Wells that are no longer used or maintained can provide a direct link from land surfaces to the water bearing subsurface zones that represent the source water for other wells and local creeks in our watersheds. An abandoned well can allow surface runoff to flow directly down to local and regional aquifers, potentially carrying organic wastes, fertilizers and other chemical residues, such as pesticides and petroleum products into the ground water. Once a groundwater source is contaminated, it is harmful to drink the water and creates a health issue for you, your family, municipal well supplies and perhaps in the case of a farm, your livelihood or your neighbours.
The Region of Durham in partnership with Central Lake Ontario Conservation is extending our stewardship efforts toward the decommissioning of abandoned wells on private property. The program is designed to protect groundwater supplies from potential contamination by providing landowners with up to $1000 in grant assistance funds to decommission unused and abandoned domestic wells on their property. There are exemptions from well abandonment requirements for water that is mineralized or not potable. Our staff can help you determine if that applies to your well.
Proper closing off the pathway from the ground surface to the aquifer involves the plugging and sealing a well. There are 9 steps to abandoning a well. (Taken from MOEE website.)
Your next steps
- Confirm that your well and property are located in the Central Lake Ontario Conservation Authority Jurisdiction – link to Geocortex Map Tool
- Make an appointment with a CLOCA staff person to identify your property and receive an application and list of licensed well contractors in our jurisdiction. Provide photograph(s), digital or hard copy, of your existing well and surrounding conditions. In some cases a site visit maybe be required.
- Request up to 3 decommissioning quotes from a licensed well contractor and make your preferred selection. Note, you must ensure the contract requires that a well technician licensed to construct the type of well that is being abandoned, be used to decommission the well.
- Inform CLOCA staff a minimum of two weeks before your scheduled decommissioning project. We will set up a visit during the work to decommission your well to ensure it is done properly.
- Submit a copy of the invoice from the well contractor, showing payment has been made, along with a copy of the well record and decommission form completed by the well contractor.
- CLOCA will issue the agreed to compensation up to $1000.00.
Link - Well Information - Durham Health Dept.
Link - Water Supply Wells – Requirements and Best Management Practices - Ontario.ca
Brochure - CLOCA Well Decommissioning Program
Durham - Well Maintenance Checklist
Booklet -Well Aware by Green Communities Canada
For more information please contact:
Director, Community Engagement
905-579-0411, ext. 126
How to Abandon a Well – Nine (9) Steps
The person abandoning the well, often the well owner, must ensure the following nine (9) steps are taken in this sequence, unless otherwise specified in the Wells Regulation:
1. If the well has a well tag, it must be removed and returned to the Director under the Act c/o Wells Help Desk; Ministry of the Environment, 125 Resources Road, Toronto Ontario M9P 3V6 within 30 days of its removal.
2. If the casing or well screen has collapsed, reasonable efforts must be made to remove the well screen or well casing. All other equipment and debris in the well must be removed.
3. The well, including any annular space (i.e. any open space beside the casing or between casings), must be plugged with abandonment barrier material from the bottom of the well upward to approximately 2 metres (6.6′) below the ground surface. This does not prevent the placement of clean, washed sand or gravel adjacent to water producing zones or bedrock fractures. The abandonment barrier must be placed in a manner that prevents any movement of water, natural gas, contaminants or other material between subsurface formations, which include aquifers, or between a subsurface formation and the top of the abandonment barrier material.
For step 3, an alternative method of abandonment for wells with a diameter greater than 65 centimetres (2.1 feet) is shown in Figure 3 at the end of this technical bulletin. For further information, see the Wells Regulation and Chapter 15: Abandonment: How to Plug & Seal Wells of the Water Supply Wells – Requirements and Best Management Practices manual.
4. After or during the placement of the abandonment barrier, the well casing or well screen must be removed, if reasonably possible. During the removal of the well screen or well casing, the bottom of the casing must remain immersed in the abandonment barrier material until the required level has been reached.
5. If all of the casing and well screen cannot be reasonably removed as above, then at least 2 metres (6.6 feet) of casing below the ground surface must be removed, if reasonably possible. Requirements for the removal of casing and well screen in sequence (i.e. steps 2, 4 and 5 previously) do not apply if a person overdrills (reams) the entire well before filling the well with abandonment barrier.
6. If the abandonment barrier contains cement, it must set until firm and, if necessary, it must be topped up to approximately 2 metres (6,6 feet) below the ground surface.
7. At any time before the upper 2 metres (6.6 feet) of the well are sealed to the ground surface (see step 8), any below ground concrete structures, foundations, and slabs must be removed unless the removal may cause the remaining structures to become destabilized, damaged or unsafe. The structures have to be removed to a depth adequate to accommodate the sealing measures described below in step 8. For clarification, the removal of the structures can occur at anytime before or during steps 1 to 7.
8. To prevent inadvertent or unauthorized access to the well, the well and the well opening (including any excavation) must be sealed up to the ground surface by placing:
• 50 cm (20″) to 150 cm (59″) of bentonite (manufactured swelling clay product) chips, pellets, granules or powder in accordance with the manufacturer’s specifications; and
• Soil cover, or other material that is more in keeping with the material immediately adjacent to the well opening, over the bentonite and up to the ground surface. The disturbed area must be stabilized to prevent erosion.
9. The disturbed area must be stabilized to prevent erosion.
Technical Bulletin Taken from MOECC website. (Link)