Targus was retained to perform an environmental site assessment (Phase I ESA and additional non-ASTM services) of an apartment property encompassing approximately 55 acres of land. The improvements were constructed in 2001 with interior upgrades in 2016.
No recognized environmental conditions were identified during completion of the Phase I ESA. Short term radon testing in ten ground floor units indicated the potential for elevated radon concentrations. Two of ten measurements were above the EPA Action Level of 4.0 picoCuries per liter of air (pCi/L). Passive radon systems were identified in the buildings and appeared to have been constructed as part of the original building design. Long-term radon testing was performed for 355 days. Elevated levels of radon were identified in one or more ground floor units in 18 of 20 residential buildings.
A pilot radon mitigation study was completed that included communication testing and visual observations in four of the buildings. The communication testing was performed to assess air movement through the sub-slab material under the foundations. Visual observations provided information about potential pathways for radon to enter the buildings.
Installation of radon fans and continuous radon monitoring before and after fan installation is in progress. Initial results indicate that the active mitigation systems are effective in significantly reducing radon concentrations in the ground floor units, and that the addition of the fans has not resulted in tenant complaints regarding noise or vibration.