While Evergreen has stated that benzene contamination moving off-site has not impacted the air quality in surrounding buildings, they have also said that no sampling of air quality in off-site buildings has been done. Evergreen needs to collect data to ensure that benzene and other contamination has not moved offsite and made its way from contaminated soils into the basements of surrounding buildings, affecting the health of residents.

Evergreen has conducted initial assessments using existing data and conservative assumptions, which did not find any potential impacts to off-site residences’ indoor air quality from the conditions in shallow groundwater moving offsite from the facility; therefore, we have no plans to test off-site buildings. However, future fate and transport evaluation will model the projected extent of groundwater contaminants, which will be used to confirm the assessment of offsite air quality effects from subsurface conditions and will be summarized future reports. Also, in general, direct sampling of indoor air is not conducted unless vapor intrusion assessment indicates potential for indoor air quality concerns. This is because there are numerous and various other potential sources for air quality.