The Middleport Community Input Group has been given maps generated by the agencies showing the arsenic soil contamination levels for the air deposition area of the village. These maps do not show levels for the areas north of the canal.
The agency maps have been drawn showing the averages for each residential property or, in the case of agricultural fields, the average for a 100 by 100 foot square. The first map shows the mean (average) for each property or square of surface soil samples. Typically surface soil sampling is taken from the top 3 inches. The second map shows the highest mean for either just surface or surface and subsurface (up to a foot deep) combined with outliers removed. Outliers are readings either so low or so high they don't make sense when compared to surrounding sampled areas. The location of these outliers are shown by dots on the map which are defined in the legend of the map. The third map is the same as the second only the outliers have not been removed for the calculation. The best map to look at is probably the one showing mean averages with outliers removed.
These maps are different than those generated by FMC which were included in the RCRA Facilities Investigation report, Volume II. The FMC maps were generated by feeding sampling results to a computer program which then drew the contamination levels. As is known for computer programs, the output is only as good as the input and the programing. The agency maps only used mathematics to determine a mean or average and do not show possible variances with in a property but draw each property or square one color. The FMC maps show how the levels of contamination may vary from one section of a property to another.
The agencies' maps are now in the document repository of this web site Click here [3] to download them.
To download the maps from the RFI Volume II FMC generated, click here [4].
