25 Pa. Code § 289.1 – Scope.

(a) This chapter sets forth application and operating requirements for residual waste disposal impoundments. The requirements in this chapter are in addition to the applicable requirements in Chapter 287 (relating to residual waste management—general provisions).
(b) This chapter applies to two kinds of residual waste disposal impoundments.
1. (1) Class I residual waste disposal impoundments involve the disposal of residual wastes with the greatest degree of potential for adverse effects on groundwater and the greatest potential impact on public health, safety and the environment.
2. (2) Class II residual waste disposal impoundments involve the disposal of residual wastes with an intermediate degree of potential for adverse effects on groundwater and an intermediate degree of potential impact on public health, safety and the environment.
(c) This chapter includes residual waste disposal at impoundments that are permitted for industrial waste water treatment and discharge under The Clean Streams Law.