“˜Hidden quarry”™ blasting could lead to higher radon levels: CRC

High levels of radon gas entering houses in close proximity to the proposed Rockwood quarry is another area of concern, according to a citizen’s group in opposition to the pit.

At the July 13 Guelph-Eramosa council meeting the Concerned Residents Coalition (CRC) made a presentation to council regarding the group’s findings on radon gas in the area.

“The CRC had been working on testing for radon but the testing sample that we did was a one-day test,” CRC vice president Perry Groskopf told the Advertiser in a phone interview.

“Health Canada suggests that you do a 30-day test between September and April when the house is closed up so that the radon is trapped in your home.”

Groskopf said the CRC was planning to do a 30-day test this winter to present a better argument to council but the group needed to present the information prior to the start of the Ontario Municipal Board hearing.  

At a council meeting on May 19 the township was told James Dick Construction Ltd.  had referred its Aggregate Resources Act application for the quarry on Highway 7 near the 6th Line to the Ontario Municipal Board because the township exceeded the two-year limit to make a decision.    

“If we do not bring forth the information we have now, when a hearing is set new information cannot be included in the evaluation during the hearing,” Groskopf explained.

Radon is the second leading cause of lung cancer – after smoking – in Canada, according to the Canadian Cancer Society.  

However, Greg Sweetnam, a spokesperson for James Dick Construction, said there hasn’t been any documented cases in the world of someone getting sick or dying from radon poisoning because of a quarry.

“Like I always say to the CRC … ‘Show me the bodies,’” Sweetnam said.

“I mean if this was the case, that every quarry in North America was causing radon poisoning in populations, there’d be bodies stacked like cordwood around all the existing quarries in Ontario and it has never happened.”

According to Groskopf’s slides, “Radon is a radioactive gas that is colorless, odorless, and tasteless and is produced naturally by the breakdown of uranium in the ground.”

According to the Radiation Safety Institute of Canada, “When uranium breaks down, it emits radon gas, which then moves through the ground into the air.”     

Sweetnam said earth emits radon and areas closer to bedrock tend to have higher levels of the gas – completely independent from pit locations.

The CRC’s concern comes when underground water is agitated and a higher level of radon gas is released, leeching up through the ground and entering a confined space, like a home.

Groskopf’s presentation indicated there are various ways radon can enter a home: cracks in foundation walls and floor slabs, construction joints, gaps around service pipes, support posts, window casements, floor drains, sumps or cavities inside walls and/or dirt floors.

Groskopf said the concern surrounding the quarry stemmed from the fact that Wellington County is classified as a high-radon area and that the blasting will be taking place in a limestone karst formation.

“The thing about limestone is geologists say water can move through rock layers from granite and carry uranium radium which gives rise to radon,” Groskopf said.

“Now this limestone that James Dick wants to blast on,  for millions of years water has been leeching through it.”

This means there are potential fissures or caves below the surface holding water that could be full of radon, he said.

“Now it’s not a problem trapped in the water, but once the water is agitated, which 30 blasts a year will be doing, it will release the radon gas into the air,” he said. “If the ground is being vibrated and fissures are being created then it will give new paths for the release of radon gas.”

Sweetnam said the CRC’s theory that the quarry will crack the countryside is unfounded.

“The quarry can only crack rock within so many borehole diameters within feet of the edge of where we’re blasting and we simply cannot, with the vibration limits that we adhere to, we cannot affect the area outside the quarry boundary and we certainly will never impact on the structural integrity of somebody’s house or cracking your foundation in the basement and all that,” he said.

Groskopf said one way to protect a home from high radon levels is to undergo remediation where potential radon entry points are sealed and a fanned pipe is installed in the basement floor to vent air to the outside.

However, he said that with continuous blasting the avenues for radon to move through the rock may change and remediation measures may give away as the foundation shifts, meaning more frequent remediation could be necessary.

“Is that applicant going to pay another $3,000 for me to remediate my house a second time?” Groskopf asked. “No, I will have to pay that.”

He said he’s concerned that multiple remediations will be needed in close houses to ensure the environment is safe throughout the quarry’s life.

“So what we’re asking is that Guelph-Eramosa do a baseline test for radon before the quarry goes in,” Groskopf explained.

“I think the [township]  deserves to have that knowledge available and I think the residents deserve to have that knowledge.”

Having the baseline levels will allow the municipality to more easily measure whether radon levels are reaching a critical point during blasting, he said.

Guelph-Eramosa council said at the June 1 meeting that a planning report is anticipated for the end of August or early September. After a public meeting the township will make a decision regarding its position on the quarry.