Standards of Performance for Nonmetallic Mineral Processing Plants

This fact sheet is intended to explain some portions of 40 CFR 60, Subpart OOO – Standards of Performance for Nonmetallic Mineral Processing Plants. This subpart typically applies to rock crushing plants in Missouri. This rule is often referred to as New Source Performance Standard, or NSPS-OOO.

It is important to note in this rule, use of the term facility does not mean a complete rock crushing plant or installation. It refers to specific equipment including, but not limited to, a screen,conveyor, bucket elevator or a crusher. As a regulated entity, the conditions of the most recent regulation must be met when considering compliance issues at your rock crushing plant.

Affected Facility - Any crusher, grinding mill, screening operation, bucket elevator, belt conveyor, bagging operation, storage bin and enclosed truck or railcar loading station used at the installation. Static (non-moving) grizzly screens are not considered a screening operation and are not considered an affected facility.

Capacity - The cumulative capacity rate of all initial crushers that are part of the plant.
Crush or Crushing - To reduce the size of nonmetallic mineral material by means of physical impaction of the crusher or grinding mill upon the material.
Fugitive Emission - Particulate matter not collected by a capture system and released to the atmosphere at the point of generation.
Initial Crusher - The point of initial crushing for any nonmetallic minerals at the plant.
Nonmetallic Mineral Processing Plant - Any combination of equipment used to crush or grind any nonmetallic mineral wherever located, including lime plants, power plants, steel mills, asphalt concrete plants, portland cement plants or any other facility processing nonmetallic minerals.

Nonmetallic Minerals
Following is a list of nonmetallic minerals as defined in the rule. A crushing plant that processes any of these nonmetallic minerals, or a mixture of which any of these are the majority, is considered a nonmetallic mineral processing plant.Crushed and broken stone ,Boron, Fluorospar,Barite,Sand and gravel ,Rock salt ,Clay ,Feldspar,Gypsum (natural or synthetic), Diatomite, Perlite ,Mica,Sodium compounds ,Pumice ,Vermiculite ,Gilsonite ,Talc and pyrophyllite,Kyanite.

Applicability and Affected Facilities
If you own or operate an affected facility (or facilities) with a manufacture date on or after Aug. 31, 1983, this rule applies to you. However, your affected facilities with a manufacture dateon or after April 22, 2008, will usually have different emission limits and different monitoring and performance testing requirements.
The rule does not apply to the following operations:
• Facilities located in underground mines.
• Plants with no crusher or grinding mill above ground.
• Wet material processing operations. See the rule text for the definition of a wet material processing operation.
• Fixed crushing or sand and gravel plants with an initial crushing capacity of 25 tons per hour or less.
• Portable crushing or sand and gravel plants with an initial crushing capacity of 150 tons per hour or less.
• Common clay plants and pumice plants with an initial crushing capacity of 10 tons per hour or less.

The rule contains an optional compliance method that allows emission measurement from any building(s) that enclose any affected facilities, instead of each affected facility within the building.The revised rule limits visible emissions from any building opening, except vents, to 7 percent opacity. To demonstrate initial compliance using this option, you must use EPA Method 9 for the initial performance test, the same way you would for a fugitive emission point. Vents must meet the stack emission limits and initial performance test requirements mentioned above. See the rule text for the definition of a vent.