APPENDIX A-1

PREPARATION OF 

PENNSYLVANIA POINT SOURCE INVENTORIES

Bureau of Air Quality

Department of Environmental Protection

Division of Air Information 

A. Introduction

This document describes the methodology used by the Commonwealth of
Pennsylvania to develop inventories of air pollutants emitted as
required by the U. S. Environmental Protection Agency’s Consolidated
Emission Reporting Rule (CERR) (40 CFR Part 51, Subpart A).  The 2002
inventory will also be the base year inventory for State Implementation
Plan (SIP) revision development for PM2.5, 8-hour ozone and regional
haze.

The CERR requires the Commonwealth to report actual emissions for the
following pollutants:  sulfur oxides, volatile organic compounds (VOC),
nitrogen oxides, carbon monoxide, lead and lead compounds, primary
PM2.5, primary PM10, and ammonia (40 CFR 51.15(a)).  The CERR lists
primary PM as an optional pollutant for reporting purposes.  The CERR
does not require the submission of hazardous air pollutant emissions
data.  

Emissions from point sources are reported for 65 of the Commonwealth’s
67 counties.  Point source emissions from sources located in Allegheny
County are reported directly to EPA by the Allegheny County Health
Department.  Point source emissions from sources located in Philadelphia
Counties are reported directly by the Philadelphia County Health
Department, Air Management Services.  

The annual emission inventory must be temporally resolved to provide
seasonal data for air quality modeling purposes.  Temporal adjustments
to the annual inventory are made because of seasonal differences in the
rate of emissions or activity, or to apportion emissions to a particular
season or day.  For the 8-hour ozone National Ambient Air Quality
Standard (NAAQS) emissions inventory, VOC, NOx, and CO emissions are
reported as actual annual and actual summer weekday.  Summer weekday
emissions are defined as an average day’s emissions for a typical
summer day during the ozone season.  For the PM2.5 NAAQS and regional
haze rule emission inventories, direct emissions (including
condensibles) of PM10 and PM2.5, and the precursor VOC, NOx, SOx, and
NH3 are reported as actual annual data.

For the ozone SIP inventories, rule effectiveness and rule penetration
are applied.  Rule effectiveness reflects the ability of a regulatory
program to achieve all the emission reductions that could have been
achieved by full compliance with the applicable regulations at all
sources at all times.  Rule penetration is an estimate of the extent to
which a regulation covers emissions from an area source category for a
specified control area.  Rule penetration is applied to the control
efficiency for a regulation to account for less than 100 percent
coverage of the emissions for an area source category.  Because the
inventory was developed prior to EPA’s issuance of the November, 2005
revision to the rule effectiveness guidance, Commonwealth followed the
previous EPA guidance and assumed an 80% rule effectiveness for
applicable sources unless specified to the contrary.

B. Point Sources

A point source is a stationary, identifiable source of air pollution
that usually emits the air pollutants through a stack or vent.  A
facility contains one or more point sources and is not limited to
industrial facilities.  Examples of an air pollution facility are steel
mills, oil refineries, electric generating facilities, and coal
preparation plants.  A non-industrial facility may contain a large
boiler or other air pollution source. 

The data for the 2002 and 2004 sulfur oxides, volatile organic compounds
(VOC), nitrogen oxides, carbon monoxide, lead and lead compounds,
primary PM2.5, primary PM10, and ammonia point source emission inventory
is  derived from the Pennsylvania Air Information Management System
(AIMS).  AIMS sources are identified and inventoried by Pennsylvania
regional air quality offices through permitting operations and regional
and central office field inspections and surveys.  The AIMS system is
designed to include all point source emission categories as required by
the CERR.

The AIMS database is linked to the Department’s eFACTS (Environment
Facility, Application, Compliance Tracking System) database.  This
allows Department-wide sharing of data for all program areas.  In
addition, the public is provided better access to the information
through the Department’s Internet website.

The point source inventories for Allegheny and Philadelphia Counties
will be prepared by the Allegheny County Health Department and the
Philadelphia County Health Department, respectively.  The two county
agencies will submit their point source emission inventories directly to
EPA’s National Emission Inventory as required by the CERR.  The county
agencies will also provide their point source data to the Department in
order that effective State Implementation Plan preparation may be
undertaken.

Paper Submittal of Inventory Data

Annually, facilities complete worksheets for each source that operated
and emitted pollutants for the year. Data required for processes include
monthly material throughputs, days and weeks the sources operated,
material processed, maximum throughput per hour, and correct Source
Classification Code (SCC) number. In addition to these process data,
combustion unit data must include fuel used, fuel characteristics such
as sulfur content and Btu. For each source, an estimate of total
criteria and hazardous pollutant emissions must be supplied, along with
the estimation method. If emissions are estimated using anything other
than emissions factors from SCC codes, methodology must be provided. In
addition to emissions estimates for each piece of equipment, site
emissions are required. If there is equipment that is too small for
individual reporting, emissions from this equipment will be reflected in
the site total.

After the facilities provide these data, DEP reviewers input the data
into the AIMS system. At this time, the system may create an error
message if emissions are significantly different from those expected,
based upon emissions factors and throughputs. At this point, the
reviewer must determine if the estimate is accurate and may either
override the error message or contact the facility for corrections,
which are then input by the reviewer.

After all data are entered, reports are generated to show comparisons
between emissions years. If there are significant differences, reviewers
must determine why emissions are different. Explanations may include
changes in production or change in material input. Once all
discrepancies have been corrected or explained, the data are accepted,
and the inventory is considered complete.

Instructions Available

DEP has developed instructions for companies to complete the annual
inventory submission, which describes the database fields in the
AIMS/eFACTS system.  This document is revised annually to reflect any
new guidance for the applicable reporting year.

Information on the emission inventory reporting system can be found at: 
 HYPERLINK
"http://www.dep.state.pa.us/dep/deputate/airwaste/aq/emission/Emission_I
nventory.htm" 
www.dep.state.pa.us/dep/deputate/airwaste/aq/emission/Emission_Inventory
.htm . Instructions for the system are attached.

	

	

