(1) The applicant for each project for which the department is the lead agency shall submit a complete environmental checklist along with a complete application for the required approval.

(2) After review of the environmental checklist, the department may require the applicant to submit additional information necessary to properly evaluate the potential environmental impacts of the project. Field investigation or research may be required of the applicant or conducted by the department at the applicant's cost.

(3) A draft and final EIS is required for each project for which a determination is made that the proposal will have a probable significant adverse impact on the environment. Preparation of the EIS is the responsibility of the department, by or under the direction of its responsible official, as specified by department procedures. No matter who participates in the preparation of the EIS, it is the EIS of the department. The responsible official, prior to distributing an EIS, shall be satisfied that it complies with this chapter and chapter 197-11 WAC.

(4) The department may have an EIS prepared by department staff, an applicant or its agent, or by an outside consultant retained by either an applicant or the department. The department shall assure that the EIS is prepared in a professional manner and with appropriate interdisciplinary methodology. The responsible official shall direct the areas of research and examination to be undertaken as a result of the scoping process, as well as the organization of the resulting document.

(5) If a person other than the department is preparing the EIS, the department shall:

(a) Coordinate any scoping procedures so that the individual preparing the EIS receives all substantive information submitted by any agency and the public;

(b) Assist in obtaining any information on file with other agencies that is needed by the person preparing the EIS;

(c) Allow any party preparing an EIS access to all public records of the department that relate to the subject of the EIS, under RCW 42.17.250 through 42.17.340.

(6) Normally, the department will prepare an EIS for its own proposals.

(7) For applicant proposals, the department normally will require the applicant to prepare or help prepare the EIS at the applicant's expense, under provisions of this chapter and chapter 197-11 WAC. Expenses shall include fees of any consultants, if required, the department's consultation time and cost of any required materials. A performance bond in an amount specified by the department may be required of the applicant to ensure payment of the department's expenses.

(8) The department may require an applicant to provide information that the department does not possess, including specific investigations.

(9) A supplemental EIS shall be prepared as an addition to either the draft or final EIS if the department determines that:

(a) There are substantial changes to a proposal which will have a probable significant adverse environmental impact; or

(b) There is significant new information relative to the probable significant environmental impact of a proposal; or

(c) Written comments on the DEIS warrant additional environmental review.

The provisions of subsections (3), (4), (5), (6), (7), and (8) of this section except for the first sentence of subsection (3) of this section, also pertain to a supplemental EIS or addendum.

(10) Upon the written request of an applicant for a project for which the department is the lead agency, the department will consider initiating environmental review and preparation of an EIS at the conceptual stage as opposed to the final detailed design state.