Lyons Creek East Sediment Cleanup Project

Lyons Creek is a small watercourse located in Welland, Ontario. It flows into the Welland River and eventually the Niagara River. The project area is the creek itself, east of the Welland Canal extending approximately 7 km to McKenney Road.

Chemicals called polychlorinated biphenyls (PCBs) were discovered in a portion of Lyons Creek East in the 1990s. While PCBs were banned in the 1970s, they remain in the environment for a long time. PCBs can negatively impact the environment and human health depending on the concentration and type of exposure.

Learn more: https://www.canada.ca/en/health-canada/services/healthy-living/your-health/environment/pcbs.html

Polychlorinated Biphenyls or PCBs are human-made chemicals used in industrial applications (e.g., lubricant and in electrical equipment) from the 1930s to 1970s. The chemical was banned in 1977 due to its negative impact on the environment. PCBs do not break down easily and remain in the environment for a long time.

PCBs can negatively impact human health depending on the concentration and type of exposure.

The contaminants are deep in the bottom of the creek. A human health risk assessment concluded the risks to humans was low and related to eating fish caught from Lyons Creek East. A community survey and field observations showed fish consumption was not occurring within the area of interest.

As an additional way to reduce risks to human health, there are fish consumption advisories in place by the Province of Ontario that limit the number and type of fish that can be eaten based on set guidelines.

Please refer to the Guide to Eating Ontario Fish for more information: https://www.ontario.ca/page/guide-eating-ontario-fish

Learn more about the potential health effects: https://www.canada.ca/en/health-canada/services/healthy-living/your-health/environment/pcbs.html#he

The PCB contamination was discovered in 1990 following an accidental spill from a transformer in Lyons Creek West (on the other side of the Welland Canal).

The spill triggered an investigation to determine the extent of contamination and led to the discovery of historic (deeper) contamination in both Lyons Creek West and East which most likely predated the construction of the Welland Canal By-Pass. 

Lyons Creek West was remediated in 2007.

No, there are no ongoing sources of PCBs in Lyons Creek. The chemical was banned in the 1970s. Based on the type of PCB and its depth in the bottom of the creek, the source is deemed historic when PCBs were used broadly across Canada.

No, the PCB contamination is limited to a specific area of Lyons Creek, east of the Welland Canal to McKenney Road. The area from Doans Ridge Road to McKenney Road is the least contaminated and currently showing signs of natural recovery.

The Lyons Creek East project area is divided into zones based on the level of PCBs determined by sediment core sampling. The highest level of PCBs in sediments are in Zones 1-4 and decrease further downstream into Zones 5-7 (see map).

Monitoring shows that the highest concentrations of PCBs are in deeper layers of the creek bottom (depth of 25-50 cm). Cleaner sediments are closer to the surface.

Following numerous technical studies, a discussion paper was prepared with potential options to manage the contaminated sediments at Lyons Creek East.

Four options with varying levels of remediation, impact, and costs were considered through public consultation. The selected option was monitored natural recovery with administrative controls to prevent disturbance of the sediments.

This option was chosen instead of removal because leaving the sediments in place posed low to no risks to wildlife and human health, protected the sensitive ecological (wetland) features, and assumed recovery would occur with the natural burial of contaminated sediments over time. The site has been monitored since 2008.