Wastewater and sewage treatment facilities. Upon compliance with ORS 307.162, the wastewater treatment facilities, sewage treatment facilities and all other property used for the purpose of wastewater treatment or sewage treatment, including the land underneath the facilities, shall be exempt from taxation if

(1) Owned by a nonprofit corporation that was in existence as of January 1, 1997; and

(2) The nonprofit corporation’s only activities consist of operating wastewater treatment and sewage treatment facilities that were constructed and in operation as of January 1, 1997. [1997 c.485 §2]