Use of geostatistics for remediation planning to transcend urban political boundaries

Soil remediation plans are often dictated by areas of jurisdiction or property lines instead of scientific information. This study exemplifies how geostatistically interpolated surfaces can substantially improve remediation planning. Ordinary kriging, ordinary co-kriging, and inverse distance weighting spatial interpolation methods were compared for analyzing surface and sub-surface soil sample data originally collected by the US EPA and researchers at the University at Buffalo in Hickory Woods, an industrial–residential neighborhood in Buffalo, NY, where both lead and arsenic contamination is present. Past clean-up efforts estimated contamination levels from point samples, but parcel and agency jurisdiction boundaries were used to define remediation sites, rather than geostatistical models estimating the spatial behavior of the contaminants in the soil. Residents were understandably dissatisfied with the arbitrariness of the remediation plan. In this study we show how geostatistical mapping and participatory assessment can make soil remediation scientifically defensible, socially acceptable, and economically feasible.

► Point samples and property boundaries do not appropriately determine the extent of soil contamination.
► Kriging and co-kriging provide best concentration estimates for mapping soil contamination and refining clean-up sites.
► Maps provide a visual representation of geostatistical results to communities to aid in geostatistical decision making.
► Incorporating community input into the assessment of neighborhoods is good public policy practice.