Miscellaneous coating manufacturing mact summary

4. What are the emission limitations and work practice standards for affected sources under this rule?

Process Vessel Vents

For stationary process vessels with capacities greater than or equal to 250 gallons at existing sources, this rule requires an overall reduction (adjusting for capture and control efficiency based on enclosure tests, as applicable) of at least 75 percent by weight of those HAPs with a vapor pressure greater than or equal to 0.6 kilopascals (kPa) [0.09 pounds per square inch absolute (psia)], and at least a 60 percent reduction by weight of HAPs with a vapor pressure less than 0.6 kPa (0.09 psia).

The rule also provides an emissions averaging alternative for stationary process vessels at existing sources that are equipped with a tightly-fitting vented cover. The overall mass reduction in HAP emissions for vessels in the averaging group must be equal to or greater than the reduction that would have resulted if each of the covered vessels were vented to a control device that achieves a 75 percent emissions reduction for HAP with a vapor pressure greater than or equal to 0.6 kPa (0.09 psia) or a 60 percent emissions reduction for HAP with a vapor pressure less than 0.6 kPa (0.09 psia).

This rule also requires that portable process vessels at existing sources with capacities greater than or equal to 250 gallons be equipped with a cover. Stationary and portable vessels at new sources must be equipped with a tightly-fitting vented cover, and the vented organic HAP emissions must be reduced by at least 95 percent by weight. As an alternative, for stationary process vessels with capacities greater than or equal to 250 gallons at existing and new sources and portable process vessels with capacities greater than or equal to 250 gallons at new sources, facilities may install a tightly-fitting vented cover and vent emissions to a condenser operated at specified temperature limits to satisfy the overall control requirement. Another option for meeting the standards for stationary process vessels at existing sources is for facilities to use the vessels to produce coatings with less than 5 percent HAP by weight.  For this option, no additional control of process vessel vents is required. 

EPA did not develop standards for process vessels with capacities less than 250 gallons. EPA examined a regulatory alternative that would require the same 75 percent emissions reduction as for larger process vessels and concluded that the total impacts of this alternative, including cost, non-air quality health and environmental impacts, and energy requirements, are unreasonable in light of the HAP emission reductions achieved.

Storage Tanks

The standards for storage tanks at existing sources require either organic HAP emissions reductions of 90 percent by weight or more, or the use of floating roofs, or vapor balancing if the storage tanks have capacities greater than or equal to 75 cubic meters (20,000 gallons) and store organic HAP material with a vapor pressure greater than or equal to 13.1 kPa (1.9 psia).

The standards for storage tanks at new sources require either organic HAP emissions reductions of at least 80 percent by weight, the use of floating roofs, or vapor balancing if the storage tanks have capacities greater than or equal to 10,000 gallons and store organic HAP material with a vapor pressure greater than or equal to 0.02 psia.  The standards for new sources also require either organic HAP emissions reductions of at least 90 percent by weight, the use of floating roofs, or vapor balancing for storage tanks that have capacities equal to or greater than 75 cubic meters (20,000 gallons) but less than 94 cubic meters (25,000 gallons) and store organic HAP material that has a vapor pressure greater than or equal to 10.3 kPa (1.5 psia), and tanks with capacities greater than 94 cubic meters (25,000 gallons) storing organic HAP material that has a vapor pressure greater than or equal to 0.7 kPa (0.1 psia).

This rule does not include standards for storage tanks smaller than 20,000 gallons at existing sources or for storage tanks smaller than 10,000 gallons at new sources because the MACT floor for these tanks was determined to be no emissions reduction.

Wastewater

For existing sources, this rule requires that wastewater containing a total partially soluble and soluble HAP load of 750 lbs/year and a concentration of 4,000 parts per million by weight (ppmw) or greater be treated as hazardous waste or in an enhanced biological treatment unit. Offsite treatment is allowed, provided the affected sources ship the wastewater to an offsite facility for treatment as a hazardous waste and notes this fact along with the name of the facility to which the wastewater is shipped in their notification of compliance status report. If the wastewater is shipped offsite for treatment in an enhanced biological treatment unit, the offsite facility must comply with the monitoring, recordkeeping, and reporting requirements in Subpart HHHHH.

For new sources, the applicability triggers for control are more stringent, affecting all streams that contain partially soluble and soluble HAP at a concentration greater than or equal to 1,600 ppmw.

Transfer Operations

Standards for transfer operations at existing and new sources require 75 percent control of HAP emissions from product loading to tank trucks and railcars if the amount of material transferred contains at least 11.4 million liters per year (3.0 million gal/yr) of HAP, and the material has a HAP partial pressure greater than or equal to 10.3 kPa (1.5 psia). Acceptable control strategies also include routing displaced vapors back to the process, or the use of condensers operated below specified temperature limits.

Equipment Leaks

This rule requires compliance with leak detection and repair (LDAR) programs for equipment leaks.

Existing sources must comply with the sensory-based LDAR provisions of 40 CFR Part 63, Subpart R, the NESHAP for Gas Distribution Facilities. Alternatively, existing sources may comply with the LDAR program in 40 CFR part 63, subpart TT, or subpart UU (the National Emission Standards for Equipment Leaks—Control Level 1 and Control Level 2, respectively) because these alternatives are equivalent to or more stringent than the sensory-based LDAR program.

New sources must comply with either the subpart TT or subpart UU LDAR provisions. For heat exchange systems at existing and new sources, the final rule requires a leak detection program, consistent with the program in 40 CFR 63.104 [the Hazardous Organic NESHAP (HON)].

Since cleaning operations are considered part of the miscellaneous coating manufacturing operations at existing and new sources, cleaning fluids are considered to be process fluids, and the requirements for process vessels, storage tanks, equipment leaks, and wastewater systems that apply to other process operations also apply to cleaning operations.