Radon invades Summit homes

SUMMIT COUNTY — A hundred years ago, when dredge boats made their stately and destructive ways up and down Summit County’s rivers in their quest for precious minerals, no one envisioned what the 21st Century would bring to the area: row after row of suburban homes constructed directly on piles of excavation waste.

Leftover dredge rock is generally benign, but some local homeowners have discovered an unexpected residual effect from the historical mining operations — high levels of radon in their modern homes.

“The dredges dug to the bedrock and removed all the insulating soil, so the ground is now incredibly porous,” said Alan Ferguson, owner of Summit Radon Solutions.

Radon, a colorless radioactive gas, is produced by the breakdown of uranium in the ground. Particularly high concentrations are found in areas where there is a high percentage of granite in the bedrock, as in much of the Rocky Mountain region.

According to most experts, problems arise indoors because modern houses are so well-insulated and the relative lower indoor pressure causes a vacuum, which pulls radon in through cracks in the home’s foundation. Because it rises from the soil, levels of the gas are generally highest in basement areas and crawlspaces.

The U.S. Environmental Protection Agency (EPA) and the Surgeon General recommend home testing of radon levels and mitigation in dwellings with levels greater than or equal to 4 picocuries per liter (pCi/L). The negative health effects from exposure to the gas occur over a long period, so an elevated level does not constitute an immediate emergency.

“You don’t have to move out of your house,” Summit County environmental health director Dan Hendershott said.

If testing results exceed 4 pCi/L, he told a group at a recent Radon Awareness workshop, it’s possible to install equipment to lower radon concentrations to acceptable levels. Often, mitigation in an existing house involves installing some sort of barrier between the ground and the house and using a fan and vent system to divert naturally occurring radon into the outside atmosphere.

In Summit County, the cost of mitigation usually ranges from about $1,000 to $2,000, Ferguson said. He founded his radon mitigation company four years ago at the request of Realtor friends, who were frequently dealing with elevated radon levels discovered as part of the home inspections required for real estate transactions. He now works on between 120 and 140 homes a year — mostly in Summit County — and of those, about 60 percent are being mitigated as conditions of a property sale.

Frisco resident Dave Love sought Ferguson’s services when he sold his house on Tiger Road.

“The buyers had a home inspector come in, and it came back a little above the limit,” he said. “They wanted it mitigated before they bought the house.”

Love shelled out $2,500 for the mitigation, which included laying ventilation pipes in the crawlspace under a plastic barrier, but has no regrets about the expense.
“It’s wise to get it tested,” he said. “It’s nothing to get alarmed about, but you’ll really be doing the right thing to get it fixed.”

Radon test kits are available online and at most hardware stores. Short-term tests measure levels over a two to four-day period, while long-term tests — in place for nine months or longer — take into account seasonal fluctuation of the gas.

Hendershott encourages homeowners to test every two years with kits labeled “EPA listed” or “NEHA approved.”

For the last two years, the Colorado State University Cooperative Extension, Summit County, and the county Environmental Health Department have received grant money from the Colorado Department of Public Health and Environment (CDPHE) for the purpose of increasing public awareness of radon.

As part of that program, they’ve tracked results from a sample of local tests. According to county extension director Laura Au-Young, in 2007, two thirds of the 69 tests her office received results on showed levels greater than 4 pCi/L, with the highest result coming back at 58.3.

Ferguson has seen even higher numbers — some greater than 100. His own house, near Warriors Mark in Breckenridge, tested at 14 pCi/L. After mitigation, the test showed the same level as that found outdoors: 0.4 pCi/L.

“I’ve never been beaten by one yet,” he said.

As awareness of indoor radon has increased, more and more builders of new homes are incorporating features to mitigate its impact during construction. Traditional Neighborhood Builders president Dan McCrerey, builder of the 140-home Wellington Neighborhood located on a dredge pile in Breckenridge, said his company has been covering crawlspaces and adding fans to new construction for several years.

“I’m not aware of any elevated levels in the neighborhood,” he said. “But we constantly try to get better.”

To register for the next Radon Awareness workshop, scheduled for March 21 between noon and 1 p.m. at the Community and Senior Center, call CSU Extension Summit County at (970) 668-3595.

<i>Harriet Hamilton can be reached at (970) 668-4651, or at hhamilton@summitdaily.com.</i>

Radon facts

• Radon is a colorless radioactive noble gas that occurs naturally from the decay of radium.
• According to the EPA, indoor air contamination by radon causes 21,000 lung cancer deaths per year in the U.S. — more than the total caused by second-hand cigarette smoke.
• The average outdoor radon level is 0.4 pCi/L (or picocuries per liter - a Curie is a unit of radiation).
• The EPA recommends home mitigation if indoor levels exceed 4 pCi/L.
• Levels can vary widely from neighborhood to neighborhood, and even from house to house.
• Concern about home radon levels started in the U.S. in 1984, when an employee at a nuclear power plant in Pennsylvania set off radiation alarms on his way into work. His house was found to have a radon level of 2,700 pCi/L - giving him an equivalent health risk of smoking 135 packs of cigarettes per day.
• The highest average radon concentrations in the U.S. are found in Iowa and in mountainous areas of southeastern Pennsylvania.
• Colorado ranks seventh nationwide in average indoor radon levels.
• There are no federal or state laws governing acceptable radon levels, only recommendations.
• For more information about radon, including mitigation resources, visit www.epa.gov/radon.