Sewer Inspection Program

A cross-connection occurs when a sanitary sewer or combined sewer is mistakenly connected to a stormwater sewer.

• Sanitary Sewer One pipe that collects wastewater from toilets, sinks, showers, washing machines and other building drains.
• Stormwater Sewer One pipe that collects rainwater and snowmelt from catch basins, roofs, downspouts and/or foundation drains. 
• Combined Sewer One pipe that collects both the wastewater from our homes and businesses and stormwater from rain or melted snow.

Wentworth Street North and Burton Street

• Spill Discovery Location: Wentworth Street North and Burton Street
• Spill Discovery Date: May 13, 2025
• Spill Discovery Method: Follow-up maintenance hole inspection required due to a watermain break which occurred on May 12, 2025.
• Background / Cause: The nearby watermain break caused gravel and debris to buildup in the trough of the main sewer. The buildup caused some flow to overflow the weir wall into the storm sewer below.
• Corrective Action: Emergency flushing and vacuuming took place to remove all debris obstructing the flow.
• Remediation Completed: May 13, 2025
• Estimated Volume: 10,800 Liters
• Estimated Duration: Estimated maximum duration is approximately 18 hours, based on the time of the watermain break. Last inspection of the maintenance hole was on January 15, 2025 with no issues identified.
• Cost of Repair - Excluding staff time: Approximately $390 for contractor response.

Wentworth Street North and Wilson Street

• Spill Discovery: March 23, 2025
• Spill Discovery Method: SCADA (real-time digital monitoring system) identified an overflow at the Wentworth Combined Sewer Overflow regulator.
• Background / Cause: Water from a large watermain break entered the combined sewer system and triggered an overflow alarm on the SCADA system.
• Corrective Action: The watermain was isolated and repaired.
• Remediation Completed: March 23, 2025
• Estimated Volume: Estimated 92,000 Litres. Predominately potable water from the watermain break.
• Estimated Duration: Approximately 1 hour.
• Cost of Repair: Staff time

King Street East and Wentworth Street North

• Spill Discovery: February 7, 2025
• Spill Discovery Method: Bi-Annual Critical Regulator Inspection
• Background / Cause: The City of Hamilton is currently replacing a watermain and upgrading the road at this location. During the work, debris fell into a maintenance hole and blocked the wastewater trough. This blockage caused wastewater to overflow into the storm sewer below, leading to the spill.
• Corrective Action: Staff manually removed debris to allow regular flow.
• Remediation Completed: February 7, 2025
• Estimated Volume: 34,560 Liters
• Estimated Duration: Maximum duration, four days based on the start of the construction project.
• Cost of Repair: No cost. 

Imperial Street

• Spill Discovery: January 20, 2025
• Spill Discovery Method: Scheduled maintenance inspection completed biannually via Go-Pro camera as a part of the Critical Regulator Inspection Program
• Background / Cause: Debris buildup in sewer downstream of the regulator
• Corrective Action: Flushing of sewer to remove buildup 
• Remediation Completed:  January 20, 2025
• Estimated Volume: ~ 360 Liters a day
• Estimated Duration: Unknown. Previous inspection was completed on August 16, 2024
• Cost of Repair: Approximately $660 for contractor costs 

Hyde Park Ave and Glenside Ave

• Spill Discovery: October 1, 2024
• Spill Discovery Method: Scheduled maintenance hole inspection completed biannually via Go-Pro camera as a part of the Critical Regulator Inspection Program
• Background / Cause: A crack was discovered along the wastewater pipe, resulting in a slow drip to the overflow storm sewer within the chamber.
• Corrective Action: A confined space entry was performed by the City’s contractor to replace the cracked portion with a new PVC pipe.
• Remediation Completed: October 1, 2024
• Estimated Volume: ~ 36 Liters a day
• Estimated Duration: Unknown. Previous inspection was completed on April 2, 2024 showed no issues.
• Cost of Repair: Approximately $3500 for contractor costs and pipe replacement

Main Street East and Emerald Street South

• Spill Discovery: September 18, 2024
• Spill Discovery Method: Regularly scheduled maintenance hole inspection via Go-Pro camera followed by a confined space entry for visual inspection
• Background / Cause: A small combined sewage leak was suspected below a newly installed pipe liner. The clay pipe running from the combined sewer main through the stormwater chamber was found to have broken, allowing a very small amount of combined sewage to make its way between the liner and the existing pipe. 
• Corrective Action: To prevent further leaks, a watertight sealant was applied between the new pipe liner and the older clay pipe. 
• Remediation Completed: September 18, 2024
• Estimated Volume: ~151 Liters a day.
• Estimated Duration: Max 140 days. The liner installation was completed on May 2, 2024
• Cost of Repair: $297 

Imperial Street

• Spill Discovery: August 16, 2024
• Spill Discovery Method: Regulator inspection completed biannually via Go-Pro camera as a part of the Critical Regulator Inspection Program
• Background / Cause: Debris buildup in sewer downstream of the regulator
• Corrective Action: Sewer flushed and spill eliminated within 2 hours of discovery
• Remediation Completed: August 16, 2024
• Estimated Volume: Unknown - flow estimated at 480 Liters a day.
• Estimated Duration: Unknown. Previous inspection completed in early May 2024 showed no issues.
• Cost of Repair: Approximately $500 for contractor flushing

Princess Street and Birch Avenue

• Spill Discovery: April 9, 2024
• Spill Discovery Method: Regulator inspection completed biannually via Go-Pro camera as a part of the Critical Regulator Inspection Program
• Background / Cause: Debris buildup in sewer downstream of the regulator
• Corrective Action: Sewer flushed and spill eliminated within 2 hours of discovery
• Remediation Completed: April 9, 2024
• Estimated Volume: Unknown. Flow estimated at 1,000 Liters a day
• Estimated Duration: Unknown. Previous inspection completed in early January 2024 showed no debris or issues
• Cost of Repair: Approximately $400 for contractor flushing

Main Street East & Tisdale Street South

• Spill Discovery: April 5, 2024, through scheduled monthly inspection
• Spill Discovery Method: Regulator inspection completed monthly at this location via Go-Pro camera
• Background / Cause: Debris buildup in sewer downstream of the regulator
• Corrective Action: Sewer flushed and spill eliminated within 2.5 hours of discovery
• Remediation Completed: April 5, 2024
• Estimated Volume: Unknown.  Debris built up between previous inspection on March 6, 2024 and inspection on April 5, 2024. Flow estimated at 2400 Liters a day
• Estimated Duration: Unknown. Maximum of 31 days
• Cost of Repair: Approximately $500 for contractor flushing

Delaware Ave & Fairleigh Ave. S

• Spill Discovery: January 24, 2024
• Spill Discovery Method: Routine scheduled inspection, as part of Hamilton Water’s sewer inspection program.
• Background / Cause: Suspended trough regulator structural failure.
• Corrective Action: Suspended trough regulator was reinstated/repaired.
• Remediation Completed: January 24, 2024
• Estimated Volume: Unknown
• Estimated Duration: Unknown – Routine scheduled twice-a-year inspection completed on July 10, 2023 showed the asset to be in good condition and operating as designed.
• Cost of Repair: $3,500

Gailmont Drive and Carene Avenue

• Spill Discovery: September 22, 2023
• Spill Discovery Method: Maintenance hole investigation via a sewer odour complaint.
• Background / Cause: The main sanitary sewer surcharged on Carene Avenue due to grease/baby wipes blockage. This led to the main sewer being pressurized and some flow exfiltrating the pipe and infiltrating into a nearby storm sewer maintenance chamber via a hole in the wall.
• Corrective Action: Emergency flushing was completed to clear the blockage from the main sewer. The blockage removal therefore stopped the infiltration into the storm sewer maintenance chamber.
• Remediation Completed: September 22, 2023
• Estimated Volume: Approximately 21,600 litres
• Estimated Duration: Unknown – up to 72 hours maximum.
• Cost of Repair: $378

Wentworth Street N & Rosemary Ave

• Spill Discovery: Wednesday Aug. 2, 2023
• Spill Discovery Method: Plant Operations Supervisory Control & Data Acquisition (SCADA) alarm notification
• Background / Cause: Gate closed for maintenance activity resulted in overflow in upstream weir.   
• Corrective Action: Gate opened upon alarm notification.  Standard practices for preventative maintenance at the site including gate operation will be reviewed and adjusted as necessary to prevent a reoccurrence.
• Remediation Completed: None
• Estimated Volume: Estimated volume at approximately 20L.
• Estimated Duration: Approximately 10 to 15 seconds.
• Cost of Repair: No cost.

Main & Tisdale

• Spill Discovery: July 5, 2023 through scheduled monthly inspection
• Spill Discovery Method: Regulator Inspection completed monthly at this location via Go-Pro
• Background / Cause: Debris build up in sewer downstream of the regulator.
• Corrective Action: Sewer flushed and spill eliminated within 2 hours of discovery
• Remediation Completed: July 5, 2023
• Estimated Volume: Unknown. Debris built up between June 6 and Inspection on July 5. Flow estimated at 180 Litres a day.  
• Estimated Duration: Unknown. Maximum of 29 days.
• Cost of Repair: Approximately $400 for contractor flushing.

Wentworth Street S & Main Street E

• Spill Discovery: February 17, 2023 through maintenance repair work
• Background / Cause: A suspended stainless-steel trough, which carries combined sewage through a maintenance chamber, was found to be trickling combined sewage from the trough to a larger box storm sewer beneath it.
• Corrective Action: Parging was completed inside and outside of the trough ensuring a full seal.
• Remediation Completed: February 18, 2023
• Estimated Volume: Unknown
• Estimated Duration: Unknown
• Cost of Repair: Excluding staff time $4,146

Kinrade Ave

• Spill Discovery: January 18, 2023 through sewer inspection pilot program
• Background / Cause: A single residential sewer lateral was connected to the proper sewer (a combined sewer), however, a design issue at this location may have allowed some of the sanitary sewage from this home to discharge to the overflow pipe leading to the storm sewer during dry weather.
• Corrective Action: The sanitary sewer lateral was rerouted into a new location within the combined sewer.
• Remediation Completed: January 19, 2023
• Estimated Volume: 0.47 million litres
• Estimated Duration: 41 years
• Cost of Repair: Excluding staff time $7,308

Rutherford Ave and Myrtle St

• Spill Discovery: January 9, 2023 through sewer inspection pilot program
• Background / Cause: An improper connection between a combined sewer and a storm sewer allowed combined sewage to outlet directly into the Hamilton Harbour. Records indicate the connection causing the spill likely occurred in the latter half of 1996 during a City of Hamilton capital construction project on Rutherford Ave.
• Corrective Action: The sewer was reconfigured by installing an additional maintenance access hole and connecting the combined sewer on Rutherford Ave directly to the combined sewer on Myrtle St.
• Remediation Completed: January 11, 2023
• Estimated Volume: 59 million litres
• Estimated Duration: 26 years
• Cost of Repair: Excluding staff time $37,529

Burlington Street East and Wentworth Street North

• Spill Discovery: November 22, 2022 through sewer inspection pilot program
• Background / Cause: In 1996 a hole was incorrectly put in the combined sewer pipe by a City contractor. The hole led to a combined sewage spill into a large storm sewer that was discharging into Hamilton Harbour.
• Corrective Action: The sewer was reconfigured so that the combined sewage is now flowing properly into a sanitary sewer.
• Remediation Completed: November 23, 2022
• Estimated Volume: 337 million litres
• Estimated Duration: 26 years
• Cost of Repair: Excluding staff time $29,830

The City created a Sewer Lateral Cross-Connection program in 2002 to identify and confirm private cross-connected sewer laterals within Hamilton. The program inspects over 45 kilometres of mainline sewer pipes each year to find existing cross-connections. Once found, the City digs up the pipes and they are properly connected. The City has fixed more than 450 cross-connections to date, resulting in over 100 million litres annually of wastewater going back into the collection system rather than out into watercourses.

Learn more about sewer lateral cross-connections

The City’s combined sewer system and the Woodward Wastewater Treatment Plant discharge into Hamilton Harbour. The City's primary drinking water source is Lake Ontario, a far greater body of water, and the drinking water is taken from more than 1km out into the Lake. Prior to drinking water making its way to residents, there are many steps and regulations in place to ensure the delivery of safe and clean drinking water. Standards for drinking water quality are set and legally enforced by the Safe Drinking Water Act. The Drinking Water Quality Management System is a set of policies and procedures the City uses to ensure the consistent delivery of clean, safe drinking water to our community.

Learn more about the City's Drinking Water Quality

Homeowners can take steps to support the wastewater treatment process by taking action at home. Learn more about safe flushing behaviours, catch basin use and cleaning, downspout disconnections and more.

Additionally, homeowners should always ensure that they’re receiving the proper building permits when renovating their homes, or adding plumbing fixtures such as basement bathrooms, etc. to ensure that their pipes are connected to the correct sewer.

All industries, businesses and households may contribute to, or cause a spill. Disposing of chemicals, paints, motor oil and other pollutants into the storm sewer catch basin, sanitary sewer or onto the ground can contaminate our waterways.

In the event of a spill Call the City of Hamilton at 905-546-2489. The City will take your calls 24 hours a day, 7 days a week.

The law requires that the owner of a spilled material notify the City of a spill as soon as possible. City staff will respond and provide you with information on clean up, site restoration and how to prevent similar spills.

Provincial regulations require that the owner of a spilled material also report spills to the Spill Action Centre operated by the Ministry of the Environment, Conservation and Parks. Call 1-800-268-6060 to report a spill.