Government Information

Chedoke Creek Spill & Remediation Activities

Updated: March 24, 2021

Background Information

In July 2018, the City of Hamilton informed the public that it had discovered that one of its combined sewer overflow tanks was discharging combined sewage into Chedoke Creek. The City immediately stopped the discharge, began clean-up activities in the area, and contacted the Provincial Spills Action Centre.

Since July 2018, the City has been working closely with the Ministry of the Environment, Conservation and Parks (MECP) to investigate the incident, respond to Orders related to the spill, and plan for remediation efforts in the Creek and Cootes Paradise.

Currently, the City is working with the MECP and various stakeholders on remediation activities in the watershed. The City has recently submitted a workplan to the MECP outlining targeted dredging activities in Chedoke Creek and a report proposing remediation/mitigation methods for Cootes Paradise and the Western Hamilton Harbour Area. This work is planned to begin soon.

The City is committed to the remediation of Chedoke Creek and Cootes Paradise.

Frequently Asked Questions

Targeted dredging is the removal of specifically identified sediments and debris from the bottom of a creek or other body of water. The planned field work in Chedoke Creek will collect bathymetric, sediment thickness, and sediment core data that will be used to determine the extent of the dredging material to be removed.

By targeting only the necessary sediments and debris, the impact to the environment, species and overall disturbance to the aquatic ecosystems will be reduced. The targeted dredging will decrease the current nutrient load in the creek and help restore the creek environment.

The City is required to engage with a number of agencies prior to and during completion of the remediation work in Chedoke Creek. The following is a list of the identified agencies who are anticipated to have an interest in the project, per their legislated mandate:

  1. Hamilton Conservation Authority (HCA)
  2. The Royal Botanical Gardens (RBG)
  3. Ministry of Transportation (MTO)
  4. Ministry of Natural Resources and Forestry (MNRF)
  5. Transport Canada (TC)
  6. Fisheries and Oceans Canada (DFO)
  7. Ministry of Environment, Conservation and Parks (MECP)
  8. Archaeology (Ministry of Heritage, Sport, Tourism and Culture Industries)
  9. Indigenous Consultation (MECP / DFO / Local)
  10. Impact Assessment Agency of Canada (MECP)

The City’s Procurement By-law encourages an open and competitive bidding process with the objective of equitable treatment of all vendors and to ensure the best value is obtained.

The City intends to proceed with a prequalification process for the targeted dredge. The prequalification process is separate from the tender process and is undertaken in advance. Only prequalified bidders will be invited to the tender stage. The objective of prequalifying is to screen and short list the most qualified potential bidders which have the required experience in similar dredging projects that used similar equipment as will be proposed.

Tendering for the construction will follow the completion of the prequalification process and will be only open to the prequalified bidders. There typically will not need to be any further technical requirements, however, the City may add new criteria if considered required.

Once construction begins it is estimated to take four to six months to complete and is conditional on the time of year, as well as the scope and need for additional offsetting projects. It will include the following phases:

  • Mobilization
  • Offshore/Onshore Pipeline Routes
  • Dredging
  • Sediment Handling/Dewatering
  • Material Disposal
  • Site Restoration
  • Demobilization

The second part of the Order issued by the Ministry of Environment, Conservation and Parks (MECP) related to the spill in Chedoke Creek is associated with the remediation/mitigation methods to offset the added nutrient loading to Cootes Paradise and the Western Hamilton Harbour Area. This report will be submitted to the MECP in March 2021 and is currently under review.

Within six weeks of approval of the Cootes Paradise Report, the City will submit a Cootes Paradise Workplan that will include specific remediation/mitigation measures for Cootes Paradise and the Western Hamilton Harbour Area. The workplan will consider and address, any items indicated in the Cootes Paradise Report including any Ministry comments.

No. Chedoke Creek is an urban watercourse, which means it collects a combination of storm water runoff and discharges from the City’s combined sewer overflow tanks during large storm events. It is also located directly beside Hwy 403 and close to an old landfill.

For many years, Hamilton Public Health Services has recommended against using the urban watercourses linked to Chedoke Creek for both primary-contact recreational water activities (such as swimming or wading) and secondary-contact recreational water activities (such as canoeing or fishing).

E.coli levels in Chedoke Creek and adjoining waterways have chronically and consistently exceeded federal recommended levels for any contact with the water, including swimming, wading, paddling, fishing and, as such, the area has had warning signs posted for many years prior to the 2018 discharge event because of the historically degraded water quality. The warning signs are expected to remain in place indefinitely.

Investigations have determined that the spill was the result of two separate malfunctions at the Main/King combined sewer overflow tank. First, a station bypass gate in the combined sewer overflow tank that should have been in a closed position appears to have been manually opened to approximately five per cent on January 28, 2014. An error in computer programming showed this as normal operation and, as such, this error remained undetected until July 2018. Additionally, a second gate that should have remained in the open position experienced a mechanical failure in January 2018. The sensor on this piece of equipment did not pick up the failure and was reporting normal operation. Despite extensive investigations, the City has not been able to determine why the first bypass gate had been opened in January 2014.

For a more detailed explanation, watch this video.

In response to the discharge, the City has taken a number of actions toward addressing the impacts of the spill. These include:

  • Immediately reporting the spill to the MECP’s Spills Action Centre.
  • Immediately informing the public that it had discovered the spill via two media releases on July 12, 2018 and July 18, 2018.
  • Upon locating the source of the spill and immediately stopping it, undertaking a number of steps to clean up the creek, including the removal of 242,000 litres of “floatable material” from the surface and edge of the creek.
  • Initiating regular monitoring of the water quality in impacted areas of Chedoke Creek. Within only a few weeks after stopping the spill, sample results showed a dramatic decrease in E.coli levels with a return to levels similar to those seen before the discharge.
  • Initiated and completed enhanced inspections of wastewater facilities and critical equipment.
  • Initiated and completed the revision of our maintenance plans and spills procedures and re-trained City staff

Older cities like Hamilton often have a “combined sewer system” where a single sewer pipe collects and handles both the storm water runoff and sanitary sewage directly from households. When there is a lot of rain or melting snow, the additional volume of water in the combined sewers can exceed the capacity of the system. To help, from the 1980s through to 2010, the City built nine large storage tanks in strategic locations across the city to hold excess water during heavy rainfall. These combined sewer overflow tanks hold more than 314,000 cubic metres of diluted wastewater. During extreme wet weather events, the combined sewer overflow tanks will fill and store the excess water. If the tanks reach their full capacity, they will overflow. If the combined sewer system didn’t have the designed overflow option to release wastewater to the natural environment, large areas of Hamilton would experience flooding, which would impact homes, businesses, roadways, public spaces and, potentially, the public’s health.

For a more detailed explanation, watch this video.

In spring 2020, the City launched a page on its website that provides automated notifications for wastewater bypasses at the treatment plant, and overflows at the City’s 14 monitored combined sewer overflow outfall locations.

Residents can access this page by visiting www.hamilton.ca/wastewatermonitoring. This page also has additional information about types of bypasses and overflows, swimming after heavy rain falls, impacts on drinking water quality and signage at CSO outfalls.

No reported illnesses (i.e. gastro-intestinal infections) have been found by Public Health Services to be associated with contact to Chedoke Creek or linked watercourses. Prior to the COVID-19 pandemic, Public Health Services began a detailed examination of several health data bases to determine if there is any evidence of an increase in human illness associated with the combined sewer overflow tank spill and resulting increased bacterial levels in Chedoke Creek. While that work is currently on hold to allow staff to focus on pandemic work, once completed, the results of that analysis will be reported to Council and the public.

The most recent edition of Health Canada's Guidelines for Canadian Recreational Water Quality states that currently no scientific evidence exists showing that secondary-contact recreational water activities (such as canoeing or fishing) leads to people becoming ill. In addition, Health Canada recognizes that secondary-contact recreational water activities are usually associated with a much lower degree of exposure to the water and, as such, would be expected to be associated with a lower risk of illness. Because of the lack of evidence regarding the bacterial levels associated with increased risk of illness, Health Canada developed its current guideline for secondary-contact recreational water activities by multiplying the limits for primary-contact recreational water activities (such as swimming and wading) by five to develop a limit of 2,000 per 100 ml.

The City now has a dedicated resource to monitor surface water quality associated with city infrastructure that provides additional visibility on the health of our natural surface water assets. The Surface Water Quality Program will sample proposed locations to build ‘baseline’ ambient stream data and review incoming data on a routine basis as well as discuss anomalies, concerns and questions with internal & external stakeholders.

The City is currently in the process of finalizing the Surface Water Quality Program Framework that proposes multiple sample locations with a comprehensive list of parameters. The framework and proposed sample locations will be reviewed by the internal HW Leadership Team, followed by external stakeholders, including the HHRAP community.

The City of Hamilton has also implemented a Quarterly Chedoke Creek Sampling Program that samples Field Dissolved Oxygen and Temperature, and laboratory analyte Escherichia coli (E. coli).

The live map is updated monthly providing current information for each water sample location and is available in an open format through Open Hamilton. This is a work in progress and new information will be added once the framework is complete. As well, data from other agencies will become available once the appropriate memorandums are in place.

Chedoke Creek Sampling Program

  • Glen Road Inspection and Monitoring Program - Calder Engineering (July 19, 2018)
    Calder Engineering was contracted to inspect the twin box channel underneath Main Street and King Street that carries Chedoke Creek under the roadways.  A physical entry was planned and executed to collect information regarding the status of the channel given identified water quality concerns.  This inspection report identifies the activities that took place to find evidence of unintended wastewater flows entering Chedoke Creek.  Observations are made in the report for a number of flow points entering the channel.  This report identifies the presence of wastewater flow entering the enclosed channel.
     
  • Quantification of Volume and Contaminant Loadings - Wood Group and Hatch (September 28, 2018)
    Hatch was sub-contracted through Wood Group as a qualified consultant to provide a report estimating the volume and loadings related to the Main & King CSO tank discharge between January 28, 2014 and July 18, 2018.  This report comments on the magnitude of the event based on a modelling exercise, producing the estimated quantity of flow and the estimated tonnage of materials it was carrying into the receiving water environment.  Limitations of the methods used to communicate quantities are outlined in the report.
     
  • CSO Facilities Inspection Report - Hatch (October 31, 2018)
  • CSO Facilities Inspection Report - Hatch (November 30, 2018 Addendum)
    In response to the Main & King CSO tank discovery, work was done to assess all of the City’s CSO facilities.  This report was written to confirm that all CSO facilities have been inspected to ensure proper functionality of all critical valves and gates that can lead to a source of environmental discharges.  An inventory of those key assets was also produced.
     
  • Chedoke Creek Natural Environment and Sediment Quality Assessment and Remediation Report - Wood Group (January 24, 2019)
    Wood provided an assessment of the natural environment and sediment quality of the Chedoke Creek that was impacted by the identified discharge from the Main & King CSO tank.  This work included field activities and looked at several parameters in the Creek both in the surface water and in the sediment in order to determine the potential impact of CSO discharge.  Based on the natural assessment information and site findings, this report also evaluated a number of remediation options and further discussed dredging as a remedial action recommendation. 
     
  • Implementation and Costing Report - Wood Group (January 24, 2019)
    This report takes the conclusions from the Natural Environment and Sediment Quality Assessment and Remediation Report by Wood and develops an implementation plan for execution of a dredging operation.  Information identifies high level tasks, approvals, stakeholders, project sequencing, high level order of magnitude cost estimation, estimated timelines and logistical elements to be aware of for implementation of the remediation activities.
     
  • CSO Facilities O&M Plan - Hatch (January 31, 2019)
    This report uses information developed as part of the CSO Facilities Inspection Report by Hatch to review and update drawings, Process Control Narratives as well as develop Operation and Maintenance Plans for all City CSO facilities that contain critical equipment identified in the previously generated inventory.  This report builds upon information developed in the CSO Facility Assessment released October and November 2018.  Updated Standard Operating Procedures and Process Control Narratives were produced in parallel with this report to improve operating documentation used by staff.
     
  • Peer Review - Chedoke Creek Natural Assessment Full Report - SLR (February 25, 2019)
  • Peer Review - Chedoke Creek Natural Assessment Summary Report - SLR (May 15, 2019)
    This report is directly connected to the Natural Environment and Sediment Quality Assessment and Remediation Report by Wood and summarizes the more technical report. SLR was contracted to confirm the appropriateness and completeness of the Environmental Report that was produced under tight timelines for January 2019. This work was focused on ensuring that the process was robust enough to arrive at defendable recommendations for moving forward.  Work included:
    1. Validate methodology including an independent review of previous work completed by Wood.
    2. Provide an opinion of the appropriateness and completeness of the conclusions made regarding impacts and recommendations.
    3. Peer review of conclusions identify some gaps in the study, mainly as a result of time constraints, that would be beneficial in confirming remediation recommendations. Work is currently progressing on a follow-up report which explores how these gaps could be filled.
     
  • Wood Response to SLR Peer Review - Wood Group (May 23, 2019)
    Wood response to the SLR Peer Review Report; Wood (May 23, 2019) – In this report the consultant Wood was provided with an opportunity to provide their perspective of the Peer review done by SLR related to the Natural Environment and Sediment Quality Assessment and Remediation Report. They reference the constraints and context that defined the nature of their report including tight timelines and boundaries of the established scope of work. A number of comments were provided by Wood to provide the context for their work and conclusions.
     
  • SLR Ecological Risk Assessment (February 2020) 
    SLR was contracted to complete and Environmental Risk Assessment for the area of Cherokee Creek that was impacted by the identified discharge from the Main & King CSO tank.  The report examines metal, nutrient and bacteria levels found within Chedoke Creek to determine potential risks to plants, fish and other wildlife.  The report concluded that water and sediment quality within Chedoke Creek has returned to pre 2014 conditions and that further remediation is unnecessary.
     
  • SLR Environmental Impact Evaluation: Cootes Paradise (April 2020)
  • On November 4, 2019, the City launched the first phase of an enhanced notification protocol for informing the public about bypasses at the wastewater treatment plant. Phase one includes notifications on the City’s website if there is a bypass at the wastewater treatment plant. Council also added public notification for the City’s 14 monitored combined sewer overflow outfall locations to phase one of the enhanced protocol. Phase two will launch in spring 2020 and will include automated notifications for bypasses at the treatment plant, and overflows at the City’s 14 monitored combined sewer overflow outfall locations.
  • As part of the 2020 Water, Wastewater and Stormwater Budget, Council added four additional staff to improve the routine physical inspection and preventative maintenance programs for Hamilton Water Infrastructure including water and wastewater treatment plants, pumping stations, and combined sewer overflow tanks; and one Water Quality Technologist to sample and analyze water and wastewater quality.
  • In the last 30 years, the City built nine combined sewage overflow facilities that can store the equivalent of 125 Olympic-sized swimming pools worth of combined sewage during wet weather – these tanks help to protect public and private infrastructure and properties (particularly basements) from sewer backups, surcharges and overflows.
  • The City has been working to implement sensors and information systems that help staff make data-based decisions around directing the flow of wastewater during wet weather. The real time control program allows for the capture of optimal amounts of wastewater within the system to ensure unnecessary discharges during severe weather do not occur.  The Real Time Control program allows staff to monitor various gates, tanks, and other key areas to make real time decisions related to which areas of the system have capacity to hold wastewater prior to discharging into the environment. Phase one of implementing the Real Time Control program began in 2010 and is now complete. Phase two is in the detailed design phase and will be implemented in the coming years.
  • The largest investment of the Clean Harbour program is a multi-phase plan to upgrade the Woodward Wastewater Treatment Plant. Because the plant is the largest single source of water flowing into Hamilton Harbour, the quality of that effluent has a direct and powerful impact on the harbour’s water quality and environmental health. The total budget for the upgrades is $340 million, $200 million of which comes from the provincial and federal governments through the Green Infrastructure Fund. The upgrades include elevating the plant’s final treatment process from the secondary level to the tertiary (third) level. This will allow the plant to reach strict discharge limits described by the Hamilton Harbour Remedial Action Plan for phosphorus, ammonia and suspended solids. Sub-projects at the Woodward plant include electrical system upgrades, a new chlorine tank and a new raw sewage pumping station and collection system control to support wet weather and flooding control initiatives
  • The Sewer Lateral Cross-Connection Program was initiated to identify and correct plumbing deficiencies that exist when a property’s sanitary lateral is improperly connected to a storm sewer.  These sewer lateral cross connections are typically present from the time the house is built and left uncorrected, results in sanitary waste discharging directly into the city’s watercourses. To date, the City has identified and corrected over 365 cross- connections.  This translates into more than 65 million litres of wastewater diverted away from the natural environment and into the sewage treatment system each year. 
  • A research study was undertaken as a part of the Clean Harbour Program with respect to floatables found in Hamilton Harbour. The study includes a baseline assessment of the City’s wastewater infrastructure, an evaluation of current performance and identifies best practices and offers recommendations to reduce the presence of floatable materials reaching the harbour.

Chronology of Events

January 28, 2014 - A station bypass gate in the combined sewer overflow tank that should have been in a closed position appears to have been manually opened to approximately five per cent. An error in computer programming showed this as normal operation and, as such, this error remained undetected until July 2018. Despite extensive investigations, the City has not been able to determine why the first bypass gate was opened.

January 2018 (Approx.) - A second gate that should have remained in the open position experienced a mechanical failure. The sensor on this piece of equipment did not pick up the failure and was reporting normal operation.

June/July 2018 - Reports of water quality issues start to come in from residents and community partners. Public Health and Public Works staff initiate initial investigations at Chedoke Creek. This includes water quality samples, CCTV inspection for all sewers in the area and at all wastewater facilities with potential overflows into Chedoke Creek. 

July 9, 2018 - Public Health Services notifies the MECP of rising levels of E.coli and concerns about the apparent contamination of Chedoke Creek.

July 12, 2018 - Public Health Services issues a media release to warn the public to avoid any contact with Chedoke Creek and adjoining waterways.

July 18, 2018 - The City discovers that the source of the spill is a gate at the Main/King combined sewer overflow tank that was opened to five per cent. The spill is reported to the MECP’s Spills Action Centre and clean-up of 242,000 litres of “floatable material” from the area begins.

Early August 2018 - Additional warning signs are installed near Chedoke Creek to advise people of the high bacterial levels and to advise them to avoid any contact with the water.

Mid-August 2018 - City completes initial clean up at Chedoke Creek. Water quality results show a substantial improvement in water quality conditions and show a dramatic decrease in E.coli levels.

August 2018 - The MECP submits a Provincial Officer’s Order to the City. A revised Provincial Officer’s Order is shared with the City in November 2019.

November 4, 2019 - The City launched the first phase of an enhanced notification protocol for informing the public about bypasses at the wastewater treatment plant. Phase one includes notifications on the City’s website if there is a bypass at the wastewater treatment plant. Council also added public notification for the City’s 14 monitored combined sewer overflow outfall locations to phase one of the enhanced protocol. Phase two launched in Spring 2020 and included a map layer with automated notifications for bypasses at the treatment plant, and overflows at the City’s 14 monitored combined sewer overflow outfall locations.

November 20, 2019 - Information is shared regarding the City’s investigation into the discharge, including an estimate that approximately 24 billion litres of combined sewage was discharged into the Creek over a period of four and a half years.

November 2019 - As part of the 2020 Water, Wastewater and Stormwater Budget, Council added four additional staff to improve the routine physical inspection and preventative maintenance programs for Hamilton Water Infrastructure including water and wastewater treatment plants, pumping stations, and combined sewer overflow tanks, and one Water Quality Technologist to sample and analyze surface water quality downstream of the City’s infrastructure.

November 28, 2019 - Mayor Eisenberger and Members of City Council issue a formal apology to the residents of Hamilton, noting “We apologize to the residents of Hamilton for the failure to publicly disclose the volume and duration of the discharge of storm water runoff and sanitary sewage into Chedoke Creek when it first became known to the Council in 2018 and at subsequent Committee and Council meetings.”

November 2019 – The MECP submits a Director’s Order to the City resulting in the completion of an Ecological Risk Assessment of Chedoke Creek and an Environmental Risk Assessment in Cootes Paradise. Results are shared in 2020.

February 2020 - The results of the Ecological Risk Assessment for Chedoke Creek are shared with Council and the public. They show it was not possible to attribute environmental impacts experienced in these areas exclusively to the spill and did not recommend further remediation.

April 2020 - The results of the Environmental Impact Evaluation for Cootes Paradise are shared with Council and the public. They show it was not possible to attribute environmental impacts experienced in these areas exclusively to the spill and did not recommend further remediation.

September 21, 2020 - The City retained the services of a consultant to complete a Chedoke Water Quality Evaluation Study. Independent to the work in the Order, the study has identified short-term and long-term operating, capital and policy work that will improve water quality within the entire Chedoke Creek watershed. This work is being done in collaboration with the Bay Area Restoration Council, Conservation Halton, Environment Hamilton, Fisheries and Oceans Canada, Hamilton Conservation Authority, Hamilton Harbour Remedial Action Plan, Indigenous Water Walker representatives, Ontario Ministry of Transportation and the Royal Botanical Gardens (with MT Planners, Consultant). More information on this study will be shared in spring 2021.

November 20, 2020 - The City receives Provincial Officer’s Order from the MECP. The Order requires the City to submit a work plan outlining dredging for Chedoke Creek, and a report outlining remediation plans for Cootes Paradise by January 22, 2021. Additionally, a work plan and implementation plan related to the remediation of Cootes Paradise would be required within five weeks of the Cootes remediation plan being approved.

November 25, 2020 - The City requests a review of the Provincial Officer’s Order to seek clarity on what specific work needs to take place and what specific water quality standards the City is being asked to meet under the Order. The City also asked the Director to consider if eight weeks is a reasonable time frame to adequately develop a plan that meets the MECP’s expectations.

December 4, 2020 - The City receives Director’s Order from the MECP, which is in response to the request for review of the November 2020 Provincial Officer’s Order. The MECP extended some deadlines outlined within the original Order but did not extend the overall time required to complete the work.

December 9, 2020 - The MECP issues charges to the City related to the discharge into Chedoke Creek, under the authority of the Environmental Protection Act and Ontario Water Resources Act

December 17, 2020 - The City chooses not to appeal the MECP’s December 2020 Director’s Order and begins planning for the work outlined in the Order.

February 22, 2021 - The City submits workplan for dredging in Chedoke Creek to the MECP.

March 22, 2021 - The City submits a report to the MECP that will propose the remediation/mitigation methods to offset the added nutrient loading to Cootes Paradise and the Western Hamilton Harbour Area.