Section 90.48.580 - Water quality data-Credible data, information, literature(1) The department shall use credible information and literature for developing and reviewing a surface water quality standard or technical model used to establish a total maximum daily load for any surface water of the state.(2) The department shall use credible data for the following actions after June 10, 2004:(a) Determining whether any water of the state is to be placed on or removed from any section 303(d) list;(b) Establishing a total maximum daily load for any surface water of the state; or(c) Determining whether any surface water of the state is supporting its designated use or other classification.(3) The department shall respond to questions regarding the data, literature, and other information it uses under this section. The department shall reply to requests within five business days acknowledging that the department has received the request and provide a reasonable estimate of the time the department will require to respond to the request.(4) The department, the United States environmental protection agency, and the Indian tribes in Washington state have developed a voluntary agreement relating to the cooperative management of the clean water act section 303(d) program. The department shall consider water quality data that has been collected by Indian tribes under a quality assurance project plan that has been approved by the United States environmental protection agency if that data meets the objectives of the plan.