Environmental impact of the chemical industry in Sarnia

Sarnia's "Chemical Valley" and the surrounding area are home to 62 facilities and refineries. A 2007 Ecojustice Canada report showed those industrial facilities located within 25 km of Sarnia, Ontario, Canada emitted more than 131,000 tonnes of air pollution in 2005.

Air pollution and disease
In January 2011, the Sarnia Observer noted "Sarnia had by far the highest levels of fine particulate matter recorded at any of the province's 40 monitoring stations, with significantly sootier air than Windsor, Hamilton, Kingston, and Chatham". In September 2011, the World Health Organization reported that "While Canada ranks third in the world when it comes to air quality, Sarnia was ranked the worst city in the country, with the most particulate matter per cubic metre of air." Pamela Calvert's 2006 documentary on the Aamjiwnaang First Nation, The Beloved Community, states that the Aamjiwmnaang birth rate of males to females is 1 to 2, the lowest live male birth rate in Canada. There is also correlation between Sarnia and cancer rates among men — 34% higher overall cancer rate than the provincial average, a lung cancer rate that is 50% higher, a mesothelioma rate five times higher and an asbestosis rate nine times higher.

However, the Observer also stated in the January 2011 article that, "Sarnia has reduced its nitrogen dioxide, carbon monoxide and sulfur dioxide problems by 30% in the last three years" and "Environment Minister John Wilkinson said it's the first time in the report's 39-year history pollutants have not exceeded provincial monitoring standards. That translated into a record low of three smog advisories and five smog days in 2009."

A Lambton County document indicated that in 2005, up to fifty-five percent of ground level ozone and fine particulate matter emissions come from neighboring US facilities, which "play a significant role in air quality considerations on a regional scale."



A 2019 study reviewed incidence of acute myeloid leukemia from 1992 to 2010 in industrial Ontario cities and found that parts of Sarnia had an incidence rate three times higher than the national average.

On May 17, 2024, after elevated benzene levels were detected at the Ineos Styrolution fence line and Aamjiwnaang First Nation, Minister of Environment and Climate Change Canada Steven Guilbeault issues an interim order under the Canadian Environmental Protection Act that would require Sarnia’s petrochemical facilities to implement vapour-control measures, “including fully closed vent systems with vapour control on certain storage tanks that store benzene.” The order applies to facilities with fence line concentrations of benzene above 29 μg/m3 measured in any of the two-week sampling periods beginning on March 1, 2023, and ending on February 29, 2024.

On June 11, 2024, Ineos Styrolution announced that it would permanently close its Sarnia facility by June 2026.

Water pollution
Water pollution is a serious concern in Sarnia. A June 2003 Ryerson University study concluded that the main source of water pollution in the St. Clair River occurs at the Sarnia Water Pollution Control Centre (WPCC) due to chemical spills and ship emissions. In 2008, the city resolved to replace the aging sewer pumps that controlled the effluent. Minutes of a meeting between Mayor Mike Bradley and Sarnia City Council state, "The cost of repairing the raw sewage pumps is a significant portion of purchasing a new unit. However, based on the performance of the existing units over the past 8 years, City staff prefers to look at other manufacturers for replacing the existing Fairbanks-Morse pumps as they require their second rebuilding." In 2010, though, the Water Distribution Report indicated that "no filter effluent turbidity exceeded the prescribed test result for adverse reporting..." Further, the Water Distribution Report concluded that "No inorganic or organic parameters exceeded half the standard prescribed in Schedule 2 of the Ontario Drinking Water Quality Standards."

Shale Gas controversy
There are plans to bring shale gas into Chemical Valley by pipeline in mid-2013. This process is environmentally divisive because it necessitates hydraulic fracturing to extract the gas. Environmentalists oppose hydraulic fracturing since it can damage water supplies and produce long-lasting toxic deposits, while supporters promote the employment benefits to the Sarnia petrochemical industry.

Warning sirens
Due to the risk of hazardous materials incidents (chemical emergencies) occurring in the industrial corridor south of Sarnia, four sirens have been placed in Sarnia south of Wellington Street, three more on nearby the Aamjiwnaang First Nation reserve, three in Corunna, and one in Point Edward. In the event of an emergency requiring immediate action by the public, the sirens are sounded for a three-minute period, serving as an alert to the public to seek shelter indoors and to tune to a local radio station for updated instructions. An emergency Command Centre located at the Sarnia Police Station can coordinate deployments of emergency responders during hazardous materials incidents.