Deadline to comment on Ash Grove Cement emissions
We are writing once again to provide an update on the local environmental concern associated with Ash Grove Mississauga Cement Plant (formerly St. Lawrence Cement then Holcim Canada) located at 2391 Lakeshore Road West, Mississauga. Ash Grove was acquired by CRH, a Dublin-based multinational company, in 2015.
Ash Grove cannot meet the 2023 provincial air quality/emission standards put in place by the Ministry of Environment Conservation and Parks (MECP). As such, they are asking the Ministry to approve an alternate standard, known as “site-specific standards” (it is comparable to an exemption) for its operations. There is an opportunity for our community to comment on Ashgrove’s proposal via the MECPs Environmental Registry of Ontario (ERO).
If granted by the Ministry, it would allow Ash Grove to continue to emit in excess of the provincial standards for the next 10 years or potentially longer.
Ash Grove’s current emissions for sulphur dioxide (SO2 ) is approximately 12 times the recommended level and nitrogen oxides (NOx), approximately 4 times the recommended level. These emissions are harmful to our health and the environment, creating smog and acid rain.
In 2018, the Ministry of the Environment notified all facilities of upcoming changes to standards and the need to determine modelling tools to ensure facilities would be able to meet provincial standards particularly SO2 and NOx. Ash Grove failed to do this and is now unable to meet provincial air quality standards unless they reduce operations.
The Clarkson area is home to the largest concentration of heavy industries in Mississauga and our air quality is stressed. Clarkson residents deserve better.
Considering the proposed residential densification of our area, air quality concerns are of increasing importance.
If you, too, feel this is an important issue and want to add your voice to the debate, please download this template letter or compose your own letter and email it to the list of people shown at the top of the letter, with cc to Park Royal Community Association. The deadline to comment on the ERO posting is September 8, 2025.
Please share this communication with neighbours and other residents in the Clarkson area and encourage them to add their voices.
