Provides that, in aquatic rehabilitation zone one established in RCW 90.88.010, the development of one or more systems of sewerage as defined in RCW 35.67.010 and 36.94.010 or the extension of an existing system of sewerage to serve areas outside a designated urban growth area is permitted when such a development or extension serves: (1) A marine recovery area created in accordance with chapter 70.118A RCW;

(2) A shellfish protection district created in accordance with chapter 90.72 RCW; or

(3) A defined geographic area determined by the secretary of health under RCW 43.70.170 to be a threat to the public health.