(a) For purposes of this section, “residuals repository” means a hazardous waste facility, or an operational unit at a hazardous waste facility, which meets all of the following requirements:

1. (1) It is sited, designed and constructed, operated, and maintained, in accordance with all applicable federal and state regulations, including, but not limited to, the regulations adopted pursuant to subdivision (b).
2. (2) The operator holds a hazardous waste facilities permit issued by the department under this chapter.
3. (3) A condition imposed in the hazardous waste facilities permit authorizes the residuals repository to accept for disposal in or on the land only treated hazardous waste, as defined in subdivision ( l) of Section 25179.3, that has been specified as suitable for disposal in a residuals repository pursuant to paragraph (1) of subdivision (b).

(b) On or before May 1, 1990, the department shall adopt, by regulation, standards for residuals repositories. In developing these standards, the department shall consult with the State Water Resources Control Board, conduct public workshops, and request comments and recommendations from appropriate state and federal agencies and the interested public. The standards shall, at a minimum, be at least as stringent, effective, and comprehensive as the standards applicable to hazardous waste land disposal facilities adopted under the federal act, including the regulations, guidelines, and policies adopted pursuant to the federal act, and shall include, but not be limited to, all of the following:

1. (1) A specification of which treated hazardous wastes the department determines are suitable for disposal in a residuals repository. The department may specify these treated hazardous wastes by listing types or categories of treated hazardous wastes or by establishing physical or chemical properties that treated hazardous wastes are required to meet.
2. (2) Design and construction standards for a residuals repository.
3. (3) Standards governing the operation, monitoring, maintenance, closure, and postclosure maintenance of a residuals repository.
4. (4) Minimum standards governing the location of a residuals repository and the subsurface geology underlying the site. In establishing these standards, the department shall also specify the specific criteria, if any, under which the department justifies a finding that engineering measures or design factors may be substituted for geological requirements.
5. (5) Requirements for hazardous waste segregation and recordkeeping.