The Air Facility Subsystem (AFS) contains compliance data and permit
data for stationary sources of air pollution regulated by the U.S. EPA,
and state and local air pollution agencies. This information is used by
the environmental regulatory community to track the compliance status
of point sources with various programs regulated under the Clean
Air Act.
Types of Data
A Plant is a facility represented by its physical location,
and defined by property boundaries. Plant-level data include plant
name, address, Standard Industrial Classification (SIC),U.S. Census
Bureau North
American Industry Classification System
and
compliance status.
A Stack is where emissions are introduced into the atmosphere.
Stack-level data include the height and diameter of the stack as well
as the temperature, flow rate, and velocity of the gas released into the
atmosphere. Stack-level data is used in emission inventory reporting.
A Point is a physical piece of equipment or a process that produces
emissions. Point-level data include normal operating schedule and the
percentage of annual activity occurring each season.
A Segment is a component of a point process, such as fuel combustion,
that is used in the computation of emissions. Segment-level data in AFS
include Source Classification Code (SCC), annual process rate, and fuel
parameters. Segment-level data is used in emission inventory reporting.
Emission inventory data can be found at the
Technology Transfer Network Clearinghouse.
Compliance Data
Compliance data in AFS are maintained at two levels: plant and point.
Plant-level compliance data track the compliance and classification status
of the plant, inspections, and other compliance actions taken against
the plant. Similar data also can be tracked at the point level.
Operating Permit Data
AFS also includes data for management of facility operating permits. Current
capability consists of tracking the steps in the permit issuance process.
State and local air agencies report to AFS when they issue a Federal operating
permit (a permit issued in accordance with Title V of the Clean Air Act
of 1990). The reported data consists mainly of the Title V permit number
and the date the permit was issued. The Operating Permits Program provides
a mechanism for gathering together in one document all of the federal,
State and local requirements applicable to air pollution sources. See
the Policy on Title V Permit Program Data Elements(pdf 39 kb )for a complete list of required
Title V data in AFS.
To view a list of Major Sources currently in AFS subject to the Title V program, see Title V Sources. (pdf
1.49 mb )
Data Input and Update
Procedures
Stationary source data in AFS are collected and updated by state and/or
local agencies. These agencies generally have direct access to the EPA
National Computer Center and AFS. There are two mechanisms for data entry
to AFS: batch and online.
For the batch update process, you create a file of transactions,
transmit the file to the EPA mainframe computer, and submit a batch job.
AFS software validates the transactions and uses them to update the AFS
database.
The online update process uses formatted screens to acquire
new or modified data. The same validation is performed online as in batch
updating, and immediate feedback is provided to diagnose errors in the
values entered into the screens.
When all the desired changes or additions have been entered
on the screens, the software updates the AFS database.
AFS Data Retrieval
Most of the facility data in AFS are available to any person or organization
with legitimate access to the EPA National Computer Center. There are
three ways to retrieve facility data from the AFS database: Online
Browse, Fixed Format Reports, and Ad hoc reporting.
The AFS Online Browse option displays data online.
You specify criteria for data selection (such as plant name and plant
identification number). The AFS software retrieves and displays the data
in formatted screens.
AFS Fixed Format reporting generates printed reports
and/or data files. You specify criteria for data selection and sorting,
and choose options that affect report format or content. The AFS software
automatically submits a batch job to produce the requested report and/or
data file. Many report formats are available, and selection criteria are
flexible enough to meet most information needs.
If the Standard Batch Retrieval and Online Browse facilities
do not satisfy their requirements, experienced users can define supplemental
reports via the AFS Ad Hoc Batch Retrieval option. You specify
which data fields are used to select data, and which fields are included
in the report and/or output data file. To do this, however, you must have
a thorough understanding of the database organization, and data field
names.
AFS History
AFS became operational in April, 1990. AFS replaced the National Emissions
Data System (NEDS), the Hazardous and Trace Emissions System (HATREMS),
and the Emissions Inventory System (EIS) for emission point source data
reporting. The Compliance Data System (CDS), previously used by EPA and
the states for compliance and emission point source data reporting, and
the Continuous Emissions Monitoring Subset (CEMS), used for the maintenance
of point continuous emission monitoring data, were also replaced by AFS.
During September 2000, AFS was replaced by the National Emissions Trends
(NET) database as the official repository of emissions data. The Plans
for Managing Air Emission, Compliance, and Permit Data letter of March
1997(pdf 47 kb, 14 pages) has more information
on how air program data will be maintained.
AFS Contacts
For technical information about AFS, call the AFS User Support Helpline
at (800) 367-1044, or contact Betsy Metcalf
at (202) 564-5962.