### Question
What does aggressive biological treatment facility mean?


### Answer
**Aggressive biological treatment facility** has the following meaning in *42 U.S.C. § 6925*:

> a system of surface impoundments in which the initial impoundment of the secondary treatment segment of the facility utilizes intense mechanical aeration to enhance biological activity to degrade waste water pollutants and


(i) the hydraulic retention time in such initial impoundment is no longer than 5 days under normal operating conditions, on an annual average basis

#### Citation:
  - *42 U.S.C. § 6925*
  - Heading: **CHAPTER 82-SOLID WASTE DISPOSAL > SUBCHAPTER III-HAZARDOUS WASTE MANAGEMENT**

