### Question
Can you define what underground storage tank means?


### Answer
**Underground storage tank** is defined as the following in *42 U.S.C. § 6991*:

> any one or combination of tanks (including underground pipes connected thereto) which is used to contain an accumulation of regulated substances, and the volume of which (including the volume of the underground pipes connected thereto) is 10 per centum or more beneath the surface of the ground

#### Citation:
  - *42 U.S.C. § 6991*
  - Heading: **CHAPTER 82-SOLID WASTE DISPOSAL > SUBCHAPTER IX-REGULATION OF UNDERGROUND STORAGE TANKS**

