Wyoming Administrative Code › Agency 037 - Engineer, State › Sub-Agency 0009 - Water Well Minimum Construction Standards › Chapter 4 - WELL COMPLETION AND MAINTENANCE › Section 4-4 - Water Well Plugging and Abandonment

Current through July 13, 2024
(a) When a well is
				temporarily removed from service, it shall be kept in a state of good repair.
				The top of the well casing shall be sealed with a secure watertight cap that
				will prevent tampering and entrance of contaminants, animals, or
				debris.
(b) The well owner is
				responsible to ensure that any well (including any test well or replaced well)
				which is permanently abandoned or removed from service shall be entirely
				plugged to prevent contamination from the surface or any other source and to
				remove any further hazard potential that an unused well or abandoned drill hole
				might pose. All pumps, pipe, wiring, caps, and other obstructions/debris that
				may interfere with adequate plugging operations shall be removed from the well.
				Suitable cement-based mixtures or bentonite mixtures shall be used for grouting
				material. If a well is permitted under DEQ-WQD rules, those rules may be
				consulted for abandonment procedures. For all other wells, an abandoned well
				shall be plugged by one of the following methods in accordance with type of
				well completion and subsurface geologic and /or hydrostatic conditions:
(i) Dug wells or excavations [Type I Wells,
				see Section
				6(a)(1) ] exposing the
				shallow water table shall be filled to static water level with clean fill such
				as gravel or sand. The remaining hole is to be filled with bentonite to 2-feet
				below ground surface. The remaining 2 feet shall be filled with native soil and
				mounded slightly at the top to allow for settling.
(ii) If possible, casing shall be removed
				from Type II Wells [See Section
				6(a)(ii) ] prior to
				plugging procedures. Cased or uncased wells in unconsolidated formations shall
				be destroyed by placement of clean fill, such as gravel or sand, opposite the
				completed (screened, perforated interval) or water bearing zone and then
				grouting to the surface. The upper surface portion of the cased well must be
				cut off a minimum of 18 inches below ground level and the area back-filled with
				enough clean soil material to allow for settling.
(iii) Type III, gravel pack wells [See
				Section
				6(a)
				(iii) ] shall be grouted from bottom to top
				in order to accomplish a complete seal. Grout slurries shall not be poured from
				the land surface through a column of water. In order to place the grout in
				wells with water columns, it shall be pumped via tremie pipe by positive
				displacement or similar method (pressure grouted) from the bottom of the well
				to a sufficient elevation such that an uninterrupted seal may be emplaced to
				the land surface. The upper surface portion of the cased well must be cut off a
				minimum of 18 inches below ground level and the area back-filled with enough
				clean soil material to allow for settling.
(iv) Plugging of open-hole completed wells
				[Type IV Wells, see Section
				6(a)(iv) ] shall consist of
				grouting the entire well. Necessary pressure grouting procedures shall be
				utilized to permanently seal off flow and/or pressure of the artesian aquifer
				such that surface or subsurface leakage will not occur.
(v) Type V Wells [see Section
				6(a)(v) ] shall be
				decommissioned in the same manner as that prescribed for Type III
				Wells.
(vi) Type I, II, or III
				wells may alternately be grouted from bottom to top with bentonite grout to
				create a complete seal.