(a) Aluminum forming includes commonly recognized forming operations such as rolling, drawing, extruding, and forging and related operations such as heat treatment, casting, and surface treatments. Surface treatment of aluminum is any chemical or electrochemical treatment applied to the surface of aluminum. Such surface treatment is considered to be a part of aluminum forming whenever it is performed as an integral part of aluminum forming. For the purposes of this regulation, surface treatment of aluminum is considered to be an integral part of aluminum forming whenever it is performed at the same plant site at which aluminum is formed and such operations are not considered for regulation under the Electroplating and Metal Finishing provisions of 40 CFR parts 413 and 433. Casting aluminum when performed as an integral part of aluminum forming and located on-site at an aluminum forming plant is considered an aluminum forming operation and is covered under these guidelines. When aluminum forming is performed on the same site as primary aluminum reduction the casting shall be regulated by the nonferrous metals guidelines if there is no cooling of the aluminum prior to casting. If the aluminum is cooled prior to casting then the casting shall be regulated by the aluminum forming guidelines.

(b) This part applies to any aluminum forming facility, except for plants identified under paragraph (c) of this section, which discharges or may discharge pollutants to waters of the United States or which introduces or may introduce pollutants into a publicly owned treatment works.

(c) This part is applicable to indirect discharging aluminum forming plants that extrude less than 3 million pounds of product per year and draw, with emulsions or soaps, less than 1 million pounds per year.

Note:

This paragraph is promulgated as an Interim Final Rule.

[48 FR 49149, Oct. 24, 1983; 49 FR 11631, Mar. 27, 1984]

In addition to the definitions set forth in 40 CFR part 401, the following definitions apply to this part:

(a) Aluminum forming is a set of manufacturing operations in which aluminum and aluminum alloys are made into semifinished products by hot or cold working.

(b) Ancillary operation is a manufacturing operation that has a large flow, discharges significant amounts of pollutants, and may not be present at every plant in a subcategory, but when present is an integral part of the aluminum forming process.

(c) Contact cooling water is any wastewater which contacts the aluminum workpiece or the raw materials used in forming aluminum.

(d) Continuous casting is the production of sheet, rod, or other long shapes by solidifying the metal while it is being poured through an open-ended mold using little or no contact cooling water. Continuous casting of rod and sheet generates spent lubricants and rod casting also generates contact cooling water.

(e) Degassing is the removal of dissolved hydrogen from the molten aluminum prior to casting. Chemicals are added and gases are bubbled through the molten aluminum. Sometimes a wet scrubber is used to remove excess chlorine gas.

(f) Direct chill casting is the pouring of molten aluminum into a water-cooled mold. Contact cooling water is sprayed onto the aluminum as it is dropped into the mold, and the aluminum ingot falls into a water bath at the end of the casting process.

(g) Drawing is the process of pulling metal through a die or succession of dies to reduce the metal's diameter or alter its shape. There are two aluminum forming subcategories based on the drawing process. In the drawing with neat oils subcategory, the drawing process uses a pure or neat oil as a lubricant. In the drawing with emulsions or soaps subcategory, the drawing process uses an emulsion or soap solution as a lubricant.

(h) Emulsions are stable dispersions of two immiscible liquids. In the aluminum forming category this is usually an oil and water mixture.

(i) Cleaning or etching is a chemical solution bath and a rinse or series of rinses designed to produce a desired surface finish on the workpiece. This term includes air pollution control scrubbers which are sometimes used to control fumes from chemical solution baths. Conversion coating and anodizing when performed as an integral part of the aluminum forming operations are considered cleaning or etching operations. When conversion coating or anodizing are covered here they are not subject to regulation under the provisions of 40 CFR part 433, Metal Finishing.

(j) Extrusion is the application of pressure to a billet of aluminum, forcing the aluminum to flow through a die orifice. The extrusion subcategory is based on the extrusion process.

(k) Forging is the exertion of pressure on dies or rolls surrounding heated aluminum stock, forcing the stock to change shape and in the case where dies are used to take the shape of the die. The forging subcategory is based on the forging process.

(l) Heat treatment is the application of heat of specified temperature and duration to change the physical properties of the metal.

(m) Hot water seal is a heated water bath (heated to approximately 180 °F) used to seal the surface coating on formed aluminum which has been anodized and coated. In establishing an effluent allowance for this operation, the hot water seal shall be classified as a cleaning or etching rinse.

(n) In-process control technology is the conservation of chemicals and water throughout the production operations to reduce the amount of wastewater to be discharged.

(o) Neat oil is a pure oil with no or few impurities added. In aluminum forming its use is mostly as a lubricant.

(p) Rolling is the reduction in thickness or diameter of a workpiece by passing it between lubricated steel rollers. There are two subcategories based on the rolling process. In the rolling with neat oils subcategory, pure or neat oils are used as lubricants for the rolling process. In the rolling with emulsions subcategory, emulsions are used as lubricants for the rolling process.

(q) The term Total Toxic Organics (TTO) shall mean the sum of the masses or concentrations of each of the following toxic organic compounds which is found in the discharge at a concentration greater than 0.010 mg/1:

p-chloro-m-cresol 2-chlorophenol 2,4-dinitrotoluene 1,2-diphenylhydrazine ethyblenzene fluoranthene isophorone napthalene N-nitro sodi phenyl amine phenol benzo(a) pyrene benzo(ghi)perylene fluorene phenanthrene dibenzo(a,h) anthracene indeno(1,2,3-c,d)pyrene pyrene tetrachloroethylene toluene trichloroethylene endosulfan sulfate bis(2-ethyl hexyl)phthalate diethylphthalate 3,4-benzofluoranthene benzo(k)fluoranthene chrysene acenaphthylene anthracene di-n-butyl phthalate endrin endrin aldehyde PCB-1242, 1254, 1221 PCB-1232, 1248, 1260, 1016 acenaphthene

(r) Stationary casting is the pouring of molten aluminum into molds and allowing the metal to air cool.

(s) Wet scrubbers are air pollution control devices used to remove particulates and fumes from air by entraining the pollutants in a water spray.

(t) BPT means the best practicable control technology currently available under section 304(b)(1) of the Act.

(u) BAT means the best available technology economically achievable under section 304(b)(2)(B) of the Act.

(v) BCT means the best conventional pollutant control technology, under section 304(b)(4) of the Act.

(w) NSPS means new source performance standards under section 306 of the Act.

(x) PSES means pretreatment standards for existing sources, under section 307(b) of the Act.

(y) PSNS means pretreatment standards for new sources, under section 307(c) of the Act.

(z) The production normalizing mass (/kkg) for each core or ancillary operation is the mass (off-kkg or off-lb) processed through that operation.

(aa) The term off-kilogram (off-pound) shall mean the mass of aluminum or aluminum alloy removed from a forming or ancillary operation at the end of a process cycle for transfer to a different machine or process.

[48 FR 49149, Oct. 24, 1983; 49 FR 11631, Mar. 27, 1984, as amended at 53 FR 52369, Dec. 27, 1988]

The following special monitoring and reporting requirements apply to all facilities controlled by this regulation.

(a) Periodic analyses for cyanide as may be required under part 122 or 403 of this chapter are not required when both of the following conditions are met:

(1) The first wastewater sample of each calendar year has been analyzed and found to contain less than 0.07 mg/l cyanide.

(2) The owner or operator of the aluminum forming plant certifies in writing to the POTW authority or permit issuing authority that cyanide is not and will not be used in the aluminum forming process.

(b) As an alternative monitoring procedure for pretreatment, the POTW user may measure and limit oil and grease to the levels shown in pretreatment standards in lieu of measuring and regulating total toxic organics (TTO).

(c) The “monthly average” regulatory values shall be the basis for the monthly average discharge limits in direct discharge permits and for pretreatment standards. Compliance with the monthly discharge limit is required regardless of the number of samples analyzed and averaged.

(Information collection requirements in paragraph (a) were approved by the Office of Management and Budget under control number 2040-0033) [48 FR 49149, Oct. 24, 1983; 49 FR 11631, Mar. 27, 1984, as amended at 50 FR 4515, Jan. 31, 1985]

The compliance date for Pretreatment Standards for Existing Sources (PSES) is October 24, 1986.

[48 FR 49149, Oct. 24, 1983; 49 FR 11631, Mar. 27, 1984]

Removal allowances pursuant to 40 CFR 403.7(a) may be granted for the toxic metals limited in 40 CFR part 467 when used as indicator pollutants.

[49 FR 11631, Mar. 27, 1984]