25 Pa. Code § 288.1 – Scope.

(a) This chapter sets forth application and operating requirements for residual waste landfills. 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 three kinds of residual waste landfills.
1. (1) Class I residual waste landfills 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 landfills involve the disposal of residual waste 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.
3. (3) Class III residual waste landfills involve the disposal of residual wastes with the least degree of potential for adverse effects on groundwater and the least potential impact on public health, safety and the environment.