The department shall:

(1) Upon receipt of an application for review and approval of an on-site sewage disposal system additive:

(a) Determine if the application is complete. The department may return incomplete applications, suspending further review until a completed application is submitted. Processing time period begins anew with resubmittal.

(b) Notify the applicant, in writing, that the completed application has been received, and inform the applicant of the anticipated time period for review. A decision of either approval or denial shall be made within forty-five calendar days of receiving a complete application.

(2) Upon review of a complete application, grant or deny approval of the on-site sewage disposal system additive for use, sale, or distribution in Washington state, informing the applicant, in writing, of either approval or denial of the application. Notice of denial shall include explanation of the reason(s) for denial.

(3) Evaluate the request for approval of an on-site sewage disposal system additive according to the following criteria:

(a) Does the additive contain any ingredients deemed unsafe by the department? If yes, the application for approval shall be denied.

(b) Does the additive contain acids or bases that raise or lower the pH of the contents of a septic tank, or wastewater in any other portion of an on-site sewage disposal system, outside of a pH range between 6.0 - 8.0? If yes, the application for approval shall be denied.

(c) Would use of the additive (when applied according to the manufacturer's product-use instructions) adversely affect public health or water quality (surface water or groundwater) by either the nature of the ingredients or the effect of the additive on the function of the on-site sewage system? If yes, the application for approval shall be denied.

(d) If the review according to the criteria listed above determines that none of these questions are answered "yes," the on-site sewage disposal system additive shall be approved.