Murky water in Green's Creek blamed on nearby Lafarge quarry

Runoff from the sprawling Lafarge Canada property on Bearbrook Road in east Ottawa is being blamed for the sudden "murky" appearance of the water in nearby Green's Creek, both the city and Ontario's Environment Ministry have confirmed.

Residents of Blackburn Hamlet began noticing discoloured water in the creek last week. One wrote in a community chat group that they "saw discoloured water and smelled something strange" while crossing a pedestrian bridge.

The Ministry of the Environment, Conservation and Parks confirmed earlier this week that its Spills Action Centre was notified of the "murky water flowing in Green's Creek" on Nov. 20. 

"We have since determined that the unpaved parking lot at the south entrance of the Lafarge site is the source of sediment observed in the creek," a ministry spokesperson wrote to CBC, adding it had detected "no spills or operational upsets within the active quarry area or at the concrete and asphalt production areas" of the Lafarge property, which sits across Bearbrook Road from Green's Creek.

The ministry has therefore deemed the incident a "municipal drainage issue" and has handed the investigation over to the city, the spokesperson said.

Cleanup underway

In a statement attributed to Marilyn Journeaux, Ottawa's director of water linear and customer services, the city said its preliminary investigation "has identified that the source of the spill was a cement truck wash and rinse area. The water used to clean the trucks flowed to the nearby ditch and then to Green's Creek nearby."

The city said it's working with Lafarge "to ensure that proper remediation and protections are in place to prevent future occurrences."

"We are looking to ensure that the spill has been contained and cleaned," the city later specified.

"Additionally, ensuring any future washing and rinsing of vehicles has protections and that sediment and erosion control measures are in place so that wastewater and runoff is captured on site and no longer enters the ditches and nearby creek."

Green's Creek and the recreational paths that run alongside it belong to the National Capital Commission (NCC).

The NCC said it's aware of the incident and is "working with the relevant authorities," but did not provide any additional information.

According to Lafarge Canada, its records show water discharges from its property upstream of the culvert "remain fully compliant with our permit limits." 

In an emailed statement to CBC, the company said the material in question "consists of road dust, limestone sediment, and concrete fines generated during site operations."

Lafarge to provide update

The city has not issued any public advisories regarding the incident, but according to a statement from Ottawa Public Health (OPH), "general concerns" related to cement and concrete products include "the potential for altering the pH levels of the water, which can harm aquatic life and the environment."

Additionally, ingestion or direct contact with concrete wastewater can cause skin and eye irritation, respiratory issues "and potential chemical burns, especially at higher concentrations," OPH said.

The area in question is also home to multiple outdoor soccer fields and a sports dome at Hornets Nest Park.

Lafarge said it's aware of the public concern over the incident.

"We understand the community's questions and we will soon provide an update to ensure transparency and address any outstanding concerns," the company said.