Gail Martin, Independent Editor
Pumping rates for Chemtura’s offsite collection and treatment system have dramatically improved in recent weeks.
That’s thanks to bypassing one of the collection wells from the ammonia treatment system (ATS), after Chemtura officials noted that ammonia levels near that particular well were below drinking water standards.
Through this change, W3 is now pumping at a rate of 18.9 L/sec, well above the target rate of 11.4 L/sec. A nearby well, W4, I snow pumping at 15.1 L/sec, again, above the target pumping rate.
Dwight Este, with Chemtura, noted that the company is still working on fixing the problems that have plagued the ATS. The system, which uses a biological component to remove ammonia from the contaminated groundwater, has been struggling for some time. The bacterial sludge used in the system has not been settling properly.
Chemtura discovered that one of the problems has been the breakthrough of other contaminants to the sludge system, adversely affecting the health of the bacteria. By replacing the activated carbon in the system, that problem is now resolved, said Este.
A consultant has also worked with Chemtura on ways to improve the overall health of the biological component, including the introduction of new bacteria to the system.
The system was also not operating during one week in June, when the activated carbon was replaced in the W3 groundwater system.
Former CPAC members Susan Bryant and Pat McLean, representing the APT-Chemtura committee, raised the issue of whether Chemtura still regenerates its activated carbon onsite, through its carbon regeneration kiln.
The concern was whether there was potential for airborne discharge of the contaminates through this system, which would be receiving more contaminated carbon.
McLean suggested that it would be time for Chemtura to do stack testing on the kiln, to ensure that the system is not emitting dioxins into the air.
Este said that Chemtura, is required to have a continuous emissions monitor on the kiln, according to the certificate of approval it has from the MOE.
McLean then asked whether these results were included in Chemtura’s monthly progress report.
Este said this information was not included.
“Then, I guess my question is, why not?” said McLean.
“It’s never been asked for before,” replied Este.
Later in the meeting, CPAC chairman Dan Holt asked Este whether this information could be included in future reports.
Este said it could, but he had concerns on how to present the information, as the test results are generated every few minutes.
“There is a lot of data,” said Este.