. Environmental Protection Agency
         Research Triangle Park, NC 27711

              September 1994

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This report has  been reviewed by the Office Of Air  Quality Planning And Standards,  U. S.
Environmental Protection Agency, and has been approved for publication.  Any mention of trade
names or commercial products is not intended to constitute endorsement or recommendation for use.
                                   EPA-454/R-94-033

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                                  CONTENTS



                                                                           Pacre

LIST OF TABLES	    iv

ACRONYMS   	    v

1.0   OVERVIEW OF DOCUMENT   .  ,	    1
      1.1   Purpose	    1
      1.2   How  to Use This Document   .	    1

2.0   DEFINITIONS AND REGULATORY REQUIREMENTS  	    2
      2.1   Definitions of PM-10   	    2
            2.1.1 Primary PM-10	    2
            2.1.2 Condensible  PM-10  	    2
            2.1.3 Secondary PM-10  (PM-10 Precursors)	  .    2
      2.2   Summary of Regulatory Retirements	    3
            2.2.1 Nonattainment Designations   	    3
            2.2.2 Classification   	    3
            2.2.3 Nonattainment Area Boundaries  .  .  :	    3
            2.2.4 SIP Requirement Submittal Timelines  	    4
            2.2.5 Attainment Demonstration   	    4

3.0   EMISSION INVENTORY  	    7
      3.1   Summary of Inventory Types   	    7
      3.2   Temporal Resolution of Inventory   	  	    9
      3.3   Inventory Preparation Plan  (IPP)   	    9
            3.3.1 IPP Point Source Requirements	    10
            3.3.2 IPP Area and Mobile Source Requirements	    10
            3.3.3 Other IPP Requirements	,	    11
      3.4   Base Year Inventory	    11
            3.4.1 AIRS Compatible Reporting	    12
            3.4.2 Geographic Coverage	    13
            3.4.3 Applicable Source Categories	•  .  .  .    13
                  3.4.3.1      Point Sources	.'	    13
                  3.4.3.2      Area and Mobile Sources	    14
            3.4.4 Rule Effectiveness	    15
      3.5   Updating Inventories   	    15
      3.6   Adjustment of Base Year Inventory  (Backcasting)	    15
      3.7   RFP  Projection Inventories   	    16
      3.8   Modeling Inventories	    16
            3.8.1 For Multi-source Areas	    16
            3.8.2 Background Sources	    18

4.0   DOCUMENTATION/DATA MANAGEMENT AND REPORTING OF THE INVENTORY   ...    19
      4.1   Documentation	    19
      4.2   Data Management and Reporting	    22

5.0   REFERENCES	•	    23

APPENDIX A  INVENTORY PREPARATION PLAN  (IPP) REVIEW CHECKLIST  	    25

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                              LIST  OF TABLES
Number                                                          '          Page

2.1  Moderate Nonattainment Area Due Dates	    5
2.2  Serious Nonattainment Area Due Dates	    6
3 .1  Basic Outline of an Inventory Preparation Plan	   12
3.2  Model Emission Input Data for Point Sources  	   17
4.1  Outline for EPA Recommended Format/Contents for PM-10 Emission
      Inventory Reports 	   20

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                                  ACRONYMS
AFS         AIRS Facility Subsystem
AIRS        Aerometric Information Retrieval System
AMS         AIRS Area and Mobile Source Subsystem
BACM        Best Available Control Measure
BACT        Best Available Control Technology
CAA         Clean Air Act as amended in 1990
CHIEF       Clearinghouse for Inventories and Emissions Factors
EPA         U.S. Environmental Protection Agency
FIRE        Factor Information Retrieval System
FTA         fail to attain
FTD         fail to demonstrate
Hr          hour
IPP         inventory preparation plan
MMBtu       million British thermal units
NAAQS       National Ambient Air Quality Standard
PM-10       particulate matter that measure less than or equal to
            10 micrometers in aerodynamic mass median diameter
QA          quality assurance
QC      .    quality control
RACM        Reasonably Available Control Measure
RACT        Reasonably Available Control Technology
RE          rule effectiveness
RFP         reasonable further progress
SCRAM       Support Center for Regulatory Air Models
SIP         State implementation plan
TTN         Technology Transfer Network
VMT         vehicle miles traveled

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                                 SECTION 1.0
                           OVERVIKW OF DOCUMENT
1.1   Purpose

      This document  describes  the .emission inventory requirements  that  are
contained, either  explicitly or implicitly,  in the  Clean Air Act as  amended in
1990  (CAA) for  those areas  that are required to submit  a State  Implementation
Plan  (SIP) for  demonstrating attainment of the National Ambient Air  Quality
Standard  (NAAQS) for PM-10.  The guidance in this document  pertains  to  PM-10
moderate nonattainment  areas and to areas that have been reclassified as
serious nonattainment areas.  The purposes of the document  are  to  (1) identify
the types of inventories  required;  (2)  briefly review the regulatory
requirements pertaining to  submission of these inventories;  (3) describe  the
objectives, components, and ultimate uses of the inventories; and  (4) define
documentation and  reporting requirements for the inventories.

1.2   How -bo Use This Document:

      This document  is  intended to be a guide for State and local  agencies to
refer to for the requirements  as prescribed by the  CAA  for  submitting their
emission inventories; it  is  not a procedures document covering  the methods for
compilation or  reporting  of  emission inventories.   The  U.S.  Environmental
Protection Agency  (EPA) will issue further guidance pertaining  to  procedures
for preparing,  compiling, and  reporting emission inventories.   It  is
recommended that State  and  local agencies consult the references listed in the
Section 5.0 of  this  document for additional  information.

      This section provides  an overview of the document organization  and
contents.  The  key points and  format of the  material presented  in  the
remaining sections of this document are as follows.

      Section 2.0  contains definitions  and discussions  of PM-10 categories and
presents a brief overview of the regulatory  requirements  and milestones for
PM-10 emission  inventories under the CAA.  State personnel  should  reference
the General Preamble for  specific language on the regulatory requirements  and
should consult  the appropriate Regional Office of EPA to  identify  any guidance
issued subsequent  to the General Preamble.

      The specific details of  inventory development  and compilation
requirements are the focus of  Section 3.0.   In this  section, requirements  for
Inventory Preparation Plans  (IPPs)  are  described.  The  major discussion in
this section focuses on the  components  of the base year inventory,  while brief
discussion is also included  regarding other  types of inventories — modeling,
and periodic [i.e.,  reasonable further  progress  (RFP) and maintenance plan]
inventories.   Presentation of  the base  year  inventory includes an  overview of
the applicable  source categories to be  included — point, area,  and mobile
sources.  In addition, requirements regarding the temporal  resolution of the
inventory and adjustments to the base year inventory are also presented in
Section 3.0.

      Section 4.0 discusses  documentation/data management and reporting
requirements for SIP inventories prepared in response to  the CAA.  Section 5.0
provides the references for  this document.   Appendix A  provides a  checklist
for IPPs.

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                                SECTION  2.O

              DEFINITIONS  AND REGULATORY REQUIREMENTS



      This section of this document  summarizes  information  in  the General
Preamble dealing with the regulatory requirements  for designations and
classifications, nonattainment area  boundaries, and SIP  submittal timelines.
State personnel should reference  the General Preamble for specific language on
the regulatory, requirements and should consult  the appropriate Regional Office
of EPA to identify any guidance issued subsequent  to the General Preamble.

2.1   Definitions of PM-10

      PM-10 is defined as particulate matter that  measures  less  than or equal
to 10 micrometers in aerodynamic  mass median diameter.   PM-10  may be directly
emitted into the atmosphere from  a source  or it may be formed  in the
atmosphere as a result of condensation or  chemical reactions of other
pollutants.

      3.1.1 Primary PM-1O

      Primary particulate matter  is  broadly defined as particles that enter
the atmosphere as a direct emission  from a stack or an open source.  It is not
formed due to a chemical reaction that occurs once the matter  has been
emitted.  The focus of emission inventories for PM-10 nonattainment areas
should be on primary PM-10 emissions.  However, in some  areas  secondary and
condensible PM-10 account for a significant portion of PM-10 in the atmosphere
and, therefore, these would need  to  be included in the emission inventory.

      3.1.2 Condensible PM-10

      Condensible particulate matter (or condensed particulate matter, as it
is synonymously described) can be broadly  defined  as material  that is not
particulate matter at stack conditions but which condenses  and/or reacts  (upon
cooling and dilution in the ambient  air) to form particulate matter
immediately after discharge from  the stack.  Condensible particle matter forms
in a few seconds in the stack exhaust due primarily to immediate cooling and
air dilution.  Condensible particulate matter is of potential  importance
because it usually is quite fine and thus  falls primarily within the PM-10
fraction.  As a consequence, condensible particulate matter should always be
included in the emission inventory.

      2.1.3 Secondary PM-1O (PM-1O Precursors)

      Secondary particulate matter can be broadly defined as particles that
form through chemical reactions in the ambient air well after dilution and
condensation have occurred (i.e.,  usually at some distance downwind from the
emission point).  An example of this phenomenon is the formation of sulfate
Particles in a plume from the oxidation of sulfur dioxide by one of several
atmospheric transformation mechanisms.   Generally, secondary particulate
matter can be distinguished from condensible particulate matter by the time
and/or distance downwind from the stack required for formation.  Precursor
emissions contributing to secondary particulate matter should not be included
in the PM-10 inventory except where EPA and the State determines that the
sources of PM-10 precursors contribute significantly to PM-10 levels which
exceed the PM-10 NAAQS in the area.  This determination will be based upon air
quality analysis in which States assess the contribution of precursors.

      If precursors contribute significantly to nonattainment.  States will
need to consider both the source-receptor relationship and the significance of

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 ?eaSI?~~ Cont"but:Lons to overall nonattainment.   In making a determination
 regarding significance, EPA will rely in part on the technical information
 contained in the State's submittal which could include .filter analyses  an
 assessment of the relative contribution of precursors to overall

 ^^mf^"11"511*1'  Snd the Date's Reasonable Available Control Technologies
  (RACT)/Reasonably Available Control Measures (RACM)  strategy   States  are
 encouraged to submit additional material for consideration,  since  all  findings
 will be made on a case-by-case basis.                                  nnaings
 2.2
       Summary of Regulatory Requirements
       State personnel  should refer to the General  Preamble  for  the
 Implementation of Title I  of the CAA of 1990  for specific language on the

            re^ui^ementf for moderate nonattainment areas according to the CAA
 secndr  PM  0                  addresses  ^sues concerning condsible and
 ProSS?^   Z'f StatSS ^ould  contact  the Sulfur Dioxide/Particulate Matter
 Programs Branch for case-by-case determinations .
                               submifc a SIP which will demonstrate attainment
      -f          n            rSa des£9nated nonattainment and classified as

 ™S?™°r«- *   nr^ ^ CAA' Wlthin 18 m°nths after beinS designated
 nonattainment for PM-10.  The Sulfur Dioxide/Particulate Matter Programs

 ?retSl^?^Pa^  a Staff W°rk product as a supplement for the General
 1993a)   Whlch addresses serious nonattainment area requirements (U.S. EPA



       3. 2.1 Wonattairunsnt naaJ.gnatJ.oas
     m,S
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to the boundaries.  A defensible^rationale must  be  submitted to EPA to  justify
an area's designation and boundaries.  The Boundaries  designated by the
Governor of a State will be  subject  to final  approval  by EPA.

      3.3.4 SXF Rayulx-ement;  SutimlfcfcaJ T±mol±naB

      Tables 2.1 and 2.2 present the schedule and due  dates  for SIPs for
moderate and serious areas,  respectively.  The moderate  area SIPs containing  a
New Source Review permit program revision, attainment  demonstration,  and RACM
are due 18 months.after being designated nonattainment.   For serious areas, a
SIP containing Best Available Control Measures (BACM)  is  due 18 months  after
reclassification.  Implementation of either RACM or BACM (dependent upon the
area's designation) is to be completed within 4  years  after  designation.1

      2.3.5 Attainment Demonstration

      Section 189(a)(1)(B) provides  that States  with moderate PM-10
nonattainment areas must submit a demonstration  (including air  quality
modeling) showing either attainment  by the applicable  attainment date or that
attainment by the applicable date is impracticable.  The  attainment
demonstration projects how the area will come  into  attainment (or will  fail to
attain)  with the NAAQS based on air quality modeling with forecasted
emissions.  The SIP must contain the emissions forecasts  used in the air
quality modeling attainment  demonstration.  In general, attainment
demonstrations for these areas will be reviewed  in  accordance with the  general
guidance addressing PM-10 [PM-10 SIP Development Guideline,  (U.S.  EPA,  1987);
PM-10 Moderate Area SIP Guidance:  Final Staff Work Product  (U.S.  EPA,  I99la) ,-
and PM-10 Serious Area SIP Guidance:  Final Staff Work Product  (U.S. EPA,
1993a)]  and any future applicable EPA guidance or regulations.   For current
compilation of available policy and guidance  for the PM-10 program,  the reader
should refer to PM-10 Guideline Document and Appendix  (U.S.  EPA,, I993b).
    RACM and BACM refer to control measures  for both point and area  sources
    in moderate and serious  PM-10 nonattainment areas, respectively.  RACT
    and best available control technologies  (BACT) refer to control  measures
    for only point sources in moderate and serious PM-10 nonattainment areas,
    respectively.  See the General Preamble  for further discussion of this
    terminology.

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               Table 2.1  Moderate Nonattainmont Area Due Dates


 Event
                                                            Months following
                                                               designation
 Designation as nonattainment                                       Q

 Classification (moderate by operation of law)                      0

 Inventory Preparation Plan (IPP)                                   3

 Draft Inventory                                                   12

 SIP due containing:                                               lg
       a)     New Source Review permit program
       b)     attainment demonstration that includes
             1)     air quality modeling
             2)     base year actual emissions inventory
             3)     modeling inventory (projected
                   allowables  at attainment [i.e.,  at 72
                   months])
             4)     inventory showing projected allowables
                   at 48 months when RACM/RACT is
                   implemented
       c)     RACM/RACT implementation program
       d)     Quantitative milestones (RFP)
       e)     PM-10  precursors  assessment

Decision by  EPA whether to  reclassify area as serious  for          36
FTD attainment  (18 months  from submission)

Implementation  of  control strategies,  including RACM/RACT          43

RFP Milestone due  date                                             54

Determination by EPA that State's  RFP milestone is met             57

SIP revision due for failure  to  report RFP milestone or            63
determination by EPA that milestone was not met

Attainment (as  expeditiously  as  possible but  no later  '           72
than)

Redesignation to serious if in violation of NAAQS after          72-78
attainment date

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                Table 2.2  Serious Nonattainment Area Due Dates
 Event                                                       Months following-
	__	reclassification
 Reclassification                                                    0

 Inventory Preparation Plan  (IPP)                                    3

 Draft Inventory  (The base year  for FTA will be  the  actual          12
 emissions for the year the area should have attained;  for
 FTD areas the base year inventory will become the modeling
 emission inventory projected to the attainment  year)
 RFP Milestone due date                                              *

 Determination by EPA that State's RFP demonstration is             **
 adequate

 BACM SIP due containing:                                           18
       a)    BACM/BACT implementation program  (schedule
             for implementation)
       b)    PM-10 precursors assessment
       c)    base year inventory

 SIP revision due for failure to report RFP milestone or            ***
 determination by EPA that milestone was not met
 Full SIP containing BACM SIP information and:                      48
       a)    attainment demonstration with air quality
             modeling
       b)    additional BACM/BACT requirements

 Implementation of BACM/BACT                                        48
 RFP Milestone is due                                               t

 Determination by EPA that State's RFP milestone is met             ft
 SIP revision due for failure to report RFP milestone or            ttt
 determination by EPA that milestone was not met
 RFP Milestone is due                                               -j-

 Determination by EPA that State's RFP milestone is met             ft
 SIP revision due for failure to report RFP milestone or            ttt
 determination by EPA that milestone was not met
 Attainment (as expeditiously as possible but no later             120
 than)
*     54 months after designation as a moderate nonattainment area for areas
      that FTD; 90 months after designation as a moderate nonattainment area
      for areas that FTA
**    3 months following *
***   6 months following **
t     3 years following previous RFP milestone due date
tt    3 months following t
ttt   6 months following tt

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                                 SKCTION 3.0
                            EMISSION INVENTORY
3.1   Summary of  Inventory Types

      For  PM-10 nonattainment areas,  there are three (3)  basic  kinds  of
inventories  that  States  may need to develop under the CAA.   These  include base
year inventories,  periodic inventories,  and modeling inventories.   The
information  presented below represents EPA's view of accurate,  complete,  and
approvable inventory submittals.

      The  base year inventory is  the primary inventory from which  all other
inventories  are derived.   All inventories  shall be consistent with data
provided in  the base year  inventory.   Section 172 (c) (3) of  the  CAA requires
States to  ensure  that this inventory is  comprehensive,  accurate, and  current
for all actual emissions of PM-10.   The  base year inventory must include
emissions  from all point,  area,  and mobile sources.

      For  moderate nonattainment  areas,  the SIP base year emission inventory
must be based on  actual  emissions.   For  moderate and serious nonattainment
areas, the base year for emission inventories must be consistent with the
3 years of data which were necessary to  designate the area  as nonattainment.
The base year inventory  is the inventory of actual emissions for the  chosen
base year.   The base year  inventory should reflect the last year of the
3 years used to determine  nonattainment.

      Should a moderate  nonattainment area "fail to  demonstrate" (FTD)
attainment,  then  the area  will be reclassified as serious.  This will require
submission of a serious  area  base year emission inventory which is due
18 months  following reclassification (see  Table 2.2).   The  serious area base
year emission inventory  also  serves as the BACM SIP  emission inventory.
Moderate areas that FTD  attainment  and have been reclassified can use the
moderate area attainment demonstration emission inventory (see modeling
inventories  below)  as  a  starting  point for their serious  area base year/BACM
emission inventory,  but  it must include  any changes  (such as shutdowns or
emission factor changes) that have  occurred since the  moderate  area SIP was
submitted.   This means that the year  that  would have been the attainment  year
under the moderate area provisions  becomes the  base year  for the serious  area
SIP inventory.  It also  assumes that  the moderate area  SIP  regulations (i.e.,
RACM)  will be implemented,  however,  should the  area be  redesignated as
serious,_ BACM requirements  will need  to  be implemented.   BACM implementation
may require  additional control measures  or technologies on  processes already
controlled under the RACM  implementation.   All  of  the above information
pertaining to  serious  areas assumes that the moderate area  SIP emission
inventory was  adequate and that if  it was  not,  it was  returned  to the State as
part of the  completeness and  SIP  review process  that is part of the moderate
area requirements.

      Should  an area classified as  serious  "fail  to attain"   (FTA),  then those
areas must reinventory the  actual emissions at  the time they should have
attained.   Such an inventory  would  be due  18 months after determining that the
area FTA.

      Modeling inventories may be used as  a tool  for a number of purposes
including model performance evaluations, projection to  future years,
evaluation of  the  impact of rulemaking, evaluation of control measures and
technology, receptor modeling reconciliation, and determination of design
concentrations.  One of the major roles  for modeling inventories will be  for
use in the attainment demonstration.   Modeling  inventories can be based upon

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 either allowable or actual emissions, depending on the purpose of the
 modeling.  For instance, modeling inventories should be based on the actual
 daily emissions for model performance evaluation.  For control measure
 evaluations and the attainment demonstration, the modeling emission inventory
 consists of allowable emissions for the base year and projected allowables for
 the attainment year.  Modeling inventories also have additional data
 requirements (e.g., stack parameters).  The Guideline on Air Quality Models
 (Revised) should be consulted to determine the additional data needed (U S
 EPA,  1986).

       For moderate areas, an attainment demonstration emission inventory that
 provides a projection of allowable emissions to the year following full
 implementation of the moderate area SIP is required.  The year of record for
 this  inventory would be the seventh year following designation as a moderate
 nonattainment area.

       For serious areas, the attainment demonstration emission inventory
 provides a projection of allowable emissions for the year following
 implementation of the serious area SIP. ' This inventory is due with the
 serious area attainment demonstration SIP (see Table 2.2)

       The CAA states that the emission inventories may be periodically updated
 as  deemed necessary by the Administrator.   A periodic inventory may be the
 consequence of RFP requirements,  a maintenance plan for an attainment area,  or
 for other reasons deemed necessary by EPA.   The PM-10 program will not
 arbitrarily require inventories every 3 years.   It will rely on "event"
 oriented periodic emission inventories and,  therefore,  will be decided on a
 case-by-case basis.   Guidance from EPA for States related to requirements and
 events that will  trigger development of a PM-10 emission inventory is
 forthcoming.   Questions related to this topic should be addressed to the
 Office of Air Quality Planning and Standards,  Air Quality Management Division,
 Sulfur Dioxide/Particulate Hatter Programs  Branch.

       As  a  result of the RFP requirement,  a detailed compliance schedule or
 inventory (RFP  projection inventory)  may be required.   If  an RFP projection
 inventory were  to be used by the  States for demonstrating  that the emission
 reductions  will be achieved,  the  following  applies.

             For moderate nonattainment areas,  the RFP projection inventory
       (i.e.,  RFP  milestone)  will  be  due 3 years  after the  SIP  inventory
       submittal (see Table 2.1).   The RFP projection  inventory is  to  be  based
       on  allowable emissions.   It  should be  based on  the base  year  inventory
       but should  incorporate any  significant  changes  including rule
       effectiveness  (RE)  and RACM  implementation.

             It  should be noted that  only one RFP milestone will  be required
       for^moderate nonattainment areas  assuming  that they are  in attainment on
       their required attainment date.   The reason  for this can be ascertained
      by  referring to Table  2.1.  The  RFP milestone is due 54 months  following
      designation as  a moderate nonattainment area.  The next RFP
      demonstration would be  due 3 years later  (i.e., 90 months  following
      designation), however,  attainment  is scheduled for 72 months.   Should
       the moderate area  fail  to reach  attainment at the scheduled time and be
      reclassified as a  serious nonattainment area, then the RFP schedule
      .continues from  the  original moderate area schedule.  Thus, an RFP
      projection  inventory for a serious nonattainment area could be required
      at  the same  time as  the BACM SIP  inventory is due if the area is
      reclassified as serious 72 months after being designated as a moderate
      nonattainment area.

      Another circumstance which would trigger a periodic inventory would be
 ™,  f* *rSa becomes.eliSTible for redesignation.  Maintenance plan emission
inventories are required once an area has reached attainment and desires to be
                                       8

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 redesignated to and continue as an attainment area.  An unclassified area
 requesting redesignation to attainment iraist also submit a maintenance plan
 emission inventory.

             The maintenance plan emission inventory should include an
       attainment inventory as well as a maintenance inventory.  The attainment
       inventory should include actual emissions at the time of attainment or
       at the time of the request for redesignation as attainment.   The
       maintenance inventory should present projections of allowable emissions
       for the ninth year following reclassification to attainment.  Another
       periodic inventory may be required within the 9-year time frame for
       failure to maintain or for a SIP call.  States should refer  to the
       redesignation policy for additional requirements for redesignations.

 3.2    Temporal Resolution of Inventory

       States will have to model short-term (daily)  and long-term (annual)  air
 quality for PM-10 to assure that both standards will be protected,  even if air
 quality measurements show exceedances for only one time period.

       Some areas may experience seasonal emissions increases which largely
 cause  their nonattainment problem.   If the problem involves only one season
 (e.g.,  summer wind blown dust),  then a seasonal inventory should be prepared
 in addition to an annual inventory.   In dual season situations (e.g.,  summer
 wind blown dust and winter wood burning) ,  an emission inventory should be done
 for each season separately,  and the  results combined for the analysis  of the
 annual  standard.   The reporting convention for seasonal emissions  must be
 consistent for point,  area,  mobile,  and natural sources.

 3.3   Inventory Preparation Plan (IPP)

      For base year inventories,  the EPA requires  States  to prepare a  brief
 IPP that_specifies how they intend to develop,  document,  and submit their
 inventories.   The plans provide States  the opportunity to notify the EPA how
 they plan to  compile the required inventories  and  to allow the EPA to  provide
 important feedback to prevent  the use of approaches  that  are not consistent
with the^ EPA  requirements.   With the use of IPPs,  the EPA can help  guide the
preparation of required inventories  and ensure that  emission estimates  are  of
high quality  and are consistent  with the PM-10 emission inventory
 requirements.   States shall  submit IPPs to the EPA Regional Offices and the
EPA headquarters  according to  the schedule shown in  Table 2.1.

      In addition to technical data,  the  IPPs  should contain a schedule
 showing  when  the  State plans to  submit  the draft and final  inventory to the
EPA.  If the  State plans  to  submit an inventory in component pieces  (e.g.,
point source  component,  area source  component,  etc.),  the IPP must  clearly
make this  distinction and indicate a draft and final  submittal date  for each
component.  The  final  submittal  dates shall be consistent with the  PM-10
emission inventory requirements.  A  complete draft inventory is  required to be
submitted to  the  EPA Regional Offices and  the  EPA headquarters within
12 months  after  the  date  that an area is designated nonattainment.    The IPP
shall also  explicitly detail the year chosen as  the base  year for  the
inventory,  and explain the basis  for the selection.   Further details on the
base year  inventory  are found in Section 3.4.

      In addition to  the  IPP submittal  to  the  EPA Regional  Office,   the  State
shall also  submit  a  copy  of  the  IPP  and any correspondence  relating  to  the  IPP
to the EPA  headquarters.  The copy should  be addressed to:   Chief,   Inventory
Guidance and Evaluation Section,  Emission  Inventory Branch  (MD-14),  Technical
Support Division, U.S.  EPA,  Research Triangle  Park, NC  27711.

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       States must prepare an IPP  for each nonattairunent  area  for which a base
 year inventory is required by the CAA,  to the extent  that  different approaches
 will be used.  If a. State has multiple  nonattaintnent  areas but plans to use
 the same overall approach for each, the State may submit a single IPP that
 details that approach and the areas to  which it will  apply.   In detailing the
 approach utilized for developing  the inventory for the area(s) , the IPP must
 clearly delineate that the IPP was prepared for the purposes  of a PM-10 SIP,
 must define the nonattainment area(s) addressed by the inventory and the
 nonattainment classification of the areas.  In addition, the  IPP should
 identify the persons responsible  for the  inventory, the  contents and
 organization of the report, submission  schedules, any modifications to the
 approach used for multiple area submittals, the source categories inventoried,
 and a summary of the emissions documentation information for  each major
 inventory component (i.e., point, area, and mobile sources).

       States must be aware that the EPA considers submittal of an IPP crucial
 to an approvable SIP inventory.  By approving an IPP, the  EPA will accept the
 intended approach for inventory compilation.  The EPA's  approval of an IPP
 does not,  however,  signify that the EPA unconditionally  accepts all of the
 information to be contained in the actual inventory.   That inventory will be
 reviewed separately and on its own merits regardless of  how well the IPP was
 assembled.

       3.3.3. IPP Point Source Re
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 the PARTS emissions model was not utilize;! or was not available prior to the
 inventory submittal deadline, the basis f*br the alternative estimation
 methods, any key modeling assumptions, and the vehicle classes covered must be
 discussed in the IPP.

       The PARTS model does not address emissions for nonroad mobile sources
 (e.g.,  construction, farm, industrial, and lawn and garden equipment;
 motorcycles; and snowmobiles).  Methodologies for estimating emissions from
 these sources are documented in Nonroad Engine and Vehicle Emission Study —
 Report (U.S. EPA, 1991b).

       3.3.3 Other IFF Ra
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            Table 3.1  Basic Outline o£ an Inventory Preparation Plan


       Introduction
       •     'Define the boundaries of  the nonattainment  area.
       •     Describe the basis  for  the  inventory (i.e., previous  efforts  that
             are viable and related);  indicate  the  starting point.
       •     Define how the plan is  structured  and  what  it contains.
             Specify who is responsible  for  the inventory and who  is actually
             compiling it (air agency, consultants, etc.).

       Point Source Approach
             How will sources be identified  and located?
             What categories will be addressed  and  why?
             What categories will be excluded and why?
             Define the use of existing data sources.
             Identify data collection methods to  be used.
             Provide the basis for activity  level data and emission estimates
             Provide the basis for control efficiencies.
             Discuss the application of RE.;
             Indicate the basis  for RE levels.

       Area and Mobile Sources Approach
       •      What categories will be addressed and  why?
       •      What categories will be excluded and why?
       •      What estimation methods will be used (e.g. AP-42, Emission
             Inventory Procedures Document,  site specific surveys, etc.)?
       •      What methods will be used for collecting activity/commodity level
             data?
       •      Provide specification of the mobile source emissions model used.1
       •      Discuss application of RE.
             Provide basis for RE levels.

       Documentation Approach
       •      Describe written presentation and documentation.
             Describe computerized compilations and documentation.
       •      Describe the data required to be submitted to EPA (as defined by
             the EPA Regional Office) and the computerized format that will be
             used to submit  the data.

       QA Plan
             Describe the QA program.
             How_will the QA program affect  and benefit the  inventory.
             Verify  adherence to previously issued QA guidance (U S  EPA
             1988b).       .                                              '
           0 ^ni;ssions factors for mobile sources should be obtained by running the
           R1OCL6 J. •
      3.4.1 AIRS CoxnpatiijJe

   (  The official repository for  all  emission inventory data will be
designated by the EPA Regional Office.   One of the options  that may be
»T«9nat!}d ^ the Regi°nal  Offices is  to have the official  data record in
T^roo*     £ " option is selected,  all  SIP  data must  be  loaded directly into
AIRS or submitted in an AIRS  compatible format.

=     Emission Inventory Branch (inventory  requirements)  and National Air Data
Branch (data system enhancements,  schedules,  and availability)  can provide
coordination with State and local  agencies  during the inventory preparation
                                      12

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 process for both batch transactions  to  the AIRS Repository and on-line
 interactive submittal of APS  and Area and Mobile Source Subsystem (AMS)  SIP
 inventory data.   As the PM-10 program defines data-system needs (now and in
    -,fU^Ure>      system will be enhanced to meet these needs.  Therefore   it
 would be appropriate for State and local agencies to coordinate with EPA
 regarding availability of new and scheduled enhancements to AIRS during  the
 preparation of IPPs and prior to actual inventory data entry.
       3.4.3 Geographic Cove.
                           >ragre
       The geographic  boundaries of the inventory area shall be determined by
 the _ area officially designated nonattainment .   At a minimum,  this  area  shall
 be included in the  emission inventory.  However,  the attainment demonstration
 developed as part of  the SIP inventory process must include air quality
 modeling.   As a consequence, sources contributing significant fractions to the
 ambient concentrations must also be included.   This may necessitate the
 inclusion of sources  outside the boundary of the nonattainment area in  the
 emission inventory.   The nonattainment area coupled with any other areas
 containing sources  that need to be included in the attainment demonstration
 modeling effort are considered the modeling domain.  Guidance on the

 oriUPS=7y?rMa5e7an%0t^er^°del:Lng criteria c«n be found in the Guideline
 on Air Quality Models (Revised) (u.s EPA,  1986).   Current code for EPA
 approved air quality  models are available through the EPA's  Office of Air
 SUa ,  T ~lanning and  Sfcandar<3s SCRAM (Support  Center for Regulatory Air
 Models)  Bulletin Board System and the related  programs can be downloaded to a
 personal computer diskette.  Information is also  included with regard to
 upgrades to  various models.

   «-  . ,The, ex1pent of the sources to be included in the emission inventory
 outside  the  immediate nonattainment area must  be  determined by the State   The
 decision is  based on  the types of sources  in upwind areas and on their  '
 potential  impact inside the nonattainment  area.   However, documentation of
 rationale  used  in determining which sources to include or exclude must be
 provided as part of the emission inventory submittal.   In addition, a brief
 discussion of this rationale should be  included in the IPP.  Coordination
staf^wieff^^^i^en^^y•PreParati0n Staff ^'^ a^ quality modeling
staff will facilitate efficient inventory preparation and submittal.

      3.4.3 Applicable Source Catesrord.es

      Base year  emission inventories are required to include all types of
                           ™°bile sources.   The particulate matter emission
                                      ±f SOUrCe ^egories ^ould be included
 n tne i™                                       egores   ou    e  nclu
and £o42 Vent°ry-  F?r ?olnt  sources, a list of source classification codes
and corresponding emission factors  can be obtained from the program,  FIRE
forCInveSf^rati0S *e*ri?val System) , by accessing the CHIEF (Clearinghouse

  r  Fsr s^^"*"™-^-^ ^^^^"^-"^sis
the TTN      training manual  by accessing the AIRS Bulletin Board System on
            3.4.3.1     PojCnt Sources
            SOUr°e?  a« physical emission points or processes usually within a
                     pollutanfc emissions.  PM-10 point sources generally refer
                       r stacks for which individual records are  collected
size    ,,     ?lassifi<=ati°n affects the facility  emissions
all sta??o          included in the base year inventory.   For moderate areas,
all stationary sources which emit directly, or have the potential to emit
(i.e.,  allowable  emissions), 100 tons per year or more of PM-10 must be-
                                     13

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 included in the inventory.  These sources are referred to as "major stationary
 sources" in Section 302(j) of the CAA.

       For serious areas, all stationary sources or groups of stationary
 sources located within a contiguous area and under common control that emit or
 have the potential to emit at least 70 tons per year of PM-10 must be
 included. (Section 189 (b) (3) )

       The EPA also believes that the States '  inventory may need to go beyond
 those sources having a tons per year limit to include other sources in the
 area that are reasonable to control.

             3.4.3.3     Aram axuSL Mobile Sources

       Area sources are generally defined as an aggregation of all sources not
 defined as point sources in a specific geographic area.   Area sources include
 fugitive dust sources; mobile sources; and stationary sources that are too
 small,  difficult,  or numerous to account for individually as point sources.
 Area sources also include residential wood combustion sources,  and prescribed,
 silvicultural and agricultural burning sources .
      ^     EPA issued technical information guidance documents  on BACMs for
 fugitive dust;  residential wood combus£ion;  and prescribed,  silvicultural and
 agricultural burning sources (U.S.  EPA,  1988,  1989a,  and 1992,  respectively) .
 Fugitive dust is particulate matter suspended in the air either by mechanical
 disturbance of  the surface material or by wind action blowing  across  the
 surface.   Mechanical disturbance includes resuspension of particles from
 vehicles  traveling over roadways, parking lots,  and other open areas.   Wind
 action  includes dust blown off disturbed open areas .   Process  fugitive
 emissions should be included in the point source inventory.  Residential wood
 combustion includes wood smoke from residential  wood stoves  and fireplaces.
 Residential wood combustion is a significant source of PM-10 particularly in
 nonattainment areas in the western  United States.   Prescribed  burning
 generally describes burning on lands that are  being managed.   This  includes
 both planned ignition and prescribed natural fire,  however,  it  does not
 include forest  and wildfires.   If a State excludes  any of the  emission sources
 addressed in the three documents from its emission  inventory,  it must  provide
 documentation on why the source ( s )  were  excluded .

      The EPA has developed the Parts model  for  estimating PM-10 emissions
 from mobile sources.   The model can be used  to estimate total particulate
 matter emissions as well as particulate  matter fractions  ranging from  1.0 to
 10 micrometers.   For gasoline  engines, total exhaust particulate matter
 includes  direct  sulfate (exhausted  as sulfuric acid) and  lead emissions.   For
 diesel engines,  total exhaust  particulate matter also  includes  emissions  for
 soluble organic  fraction and the remaining carbon portion.   Each of these
 emission  components can also be estimated individually.   The Parts model  can
 also be used to  estimate the following:

             Particulate matter from brake and  tire wear,

      •      Gaseous sulfur dioxide  exhaust emissions,

             Indirect  sulfate emissions formed  later in  the atmosphere
             associated with sulfur  dioxide exhaust emissions,

             Fugitive  dust  emissions  from paved and unpaved roads, and

      •      Idle-speed exhaust  emissions.

      The Parts model  and  user's manual may be obtained from EPA's Bulletin
Board System for  the  Office  of  Mobile Sources  on the TTN.



                                      14

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       3.4.4 Rula E££ectz±vanaBa

       Rule effectiveness,  currently not required,  may be required by EPA at a
 later date.   The feasibility of and guidance on using RE are being studied by
 EPA at this time.   Until guidance is issued by EPA,  RE may be considered by
 the State  at its option.  Should the State exercise this option,  RE should be
 applied to all sources that are affected by a regulation and for which
 emissions  are determined by means of emission factors and control efficiency
 estimates.   No RE factor is needed in cases where  no control is applied or
 there is no applicable regulation.

       Past inventories have assumed that regulatory programs would be
 implemented with full effectiveness, achieving all of the required or intended
 emission reductions and maintaining that level over time.  However,  experience
 has shown  regulatory programs to be less than 100  percent effective for most
 source categories  in most  areas of the country.  The concept of applying RE in
 a  SIP emission inventory has evolved from this observation.   In short,  RE
 reflects the actual ability of a regulatory program to reduce emissions from
 all sources  at all times that are subject to a specific regulation.

       Several factors should be taken into account when estimating the
 effectiveness of a regulatory program.   These include:   (1)  the nature  of the
 regulation (e.g.,  whether  any ambiguities or deficiencies exist,  whether test
 methods  and/or recordkeeping requirements are prescribed) ,-  (2)  the nature of
 the compliance procedures  (e.g.,  taking into account the long-term performance
 capabilities  of the control);  (3)  the performance  of the source in maintaining
 compliance over time (e.g.,  training programs, maintenance schedule,
 recordkeeping practices);  and (4)  the performance  of the implementing agency
 in  assuring  compliance (e.g.,  training programs, inspection schedules,  follow-
 up  procedures).

       For base year PM-10  inventories under the CAA,  the EPA will allow the
 use of reasonable  default  values  provided the values are -justified bv the
 State.   Justification may  include a RE study performed according  to  the March
 24,  1988 National  Protocol.   The  RE factor shall be  applied along with  the
 estimated control  efficiency in the calculation of emissions from a  source.
An  example of  the  application is  as follows:
            Uncontrolled emissions        =
            Estimated control efficiency  =
            RE                            =
            Emissions after control       =
                                                50 Ibs/day
                                                90%
                                                75%
                                                50 [1 -  (0.90)(0.75)]
                                                50 (1 -  (0.68]
                                          =     16.25 Ibs/day

Thus, the application of RE results in a total emission reduction of
68 percent.
3.5
      Updating1 Inventories
      Updating of prior year inventories to the base year inventory will, in
general, not be acceptable.  A new inventory for the appropriate base year
should be prepared.  A State that believes that a special situation exists in
which. EPA should allow an existing inventory to he updated should apply  to the
appropriate Regional Office for a written exception.
3.6
      Adjustment of Base Year Inventory  (Backcasting)
      The EPA recognizes that adjustment of the base year inventory, or
backcasting, may be necessary.  Backcasting is the recalculation of a previous
inventory due to changes in the parameters used to calculate the emissions
initially.  Situations where backcasting may be invoked include changes in
emission factors, changes in calculational methods, or insufficient data for
                                      15

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 the base year that may be more complete in a. previous year.  States may make
 adjustments to ba.ua year inventories only with tha approval of the EPA.

 3.7   RP"P Projection Inventories

       The RFP inventory should "track" all sources that are subject to
 regulations for the nonattainment area, whether or not they are actually in
 the area.  The inventory must be able to answer the question:  "Is the State
 achieving the agreed emission reductions specified in the SIP at any
 particular time?"  The basis for the reductions required will be the
 attainment demonstration.  Since there are no specific level of reductions
 required under the CAA for PM-10 as there are for volatile organic compounds
 the level of reductions required will be determined by the RACM requirements
 and what is necessary to demonstrate attainment of the PM-10 NAAQS by the
 appropriate attainment date.

       RFP projection inventories are to be projections of allowable emissions.
 In addition,  the RFP projection inventory should include the effects of
 control strategy implementation (such as RACM or BACM) .   Emission reductions
 determined from the RFP projection inventories are to be based upon the base
 year inventory which uses actual emissions.   It is important to remember that
 attainment will be based upon a target level  of emissions (i.e.,  an amount of
 emissions required to meet attainment)  and that backcasting may necessitate an
 adjustment of the target level of emissions.   Some air planning agencies may
 toe used to thinking in terms of the emissions reduction  required relative to a
 current control strategy projection,  rather than a target level  of emissions.

     _  Projections of attainment year emissions would be  used to  calculate the
 required emissions reductions expressed on such a basis,  by simply taking the
 difference between the attainment year projection inventory (without  controls
 applied)  and  the attainment year target level of  emissions.   However,  States
 that  choose this approach should be aware  that the attainment year target
 level  is  dependent only on the base year inventory,  whereas  the  calculation of
 an emission reduction required relative to the current control strategy
 projection depends on the  accuracy of  the  attainment  year projection,  which in
 turn depends  on the estimate of future  growth in  activities.  The  assessment
 of whether an area has met  the emission reduction requirement will be  based on
 whether the area is at  or below the target level  of emissions and  not  whether
 the area  has  achieved a  certain actual  emission reduction relative to  having
 maintained the  current  control  strategy.

 3.8  Modeling'  Inventories

      Modeling  inventories may require  inclusion of additional sources  outside
 the nonattainment  area,  as defined  by the modeling domain.  For this reason
                                                          .
             domain should be defined as early as possible so that emission
data for point, area, mobile, and natural sources can be gathered for the
entire modeling domain as part of the base year inventory preparation process.
      3.8,1 For Mai ti — soturera
•^oa*^ Accordin9- to the Guideline on Air Quality Models  (Revised) (U.S. EPA,
1986) ,  all sources expected to contribute significantly to the ambient
concentrations in the nonattainment area or near the critical receptor for
                                      16

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                    Tabl* 3.2  Model Emission Input: Data for Point: Sources  *
                                Emission Limit
                                  (#/MMBtu)**
                           Operating Level
                            (MMBtu/Hr)**  '
                                                                      Operating Factor
                                                                     (e.g. Hr/Yr, Hr/day)
For  Stationary Point Source(s)  Subject to SIP Emission Limit(s)  Evaluation for Compliance with
Ambient  Standards  (Including Areawide Demonstrations)	
Averaging time
Annual  &  quarterly
Short-term
Maximum allowable
emission limit or
federally
enforceable permit
limit.
                             Maximum allowable
                             emission limit or
                             federally
                             enforceable permit
                             limit.
                                             Actual  or design
                                             capacity (whichever
                                             is  greater), or
                                             federally
                                             enforceable permit
                                             condition.

                                             Actual  or design
                                             capacity (whichever
                                             is  greater) , or
                                             federally
                                             enforceable permit
                                             condition.» * « *
Actual operating
factor averaged over
most recent
2 years.***
                                               Continuous
                                               operation,  i.e.,  all
                                               hours  of  each  time
                                               period under
                                               consideration  (for
                                               all hours of the
                                               meteorological data
                                               base).*****
For Nearby Background
Source(s)
Same input requirements as for stationary point source(s) above.
For Other Background
Source(s)
If modeled (see Section 9.2.3), input data requirements are defined
below.
Averaging time Annual &
quarterly
Maximum allowable
emission limit or
federally
enforceable permit
limit.
                                            Annual level when
                                            actually operating,
                                            averaged over the
                                            most recent
                                            2 years.***
Actual operating
factor averaged over
most recent 2
years.* * *
Short-term
                            Maximum allowable
                            emission limit or
                            federally
                            enforceable permit
                            limit.
                       Annual level when
                       actually operating,
                       averaged over the
                       most recent
                       2 years.***
                                                                   Continuous
                                                                   operation, i.e., all
                                                                   hours of each time
                                                                   period under
                                                                   consideration (for
                                                                   all hours of the
                                                                   meteorological data
                                                                   base).*****

The model input data requirements shown on  this  table apply to stationary source control
strategies for STATE IMPLEMENTATION PLANS.  For  purposes of emissions trading, new
source review, or prevention of significant deterioration, other model input criteria
may apply.  Refer to the policy and guidance  for these programs to establish the input
data.

Terminology applicable to fuel burning sources;  analogous terminology, e.g.,
#/throughput may be used for other types of sources.

Unless it is determined that this period is not  representative.

Operating levels such as 50 percent and 75  percent of capacity should also be modeled to
determine the load causing the highest concentration.

If operation does not occur for all hours of  the time period of consideration (e.g.,
3 or 24 hours) and the source operation is  constrained by a federally enforceable permit
condition, an appropriate adjustment to the modeled emission rate may be made (e.g., if
operation is only 8:00 a.m. to 4:00 p.m. each day, only these hours will be modeled with
emissions from the source.  Modeled emissions should not be averaged across nonoperatinq-
time periods).                                                                    .
                                              17

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 emission limit(s) should be explicitly modeled.  For evaluation for compliance
 with the short term and annual ambient standards, the nearby sources should be
 modeled using the emission input data shown in Table 3.2.  The number of such
 sources is expected to be small except in unusual situations.  The nearby
 source inventory should be determined in consultation with the reviewing
 authority.  It is envisioned that the nearby sources and the sources under
 consideration will be evaluated together using an appropriate model [typically
 selected from Appendix A of the Guideline on Air Quality Models (Revised)
 (U.S.  EPA, 1986)].

       The impact of the nearby sources should be examined at locations where
 interactions from several sources (plus natural background)  can occur
 Significant locations include:   (1)  the critical receptor(s)  identified as
 exceeding the NAAQS;  (2)  areas  having a large number of significant sources in
 a small area; (3) areas close to major sources; and (4)  areas with peculiar
 topography and/or meteorology that may result in enhanced impacts  from several
 sources.   These  locations may be identified through trial and error analyses
 or by  using screening model approaches.

       3.8.2 Background Sources

       Other sources not expected to  contribute significantly to the ambient
 concentration may include minor sources  and distant major sources    That
 portion of the background attributable to these sources  should be  determined
 by application of a model using Table 3.2 or by the following procedure.

             If there  are  no ambient  PM-10 monitoring stations in the vicinity
       of  the source,  a "regional site" may be used  to determine the
       background.   A  "regional  site"  is  one that is not  influenced by  major
       sources.

             Alternatively,  air  quality data collected in the  vicinity  of  the
       source can  be used  to determine the background concentration.  The
       average annual  background concentration can be calculated by excluding
       those  values  when the source impacts  the monitoring site.

             Line  sources  commonly included  in emission inventories  are
       roadways and  streets  along which there  are  well-defined movements of
       motor  vehicles, but  they  may be lines of  stacks such as in aluminum
       refineries.   Area and volume sources  are  often collections of  a
      multitude of  minor  sources with individually  small emissions  that are
       impractical to  consider as separate point or  line  sources.  Large area
       sources are typically treated as a grid network of square areas, with
      pollutant emissions distributed uniformly within each grid square.

      After  determining emissions for background  sources, they may be entered
into the data system.   For example, if AIRS is the data  system and the source
is large_enough to be tracked as a facility, data for the source could be
entered in AFS._  To enter data  in AMS, the activity or emission values must be
summed, or partitioned, to  fit  the geographic units used.  For example,
highway data are not entered in AMS as "line sources."  Highway data for the
appropriate vehicle-type and road-type categories are entered for the County
 (if the County as a whole is the geographic unit being tracked)
                                      18

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                                 SECTION 4.0
DOCUMENTATION/DATA MANAGEMENT  AND REPORTING OF  THE INVENTORY



4.1   Documentation

     . Base year  emission inventory information under the CAA  shall  be provided.
to EPA in written format.   The written  presentation must contain documentation
sufficient for the Agency to reproduce  the emission estimates that  are
submitted in  the inventory.   Written documentation requirements  are summarized
in this  section.

      Under the  CAA,  EPA is  requiring that States  prepare written inventory
documentation reports according to a more standardized set  of guidelines.
Although the  organization of the inventory report  is somewhat flexible.
Table 4.1 presents EPA's recommended outline for this report.  Inventory
reports  that  are not  prepared according to the outline will be harder for  EPA
to review and are more likely to be deemed unacceptable by  the Agency.  The
EPA's primary interest is  that all inventories address the  crucial  elements
inherent in a good inventory and provide summary data and documentation that
allow the quality of  the inventory effort to be effectively judged.
Inventories not  meeting the  minimum data reporting and documentation standards
established in this discussion shall be deemed unacceptable and  returned to
the States for modification  before any  further technical quality review will
be performed.

      The introduction to  an inventory  report shall contain a description  of
the nonattainment area that  has been inventoried,  a listing of the
counties/areas covered,  a  map of the area,  an identification  of  who  prepared
the inventory and the respective contacts for major inventory components,  a
description of major  inventory problems or deficiencies,  and  a discussion  of
how'the  remainder of  the report is organized.   After the introduction, the
report must contain a thorough summary  of the emissions  data  by  source type
(point,  area, mobile,  and  natural)  and  geographic  area.   At a minimum, the
report must include summary  emissions tables  by source type,  summary emissions
tables by county/area,  and graphics  illustrating the contribution to areawide
emissions by  source type.  If PM-10  precursor emissions  are reported,  they
should be presented in separate tables  from primary and  condensible  PM-10
emissions.  States are required to report emissions  data on an annual basis.

      Separate discussions must be presented  to describe inventory development
procedures and results  for point,  area, mobile,  and natural sources.   In
addition to the  specific parameters  germane  to these source types, each source
type discussion needs  to explain how emissions were  temporally allocated to a
daily basis and how RE was incorporated into  each  emission estimate.

      The point  source discussion shall  include a  description of how the list
of sources to be  inventoried was identified.   The  report must  also state if
any source categories  were not  considered in  the inventory and why.   The
discussion shall  address the issue of completeness  of  source  coverage.  Data
collection methods and tools shall be thoroughly explained and documented.
All information surveys  that may have been conducted must be  discussed and the
results provided  (probably in an appendix).   All sources  inventoried shall  be
listed according  to their  source category type (e.g.,  refinery, plant, etc.).
The methodology by which activity levels  and  emissions were determined for
each plant or source  category (when  applicable)  shall  be succinctly  but
explicitly explained.   Large volumes of detailed data  shall be put into
appendices but clearly linked to the text  discussion in  terms  of how they  were
                                      19

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   Table 4.1  Outline  for EPA Recommended Format/Contents for PM-10  Emission
   	 	Inventory Reports
 I.   Cover and Title Page
     A.  Title (geographic area, type of inventories, pollutants, base year)
     B.  Responsible agency [e.g., NC Dept of Health and Natural Resource]
     C.  Report date (completed/distributed)
     D.  Preparer (if different from responsible agency - e.g., contractor)

 II.  Table of Contents
     A .  Cont ent s
     B .  Tables
     C .  Figures

 III .     Introduction
     A.  Reason for report being prepared,  purpose

         [For example.  In response to letter from _ to _ , dated _
         requesting preparation of a SIP for demonstration of attainment of
         PM-10 NAAQS in (geographic area) ,  beginning with an emission inventory
        •for  the base year.   Base year emission inventory serves as  the basis
         for  emissions  modeling and projections for future years.]

     B.   Geographic  area covered,  base year,  type of inventory (PM-10)
         pollutants  included (PM-10,  others)

     C.   Brief discussion of contents of report

         [Note:   Include a paragraph or less  describing each major report
         section.  For  example.  Section 2 summarized stationary point,  area  and
         mobile  source  emissions by county.   Section 3  describes stationary
         point source emissions  and includes  a  discussion of methods  used to
         gather  data, calculate  annual and/or seasonal  emissions, and presents
         a summary of emissions  by plant.   Detailed point source emissions data
         are presented  in Appendix F.   Section  4  discusses  ...]

     D.   Discussion  of  automated data systems used  (AFS/AMS,  State system)

     E.   Major problems,  deficiencies,  portions of  inventory not  included

     F.   List of primary guidance  documents and references used  (EPA  guidance
         documents , AP-42 , etc . )

    G.  List of contacts for each  distinct portion  of  the inventory

IV.  Summary
    A.  Emissions (annual and/or seasonal)  of each  pollutant by major category
         (point, area, and mobile sources) in both tabular and graphical  form;
        brief discussion in footnote, etc.  to clarify what each includes.
    B'  no^, exampi
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   Table 4.1  Outline for EPA Recommended Format/Contents  for PM-10 Emission
 	Inventory Reports (Continued)	

 V.   Documentation of Emissions Methods/Data/Estimates
     A.  Point Source Emissions

         I'         discussions  of procedures and methodologies  including sample
                   calculations
         2-         example  surveys/questionnaires
         3 •         list  of  plants by primary product and total  emissions
         4 •         summary  data for each plant by  source classification code
                   with  details in an appendix
         5.         point source emissions summary

     B.  Area  Source  Emissions

         1-         discussions  of procedures and methodologies  including sample
                   calculations
         2-         list  of  and  emissions by source category
         3•         calculations  and discussion for each source  category
         4.         area  source  emissions summary

     C.  Mobile  Source Emissions

         1-         discussion of procedures and methodologies including sample
                   calculations
         2-         list  of vehicle classes and emissions
         3•         discussion of how  VMT estimates were derived
         4-         discussion of key  assumptions involved in the use of the
                   PARTS model  (or the  latest  available version)
         5-         calculations  and discussion for each vehicle class
         6 •        mobile source emissions summary

VI.  Quality Assurance/Quality  Control (QA/QC)
     A.  QA/QA plan - discussion of QA/QC methodologies used

     B.  Results from the application of  the QA plan

     C.  QA procedures can also  be discussed in individual  source category
        sections

VII.    Appendices
     A.  Lengthy data, calculations,  documentation of methodologies/models


Notes: Annual and/or seasonal emissions shall be  presented in the summary and
       sections describing emissions.

       All pages  in the report  (including appendices)  shall be numbered
       Sources of information shall  be referenced throughout.  Include
       complete list(s) of references  within  body of report (preferably at  end
       of each section).

       Margins of report shall  be adequate so that copying of report will not
       lose text, page numbers,  or other important information.
                                      21

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 used to determine emissions.  Summary tables and graphics shall be prepared to
 address just point source emissions.

       For area and mobile sources, the report must state if any source
 categories were not considered in the inventory and why.  All of the source
 ?So^°^e! C0v1!red shall be listed and the method used to determine emissions
 identified.  If an EPA method was used, but a different emission factor was
 used, this must be noted.  For all approaches used (EPA or otherwise) , the
 derivation of activity/commodity level data shall be thoroughly discussed   As
 needed, supporting data can be put into appendices but the appendices shall be
 fully explained and clearly linked back to the text discussion and emission
 estimates.  Like point sources, emission summaries shall be developed for area
 and _ mobile sources.  The summaries must reflect emissions by county and for the
 entire nonattainment area.

       As an aid to States in the preparation and checking of their inventories
 prior to submittal to EPA, the Agency has been preparing a set of quality
 review guidelines.  These guidelines will contain what is essentially a
 checklist of items that an inventory must contain or address in order for the
 inventory to be considered acceptable for review by EPA.   The guidelines will
 address whether inventories meet developed specifications for completeness
 consistency (both internal and with national trends) ,  reasonableness of
 emission values,  and emissions documentation.

       States are _ required to design and implement a QA program to enhance the
 ine£;£ion«oX?X^tyr^d ^^^ °f the P1*-10  SIP emission inventories prepared
 in response to the CAA.   The inventory report  shall have  a separate section
 that  describes the implementation of the State's QA plan  and the results
 «St?VS^ y   *v,QA Pro?ram-   For a11 source category types,  the QA discussion
 shall address  the  completeness of the inventory (e.g.,  are all of the EPA-
 recommended area source  categories accounted for) ,  reasonableness of the
 emission estimates (e.g.,  are estimates  for a  category consistent with some
 other related  parameter  for the area),  and relative accuracy of the data (e g
 ?£   i  ?      indlZidual c«»ty emission figures total  to the sums given for " '
 the whole area) .   The  QA discussion must show  the  range of quality review that
 SouldlXl^i-3?*  h°?  ^ nriSW benefitted the inventory.   This QA discussion
 should  reflect the planned QA program that was  approved as a part of the IPP
 The QA  section should  discuss how the QA plan was  actually implemented,  what '
 ^Si0",0* ?{! QA  program did and did not work,  the results  of any internal or
 external  audits that were  performed,  and a general  QA of  the  inventory  data.

 4.2  Data Management  and Reporting

      Emission inventory information  for  base year  and periodic  (if  recruired)
 inventories under  the  CAA shall be provided to EPA  in electronic  formal The
 level of detail required to be reported to  EPA is currently being determined

             e  Sje   of  fue EPA
  aion   of
2SSSSL 5 S% °? t^SpeClfiC level °f detail re<3uired for the electronic
reporting of data to EPA.  If a State elects to use the EPA' s AIRS, the level
°Lde^ai1 reined for AIRS submittals would be sufficient for EPA data
reporting in coordination with EPA Regional Office requirements   The
requirements and instructions for data coding, updating, editing, storage  and
£^leVe4 af6 sPecified in the AIRS User's Guide manuals.  The AIRS User^s
Guide manuals, along with several other reference documents for using AFS and
AMS, are available on the AIRS Bulletin Board System on the TTN   The AFS Dafa
System Helpline (1-800-367-1044) is available tS hand?! technical syltJm
questions, software malfunctions, and problems with the system   The AMS also
has a user's Help Line (1-800-333-7909)  for assistance in^lfaspects^f usfng
AMS.  For more information, contact the EPA Regional Office.             using
                                       22

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                                  SECTION 5.O
                                   REFERENCES



 U.S.  EPA,  1986:  U.S. Environmental Protection Agency, Guideline On Air Quality
       Models (Revised), EPA 450/2-78-027R, and its supplements, July 1986.
       (Codified in Appendix W of 40 CFR 51.)

 U.S.  EPA,  1987:  U.S. Environmental Protection Agency, PM-10 SIP Development
       Guideline,  EPA 450/2-86-001, June 1987  and Supplement June 1988.

 U.S.  EPA,  1988a:   Control of Open Fugitive Dust Sources,  EPA-450/3-88-008,
       September 1988.

 U.S.  EPA,  1988b:   U.S.  Environmental Protection Agency,  Guidance for
       Preparation of Quality Assurance Plans  for Ozone/Carbon Monoxide SIP
       Emission Inventories,  EPA 450/4-88-023,  December 1988.

 U.S.  EPA,  1989a:   U.S.  Environmental Protection Agency,  Guidance Document
       ror  Residential Wood Combustion Control  Measures,  EPA 450-2-89-015
       September 1989.                                                   '

 U.S.  EPA,  1989b:   U.S.  Environmental Protection Agency,  Example Emissions
       Inventory Documentation for Post-1987 Ozone State  Implementation
       Plans  (SIPS),   EPA-450/4-89-018,  October 1989.

 U.S.  EPA,  1990:   U.S. Environmental  Protection Agency, Guideline on Air
       Quality Models  (Revised),  memorandum from Joseph Tikvart and Robert
       Bauman, July 5, 1990.

 U.S.  EPA,  1991a:  U.S. Environmental  Protection Agency, PM-10  Moderate  Area
       SIP  Guidance:   Final Staff Work Product, memorandum from John
       Calcagni, April 2,  1991.

 U.S.  EPA   1991b:  U.S. Environmental  Protection Agency, Nonroad Engine  and
       Vehicle Emission  Study —  Report, EPA-21A-2001, November 1991.

 U.S.  EPA,  1992:   U.S. Environmental  Protection Agency, Background
       Information Document for Prescribed  Burning Best Available Control
      Measures, EPA 450/2-92-003,  September 1992.

U.S.  EPA,  1993a:  U.S. Environmental  Protection Agency, PM-10  Serious Area
      SIP  Guidance:   Final Staff Work Product, memorandum from Joseph W
      Paisie, September 24,  1993.

U.S. EPA,  1993b:  U.S. Environmental Protection Agency, PM-10  Guideline
      Document and Appendix, EPA  452/R-93-008, April 1993.
                                       23

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24

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                                  APPENDIX  A
        INVENTORY PREPARATION PLAN  (IPP) REVIEW CHECKLIST
      The purpose of this checklist is to provide a decision tool for
determining if an IPP meets EPA's minimum requirements.  The Questions marked
with an asterisk (*) are considered crucial to an acceptable IPP, but are not
required.  Those questions not so marked are considered desirable items.
1.0
      APPROACH
*1.1  Does the IPP indicate whether it was prepared for the purposes of a PM-10
      SIP inventory?
          Yes
                 No
                                             Comments
"1.2
      Does the IPP define the nonattainment area(s) that the inventory will
      address, and indicate the nonattainment classification for the area(s)?
          Yes
                No
                                             Comments
 1.3   Are the groups/persons responsible for the inventory and the
      groups/persons compiling the inventory specified?
Yes

No

Comments


 1.4
      Does  the IPP contain a suitable outline for content  and organization
      review of the planned inventory report?
         Yes
                No
                                             Comments
                                      25

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       Does  the IPP contain schedules of submission dates for draft and final
       inventories  or inventory components  if the State plans to submit the
       inventory in component  pieces?
          Yes
                 No
                                              Comments
 *1.6  If the  IPP covers multiple nonattainment areas,  are differences  in  the
      approach  for the nonattainment areas clearly defined?
Yes

No

Comments


 1.7  Does the IPP address which source categories of PM-10, regardless of size
      will be inventoried?                                                     '
          Yes
                 No
                                             Comments
*1.8  Are stationary point, stationary area, on-road mobile, and nonroad mobile
      where applicable, addressed?
          Yes
                No
                                             Comments
*1.9  Does the IPP summarize the basis for the inventory and the source(s)  of
      basic emissions documentation information for each principal inventory
      component (point,  area,  on-road mobile,  etc.)?
         Yes
                No
                                             Comments
                                      26

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2.0   POINT  SOURCES


*2.1  Does the  IPP  define  how all pertinent emission sources will be  identified
      and located?
          Yes
                 No
                                              Comments
 2.2  Does the IPP describe how point source activity levels and associated
      parameters will be developed and discuss how these data will be used to
      calculate emission estimates?
          Yes
                 No
                                              Comments
*2.3  Does the IPP discuss how and when statewide point source reporting to the
      EPA will be conducted and how it will be coordinated with reporting for
      nonattainment area sources?
          Yes
                 No
                                             Comments
*2.4  Does the IPP indicate whether rule effectiveness (RE)  was applied and
      discuss the basis for its application if it was included in the emission
      calculations ?

Yes

2 . 5 Does the

Yes

No
-
Comments


IPP discuss what emission control efficiencies will be based on
No

Comments


                                      27

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 3.O    STATIONARY AREA AND NONROAD MOBILE SOURCES

 *3.1   Does  the  IPP  explicitly state  which source categories  will be  addressed?
          Yes
                 No
                                              Comments
 *3.2  Does the IPP explicitly state which source categories  from EPA's emission
      inventory requirements will not be addressed and provide justification?
          Yes

                 No
                                              Comments
*3.3  For source categories included, does the IPP indicate or reference the
      approach used to calculate emissions?
          Yes
                 No
                                             Comments
*3.4  If there are alternate EPA methods for a category, does the IPP clearly
      indicate the method the State intends to use?
          Yes
                No
                                             Comments
*3.5  Are the major assumptions stated for approaches that differ from EPA's
      guidance?

Yes

*3.6 Does the

Yes

No

Comments


IPP define the source of activity level data?
No

Comments


                                      28

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 "3.7  If RE was applied,  does the IPP discuss the basis for the application
      of RE?
IYes

No

Comments


*3 . 8 Does the IPP discuss what emission control efficiencies will be based on'
IYes

No

Comments


4.0   ON-ROAD MOBIIiE SOURCES


*4.1  Does the IPP provide a clear indication of how the State  intends to
      develop a VMT estimate?
!Yes

No

Comments


*4.2 Does the IPP indicate that PARTS will be used to develop mobile source
emission factors?
Yes

No

Comments


*4.3 If PARTS will not be used, does the IPP discuss the alternate emissions
estimation methods?
IYes

No

Comments


*4.4 Are the key assumptions for the PARTS model identified (i.e., vehicle
speed) ?
IYes

No


Comments


4.5  Does the IPP  specify the vehicle classes that will be covered?


                                       29

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          Yes
                 No
                                              Comments
5 . O   MODKLING
*5.1  Is the modeling inventory and the modeling approach for the attainment
      demonstration discussed in the IPP?
5.2 Is
Yes

No

Comments


the modeling area defined?
Yes

No


Comments
-

 5.3   Does  the  IPP  indicate  when  initial  modeling inventory data will be
      submitted?
         Yes
                No
                                             Comments
5.4  Does the IPP discuss early coordination between inventory and modeling
     personnel in inventory planning?
         Yes
                No
                                             Comments
5.5  Does the IPP discuss how the temporal and spatial resolution will be
     determined for model inputs?
                                      30

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 6 . O
DOCUMENTATION


             ,l?arly describe how the Stafce
           the inventory to EPA?
                                                          to present, document,
                                               Comments
  6.2  Does the IPP discuss how emission estimates will be summarized for each
       nonattainment area?
 "6.3   Was  the Regional Office contacted to establish the specific level of

       Sp^L^f** f°r fc^ ?le=tronic Deporting of data to EPA,  and does the
       to EPA*         computerized methods for compiling and submitting the data
7.0   QUALITY ASST3RANCE (QA) FLAN


*7.1  Does the IPP contain a QA plan for the inventory?
                                       31

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 *7.2  Does  the QA plan describe  the  overall  QA program that  the  State intends  to
      use during Compilation  of  the  inventory?
Yes

No

Comments


S.O   QA POLICY  STATEMENT

*8.1  Does  the QA plan contain a Policy Statement with a  formal declaration of
      management's commitment to the development and  implementation of  the QA
      program?
IYes

No

Comments


*8.2  Does the Policy Statement indicate that there is a commitment to develop a
      Quality emission inventory, including the allocation of resources for the
      QA program?
Yes

No

Comments


 *8.3  Is the Policy Statement signed by the QA Coordinator and Agency
      Administrator?
IYes

No

Comments


9.0
      SUMMARY
 9.1  Does the QA plan's summary include an overview, of the major components of
      inventory development?
Yes

No

Comments
'

                                       32

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 *9.2   Does the summary include a description of the flow of the inventory data
       through the Agency or refer to such a flow chart elsewhere in the IPP?
          Yes
                 No
                                              Comments
 *9.3  Does  the  summary indicate the critical points at which QA is  applied
      during the  development of the inventory?
          Yes
                 No
                                              Comments
 9.4  Are the data QC techniques  given  in  the  summary,  including an  indication
      of the frequency that  they  will be applied?
          Yes
                 No
                                              Comments
 9.5  Does the summary contain the objectives for emission inventory
      development?
          Yes
                 No
                                             Comments
 9.6  Does the summary discuss the constraints relative to the development of
      the emission inventory (i.e., given personnel,  time, resources,  data
      processing capabilities)?
          Yes
                No
                                             Comments
"9.7   Does the summary include an organizational chart showing the technical as
      well as QA personnel?
         Yes
                No
                                             Comments
                                      33

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*9.8  Does the organizational chart show the QA coordinator reporting to upper
      management not directly involved in the development of the inventory?
          Yes
                 No
                                             Comments
*9.9  Does the summary provide the names and telephone numbers of the QA
      coordinator and directors?
Yes

No

Comments


10.0  TECHNICAL CONSIDERATIONS	PLANNING

 10.1 Does the QA plan contain a schedule of QA activities?
IYes

No

Comments


10.2 Are the responsibilities of the QA Coordinator given?
IYes

No

Comments


10.3 Is the personnel training program explained in the QA plan?
IYes

No

Comments


10.4 Are the checkpoints for problem detection given in the QA plan?
Yes

No


Comments


                                      34

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 *10.5 Does the QA plan show that the QA/QC program includes assessing data
       completeness and standard range checking?
          Yes
                 No
                                              Comments
 *10.6  Does  the QA plan give the critical data elements relative to assessing the
       completeness of the source data?                             -assessing cne
          Yes
                 No
                                              Comments
11.0  TECHNICAL CONSIDERATIONS	DATA COLLECTION AND ANALYSIS


*11.1 Does the QA plan explain data  collection procedures  and QA/QC procedures

      used to insure quality data were  collected?
          Yes
                 No
                                              Comments
 11.2 Does the QA plan indicate what QA/QC procedures will be implemented to
      account for all sources?
          Yes
                 No
                                             Comments
*11.3 Does the QA plan describe QA/QC procedures that will prevent double
      counting of sources?
         Yes
                No
                                             Comments
                                      35

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*11.4 Does the QA plan explain how the quality and accuracy of the calculations
      will be evaluated for:

            -     Consistency in methodology?

IYes

No

Comments


- Review of engineering judgement?
Yes

No

Comments


- Accuracy of units and unit conversions?
IYes

No

Comments


- Transposition of figures?
Yes
1
No

Comments


Misinterpretations of the use of emissions factors?

Yes

No


Comments


*11.5 Does the^QA plan explain how the completeness, reasonableness,
reliability, and consistency in the use of equations for specific methods
will be evaluated?

Yes

No


Comments


                                      36

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  11.6 Does the QA plan indicate that the person responsible for evaluating the
                     e Calculations is not directly involved in the inventory
 12.0  TECHNICAL CONSIDERATIONS	DATA HANDLING

 *12.1 Does the QA plan explain the data management procedures (i.e ,  coding
       tracking,  securing,  storing on disks)?
 *12.2 Does  the QA plan include procedures  which explain how data will be
      corrected and  these corrections  tracked?
*12.3 Are data documentation procedures given  (i.e., use of notebooks
      computers, work sheets)?
13 .0  QA REPORTING
      inventor
                       indic?te how applicable data checks (e.g., consistency,
                    reasonableness< and proofing) will be reported in the
                                       37

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14.0  QA AUDITS

*14.1 Does the QA plan contain a statement that the Agency is willing to be
      audited by EPA?
IYes

No

Comments





14.2 Does the QA plan indicate that the QA program includes routine assessments
of the effectiveness of the inventory development procedures (i.e. ,
internal audits) ?
IYes

No

Comments


14.3 Does the QA plan indicate the frequency of internal audits?
IYes

No

Comments


14.4 Are the objectives of the audits given?
IYes

No


Comments
-

14.5 Does the audit procedure include documentation of the findings and
periodic reports to management?
IYes

No


Comments






                                      38

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                                     TECHNICAL REPORT DATA
                                (Please read Instructions on reverse before completing)
   i. REPORT NO.
     EPA-454/R-94-033
                  3. RECIPIENT'S ACCESSION NO.
  4. TITLE AND SUBTITLE

     PM-10 Emission Inventory Requirements Final Report
                  5. REPORT DATE
                     September 1994
                                                                    6. PERFORMING ORGANIZATION CODE
  7. AUTHOR(S)
    Randy Strait
                  8. PERFORMING ORGANIZATION REPORT NO.
  9. PERFORMING ORGANIZATION NAME AND ADDRESS

    E. H. Pechan & Associates, Inc.
    3500 Westgate Drive, Suite 103
    Durham, NC 27707
                  10. PROGRAM ELEMENT NO.
                  11. CONTRACT/GRANT NO.

                    68-D2-0159, WA 13
  12. SPONSORING AGENCY NAME AND ADDRESS

    Emission Inventory Branch (MD-14)
    Sulfur Dioxide/Particulate Matter Programs Branch (MD-15)
    U. S. Environmental Protection Agency
    Research Triangle Park, NC  27711
                  13. TYPE OF REPORT AND PERIOD COVERED
                    Final
                  14. SPONSORING AGENCY CODE
  15. SUPPLEMENTARY NOTES
  EPA Contacts:  Robin Dunkins, SDPMPB (MD-15) and Bill Kuykendal, EIB (MD-14)
  16. ABSTRACT

  This document describes the emission inventory requirements that are contained, either explicitly or
  implicitly, in the Clean Air Act as amended in 1990 (CAA) for those areas that are required to submit a
  State Implementation Plan (SIP) for demonstrating attainment of the National Ambient Air Quality
  Standard (NAAQS) for PM-10.  The guidance in this document pertains to PM-10 moderate
  nonattainment areas and to areas that have been reclassified as serious nonattainment areas.  The
  purposes of the document are to (1) identify the types of inventories required; (2) briefly review the
  regulatory requirements pertaining to submission of these inventories; (3) describe the objectives,
  components, and ultimate uses of the inventories; and (4) define documentation and reporting
  requirements for the inventories.
  17.
                                      KEY WORDS AND DOCUMENT ANALYSIS
                    DESCRIPTORS
                                                 b. IDENTIFIERS/OPEN ENDED TERMS
                                                                                     c. COSATI Field/Group
    Emissions
    Particulate
    Emission Inventories
    PM-10
    Guidance
 18. DISTRIBUTION STATEMENT

    Unlimited
19. SECURITY CLASS (Report)
   Unclassified
21. NO. OF PAGES
       45
                                                 20. SECURITY CLASS (Page)
                                                    Unclassified
                                    22. PRICE
EPA Form 2220-1 (Rev. 4-77)   PREVIOUS EDITION IS OBSOLETE

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