The two maps showing lead and arsenic levels were derived from soil samples from around Pierce County. The soil samples were on two different tables that had mixed data for both lead and arsenic. This date was then converted to a point feature and then merged into one feature class using the append tool. Once merged into a single feature class, arsenic and lead were broke out into their own feature classes. Interpolation using the ‘Kriging’ method was then conducted on both lead and arsenic feature classes. This resulted in two continuous surfaces, one for arsenic and one for lead. This showed where the highest concentration of lead and arsenic were.
The density of kids map was created using block group level demographic data for ‘Sex by Age for the population under 20 years’ for Pierce County. The data was used in Excel to find all ages of kids 10 years old and younger. This was then broken up by total of males, total of females and total kids. The tables from the Excel file were then joined to Census Block data for Pierce County. Two new fields were then created, Square miles geometry, to calculate how many kids per square mile, and kid density. Kid density was used to create a continuous surface. This was accomplished by using the inverse distance weighted (IDW) interpolation tool.
The Toxic Remediation map was created by overlaying the three raster’s from lead surface, arsenic surface, and the kid density surface to find areas that are highly contaminated with arsenic and lead, that are also densely populated with kids.This was done using the raster calculator to create one raster that was then symbolized using the surface color ramp.The symbolization is ranked low to high.The higher ranked areas are where there is areas of high concentration of both lead and arsenic along with a high density of kids.The lower ranked areas are areas that have a lower concentration of one or all there fields.