(a) A manufacturing or processing establishment, commonly known as a rendering plant, that processes waste materials originating from animals and from materials of vegetable origin, including animal parts and scraps, offal, paunch manure, and waste cooking grease of animal and vegetable origin, is subject to regulation under the industrial solid waste provisions of this chapter and may be regulated under Chapter 26, Water Code.
(b) If a rendering plant is owned by a person who operates the plant as an integral part of an establishment that manufactures or processes for animal or human consumption food derived wholly or partly from dead, slaughtered, or processed animals, the combined business may operate under a single permit issued under Chapter 26, Water Code.

(c) This section does not apply to a rendering plant in operation and production on or before August 27, 1973.
(d) In this section, “animals” includes only animals, poultry, and fish.