Elmira aquifer cleanup work expected to go past 2028 deadline

Latest computer model shows Chemtura’s treatment efforts may not be completed as targeted; watchdog group to discuss implications

WITH NEW COMPUTER MODELS showing the efforts to restore contaminated aquifers under Elmira may not meet the 2028 deadline, the public group charged with monitoring the process is now contemplating what happens afterwards.

The township’s Technical Advisory Group (TAG) met last week to go over a report released by Chemtura on June 29 detailing the most recent findings from the chemical company’s model check point analysis. Completed last year, the report predicts that N-Nitrosodimethylamine (NDMA) in the groundwater will be almost completely gone by the provincially-mandated 2028 deadline, but not totally.

Chemtura Co. has been using a pump-and-treat process to remove a pair of toxins – NDMA and chlorobenzenes – from the former drinking water aquifers underneath Elmira. Discovery in 1989 of the carcinogenic NDMA precipitated a water crisis, leading to the construction of a pipeline from Waterloo, which supplies the town with water to this day.

Jeff Merriman, Chemtura’s manager of environmental remediation, wasn’t at the July 14 meeting, but he says according to the computer-generated model, the site will be 99.7 per cent cleaned up by the 2028 deadline, but even that number isn’t certain. It could be completed earlier.

“This is a computer model. This is a mathematical representation of a complex hydrogeological system and it is not meant to be a definitive predictor of what the groundwater concentration would be like. This is not an absolute,” he said. “This model uses conservative assumptions. They are assumptions that tend to over predict the contaminant concentration. So, the actual NDMA that is present in 2028 may not be as high as this model predicts. It could be better.”

TAG chairman Dick Jackson said there was a sense of disappointment at last week’s meeting when the group heard the cleanup could possibly have to continue past the 2028 target date. There was also a deeper understanding among members about the process of cleaning up the contaminants.

“Fifteen years after the pump-and-treat operation started up, we understand better how difficult it is when you have contamination in the silts and clays of

the aquatard, to clean up the aquifer. I really didn’t want people to be of the belief that things will be met, that that deadline will be met,” he said after the meeting. “There are various community activists who feel this is us being misled, but that is what we are going to discuss in our next TAG meeting in the first week of September.”

Merriman said that there is an expanded pump-and-treat system currently being installed at the contaminated sites. They should be up and running in the fall. Then, Chemtura will do more modelling to see where the process stands. The expanded system was planned and put in place after a 2012 analysis showed slower than desired progress in the cleanup of left behind contaminants.

When TAG meets again in late September, Jackson said he is planning to see a conceptual site model put together for reference, encompassing all of the information about the Elmira contamination and the processes involved in the cleanup.

“It will make it easier for people to understand what is going on,” he said. “We also believe that it will make it easier to plan for the future and for future remediation. Based on the this recent modeling exercise, everybody is essentially going away to think this through.”

For Jackson and TAG, the next step is to ponder the implications of not meeting the predicted 2028 deadline for contamination cleanup.

“That is where we are. That will be the first week of September,” he said. “That, and the Canagagigue Creek, because the creek is still very much on our minds.”