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Air Toxics Program

New York's air toxics program was established to protect the public and the environment from the adverse effects of exposure to toxic air contaminants. The air toxics program employs the latest in computer modeling, air monitoring, and risk assessment methodology. As part of this program, DEC has also accepted delegation of all federal requirements regulating air toxics under the National Emission Standards for Hazardous Air Pollutants (NESHAPs) program for process sources.

Air Toxics Regulatory Requirements

The regulatory requirements of the air toxics control program are principally contained in 6 NYCRR Part 212. This regulation specifies the degree of air cleaning required for sources of toxic air contaminants and is based on an Environmental Rating assigned by a DEC permit engineer. Ratings are based on a contaminant's toxicity (high, moderate or low), predicted offsite air concentrations, the proximity of ambient impacts to neighboring communities, existing background concentrations and the potential future growth of the impacted area.

Regulatory Guidance for Toxics

Part 212 was updated and promulgated on June 14, 2015. To assist the public with understanding the changes, the Division of Air Resources released DAR -1. DAR-1 provides guidance to DEC permitting staff, the public, and the regulated community on the requirements of the air toxics program (Part 212). DAR-1 will outline the control requirements for the emissions of air toxics and provide guidance for implementing the regulation.

AERSCREEN Modeling Software (Version 18081)

An essential component of deriving an Environmental Rating is calculating the offsite air concentration of the air contaminant. The AERSCREEN modeling software calculates the ambient concentration resulting from the operation of a source, or multiple sources, of an air contaminant. Predicted impacts are compared to guideline concentrations and this comparison is used in determining the appropriate Environmental Rating and subsequent degree of control required for the acceptable operation of the source(s) under review.

To assist Regional staff and the public to calculate offsite ambient air concentrations, DEC is offering access to the USEPA's AERSCREEN model. The AERSCREEN model includes several component files which need to be incorporated into the AERSCREEN executable file to run properly. The AERSCREEN model can be downloaded as a zip file with the needed components. DEC has included both the USEPA's user guide and a condensed DEC user guide with suggestions on default options and programmatic contacts.

As of January 2017, a new feature has been added to the AERSCREEN download, an Excel spreadsheet incorporating the AGC/SGC tables. This spreadsheet will allow the user to input data from multiple emission points and evaluate the offsite emissions by emission point and facility wide.

AERSCREEN Software Program Files

File Download and Set-up:

  • On the C:\ drive, create a subfolder called C:\AERSCREEN.
  • Using WinZip, extract the files to the C:\AERSCREEN directory. The program needs all the files within the zip bundle to execute properly.
  • After unzipping the files to the C:\AERSCREEN directory, locate the DEC AERSCREEN User Guide.pdf for instructions to properly set up working directories and running the model.

Download AERSCREEN-32

Download AERSCREEN-64

2016 DAR-1 AGC/SGC Tables

To satisfy the requirements described in Part 212-1.3 Table 1, DEC established a listing of non-criteria air contaminants with acceptable ambient air concentrations to help the user of DAR-1 make an appropriate Environmental Rating determination. The acceptable air concentrations, in micrograms per cubic meter, are listed for annual emission rates (called Annual Guideline Concentrations (AGC)) and for hourly emission rates (called Short-Term Guideline Concentrations (SGC)). A listing of AGC/SGCs were incorporated into the 1991 draft version of Air Guide-1 (DAR-1) under Appendix C and revised in 1995, 2000, 2003, 2007, 2010 and 2014. The current 2016 AGC/SGC tables are located in Appendix A of DAR 1.

Questions on DEC's air toxics program can be directed to 518-402-8402.

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