What was the sampling methodology, or the criteria used, to select the residential properties to be sampled?

All properties in Winona Homes were selected for potential sampling based on the complaint EPA received in August 2016 which alleged that soil used to grade the land for construction of the homes may have come from a contaminated source and may be a contributing environmental factor affecting the health of people living in this neighborhood.  EPA contacted over 300 residences via email and postcard mailings to stimulate participation in the sampling.  Fifty-seven properties in Winona Homes responded and provided EPA access to sample their soil.  Once EPA determined the number of properties that would participate, another layer was applied to select certain properties for the collection of shallow sub-surface and deep soil samples.  Properties chosen for these deeper samples were based on geographic location and were located as close to equally distance from each other to provide a representative picture of soil at these depths across the neighborhood.  In some cases, a deep 8’-10’ sample was selected at properties nearest to parts of the neighborhood believed to contain the deepest layers of fill, as determined through review of historic aerial photography.