The rehabilitation of the culvert over Big Creek on Forestry Farm Road in Nofolk County is going smoothly considering it’s next to a problem gas well in Silver Hill.
Weathertech Restoration Services of Dorchester hoped to have the road re-opened sooner but the contractor now thinks that will happen at the end of the 2020 construction season.
“The job is bigger than we thought but it’s moving along,” said Weathertech president Todd Bogart. “It’ll be November now, best case.”
The culvert is uncomfortably close to an old gas well that spews intermittent levels of toxic hydrogen sulphide gas. Norfolk County has posted skull-and-cross-bone signage along this stretch of Forestry Farm Road as a warning that inhaling the fumes could pose a health hazard. Motorists passing by report a strong smell of rotten eggs.
The construction zone is about 400 metres north of the well but Bogart says there have been no odour problems or need to take extraordinary precautions. Norfolk’s budget for the project was set at $1.75 million.
Hydrogen sulphide emissions in Silver Hill have been a problem since the Ministry of Natural Resources plugged a natural gas vent beside Big Creek in the area of North Walsingham Road 10 several years ago. MNR acted because the vent was spewing toxic mineral compounds and fumes into the Big Creek ecosystem.
This has created a whack-a-mole effect whereby underground gas pressure seeks relief in new locations after subsequent ventings are capped.
The most recent vent is submerged in a wetland area on county property next to Forestry Farm Road immediately north of McDowell Side Road. A recent, elaborate attempt to address the situation failed due to the high water table in Silver Hill.
Hydrogen sulphide gas is corrosive and flammable. Even in trace amounts, it irritates eyes, throats and nasal passages. Studies have yet to be done on the health impacts of long-term exposure.