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Checking in on New York’s Air Toxics Program: Part 212

Posted: April 1st, 2021

Authors: Rich H. 

The goal of the New York State Department of Environmental Conservation’s (NYSDEC’s) air program is to protect the public and the environment from the adverse effects of exposure to air contaminants.  As part of this protection, Title 6 Part 212 of New York Codes, Rules, and Regulations (NYCRR) includes regulations applicable to process operations at stationary sources of emissions.

Since the last time we looked at Part 212, NYSDEC has proposed some changes to DAR-1 (Guidelines for the Evaluation and Control of Ambient Contaminants under Part 212), which provides guidance on how to comply with the requirements of the Part 212 regulations. Most importantly, the proposed changes tightened the guideline concentrations on some non-criteria pollutants and added others. NYSDEC took public comments until February 22nd, 2021 and we now await the final rule update. The changes to DAR-1 include:

  • A number of clarifications and revised text to make the requirements clearer.
  • A revision to Subpart 212-1.4(k) related to facilities in the iron and steel industry that removes the exemption for those toxics defined at the highest risk level.
  • A revision to Subpart 212-1.5(e)(2) to include an alternate toxic impact assessment method that does not require modeling. Specifically, process emission sources subject to the Federal National Emissions Standards for Hazardous Air Pollutants (NESHAP) under 40 CFR Part 61 or 63 may now demonstrate compliance by meeting a mass emission limit specified in Subpart 212-2.2, Table 2 for the non-criteria pollutant in question.
  • The guideline concentrations for benzyne and ethylene oxide were lowered significantly.
  • Perfluorooctanoic acid (PFOA) has been added as a High Toxicity Air contaminant (HTAC), the first of the Per- and polyfluoroalkyl substances (PFAS) to be regulated under Part 212.

As a refresher, the Part 212 regulations achieve public and environmental protection via assessments of emissions control technologies and through an assessment of site-specific emissions and resulting ambient air concentration levels.  There are three groups of air contaminants for process sources that include pollutants with a National Ambient Air Quality Standard (i.e., NAAQS or criteria pollutant), High Toxicity Air Contaminant (HTAC), and other non-criteria/HTAC air contaminants The program codified in Title 6 Part 212 of New York Codes, Rules, and Regulations (NYCRR) requires an analysis to determine how much control is needed to reduce air emissions to concentration levels such that human health is not adversely impacted.  Although the Part 212 regulations have been in place for some time, NYSDEC has become more diligent in making sure facilities are addressing it with permit modifications and renewals.

Part 212 regulates air pollutant and air contaminant emissions from emissions sources associated with any process operations at facilities in the state of New York. For the purposes of the rule, the definition of process operation is:

“Any industrial, institutional, commercial, agricultural or other activity, operation, manufacture or treatment in which chemical, biological and/or physical properties of the material or materials are changed, or in which the material(s) is conveyed or stored without changing the material(s) if the conveyance or storage system is equipped with a vent(s) and is non-mobile, and that emits air contaminants to the outdoor atmosphere. A process operation does not include an open fire, operation of a combustion installation, or incineration of refuse other than by-products or wastes from a process operation(s).”

To assist regulated facilities with understanding Part 212 regulations, the Division of Air Resources developed DAR -1, which provides guidance on how to comply with the requirements of the Part 212 regulations. Prior to the pending update, the last time DAR-1 was updated was in August 2016. DAR-1 outlines the control requirements for the emissions of each air contaminant based on an assigned Environmental Rating and provides guidance for implementing the regulation.

Part 212 applies to all facilities with process operations, whether they have Title V permits, State Facility permits, or have Minor Facility Registrations:

(1) upon issuance of a new or modified permit or registration for a facility containing process emission sources and/or emission points;

(2) upon issuance of a renewal for an existing permit or registration.

Some process operations are exempted from the rule as described in Subpart 212.4 as they are regulated by other rules that take precedence. Additionally, 40 CFR Part 60 New Source Performance Standards (NSPS) and 40 CFR Part 61 and 63 National Emission Standards for Hazardous Air Pollutants (NESHAP) sources may be considered in compliance with Part 212 under certain conditions as described in the Part 212 regulation for those pollutants covered under those rules.

Facilities that are regulated under Part 212 must evaluate the amount of their air contaminant emissions, including criteria, HTAC, and non-criteria/non-HTAC compounds. For those contaminants on the HTAC list, the emissions rate in pound per year (lb/year) is compared to the threshold given in Part 212 Subpart 2.2 Table 2 to determine if the regulations apply. For those air toxics emitted as part of the process operation but not listed in the HTAC table, a threshold of 100 lb/year is used for assessing regulatory applicability.

For those air contaminants for which the emission thresholds are exceeded, the following steps are required to demonstrate compliance:

  1. Perform an air modeling screening analysis for the air contaminant using U.S. EPA’s AERSCREEN air dispersion model.
  2. Should the screening analysis not demonstrate compliance, perform refined air dispersion modeling using U.S. EPA’s AERMOD air dispersion model. When refined modeling is required, an air modeling protocol proposing the methodology to be used in the AERMOD demonstration must be submitted to NYSDEC and approved before the modeling can be executed.
  3. If compliance with Part 212 cannot be demonstrated with air dispersion modeling at the current emissions rates, a more stringent permit limit must be taken to bring concentrations below the applicable Short-term and Annual Guideline Concentrations (SGC/AGC) or the installation of additional controls may be required.

Facilities that are performing a Part 212 analysis during a permit renewal process are also often required to perform 1-hour nitrogen dioxide (NO2) and 24-hour and annual particulate matter with a diameter of less than 2.5 micrometers (PM2.5) demonstrations if the facility has not been required to do one since those NAAQS were promulgated, in 2010 and 2012, respectively.

How can ALL4 help?

ALL4 air quality experts are actively involved in helping facilities in New York demonstrate compliance with Part 212. Determining the applicability of the regulation, characterizing the sources and emissions that are affected, and completing the required air dispersion modeling demonstration can be a challenge, especially given the low thresholds of many of the HTACs. If your facility’s permit or registration is nearing time to renew, or you are planning a project that requires a permit modification, ALL4 can help:

  • Determine whether your facility has a process operation that is subject to Part 212.
  • Quantify your toxics emissions and sources to determine which need to be evaluated to show compliance with the rule.
  • Perform an AERSCREEN modeling analysis to assess compliance for each applicable toxic.
  • For those toxics for which the AERSCREEN analysis is unsuccessful, perform refined modeling using the AERMOD dispersion model to show compliance.
  • Work with you to determine control requirements or other ways to reduce emissions to bring the facility into compliance should modeling show concentrations above the thresholds.
  • Perform NO2 and/or PM5 modeling if NSYDEC has also asked for those analyses.

In ALL4’s experience, AERSCREEN often overstates concentration levels because of the screening meteorology it uses that is designed to replicate worst case dispersion conditions. As a result, we find that in most cases facilities that have to demonstrate compliance with Part 212 air dispersion modeling will need to go to AERMOD. Typically, we would suggest skipping the AERSCREEN analysis and straight to AERMOD refined modeling. However, since DAR-1 requires an air modeling protocol be submitted to NYSDEC before AERMOD can be used to satisfy the Part 212 requirements, which requires additional time and effort to gain approval, and because in the course of setting up the AERMOD analysis most of the information required for AERSCREEN is generated as part of that process, we recommend trying AERSCREEN first to confirm that a refined air dispersion modeling analysis is required..

If you’d like to discuss whether your facility is subject to Part 212 as part of an upcoming renewal or modification, feel free to contact your ALL4 Project Manager or Rich Hamel. We’d be happy to share what we’ve learned in our experiences with this regulation and assist you in any way we can.


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