Resolving the radon problem in Clinton, New Jersey, houses

Significantly elevated radon concentrations were found in several adjacent houses in Clinton, New Jersey. The United States Environmental Protection Agency screened 56 of the houses and selected 10 for demonstration of radon-reduction techniques. Each of the 10 houses received an intensive radon diagnostic evaluation before a house-specific radon reduction plan was developed. Depressurization effects caused by temperature differentials and the operation of mechanical equipment were quantified. Before and after radon reduction plans were implemented, radon concentrations were determined by charcoal canisters and continuous radon monitors. A variety of sealing and subslab depressurization techniques were applied to the 10 houses. Radon concentrations were reduced by over 95% in all 10 houses. The cost of applying radon reduction techniques ranged from $1500 to $8500 per house. House construction characteristics were described which contributed to the high cost of radon reduction. In summary, the 10-house radon reduction demonstration in Clinton, New Jersey was successful in showing homeowners with similar house types some effective ways of reducing radon concentrations.