2017 CANAGAGIGUE CREEK SEDIMENT & FLOODPLAIN INVESTIGATION

The final draft of this report came out last week. I received part of the hard copy of it yesterday as reported here yesterday. The title is poorly named because of the very few floodplain soil samples taken. There were numerous soil samples taken but they were creekbank soils (i.e. above the normal water level of the creek). Following are a list of the dates here in the Advocate that I posted about the draft copy of this report one year ago. The dates are March 24 & 28, 2018 as well as April 5, 6, 9, 10, 11, 14, 15, 16, 2018. Most of these posts are very critical of the draft report due to its user unfriendliness and fatal errors such as locational biases as well as method detection limits (MDL) that far exceeded the environmental criteria for DDD, DDE and DDT. I believe that the stated exceedances of criteria were minimized for the DDT compounds and break down products by these far too high MDLs.

To be more specific the standard MDLs seem to be 20 parts per billion (ppb) which is the same as .020 parts per million (ppm). This means that any concentrations below this 20 ppb value will be designated as ND (.020) which means Non-Detect at a detection limit of 20 ppb. The criteria for DDD, DDE and DDT in sediments is 8, 5, and 7 ppb. Therefore exceedances are only noted for DDD when the concentrations are actually 2 1/2 times higher or more than the criteria of 8. Exceedances for DDE are only acknowledged when they are four times or more higher than the criteria of 5 ppb. Exceedances for total DDT are only acknowledged when they are almost triple the criteria (7) or higher. Therefore these unreasonably high MDLs serve to downplay and minimize the extent of DDT & metabolytes contamination in the sediments of the Canagagigue Creek.

It gets worse of course. I stated that the normal or standard MDL for DDT compounds was 20 ppb. In fact there are numerous instances when the MDL is at 30, 40 or 60 parts per billion.Incredibly there are even a few instances of MDLs for these contaminants at 100, 110 and 140 ppb. Of course the figures and maps have the highest DDD, DDE and DDT exceedances coloured for quick and easy reference. Oddly they don't have any of the high or extremely high MDLs coloured for easy reference. Based upon the number of Non Detects at detection limits (MDL) far in excess of the criteria it is my opinion that this report is intentionally deceptive and misleading and greatly understates the extent of toxic contamination in the Creek.