21.1 (1) If a well is abandoned, the person abandoning the well shall ensure that the following steps are taken and, unless otherwise specified, they shall be taken in the sequence in which they are set out in this subsection:   1. If the well already has a well tag, the well tag shall be removed and returned to the Director within 30 days after its removal. 2. If the well casing or well screen has collapsed, reasonable efforts shall be made to remove it, and all other equipment and debris in the well shall be removed. 3. The well, including any annular space, shall be plugged by, i. in the case of any well, placing a continuous column of an abandonment barrier from the bottom of the well upward to approximately two metres below the ground surface so that it prevents any movement of water, natural gas, contaminants or other material between subsurface formations or between a subsurface formation and the top of the abandonment barrier, or ii. in the case of a well that is greater than 65.0 centimetres in diameter, placing a continuous column of an abandonment barrier by taking the steps described in subsection (5) until the materials placed in the well under that subsection reach to approximately two metres below the ground surface. 4. If a well casing or well screen was not removed under paragraph 2, it shall be removed, where reasonably possible, during the taking of the steps required by paragraph 3, with the bottom of the casing immersed in the rising accumulation of the abandonment barrier until the required level has been reached. 5. If a well casing or well screen was not removed under paragraph 2 or 4, it shall be removed, where reasonably possible, to a minimum depth of two metres below the ground surface. 6. If an abandonment barrier placed under paragraph 3 contains cement, it shall be allowed to set until firm and, if necessary, it shall be topped up to approximately two metres below the ground surface. 7. Unless to do so may cause remaining structures to be destabilized, damaged or unsafe, below ground concrete structures, foundations and slabs shall be removed, at any time before the steps required by paragraph 8 are taken, at least to a depth adequate to accommodate the sealing measures described in paragraph 8. 8. The well shall be sealed at the ground surface by, i. placing between  50 and 150 centimetres in vertical thickness of bentonite chips, pellets, granules or powder in the well opening in accordance with the manufacturer’s specifications, and ii. fill the remaining well opening to the ground surface with soil cover, or other material that is more in keeping with the surface material immediately adjacent to the well opening, to prevent inadvertent or unauthorized access. 9. The disturbed area shall be stabilized to prevent erosion.  O. Reg. 372/07, s. 20. (2) Paragraphs 2, 4 and 5 of subsection (1) do not apply to a person who abandons a well by overdrilling the entire well.  O. Reg. 372/07, s. 20. (3) The following rules apply for the purpose of subparagraphs 3 i and ii of subsection (1): 1. The abandonment barrier must be compatible with the quality of the water found in the well. 2. The abandonment barrier must not contain any materials that may impair the integrity of the abandonment barrier, including soil or drill cuttings. 3. If the well is in contact with contaminants, the abandonment barrier must be stable in the presence of the contaminants. 4. If the well is less than or equal to 6.5 centimetres in diameter and the well casing and well screen have been removed under paragraph 2 of subsection (1) or are being removed under paragraph 4 or 5 of subsection (1), the abandonment barrier must be, i. a slurry consisting of clean water, Portland cement and not more than 5 per cent bentonite solids by weight, or ii. a slurry consisting of clean water and at least 20 per cent bentonite solids by weight, and the abandonment barrier must be placed using a tremie pipe, with the bottom of the tremie pipe immersed in the rising accumulation of the abandonment barrier until the required level has been reached. 5. Paragraph 4 also applies, with necessary modifications, to an uncased well that is less than or equal to 6.5 centimetres in diameter. 6. If the well is less than or equal to 6.5 centimetres in diameter and the well casing and well screen have not been removed under paragraph 2 of subsection (1) and are not being removed under paragraph 4 or 5 of subsection (1), the abandonment barrier must be, i. a slurry consisting of clean water, Portland cement and not more than 5 per cent bentonite solids by weight, or ii. bentonite chips or pellets that have been screened and placed in accordance with the manufacturer’s specifications. 7. If the well is more than 6.5 centimetres in diameter, the abandonment barrier must be, i. a slurry consisting of clean water and at least 20 per cent bentonite solids by weight, ii. a slurry consisting of clean water, Portland cement and not more than 5 per cent bentonite, iii. a slurry consisting of clean water and Portland cement, iv. a slurry consisting of clean water, Portland cement and clean sand, v. a slurry consisting of equal weights of Portland cement and clean gravel, mixed with clean water, vi. a slurry (sometimes called a concrete slurry) consisting of clean water, Portland cement, clean sand and clean gravel, vii. bentonite chips or pellets that have been screened and placed in accordance with the manufacturer’s specifications, or viii. other material approved in writing by the Director, if the Director is of the opinion that the performance of the other material is the equivalent of the performance of a slurry referred to in subparagraphs i to vi. 8. A wet abandonment barrier for a well that is more than 6.5 centimetres in diameter shall be placed using a tremie pipe, with the bottom of the tremie pipe immersed in the rising accumulation of the abandonment barrier until the required level has been reached.  O. Reg. 372/07, s. 20. (4) Subparagraph 3 i of subsection (1) and subsection (3) do not prevent the placing of clean, washed sand or gravel in the well bore, adjacent to water producing zones or fractures, to minimize the loss of sealant material.  O. Reg. 372/07, s. 20. (5) The steps referred to in subparagraph 3 ii of subsection (1) with respect to a well that is greater than 65.0 centimetres in diameter, which shall be taken in the sequence in which they are set out in this subsection, are the following: 1. Clean sand or pea gravel shall be placed from the bottom of the well to the top of the deepest water producing zone or the top of the well screen, whichever is deeper. 2. At least 0.1 metre of bentonite chips or pellets shall be placed over the sand or pea gravel. 3. If the water level can be drawn down to the top of the bentonite chips or pellets, i. the water level shall be drawn down to the top of the bentonite chips or pellets, ii. at least 0.3 metres of a bentonite slurry that consists of clean water and at least 20 per cent bentonite solids and that is compatible with the quality of the water found in the well shall be placed over the bentonite chips or pellets, and iii. clean gravel, sand, silt or clay shall be dropped over the bentonite slurry to fill the remainder of the well, while maintaining at least 0.3 metres of the bentonite slurry above the rising accumulation of gravel, sand, silt or clay. 4. If the water level cannot be drawn down to the top of the bentonite chips or pellets, the remainder of the well shall be filled to approximately two metres below the ground surface with an abandonment barrier, which may be interspersed with clean sand or pea gravel placed in each water producing zone of the well.  O. Reg. 372/07, s. 20. (6) If the well is greater than 65.0 centimetres in diameter, the person abandoning the well shall ensure that sealing materials are selected and placed for the purpose of paragraphs 3 and 8 of subsection (1) so that they will provide the appropriate structural strength to support the weight of persons and vehicles that may move over the area after it is filled.  O. Reg. 372/07, s. 20. (7) If the well is a flowing well, commercially manufactured drilling mud that does not impair the quality of the water with which it comes in contact may be used, in taking the steps required by subsection (1), to assist with drilling or placement of an abandonment barrier, but the drilling mud may not be used as an abandonment barrier.  O. Reg. 372/07, s. 20. (8) Paragraphs 2 to 9 of subsection (1) and subsections (3) to (7) do not apply to a person who abandons a well by excavation of the entire well in the course of work carried out for another purpose.  O. Reg. 372/07, s. 20. (9) This section also applies, with necessary modifications, to a well pit and, for that purpose, a reference in subsections (1) to (8) to a well shall be deemed to be a reference to a well pit.  O. Reg. 372/07, s. 20. Protection of Well Tag