Companies that build or have built buildings intended for the purification of industrial water, in accordance with the provisions of the loi n° 64-1245 du 16 décembre 1964 as amended, may, upon completion of these buildings, take exceptional depreciation equal to 50% of their cost price.
The residual value of the buildings may be depreciated over their normal useful life.
The provisions of this article apply to buildings completed before 31 December 1990 provided that they are incorporated into production facilities existing on 31 December 1980.
Structures meeting the criteria defined in the first paragraph and completed before 1 January 2011 may be subject to exceptional depreciation over twelve months provided that they are incorporated into production facilities.