(1) WAC 197-11-253 through 197-11-268 integrate the procedural requirements and documents of this chapter with those required under the Model Toxics Control Act (MTCA), chapter 70.105D RCW, and chapter 173-340 WAC.

(2) Both MTCA and SEPA provide opportunities for early public review of a proposal. The following sections contain procedures to combine the MTCA and SEPA processes to reduce duplication and improve public participation. These sections supplement the other requirements of this chapter. To the extent there is a conflict, these sections supersede any conflicting provisions of this chapter.

(3) WAC 197-11-253 through 197-11-268 apply to remedial actions as defined in RCW 70.105D.020(12) and conducted by ecology or by a potentially liable person (PLP) under an order, agreed order, or consent decree under MTCA. These sections do not apply to independent remedial actions; rather, the remainder of this chapter applies to independent remedial actions that are subject to SEPA.

(4) When the remedial action is part of a development proposal, the procedures in WAC 197-11-256 through 197-11-268 shall be used to combine the procedural requirements of SEPA and MTCA, to the extent practicable.

(5) To effectively integrate the procedural requirements of SEPA and MTCA, the SEPA elements of the environment that could be impacted need to be identified as early in the MTCA process as possible. Early consideration of SEPA facilitates identification of study areas prior to conducting the remedial investigation/feasibility study (RI/FS) and effective, timely integration of SEPA and MTCA documents. The threshold determination may be delayed until later in the MTCA process.

(6) WAC 197-11-256 through 197-11-268 do not change the categorical exemption for information collection in WAC 197-11-800(17) or the emergency exemption in WAC 197-11-880.

(7) Interim actions (WAC 173-340-430) conducted as part of a remedial action conducted by ecology, or by a potentially liable person under an order, agreed order, or consent decree under MTCA are governed by WAC 197-11-268.