Posted on July 24, 2023
The long-awaited dredging of Chedoke Creek is now underway. This week large obstacles such as tree branches are being removed from the waterway. Next wee a hydraulic dredge mounted on a barge will begin the process of vacuuming sediment from the creek bed. Once the sediment is removed from the creek, it is transported via pipeline to the dredge material management area which is located on the bridge at Kay Drage Park. At that site water is removed from the sludge A lined trench will be built within the material management area to facilitate the dewatering process. The sediment slurry (mix of solid material and water) will be pumped into a geotextile container. An environmentally safe polymer is added to help bind the solids together and separate the water. The separated water will then drain from the geotextile container while the sediment remains inside. The separated water will be pumped to a nearby sanitary sewer main (on dry days only) to be treated at the Woodward Wastewater Treatment Plant. Once the container is full of sediment and the contents have dried, it will be hauled to a a non‐ hazardous waste disposal facility. The disposal timeline will depend on the dredging completion date and the dewatering rate of the sediments. The contractor will monitor the dewatered sediment prior to disposal to ensure the material is fully dewatered, dry and passes a slump test to be classified as solid non‐ hazardous waste.
The dredging is completed hydraulically. Crews will be vacuuming up the sediments (or solids) from the bottom of the creek. The hydraulic dredge utilizes a cutterhead and pump to vacuum and transport the sediments to the dredge material management area via pipeline. The average combined dredge depth will be approximately 1.0 m which will remove approximately 11,300 m3 of sediment from the bottom of the creek.
The work was ordered after the city reported a four-year seepage of billions of litres of untreated waste from the combined sewer overflow tank at Kay Drage Park in 2018 due to an undetected mechanical failure.