2011 BIOMONITORING STUDY USING CLAMS and LEECHES

This used to be annual, now biannual, study is conducted in the Canagagigue Creek at Chemtura in Elmira. Essentially clams and leeches in separate cages are left in the creek for a number of weeks and then they are removed, counted for mortality, and the surviving ones killed and their tissues studied. Apparently both these creatures rapidly uptake certain contaminants from the water column. The clams tissues are examined for Dioxins/Furans as well as DDT. The leeches are examined for Chlorophenols.

There really aren't too many surprises. Chlorophenols which don't adhere readily to soil particles the way Dioxins and DDT do, were quickly diminished in the water column after the UACS (Upper Aquifer Containment & Treatment System) was implemented in 1997. Dioxins and Furans however were not so dramatically removed from the clams until after the excavations along the south-west portion of the creek in 2006.

There are a couple of surprises/anomolies however. Table 4.2 shows that the highest Toxic Equivalents (TEQS) for Dioxins and Furans were at Stations 6, 8 and 10 in 2011. When one checks the map (Fig 1.1) Station 6 corresponds with Shirt factory Creek which runs through Chemtura's property and 8 & 10 are immediately downstream from it. It is possible that these Dioxins are coming from either Chemtura's property or from upstream in Elmira.

Table 5.1 shows the expected distribution of Dioxins predominantly in the south-west (ie. Stations 10- 17). It also shows the expected decreases after the excavations of the creekbanks and island in 2006. One interesting point is the consistent detections of Dioxins in the northern half of the site (Stations 1- 8). 2011 results are higher than they've been for a number of years at three Stations.This is a little surprising as there has been some remedial work done along the creek in the northern half as well.

Table 5.2 deals with DDT in clam tissues. Table 5.3 deals with Chlorophenols in Leech tissues. Again as expected, SOURCE REMOVAL is an excellent remediation tool and these Tables prove that.

These biannual monitoring reports prove that Source Removal works. They do NOT prove that hydraulic containment is a permanent long term solution. For example Conestoga Rovers and Chemtura would have you believe that locking up illegal drugs in the household is a better solution than removing them entirely.