Section 173-401-533. Units and activities defined as insignificant on the basis of size or production rate.

(1) General. This section contains lists of units or activities that are exempt from this chapter on the basis of size or production rate. Units and activities listed in this section must be listed on the permit application.

(2) The following units and activities are determined to be insignificant based on their size or production rate:

(a) Operation, loading and unloading of storage tanks and storage vessels, with lids or other appropriate closure and less than two hundred sixty gallon capacity (35 cft), heated only to the minimum extent to avoid solidification if necessary.

(b) Operation, loading and unloading of storage tanks, not greater than one thousand one hundred gallon capacity, with lids or other appropriate closure, not for use with hazardous air pollutants (HAPs), maximum (max.) vp 550mm Hg.

(c) Operation, loading and unloading of VOC storage tanks (including gasoline storage tanks), ten thousand gallons capacity or less, with lids or other appropriate closure, vp not greater than 80mm Hg at 21°C.

(d) Operation, loading and unloading storage of butane, propane, or liquified petroleum gas (LPG), storage tanks, vessel capacity under forty thousand gallons.

(e) Combustion source less than five million Btu/hr. exclusively using natural gas, butane, propane and/or LPG.

(f) Combustion source, less than five hundred thousand Btu/hr., using any commercial fuel containing less than 0.4% by weight sulfur for coal or less than 1% by weight sulfur for other fuels.

(g) Combustion source, of less than one million Btu/hr. if using kerosene, No. 1 or No. 2 fuel oil.

(h) Combustion source, not greater than five hundred thousand Btu/hr. if burning used oil and not greater than four hundred thousand Btu/hr. if burning waste wood or waste paper.

(i) Welding using not more than one ton per day of welding rod.

(j) Foundry sand molds, unheated and using binders with less than 0.25% free phenol by sand weight.

(k) "Parylene" coaters using less than five hundred gallons of coating per year.

(l) Printing and silkscreening, using less than two gallon/day of any combination of the following: Inks, coatings, adhesives, fountain solutions, thinners, retarders, or nonaqueous cleaning solutions.

(m) Water cooling towers and ponds, not using chromium-based corrosion inhibitors, not used with barometric jets or condensers, not greater than ten thousand gpm, not in direct contact with gaseous or liquid process streams containing regulated air pollutants.

(n) Combustion turbines, of less than 500 HP.

(o) Batch solvent distillation, not greater than fifty-five gallons batch capacity.

(p) Municipal and industrial water chlorination facilities of not greater than twenty million gallons per day capacity. The exemption does not apply to waste water treatment.

(q) Surface coating, using less than two gallons per day.

(r) Space heaters and hot water heaters using natural gas, propane or kerosene and generating less than five million Btu/hr.

(s) Tanks, vessels, and pumping equipment, with lids or other appropriate closure for storage or dispensing of aqueous solutions of inorganic salts, bases and acids excluding:

(i) 99% or greater H2SO4 or H3PO4

(ii) 70% or greater HNO3

(iii) 30% or greater HCl

(iv) More than one liquid phase where the top phase is more than one percent VOCs.

(t) Equipment used exclusively to pump, load, unload or store high boiling organic material, material with initial boiling point (IBP) not less than 150°C. or vapor pressure (vp) not more than 5mm Hg at 21°C. with lids or other appropriate closure.

(u) Smokehouses under twenty square feet.

(v) Milling and grinding activities, using paste-form compounds with less than one percent VOCs.

(w) Rolling, forging, drawing, stamping, shearing, or spinning hot or cold metals.

(x) Dip-coating operations, using materials with less than one percent VOCs.

(y) Surface coating, aqueous solution or suspension containing less than one percent VOCs.

(z) Cleaning and stripping activities and equipment, using solutions having less than one percent VOCs by weight. On metallic substrates, acid solutions are not considered for listing as insignificant.

(aa) Storage and handling of water based lubricants for metal working where the organic content of the lubricant is less than ten percent.

(bb) Municipal and industrial waste water chlorination facilities of not greater than one million gallons per day capacity.

(3) The following units or activities may be determined to be insignificant on a case-by-case basis by the permitting authority:

(a) Pilot plants.

(b) Cold feed aggregate bins for asphalt and concrete production equipment.

(c) Chemical or physical analytical laboratory operations or equipment including fume hoods and vacuum pumps.

(d) NPDES permitted ponds and lagoons utilized solely for the purpose of settling suspended solids and skimming of oil and grease.

(e) Coffee roasters, under fifteen lbs./day of coffee.

(f) Tire buffing of less than six thousand six hundred tires per year.

[Statutory Authority: Chapter 70.94 RCW. WSR 94-11-105 (Order 93-30), § 173-401-533, filed 5/17/94, effective 6/17/94.]

Chapter 70.94 RCW. WSR 94-11-105 (Order 93-30), § 173-401-533, filed 5/17/94, effective 6/17/94.