Cabot Canada Ltd. proactively curtailed one of its production units on Thursday afternoon.
The action was taken at the Tashmoo Avenue plant in response to elevated sulfur dioxide (SO2) levels observed at the Ada (Lockridge) Rogers Air Monitoring Station -- located in the area of the Aamjiwnaang First Nation Band Office.
"While there have been no operational upsets or changes that would increase our emissions, this measure has been taken to minimize our contribution to the elevated levels in the area," Cabot said in a message shared by Sarnia-Lambton Alerts at 3:30 p.m.
Cabot said the unit will remain offline until community SO2 levels return to acceptable thresholds.
UPDATE: Cabot returned to normal operations just before 9:30 a.m. on Friday, May 9. The company said SO2 levels at the monitoring station had returned to acceptable thresholds.