### Question
How is the "sludge" defined?


### Answer
The term **sludge** is defined in *42 U.S.C. § 6903* as follows -

> any solid, semisolid or liquid waste generated from a municipal, commercial, or industrial wastewater treatment plant, water supply treatment plant, or air pollution control facility or any other such waste having similar characteristics and effects

#### Citation:
  - *42 U.S.C. § 6903*
  - Heading: **CHAPTER 82-SOLID WASTE DISPOSAL > SUBCHAPTER I-GENERAL PROVISIONS**

