Environmental Stewardship
Chedoke Creek Remediation
Council Communication Updates
Chedoke Creek updates provided to Hamilton City Council and Standing Committees.
Chedoke Creek Remediation Workplan
The City of Hamilton was served a Ministry of the Environment, Conservation and Parks (MECP) Order on December 4, 2020, as a result of the Main/King Combined Sewer Overflow discharge that occurred between January 2014 and July 2018. The City of Hamilton has been working closely with the MECP and the Royal Botanical Gardens (RBG) to develop a remediation workplan for both Chedoke Creek and Cootes Paradise in response to the Order.
Chedoke Creek Targeted Dredging
The goal of the targeted dredge project is to improve the condition of the creek prior to the beginning of the discharge event. As indicated in the MECP approved Chedoke Creek Workplan, the City implemented short term offsetting remediation projects in areas around lower Chedoke Creek and Princess Point to further improve the condition of the water. The Cootes Paradise Workplan addresses the long term offsetting work required by the order. The goal of the Cootes Paradise Workplan is to improve the quality of water into both Chedoke Creek and the receiving bodies of water.
Project Update:
On December 20, 2022, the MECP Director approved the City’s requested deadline extension to December 31, 2023, with all other items in the Order remaining in effect, and unaltered. On March 3, 2023, the MECP Director issued a revised amendment which requires that the in-water targeted dredging work be completed by August 31, 2023, with the remaining activities in the approved Chedoke Creek Workplan completed by December 31, 2023.
Subsequently on March 14, 2023, after positive and collaborative discussions between the City and the MECP, the MECP Director issued a revised amendment, which supports the City’s concerns regarding the previous deadline and still expedites the remediation of Chedoke Creek. As such, the City is now required to complete the in-water targeted dredging work on or before October 31, 2023. The City has completed the permitting and approvals process and will inform the various internal and external stakeholders of this amendment to the Order.
Offsetting projects, removal of sediment (targeted dredging) and potential impacts to the community
As part of the Chedoke Creek Workplan, offsetting remediation projects have been completed to complement the targeted dredging work. Two initiatives including the installation of floating treatment wetlands and the installation of a small scale aeration system were undertaken to improve water quality conditions in the creek.
Floating vegetative mats, also known as floating treatment wetlands, are used to manage and remove excess nutrients from surface waters under a variety of conditions. These wetlands are artificial floating platforms that allow aquatic plants to grow in sites of varying water levels. Native wetland species are planted on the platforms allowing aquatic root growth below into the underlying water. The roots trap suspended sediment and discourage growth of algae by reducing phosphorus and nitrogen, thereby improving water quality. The City has installed one floating treatment wetland within Cootes Paradise, with support from the RBG, which can be seen from the Desjardins Trail. Expansion of the project to other areas within Cootes Paradise is currently under evaluation.
Diagram description
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As pollutants enter the waterway, algae feeds off the harmful nutrients. The algae then multiplies, causing disruption to the natural ecosystem.
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The floating wetlands allow plants to grow above the algae. The roots then trap suspended sediments and discourages the growth of algae by reducing phosphorus and nitrogen from the water.
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Reduction in phosphorus and nitrogen therefore improves water quality, stimulating greater natural plant growth and a healthier habitat for fish, birds, insects and other wildlife.
Together the plants and bacteria create a living, breathing filter system that helps reduce the amount of contaminants and harmful nutrients in the water.
The City of Hamilton has installed a small scale aeration system in Chedoke Creek to help increase oxygen levels at the bottom of the creek while decreasing the amount of excess nutrients that contribute to algae blooms and cloudy water. Due to a decrease in temperature, the pumps are turned off in the winter months. The system is required to be removed for the targeted dredging activities to take place, but will be re-installed at the end of the project. A larger aeration system will be considered during the Lower Chedoke Creek Environmental Assessment Study.
How does it work?
- A compressor pumps air to the bottom of the creek through diffusers.
- In this process, the oxygen-poor water rises to the surface where it picks up oxygen from the diffusers and the surface.
- The oxygen-rich water then returns back down to the bottom where beneficial aerobic bacteria use the oxygen to digest organic matter, eliminating harmful excessive nutrients.
The dredge activity will remove approximately 11,000 cubic metres of sediment including 24 tonnes of total phosphorus (TP) and 31 tonnes of total Kjeldahl nitrogen (TKN) from Chedoke Creek over a 4-5 month period.
Pre – Targeted Dredging
Work to complete the dredge design included a topographic survey, species at risk investigations, hydrologic & hydraulic modelling and sedimentation investigations. The sediment quality samples were collected at numerous locations within Chedoke Creek, the Princess Point Embayment and Cootes Paradise in the spring of 2021. Additional deeper samples were collected in August 2021 to better inform the dredge design. Based on the results and the design process, the project expects to remove 24 tonnes of TP and 31 tonnes of TKN within the targeted dredging area
Dredging
Targeted dredging will occur within an identified area of Chedoke Creek to remove contaminated sediment from the creek bottom. Over a 4 – 5 month process the following activities will be completed:
- Preparation Work areas within the creek will be isolated using a turbidity/silt curtain that will have a weighted line to maintain contact with the bottom of the creek. The top float line will help isolate the work area at the surface. Fish and wildlife will be removed from the work area prior to the dredging activities by a qualified aquatic biologist, reducing potential interaction with the dredging operation in accordance with governing protocols.
- Removal Sediment will be removed from the creek bottom using a hydraulic dredge which utilizes a cutterhead and pump to vacuum and transport the sediments to the dredge material management area which is located within Kay Drage Park. The average combined dredge depth will be approximately 1.0 m which will remove approximately 11,000 m3 of sediment from the bottom of the creek.
- Dewatering Dewatering is the intentional removal of water from solid material or soil. In order to remove and dispose of the sediment efficiently, dewatering will occur at the dredge material management area. A 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 landfill.
- Repeat The dredge area has been broken up into two zones, North and South. The total dredge area spans between 100m north of the Desjardins Trail pedestrian bridge and 100m south of the Kay Drage Park bridge. Each zone will be broken-down into small sections so that only half the creek, as required by permitting, is blocked by dredging operations. Starting in the North Dredge Zone, after each section is completed, the contractor will reset in the next section and continue to dredge until complete.
Post – Dredging
- Restoration works will occur at the material management area, Kay Drage Park in spring 2023.
- Surface water quality testing will continue after the dredge work has been completed. Results will be compared to historic data to determine the impacts of the dredge activity.
- Various post dredging monitoring efforts will take place to support each agency’s permitting and approval requirements including any changes in water levels, sediment quality of the newly exposed creek bottom and the functionality of any added species at risk habitat.
- Park Closure - Kay Drage Park will be closed for public access for the duration of the dredge activities. Starting June 2022 the Park will be used as a staging area for dredge preparations and will be utilized throughout the project as the dredge material management area. Upon project completion, the park will require restoration work.
- Access Trail Closure - Located behind the Nicholas Mancini Centre (44 Hunt Street), is a trail that accesses Kay Drage Park. This trail will be closed to the public for the duration of the dredge activities and will reopen once the park restoration work has been completed. In order to facilitate the dredge machinery entering the Creek, the Desjardin Recreation Trail Bridge is required to close for 2 half days. Once confirmed, the date will be posted. Signs will also be posted during both closures.
- Transportation Routes - Trucks will be used to remove the sediment from the dredge material management area. Dredging activities will occur 5 days a week (Monday to Friday) with approximately two trucks an hour removing sediment.
- Odour - no expected impact due to the dredging method (hydraulic) and the dewatering method (geotextile containers) keeping the dredged material contained. Provisional odour mitigation tools will be utilized should odours become a nuisance.
- Noise - no expected impact, but should a concern arise, please report a noise concern to the number below.
- HSR - no expected impact as buses will be given priority on the trucking route.
- Public Health Services Advice - Avoid contact with water. Water may contain high levels of bacteria that can make you sick.
To report a concern please call 905-546-2489 and state the call is related to Chedoke Creek.
| Agency | Required Permitting | Approved Permit |
|---|---|---|
| Ministry of Environment, Conservation and Parks | Permit to Take Water Overall Benefit Permit |
MECP PTTW (DRAFT) No P-300-716143259_v.1.1 MECP SAR WC-C-001-22 |
| Hamilton Conservation Authority | Conservation Authority Work Permit | HCA – 2022 – 06 |
| Ministry of Transportation | Building and Land Use Permit | MTO – BL – 2022-20T-00000036 |
| Transport Canada | Canadian Navigable Waters Act Permit | TC – 2021-405815 |
| Fisheries and Oceans Canada | Species at Risk Act Permit | DFO- SARA- 21-HCAA-00211 |
| Royal Botanical Gardens | Research Permit | RBG – 2021-07 |
| City of Hamilton | Construction Dewatering Sewer Discharge Permit | #220701-G (22760) |
Chedoke Creek Remediation
Frequently Asked Questions
The City of Hamilton has taken all necessary steps to ensure wildlife and species at risk located within Chedoke Creek and Cootes Paradise are protected throughout the remediation process. These steps have been in accordance with all six governing bodies including the MECP, Hamilton Conservation Authority, Ministry of Transportation, Transport Canada, Fisheries and Oceans Canada and Royal Botanical Gardens to proceed with remediation work. Some of the measures taken include:
Pre-dredge/during dredge:
- Before moving ahead with targeted dredging, Species at Risk (SAR) investigations were required by Fisheries and Oceans Canada and the Ministry of Conservation and Parks to be completed by the City of Hamilton in 2021. The investigation concluded that the Lilliput mussel was the only SAR identified that has the potential to be within the project area.
- In June 2022, Lilliput mussels were collected and relocated by two qualified aquatic biologists hired by the City.
- In August 2022, The City of Hamilton completed bluegill habitat enhancement work in Cootes Paradise as part of its Ministry of Environment, Conservation and Parks (MECP) permit. By installing over 10 brush piles, 35 nesting structures and five root wads, the City is improving bluegill habitats, and by extension, Lilliput mussels that latch on to bluegill fish.
- Based on the Ministry of Northern Development, Mines, Natural Resources and Forestry regulations and the fish species present, in-water work is prohibited from March 15 to July 15 each year to ensure no negative impacts on fish spawning.
- Prior to dredging activities, each work area in the creek is isolated using a turbidity/silt curtain that includes a weighted line to maintain bottom contact, and a floating line to isolate the work area at the surface. Fish and wildlife are excluded from the work area prior to the dredging activities by a qualified aquatic biologist, mitigating potential interaction with the dredging operation in accordance with governing protocols.
Post-dredge:
- Various post-dredging monitoring efforts will take place to support each agency’s permitting and approval requirements including monitoring any changes in water levels, sediment quality of the newly exposed creek bottom and the functionality of any added species at risk habitat.
The dredging will occur in two separate dredge zones – north and south. Work will start at the north end of Chedoke Creek, near the Desjardin pedestrian bridge and will move southwards toward Kay Drage Park. Residents will be able to see the dredge machine from the waterfront trail and Desjardin pedestrian bridge while work occurs in the north zone.
Residents can still expect to see some work occurring in wet weather conditions.
Permitting requires that the creek flow remain unimpeded, so each dredge zone will be broken down into smaller isolated sections covering only ½ the creek.
Turbidity curtains separate the work zone and allow the creek to continue flowing, while also allowing the City to safely isolate from any wildlife and keep the dredge material from disrupting the rest of the creek.
The Chedoke Creek Workplan outlines the steps associated with targeted dredging in Chedoke Creek. This work will remove nutrient laden sediment from the creek bottom and is scheduled to be completed before the end of 2023. The goal of the targeted dredge project is to improve the condition of the creek prior to the beginning of the discharge event.
The Cootes Paradise Workplan addresses the long-term offsetting work required by the order. The goal of the Cootes Paradise Workplan is to improve the quality of water into both Chedoke Creek and the receiving bodies of water.
Once the sediment is removed from the creek using the hydraulic dredge, it will be transported via pipeline to the dredge material management area which is located within Kay Drage Park. In order to remove and dispose of the sediment efficiently, dewatering will occur at the dredge material management area. 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 landfill.
Sediment remaining in the Geotubes are anticipated to be disposed of offsite at 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.
Dredging will be completed hydraulically. This means we 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.
No – the site will look as it did before work started. Kay Drage Park is expected to be restored to its original condition and re-open to the public at project completion.
Date modified
March 31, 2023