AVERAGING & COMPOSITE SAMPLES (TEQ-Dioxins)

The purpose is to cover more geographical area while lowering costs by combining a number of soil samples into one and hence only paying the price for one sample. In the case of dioxin/furan samples the price can be between $850 to $1,000 per sample. Here comes the mathematics of averaging. If four soil samples are combined equally, mixed well and then one sample taken from the composite and analyzed, the resulting concentration will be the average of the four samples if analyzed individually. For example if four soil samples individually had concentrations of dioxin of 8, 3, 4.06 and 1.18 parts per trillion (ppt) their composite average would be the sum of the four concentrations (i.e. 16.24) divided by 4 which equals 4.06 ppt. ....................................................................................................... The thing is you end up with only the composite average not the individual concentrations. In all the following possibilities you will see that to have an average concentration of 4.06, the majority of possibilities have some individual concentrations greater than 4.06 and in fact greater than the Ontario criteria of 7 ppt. .......................................................................................................................................... Examples:...................................................................................... 3, 3, 3, 7.24.......16.24, 0, 0, 0.......5, 5, 5, 1.24.......2, 2, 2, 10.24.......1.06, 1.06, 1.06, 13.06.......7, 7, 1.24, 1....... ................................................................................................................................ 8, 8, .12, .12.......9, 2.24, 3, 2.......10.15, 2.03, 4.06, 0.......11, 2, 2.24, 1.......6, 6, 3, 1.24......4.24, 7, 2, 3......4, 4.24, 7, 1....... .......................................................................................................................................... The point of all these examples is simply to show that a composite result of 4.06 ppt from four soil samples is a significant result demanding further sampling and analyses. I also yesterday compared this soil sample (composite) result to the soil samples taken in the 2017 and 2020 Canagagigue Creek Soil & Sediment Investigations. As indicated yesterday the 4.06 ppt concentration exceeds 56% of the dioxin/furan concentrations found in the most recent 2020 Creek Investigation and 44% of the dioxin/furan concentrations found in the 2017 Creek Investigation. All of these dioxin results are from areas either on the former Uniroyal Chemical site or in the immediate vicinity. These dioxins especially 2,3,7,8 TCDD are Uniroyal Chemical signature chemicals from the production of Agent Orange for sale to the U.S. military in the American War against Vietnam.