A. Any taxpayer may elect to amortize the adjusted basis of any device, machinery or equipment for the collection and control at the source of atmospheric and water pollutants and contaminants based upon a period of sixty months. In computing Arizona taxable income, such amortization shall be allowed as a subtraction ratably over the period allowed under this subsection beginning with the month in which such device, machinery or equipment is completed or acquired and is placed in service by the taxpayer. This election shall be indicated by the taxpayer in an appropriate statement in the taxpayer’s income tax return for the taxable year of the acquisition or completion and placement in service of such devices, machinery or equipment. An election to discontinue amortization with respect to the remainder of the amortization period is permitted and shall be indicated by an appropriate statement in the taxpayer’s income tax return for the taxable year of discontinuance.

B. If the taxpayer does not elect to amortize pursuant to subsection A, there shall be allowed a deduction for normal exhaustion, wear and tear of property. The amount of such deduction shall be computed pursuant to the provisions of section 167 of the internal revenue code.

C. In determining the adjusted basis for the purposes of subsection A, such device, machinery or equipment upon certification by the department of environmental quality as a device, machinery or equipment for the collection and control at the source of atmospheric and water pollutants and contaminants shall include only an amount that is properly attributable to the construction, reconstruction, remodeling, installation or acquisition of such device, machinery or equipment as certified by the department of environmental quality.