Second Silver Hill gas well capped
Emissions of hydrogen sulphide gas led to an evacuation order in Silver Hill this summer. Simcoe Reformer file photo
The toxic gas crisis in Silver Hill could be over as early as Thursday afternoon.
Marlene Miranda, Norfolk and Haldimand’s general manager of health and social services, reported this week that the second of two natural gas wells emitting toxic hydrogen sulphide has been capped.
The second well had gone 24 hours without emissions as of Tuesday night. If the readings remain at zero through Thursday morning the health unit plans to lift an evacuation order affecting three households.
“They could be back in their homes by Thursday afternoon,” Miranda said at the end of Tuesday’s meeting of Norfolk council.
Several households on North Walsingham Road 10 were evacuated Aug. 18 after unusually high readings of hydrogen sulphide gas were detected in an area between Forestry Farm Road and the North Walsingham East Quarter Line Road.
Hydrogen sulphide is an occasional byproduct of natural gas wells. It is toxic, corrosive, flammable and smells like rotten eggs.
The number of households served with evacuation orders rose to six when unusually high readings of hydrogen sulphide gas were recorded at a second well immediately west of the first.
Norfolk County blocked a section of the concession road measuring nearly a kilometre in length in response to the situation
Ian and Kim Grant brought the situation to the attention of the Haldimand-Norfolk health unit this summer. They have smelled hydrogen sulphide in the neighbourhood for nearly two years and became concerned when metal objects on their property began to discolour.
The health unit and the Environment and Natural Resources ministries inspected the situation before Dr. Malcolm Lock, Norfolk’s acting medical officer of health, issued the evacuation orders.
The capping work was performed by Bradco Drilling of Merlin.
The well capped this week was on the Grant property. Funds for the capping will be drawn from the MNR’s abandoned gas well budget.
The first well capped last week is also on private property but was under licence to Union Gas. Because it was a commercial well, the owner of the land where the well sits is responsible for the capping expense.
Several sources in the Silver Hill area say this summer’s hydrogen sulphide problem was predictable after the MNR capped a natural gas vent in the area at Big Creek a couple of years ago.
There are about a dozen natural gas wells in the area. There was concern that pressure within the well field would seek release elsewhere once the vent at Big Creek was blocked.
Miranda said health and ministry officials are aware of the well network.
Norfolk has hired a consulting firm to alert the county if hydrogen sulphide gas finds another release point in the neighbourhood.