OAR 690-240-0035: Geotechnical Holes: General Performance and Responsibility Requirements

(1) A geotechnical hole is defined in OAR 690-240-0010(36). Geotechnical holes, cased or uncased, are generally constructed to evaluate subsurface data or information (geologic, hydrogeologic, chemical, or other physical characteristics). Geotechnical holes are divided into the following classifications: (a) Temporary (abandoned within 72 hours) geotechnical holes; (b) Cased permanent geotechnical holes; (c) Uncased permanent geotechnical holes; or (d) Slope stability geotechnical holes. (2) A geotechnical hole report shall be signed by a professional and must be submitted to the department if the geotechnical hole is: (a) Greater than 18 feet deep; (b) Within 50 feet of a water supply or monitoring well; (c) Used to make a determination of water quality; or (d) Constructed in an area of known or reasonably suspected contamination. (3) Geotechnical holes that do not meet any of the criteria spelled out in OAR 690-240-0035(2) do not require a geotechnical hole report to be filed with the Department, but shall be required to have a professional as described in 690-240-0035(4)(c) be responsible for the construction and abandonment of the geotechnical hole. (4)(a) Although enforcement actions may be exercised against other parties, the landowner of the property where the geotechnical hole is constructed is ultimately responsible for the condition, use, maintenance, and abandonment of the geotechnical hole; (b) Conversion of a geotechnical hole to a water supply or monitoring well shall be considered by the Department on a case by case basis (c) When a geotechnical hole report is required, the professional responsible for the construction, alteration or abandonment of a geotechnical hole shall have one of the following certifications or licenses at the time the professional signs the geotechnical hole report: (A) A valid Oregon Monitoring Well Constructor's License; (B) A valid Oregon Water Supply Well Constructor's License; (C) Valid certification by the State of Oregon as a Registered Geologist; or (D) Valid certification by the State of Oregon as a Professional Engineer. (d) The professional shall provide proof of license, certification or registration and photo identification to Department employees upon request. (e) In order to protect the groundwater resource, all geotechnical holes shall be constructed, operated, used, maintained, and abandoned in such a manner as to prevent contamination or waste of groundwater, or loss of artesian pressure. (f) If the geotechnical hole is completed above ground, it shall have a minimum casing height of one foot above finished grade and a lockable cap with lock shall be attached to the top of the casing. If a geotechnical hole, except a slope stability hole, is completed flush with the land surface, a lockable watertight cap with lock, shall be attached to the top of the casing. A vault or monument designed to be watertight, level with the ground surface, shall be installed to prevent the inflow of surface water. The cover must be designed to withstand the maximum expected loadings. (5)(a) A 'Geotechnical Hole Report' shall be prepared for each geotechnical hole, including unsuccessful geotechnical holes, constructed, altered, converted, or abandoned if the hole meets any of the requirements of OAR 690-240-0035(2) above. (b) The 'Geotechnical Hole Report' shall be filed with the Department within 30 days of the completion of the geotechnical hole; (c) The report shall be prepared in triplicate on forms furnished or previously approved in writing by the Water Resources Department. The original shall be furnished to the Director, the first copy shall be retained by the professional, and the second copy shall be given to the landowner or customer who contracted for the construction of the geotechnical hole; (d) In the event any drilling equipment or other tools are left in a geotechnical hole the professional shall enter this fact on the Geotechnical Hole Report; (e) A copy of any special authorizations or special standards issued by the Director shall be attached to the Geotechnical Hole Report. See OAR 690-240-0006 for information concerning special standards; (f) The report of geotechnical hole construction shall include, as a minimum, the following: (A) Landowner name and address; (B) Started/Completed date; (C) Location of the geotechnical hole by County, Township, Range, Section, tax lot number, if assigned, street address, or nearest address, and either the 1/4, 1/4 section or Latitude and Longitude as established by a global positioning system (GPS); (D) Use of geotechnical hole; (E) Type of geotechnical hole; (F) Depth; (G) Map showing location of geotechnical hole on site must be attached and shall include an approximate scale and a north arrow; (H) General hydrologic and geologic information as indicated on the Geotechnical Hole Report; and (I) Such additional information as required by the Department. (6) Temporary geotechnical holes: (a) Temporary geotechnical holes include but are not limited to: drive points, soil and rock borings, temporary sample holes, permeability test holes, and soil vapor holes; (b) Temporary geotechnical holes shall be abandoned within 72 hours of initial construction; (c) Any temporary casing that has been installed shall be removed as part of the abandonment. (7) Cased permanent geotechnical holes (a) Cased permanent geotechnical holes include but are not limited to: gas migration holes, cathodic protection holes, wet soil monitoring holes, and vapor extraction holes; (b) Permanent casing installed in a geotechnical hole shall meet the casing requirements in OAR 690-240-0430, 690-210-0210, or 690-210-0190. (c) The borehole diameter for cased permanent geotechnical holes shall be at least four inches larger than the nominal casing diameter. If the cased permanent geotechnical hole is constructed using a hollow stem auger drilling machine, the inside diameter of the auger must be at least four inches larger than the nominal diameter of the casing to be installed. Cased permanent geotechnical holes installed using direct push technology shall meet the annular space requirements in OAR 690-240-0540. (d) Cased permanent geotechnical holes, except wet soil monitoring holes, shall be sealed in accordance with the filter pack seal requirements in OAR 690-240-0460, and the casing seal requirements in OAR 690-240-0475. (e) Wet soil monitoring holes shall have a casing seal that extends to a minimum depth of one-foot. The casing seal shall be placed in accordance with OAR 690-240-0475. (f) Wet soil monitoring holes shall not exceed three and one-half feet in depth. (8) Uncased permanent geotechnical holes: (a) Uncased permanent geotechnical holes include but are not limited to: pneumatic and electrical piezometers; (b) Temporary casing can be used during the construction of the uncased permanent geotechnical hole but must be removed prior to completion. Surface casing (5 feet maximum) may be installed for placement of logging or recording equipment. (9) Slope stability geotechnical holes. (a) Slope stability geotechnical holes include but are not limited to: slope instrumentation holes such as slope inclinometers, and slope remedial holes. (b) Slope stability geotechnical holes are defined in OAR 690-240-0010(74). Such holes shall be constructed, operated, used, maintained, and abandoned in such a manner as to prevent contamination or waste of groundwater. (c) When a Geotechnical Hole Report is required under OAR 690-240-0035(2) for a slope stability geotechnical hole that is constructed to facilitate water level measurements, an affidavit from an engineer or geologist qualified to perform geotechnical investigations shall be attached to the Geotechnical Hole Report. The affidavit shall have the qualified engineer or geologist's stamp on it and shall certify that the slope stability geotechnical hole is on a landslide or a mass-wasting feature. (10) Geotechnical Holes abandonment: (a) Geotechnical holes shall be abandoned in the following manner: (A) If it can be verified that the geotechnical hole was constructed in accordance with these rules, it shall be abandoned by filling the well from the bottom up with an approved grout as described in OAR 690-240-0475. The casing shall then be removed below grade, as compatible with local site conditions and land practices. The following are acceptable methods of original geotechnical hole construction verification: (i) A geotechnical hole report previously submitted to the Water Resources Department; (ii) Geotechnical hole information submitted to the Oregon Department of Environmental Quality; (iii) Other information as approved by the Water Resources Department; (B) If the geotechnical hole construction cannot be verified by means listed in section (A) of this rule, or if the geotechnical hole was not constructed in accordance with these rules, the geotechnical hole shall be abandoned by completely redrilling the hole to a minimum of the original diameter. All casing, screen, annular sealing material, drill cuttings, debris, and filter pack material shall be removed prior to sealing. (b) Geotechnical holes constructed to collect a water quality sample shall be abandoned in accordance with OAR 690-240-0510.