4. For paragraph 8 there shall be substituted the following paragraph—
“8. Where in the course of, or as a process ancillary to, any prescribed process the person carrying on that process uses, treats or disposes of waste at the same location (whether as fuel or otherwise), the use, treatment or disposal of that waste shall, notwithstanding the rule set out in paragraph 2, be regarded as falling within the description of that process, whether the waste was produced by the person carrying on the process or acquired by him for such use, treatment or disposal.”.