OAR 340-071-0340: Holding Tanks

(1) Criteria for approval. Except as section (5) of this rule provides, installing a holding tank system requires a construction-installation or WPCF permit. A construction-installation permit may be issued for sites that meet all the following conditions. (a) Permanent use. (A) The site cannot be approved for installation of a standard subsurface system. (B) No community or area-wide sewerage system is available or expected to be available within five years. (C) The tank is intended to serve a small industrial or commercial building or an occasional use facility such as a county fair or a rodeo. (D) Unless DEQ allows otherwise, the projected daily sewage flow is not more than 200 gallons. (E) Setbacks required for septic tanks can be met. (b) Temporary use: A holding tank may be installed in an area under the control of a city or other legal entity authorized to construct, operate, and maintain a community or area- wide sewerage system if: (A) The application for permit includes a copy of a legal commitment from the legal entity to extend a community or area-wide sewerage system meeting the requirements of this division to the property covered by the application within five years from the date of the application; and (B) The proposed holding tank complies with other applicable requirements in OAR chapter 340, divisions 071 and 073. (2) Operation and maintenance. The operation and maintenance of a holding tank must meet the requirements under OAR 340-071-0132 and this rule. (3) Design and construction requirements. Except as provided in section (5) of this rule, holding tanks must comply with the following requirements: (a) Plans and specifications for each holding tank proposed to be installed must be submitted to the agent for review and approval. (b) Each tank must: (A) Have a minimum liquid capacity of 1,500 gallons; (B) Comply with tank standards in OAR 340-073- 0025; (C) Be located and designed to facilitate removal of contents by pumping (D) Be equipped with both an audible and a visual alarm placed in locations acceptable to the agent to indicate when the tank is 75 percent full. Only the audible alarm may be user cancelable; (E) Have no overflow vent at an elevation lower than the overflow level of the lowest fixture served; and (F) Be designed for antibuoyancy if test hole examination or other observations indicate seasonally high groundwater may float the tank when empty. (4) Special requirements. The application for a holding tank permit must include: (a) A copy of a contract with a licensed sewage disposal service that requires the tank to be pumped periodically at regular intervals or as needed and the contents treated in a manner and at a facility the agent approves; and (b) Evidence that the owner or operator of the proposed treatment facility will accept the pumpings for treatment. (5) Portable holding tanks may be temporarily placed at sites having limited duration events such as county fairs or construction projects or at temporary restaurants if the following requirements are met: (a) The tanks must be owned and serviced by a licensed sewage disposal service with sewage pumping equipment having a 550-gallon or larger tank and meeting all other requirements in OAR 340-071-0600(11). (b) Tank placement and use must comply with all local planning, building, and health requirements. (c) Only domestic sewage may be discharged into the tank. (d) The tank must be maintained in a sanitary manner to prevent a health hazard or nuisance. (e) The tank must not be buried. (f) A person may not use the tank to serve a dwelling, recreation vehicle, or any other structure having sleeping accommodations, except that a portable holding tank may be used temporarily to serve a contractor's job shack or night watchman's trailer. (g) The tank must meet the following standards: (A) The tank must be watertight with no overflow vent lower than the overflow level of the lowest fixture served. (B) Tank capacity may not exceed 1,000 gallons unless otherwise authorized by the agent. (C) The tank must be structurally sound and made of durable, noncorrosive materials. (D) The tank must be designed and constructed to provide a secure, watertight connection of the building sewer pipe. (E) The tank must be marked with the name and phone number of the licensed sewage disposal service responsible for maintaining the tank.