AG 2022: With five inspectors, government struggles to track thousands of abandoned oil and gas wells

The Ministry of Natural Resources and Forestry has just five inspectors to keep track of Ontario's 27,000 oil and gas wells, the province's auditor general has found.

More than 15,300 of the wells were known to be abandoned, while the ministry couldn't say whether another 7,300 were abandoned or not, an AG report said.

"Wells that are poorly maintained and improperly plugged can lead to contaminants getting into the province’s groundwater or rising to the land surface around the well," a report warns.

Over 8,000 "were plugged prior to 1970 when materials used to plug them included logs, gravel and lead, which can lose their integrity over time."

In August 2021, leaking gas from a poorly capped well in Wheatley, east of Windsor, caused an explosion that destroyed two buildings and injured at least 20 people.

Some 1,625 abandoned wells in Ontario were never plugged at all, the AG points out.

Three high-risk wells have been leaking since at least 2018, but only one is planned to be plugged in 2022-23.

Ontario's orphan wells are concentrated along the shore of Lake Erie, and to a lesser extent near Lake Huron.

Of those that have been inspected, 1,966 haven't been inspected since 2010 and 1,982 haven't been inspected since 2016. Most inspections were reactive.

"The ministry acknowledges the concerns related to the ministry’s oil and gas well inspection program," the ministry said in a written response.

"Over the next three years, the ministry will review its inspection framework as part of a comprehensive long-term action plan to address the complex challenges associated with legacy oil and gas wells."

The ministry could not provide the AG with a list of high-risk wells that have or have not been plugged, the AG said.

The Ministry's Petroleum Operations Section told the AG that they knew of 1,049 wells for which they didn't have an exact location, and "acknowledged that there may be thousands of additional wells for which it did not have any information."

Within the province, Aylmer is thought to have the most wells, followed by Guelph.

Looking more generally at disaster preparedness:

• The Ministry of Mines "has not rehabilitated the majority of known abandoned mines in the province and does not know the rehabilitation status of another quarter of them. In addition, almost three-quarters of abandoned mines have not been inspected in over a decade."
• Less than a third of ministry-owned dams that will reach the end of their serviceable life within 20 years have been assessed, and more than 1,000 privately owned dams have not been assessed at all.
• Ontario’s level of flood preparedness is lagging, in part because of gaps in flood maps.
• The ministry completes after-action reports for fewer than half of the floods it responds to.