§ 257.21 Applicability.
(a) The requirements in this section apply to units identified in § 257.5(a), except as provided in paragraph (b) of this section.
(b) Ground-water monitoring requirements under §§ 257.22 through 257.25 may be suspended by the Director of an approved State for a unit identified in § 257.5(a) if the owner or operator can demonstrate that there is no potential for migration of hazardous constituents from that unit to the uppermost aquifer during the active life of the unit plus 30 years. This demonstration must be certified by a qualified ground-water scientist and approved by the Director of an approved State, and must be based upon:
(1) Site-specific field collected measurements, sampling, and analysis of physical, chemical, and biological processes affecting contaminant fate and transport; and
(2) Contaminant fate and transport predictions that maximize contaminant migration and consider impacts on human health and environment.
(c) Owners and operators of facilities identified in § 257.5(a) must comply with the ground-water monitoring requirements of this section according to the following schedule unless an alternative schedule is specified under paragraph (d) of this section:
(1) Existing units and lateral expansions must be in compliance with the ground-water monitoring requirements specified in §§ 257.22 through 257.25 by July 1, 1998.
(2) New units identified in § 257.5(a) must be in compliance with the ground-water monitoring requirements specified in §§ 257.22 through 257.25 before waste can be placed in the unit.
(d) The Director of an approved State may specify an alternative schedule for the owners or operators of existing units and lateral expansions to comply with the ground-water monitoring requirements specified in §§ 257.22 through 257.25. This schedule must ensure that 50 percent of all existing units are in compliance by July 1, 1998, and all existing units are in compliance by July 1, 1999. In setting the compliance schedule, the Director of an approved State must consider potential risks posed by the unit to human health and the environment. The following factors should be considered in determining potential risk: