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“This is Step 1. There should be a rig in there a couple weeks from today. It’s not going to correct anything but it will give us the information we need for the drilling of the relief well and the treatment process to come.”
Experts concluded last year that Silver Hill’s problem with toxic gas wells began in 2015. That was the year the Ministry of Natural Resources capped an artesian well on the banks of Big Creek on North Walsingham Road 10.
The well was spewing chloride, sulphite, iron and other minerals in high concentrations, contaminating the ecosystem.
Dr. Richard Jackson, a hydrogeologist at the University of Waterloo, told Norfolk council that capping the artesian well had a domino effect on abandoned gas wells nearby.
Jackson said the capping raised the local water table, allowing methane fumes from the gas wells to combine with sulphur deposits to create hydrogen sulphide. Hydrogen sulphide is a frequent byproduct of natural gas production. It is corrosive, flammable and smells like rotten eggs.
“This is not an abandoned gas well problem,” Jackson said. “It’s a water problem.”
The long-term effects of hydrogen sulphide gas are unknown. However, in small concentrations it causes headaches while irritating eyes and breathing passages.
The plan is to de-water the problem wetland on Forestry Farm Road. The goal is to lower the water table in this area and eliminate the intersection of methane gas with sulphur deposits near the surface.
The county is acting because several homes are located near the gas vent. Monitoring devices have been installed at these locations. Hydrogen sulphide concentrations fluctuate depending on forces within the Earth.
Norfolk County is bracing for similar situations in the future. The county is home to 1,600 abandoned gas wells. Many were capped improperly and are expected, over time, to emit fumes of their own.
