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Outdated Exemption List, Subchapter T - June 18, 1997

Synopsis of specific exemptions from air permitting that were in effect on this date.

30 TAC 106 - Subchapter T Surface Preparation

106.451 Wet Blast Cleaning (Previously SE 31)
106.452 Dry Abrasive Cleaning (Previously SE 102)
106.453 Washing and Drying of Glass and Metal (Previously SE 42)
106.454 Degreasing Units (Previously SE 107)

106.451 Wet Blast Cleaning (Previously SE 31)

Blast cleaning equipment using a suspension of abrasives in water is exempt.

106.452 . Dry Abrasive Cleaning (Previously SE 102)

Any abrasive cleaning operation that will satisfy paragraph (1) or (2) of this section is exempt:

(1) enclosed abrasive cleaning:

(A) the particulate matter emissions are evacuated through a fabric filter with a maximum filtering velocity of 4.0 feet per minute (ft/min) with mechanical cleaning or 7.0 ft/min with air cleaning; and

(B) there are no visible fugitive emissions from the facility;

(2) outside blast cleaning:

(A) abrasive usage rate shall not exceed 150 tons per year, 15 tons per month, and one ton per day; and

(B) the blast cleaning is performed at least 500 feet from any recreational area or residence or other structure not occupied or used solely by the owner of the facility or the owner of the property upon which the facility is located; and

(C) records shall be maintained of operating hours and abrasive material usage; and

(D) before construction begins, the facility is registered with the commission's Office of Air Quality in Austin using Form PI-7; and

(E) before construction of the facility begins, written site approval shall be received from the executive director.

106.453 Washing and Drying of Glass and Metal (Previously SE 42)

Equipment used for washing or drying products fabricated from metal or glass is exempt, provided no volatile organic materials are used in the process and no oil or solid fuel is burned.

106.454 Degreasing Units (Previously SE 107)

Any degreasing unit that satisfies the following conditions of this section is exempt.

(1) The following general requirements are applicable to all degreasers unless specifically exempted by the conditions of this section.

(A) Units subject to paragraphs (3) - (5) of this section shall meet the following:

(i) register with the commission's Office of Air Quality in Austin using Form PI-7 and a Degreasing Unit Checklist;

(ii) on a monthly basis, records shall be kept of total solvent makeup (gross usage minus waste disposal).

(B) Waste solvent from all degreasing operations shall be stored in covered containers, and be removed by a licensed disposal service or until emptying into an authorized on-site waste management facility.

(C) Porous or absorbent materials, such as cloth, leather, wood, or rope shall not be degreased.

(D) Leaks shall be repaired immediately, or the degreaser shall be shut down until repairs are completed.

(E) A permanent and conspicuous label summarizing proper operating procedures to minimize emissions shall be posted on or near the degreaser.

(F) Each unit, regardless of the county in which it is located, shall meet the requirements of 115.412 and 115.415 of this title (relating to Control Requirements and Alternate Control Requirements).

(2) The following conditions apply only to remote reservoir cleaners.

(A) The cleaner shall be designed to prevent exposure of the solvent reservoir to the atmosphere except for the drain openings. The drain openings shall not exceed 3.0% of the total cleaner open area and shall under no conditions exceed 16 square inches.

(B) All solvent sprays shall be a solid fluid stream (not a fine, atomized, or shower type spray) and at a minimal operating pressure that is necessary to prevent excessive splashing, but not to exceed ten pounds per square inch, gauge (psig).

(C) The true vapor pressure of the solvent shall not exceed 0.6 pounds per square inch, absolute (psia) as measured or calculated at an operating temperature of 100 degrees Fahrenheit.

(D) The solvent shall not be heated.

(3) The following conditions apply only to cold solvent cleaners.

(A) The cleaner shall have a freeboard that has a minimum four-inch water cover or provides a freeboard ratio (the distance from top of the solvent level to the top edge of the degreasing tank divided by the degreaser width) equal to or greater than 0.7. For water covers, the solvent must be insoluble in and heavier than water.

(B) The unit shall be equipped with a cover which is closed whenever parts are not being handled in the cleaner. Also, the cover must be designed for easy one-handed operation if any of the following conditions are present:

(i) the true vapor pressure of the solvent is greater than 0.3 psia as measured or calculated at 100 degrees Fahrenheit;

(ii) the solvent is agitated;

(iii) the solvent is heated.

(C) If a solvent spray is used, it shall be a solid fluid stream (not a fine, atomized, or shower-type spray) with a minimal operating pressure that is necessary to prevent splashing above the acceptable freeboard. The operating pressure shall not exceed ten psig.

(D) An internal-cleaned parts drainage rack or facility, for enclosed draining under a cover, shall be provided. An external-cleaned parts drainage rack or facility, for enclosed draining under a cover, may be used if the vapor pressure of the solvent is less than 0.6 psia at 100øF. In all cases, parts shall be drained for at least 15 seconds or until dripping ceases.

(E) The Form PI-7 registration is not required if total solvent makeup (gross usage minus waste disposal) is 110 gallons per year (gallon/yr) or less.

(F) Total solvent makeup shall not exceed the following:

(i) chlorinated solvents - 660 gallons/yr;

(ii) all other solvents - 1,500 gallons/yr.

(4) The following conditions apply only to open top solvent vapor degreasers.

(A) The surface area of the solvent shall not exceed 15 square feet.

(B) The unit shall be equipped with a cover that can be opened and closed easily without disturbing the vapor zone. If the degreaser opening exceeds ten square feet, a powered cover shall be required.

(C) The cover shall be closed at all times except when parts are moved into and out of the degreaser.

(D) The unit shall be equipped with a properly sized refrigerated chiller, or the unit shall have a freeboard ratio (the distance from top of the vapor level to the top edge of the degreasing tank divided by the degreaser width) equal to or greater than 0.75.

(E) Exhaust ventilation for the unit shall operate between 50 and 65 cubic feet per minute (cfm) per square foot of degreaser open area unless this conflicts with Occupational Safety and Health Administration (OSHA) requirements. Ventilation fans or other sources of air agitation shall not be operated near the degreaser opening.

(F) The exhaust stacks shall discharge vertically with no restrictions or obstructions to flow. The stack height shall extend at least 1.3 times the building height as measured from ground level.

(G) Total solvent makeup (gross usage minus waste disposal) shall not exceed the following:

(i) chlorinated solvents - 660 gallons/yr;

(ii) all other solvents - 1500 gallons/yr.

(5) The following conditions apply only to conveyorized degreasers.

(A) The inlet and outlet openings shall be closed at all times except when processing work through the degreaser.

(B) The unit shall be equipped with a properly sized refrigerated chiller which has a volatile organic compound removal efficiency of at least 85%, or the unit shall have a freeboard ratio (the distance from top of the vapor level to the top edge of the degreasing tank divided by the degreaser width) equal to or greater than 0.75.

(C) A drying tunnel or other means of control shall be used to limit liquid or vapor carry-out.

(D) Entrances and exits to the degreaser shall be designed to silhouette work loads.

(E) Exhaust ventilation for the unit shall operate between 50 and 65 cfm per square foot of degreaser opening unless this conflicts with OSHA requirements. Ventilation fans or other sources of air agitation shall not be operated near the degreaser openings.

(F) The exhaust stacks shall discharge vertically with no restrictions or obstructions to flow. The stack height shall extend at least 1.5 times the building height as measured from ground level.

(G) Total solvent makeup (gross usage minus waste disposal) shall not exceed the following:

(i) chlorinated solvents - 660 gallons/yr;

(ii) all other solvents - 1,500 gallons/yr.

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