When either health or ecology is the lead agency under this section, the other agency will be the nonlead agency. On a case-by-case basis, ecology and health may agree to change the lead agency designation. If the lead agency changes, the new lead agency must notify the generator within ten calendar days of the change.

(1) Ecology as lead agency. Ecology is the lead agency and will issue permits when:

(a) The reclaimed water facility source water is wastewater effluent from a water pollution control facility permitted by, or requiring a permit from, ecology.

(b) Reclaimed water or inadequately treated water, is released to:

(i) Water bodies regulated under chapter 90.48 RCW and, if applicable, the Federal Water Pollution Control Act.

(ii) A water pollution control facility permitted by ecology.

(2) Health as lead agency. Health is the lead agency and will issue permits when:

(a) The reclaimed water facility source water is wastewater effluent from an on-site sewage system with a design flow less than or equal to one hundred thousand gallons per day, regulated under chapter 246-272A or 246-272B WAC and there is no direct release of reclaimed water to the waters of the state.

(b) The reclaimed water permit is dependent on or supplemental to an on-site sewage treatment system operating permit issued for required treatment and reliability.

(c) The only release of inadequately treated water, surplus source water, or surplus reclaimed water is to an on-site sewage system.