Air Toxics Notebook
Ethylene Manufacturing Process Units (Heat Exchange Systems & Waste Operations) -  Subpart XX

Applicability: eCFR Subpart XX [ecfr.gov]

This subpart applies to:
  1. Affected sources at ethylene production units subject to NESHAP YY that are Major Sources of HAPs*.
Affected sources:
  1. Heat exchange systems;
  2. Waste streams.
Target HAPs:
  1. Benzene;
  2. 1,3-Butadiene;
  3. Cumene;
  4. Hexane;
  5. Napthalene;
  6. Styrene;
  7. Toluene;
  8. Xylene (o-,m-,p-).
*Major Sources of HAPs emit or have the potential to emit:
  • ≥ 10 tons/year of any single HAP; or
  • ≥ 25 tons/year of total HAPs.
  • Area Sources emit less than Major Sources.

Not subject to this subpart:
  1. Heat exchange systems that meet any of the following criteria:
    1. Operates with the minimum pressure on the cooling water side at least 35 kPa greater than the maximum pressure on the process side;
    2. Contains an intervening cooling fluid containing less than 5% by weight of total target HAPs between the process and the cooling water. This intervening fluid must serve to isolate the cooling water from the process fluid and must not be sent through a cooling tower or discharged;
    3. Once-through heat exchange systems subject to a NPDES permit with an allowable discharge limit of 1 ppmv or less above influent concentration, or 10% or less above influent concentration, whichever is greater;
    4. Once-through heat exchange systems subject to a NPDES permit that meets all of the conditions in 63.1084(d)(1)-(4);
    5. Recirculating or once-through heat exchange systems that cool process fluids that contain less than 5% by weight of total target HAPs.
  2. Wastes in the form of gases or vapors that are emitted from process fluids;
  3. Wastes that are contained in a segregated storm water sewer system.
Rules apply to small, area sources? No
Known Sources in NDEQ Jurisdiction:
Facility ID #
Source
City
58562
Clean Harbors
Kimball
Date of Original Final Rule: 7/12/02
Amendments Dates: 04/13/2005 - Final Rule; Amendments
07/12/2002 - Final Rule
State Regulations (Title 129): Title 129, Chapter 13, Section 002.37

Previously: Chapter 28, Section 001.91.

Sources are also responsible for ensuring they are in compliance with current federal requirements found for this subpart in the CFR.
Federal Regulations: 40 CFR 63.1080
Related Rules:

NESHAP - 40 CFR 63

Subpart SS - Close Vent Systems
Subpart TT - Equipment Leaks Level I
Subpart UU - Equipment Leaks Level II
Subpart WW - Storage Tanks Level II
Subpart YY - Generic MACT
Regulations and Federal Registers:
eCFR Subpart XX [ecfr.gov]

(See attached file: 2X - Fed. Reg. 2005-04-13 - Direct Final Rule; amendments.pdf)

(See attached file: 2X - Fed. Reg. 2002-07-12 - Final Rule; amendments.pdf)

SizeFile Name
204 KB 2X - Fed. Reg. 2005-04-13 - Direct Final Rule; amendments.pdf
286 KB 2X - Fed. Reg. 2002-07-12 - Final Rule; amendments.pdf
Forms:
Important Dates:
FAQs, Fact Sheets, and Rule Summaries: EPA's Generic MACT Website [epa.gov] - contains federal register notices and implementation tools
Presentations, Training and Articles:
Other Information and Resources:
Notes:
Page Last Updated: 12/16/22