632-015-0040 Plugging Requirements (1) Proper completion and decommission require adequate protection of the environment and of aesthetic qualities of the surface in the area of operation. (2) An information hole or seismic shot hole is properly completed for the purposes of this chapter when the permittee demonstrates to the satisfaction of the department that the information hole or shot hole has been constructed to the standard and requirement of the permit. (3) An information hole or seismic shot hole is considered properly plugged and abandoned, for the purposes of this chapter, when the conditions of ORS 520.005 to 520.991 and these rules are fulfilled and the permittee has shown to the satisfaction of the department that all proper steps have been taken to protect groundwater and surface water from contamination resulting from the drilling or drilling related activities and to prevent the commingling of fluids between zones or the conveyance of fluids to the surface. (4) All holes must be plugged and all related disturbance must be reclaimed in accordance with these rules as soon as practical. A hole may not be left unplugged for longer than 30 days from the completion of operations without prior written approval from the department. (5) An Information hole must be cemented from the bottom up to a depth 4 feet from the ground surface through tubing to prevent cross-flow, erosion, waste, or contamination of groundwater. (a) The hole must be filled and pressure grouted from bottom to top with cement, consisting of a neat cement weighing in excess of 15.0 pounds per gallon with not less than a viscosity of 36 (API Full Funnel Method); (b) In no case may sand or aggregate be added to cement grout seal mixtures; (c) Other fluids may be used upon approval of the department; (d) Cement grout used as a sealing material must be placed or forced upward from the bottom of the hole in one continuous operation without significant interruption. If temporary outer surface casing is used in the construction of the hole, it must be withdrawn as the grout is placed; (e) The top of all casing strings must be cut off at least 4 feet below ground surface and buried to a depth of at least four feet in such a manner as not to interfere with soil cultivation. (6) All seismic shot holes must be plugged and reclaimed in a manner that prevents vertical movement of water in the hole. (a) Seismic shot holes encountering groundwater must be cased and sealed with unhydrated bentonite at least 3/8 inch in diameter to 10 feet above the groundwater before explosives are used. Unhydrated bentonite materials used in plugging of a hole must be specifically designed for sealing wells and be within industry tolerances for dry western sodium bentonite. The bentonite must be placed in the hole in a manner that prevents cross-flow, waste or contamination of groundwater. (b) The following requirements apply to seismic shot holes not encountering groundwater: (A) Such shot hole must be sealed with unhydrated bentonite at least 3/8 inch in diameter below the elevation that the explosives are used; (B) Above the elevation that the explosives are used unhydrated bentonite at least 3/8 inch in diameter must be added from the top of the bentonite to the surface; (C) A nonmetallic plug must be set at a depth of 3 feet below ground surface; cuttings added above the nonmetallic plug must be tamped; (D) The operator must place a bentonite plug no less than 10 feet in length. If the shot hole is less than 10 feet in length, the entire hole must be plugged with unhydrated bentonite at least 3/8 inch in diameter. (E) A small mound of cuttings must be left over the hole to allow for settling; and (F) Any cuttings deposited on the surface around the seismic hole or information hole must be raked or otherwise spread so that the cuttings do not exceed 2 inches of the pre-existing land surface, except for a small mound left for settling. (c) A seismic shot hole that encounters groundwater and caves in after detonation of an explosive charge must provide for the protection of groundwater by reopening the hole and plugging with cement and by placing a mound over the hole for settling as provided in subsections (3)(C) and (3)(D) of this rule. (d) Alternative plugging procedures and materials may be utilized with the department’s written approval when the operator has demonstrated to the department's satisfaction that the alternatives will protect water quality. (7) All ground disturbance related to well site operation must be reclaimed to a secondary beneficial use that is compatible with the applicable local land comprehensive plan and land use regulations. (8) Affidavit on completion: Within 60 days after an information hole or seismic shot hole is plugged, the operator must file a written statement with the department certifying that the well was properly plugged and affected areas reclaimed. Statutory/Other Authority: ORS 516.090 & 520.095 Statutes/Other Implemented: ORS 520.027 & 520.095 History: DGMI 2-2013, f. & cert. ef 3-21-13 GMI 2-1995, f. & cert. ef. 3-10-95 GMI 2-1990, f. 8-9-90, cert. ef. 8-31-90