Wastewater Infrastructure, Sewage and Lessons Learned from 24 Billion Litre Spill

Given that Hamilton is currently in the midst of a water workers' strike, the timing of the following Q\&A with Nick Winters, Director of Hamilton Water, may seem somewhat awkward. However, we believe the information shared in this piece remains highly informative and of value to our readers. We extend our thanks to Nick for engaging with Hamiltonians through The Hamiltonian.

What major upgrades or investments have been made in Hamilton’s wastewater infrastructure in the past five years?

As part of the City’s continued commitment to our critical water operations, over the past three years, Council has approved over $856 million in capital investments to our water, wastewater, and stormwater systems; including treatment plants, pumping stations and distribution networks. These investments help ensure continued delivery of clean, safe drinking water and ensure our systems are operating reliably.

Examples of these investments include:

Woodward Wastewater Treatment Plant Upgrades

The completion of the $340-million Woodward Upgrade Project is a significant milestone towards the restoration of Hamilton Harbour, a designated Area of Concern under the Canada-U.S. Great Lakes Water Quality Agreement.

With all three levels of government partnering in the project, the upgrades add up to one of the largest environmental projects in the region. For example, the project is reducing the total phosphorus reaching Hamilton Harbour by approximately 500 tonnes over a 10-year period.

More information on the upgrades can be found here: https://www.hamilton.ca/home-neighbourhood/environmental-stewardship/our-harbour/completed-clean-harbour-projects#woodward-wastewater-treatment-plant-upgrades

Phase 2 of the Real Time Control Project

This project consists of sites across Hamilton reducing storm and wastewater overflows into sensitive waterways, such as Cootes Paradise and Red Hill Creek. The results of the project have been significant. Advanced computer software responds to sensors that measure factors such as flow, level, pressure and rainfall, real-time controls operate gates, weirs, chambers, and pumping stations to optimize the wastewater system. These responses and adaptations occur in real-time strengthening the City’s ability to protect the water quality of Hamilton Harbour.

City-wide Sewer Separation

Hamilton is planning a long-term, city-wide sewer separation project to address issues brought on by the City’s century’s-old combined sewer system . The project involves separating the combined sewer system, which currently carries both sewage and stormwater, into separate systems for each. This separation will reduce the risk of flooding and environmental damage.

Airport Employment Growth District (AEGD) –

To ensure we have the infrastructure to build more homes and create jobs, wastewater upgrades continue in the Airport Employment Growth District.

More information can be found here: https://pub-hamilton.escribemeetings.com/filestream.ashx?DocumentId=242305 https://www.hamilton.ca/build-invest-grow/planning-development/official-plan/secondary-plans/airport-employment-growth

 How is the city addressing vulnerabilities in stormwater and sewage systems in light of increasingly extreme weather events?

The City of Hamilton is taking a proactive approach to strengthen its wastewater and stormwater infrastructure in response to more frequent and intense weather events.

As part of the Woodward Wastewater Treatment Plant Upgrades completed in 2024, a new Main Pumping Station was constructed with significantly increased capacity. This upgraded Station now provides 1.7 billion litres per day of pumping capacity, in line with the capacity of sewers flowing into the Plant. A deeper and larger wet well was also added to improve system storage and help mitigate the risk of flooding in Hamilton’s wastewater system. More information on the upgrades can be found here:. https://www.hamilton.ca/home-neighbourhood/environmental-stewardship/our-harbour/completed-clean-harbour-projects#woodward-wastewater-treatment-plant-upgrades

As a continuation of the recently completed Upgrades Project, the City is currently in the early design phase of the Woodward Wastewater Treatment Plant Phase 2 Expansion Project which will further enhance the City’s resiliency to extreme weather events. The expansion will provide more protection to our natural environment when there are incidents involving significant volumes of precipitation. The protection will include greater capacity to provide enhanced treatment to storm and wastewater flows when the Treatment Plant is receiving high volumes. More information on the expansion can be found here:https://www.hamilton.ca/home-neighbourhood/environmental-stewardship/our-harbour/woodward-wastewater-treatment-plant

Watershed and Water Infrastructure Planning also play a role in future preparedness.

Examples include:The Watershed Action Plan outlines strategies to improve watershed health and supports efforts to delist Hamilton Harbour as an International Joint Commission Area of Concern.
The Water, Wastewater and Stormwater Master Plan is a comprehensive infrastructure planning tool that supports long-term resiliency by addressing infrastructure needs in alignment with population growth and environmental goals.

What was learned from previous incidents, such as the 24-billion-litre sewage spill, and how has the City changed its oversight or maintenance practices since?

Since the Chedoke Creek spill, the City of Hamilton has worked closely with Ontario’s Ministry of the Environment, Conservation and Parks (MECP) to investigate the incident and comply with a series of environmental orders. This has included targeted dredging in Chedoke Creek and initiatives aimed at improving the ecological health of Cootes Paradise.

In response to the spill, the City has taken several corrective and preventative steps to strengthen oversight and protect Hamilton’s watersheds. These include:

Enhanced operator training
Improved maintenance oversight
Creation of a surface water quality monitoring program
Development of a Watershed Action Plan to protect, restore and enhance natural resources, and guide long-term environmental stewardship

These actions reflect the City’s commitment to learning from past incidents and ensuring stronger environmental protections going forward.

More information about the spill and ongoing remediation efforts is available here: https://www.hamilton.ca/home-neighbourhood/environmental-stewardship/chedoke-creek-remediation/chedoke-creek-spill.

Is Hamilton meeting or exceeding provincial or federal standards for wastewater treatment and discharge in 2025?

The City of Hamilton is meeting all federal and provincial regulatory requirements. From an Environmental Compliance Approval perspective, both the Woodward and Dundas Wastewater Treatment Plants are operating in full compliance. The City remains committed to maintaining the highest standards of environmental protection in the operation of its wastewater facilities.

A copy of the 2024 Wastewater Facilities Report, submitted to Ontario’s Ministry of the Environment, Conservation and Parks, is available here: https://www.hamilton.ca/sites/default/files/2025-04/wastewatercollection-wastewater-facilities-annual-report-2024.pdf

What role does climate change play in current infrastructure planning, and are there risk assessments in place for future flooding or system failure?

A Term of Council Priority, climate change plays a critical role in shaping the City’s infrastructure planning and capital project development to strengthen our community’s climate resilience and readiness. The City builds in climate considerations into the design and construction phase of all major infrastructure projects, guided by strategic frameworks such as the Community Energy and Emissions Plan, the Climate Change Impact Adaptation Plan, and the Corporate Energy and Sustainability Policy.

To further safeguard the community against climate-related risks:Floodplain compliance is a key requirement. All infrastructure projects must adhere to Hamilton Conservation Authority’s floodplain regulations, ensuring developments are designed with resilience to flooding and stormwater impacts in mind.

The Main Pumping Station at the Woodward Wastewater Treatment Plant has been upgraded to handle greater wet weather flow, improving the City's ability to manage intense rainfall and prevent system backups during extreme weather events.

As part of ongoing climate risk assessment, the City reviews its rainfall design standards every five years through the Intensity-Duration-Frequency (IDF) Curves Review, which helps ensure that stormwater infrastructure remains prepared in the face of updated climate data and projected rainfall patterns.
City of Hamilton’s Public Works Department uses a “climate lens” for all projects, ensuring that every City project characterizes their climate benefits or potential impacts.

Additional resources:

· Hamilton’s Community Energy and Emissions Plan: https://www.hamilton.ca/home-neighbourhood/environmental-stewardship/environmental-plans-strategies/hamiltons-climate-0

· Hamilton’s Climate Change Action Strategy: https://www.hamilton.ca/home-neighbourhood/environmental-stewardship/environmental-plans-strategies/hamiltons-climate

· Hamilton’s Climate Change Impact Adaptation Plan: https://www.hamilton.ca/home-neighbourhood/environmental-stewardship/environmental-plans-strategies/hamiltons-climate-1

· Hamilton’s Corporate Energy and Sustainability Policy: https://www.hamilton.ca/home-neighbourhood/environmental-stewardship/environmental-plans-strategies/office-energy

How does the City engage with residents to ensure transparency and accountability regarding wastewater management?

To continue to build trust, the City of Hamilton is committed to engaging residents in meaningful, transparent, and accountable ways when it comes to wastewater management. With communication channels, education, digital platforms, and public consultation processes, the City has a suite of tools to ensure residents are informed and involved.

One example of a public awareness tool includes the City’s Sewer Inspection Program page, which outlines ongoing efforts to monitor and maintain sewer infrastructure. This provides residents with a better understanding of how the City maintains and improves the sewer system and reduces environmental risks.

The City uses a variety of educational tools to inform residents about their role in protecting water quality. These include dedicated webpages such as Beware the Berg and Own Your Throne, which promote responsible at-home wastewater practices.

The City has also recently introduced social media channels dedicated to City water and wastewater initiatives, and providing tips and alerts.

Additionally, the City delivers in-school programming and participates in community events to build awareness across all age groups.

For major capital upgrades, the City consults directly with affected neighbourhoods and establishes Community Liaison Committees to ensure ongoing meaningful listening and dialogue.

Through the Engage Hamilton platform, residents can participate in Environmental Assessment processes and other large-scale initiatives, such as the Watershed Action Plan, ensuring community voices are heard in long-term planning.

We know there’s more work to do in strengthening outreach efforts and listening opportunities with neighbourhoods across the community, and these efforts will be enhanced as part of the Mayor’s Task Force on Transparency, Access, and Accountability.

Is there a long-term resiliency plan or green infrastructure strategy in place to support environmental sustainability?

Yes, the City of Hamilton has implemented multiple long-term plans and guidelines that prioritize green infrastructure, climate resilience and nature-based solutions into its growth and asset management strategies.

Green Infrastructure and Planning Standards

In October 2024, Council approved the Green Standards and Guidelines for Site Servicing, a framework that prioritizes on-site stormwater management through green infrastructure, low-impact development , and natural assets. The Green Standards and Guidelines defines green infrastructure as both natural and built features—such as permeable pavements, green roofs, street trees, wetlands, and forests—that deliver ecological and hydrological benefits. Low-impact development are engineered practices, such as infiltration systems, that minimize stormwater runoff at its source, complementing natural features.

Natural Asset Management

The 2024 Natural Asset Management Plan provides a roadmap for identifying, managing, and valuing the City’s natural assets, aligning with Provincial regulations under O.Reg 588/17.

Through this initiative, the City is developing an inventory and conducting lifecycle activities for green infrastructure elements like wetlands, woodlands, and watercourses.

Watershed and Water Infrastructure Planning

The Watershed Action Plan outlines strategies to improve watershed health and supports efforts to delist Hamilton Harbour as an International Joint Commission Area of Concern.

The Water, Wastewater and Stormwater Master Plan is a comprehensive infrastructure planning tool that supports long-term resiliency by addressing infrastructure needs in alignment with population growth and environmental goals.

These strategies as a whole reflect the City’s commitment to sustainable development, climate adaptation, and responsible management of both built and natural water systems.

How does Hamilton’s infrastructure compare with that of other cities in Ontario when it comes to resiliency and innovation?

While the City faces challenges common to older urban centres, we have taken significant steps to modernize systems, invest in sustainable technologies and lead the province in several key areas of infrastructure resiliency.

Legacy System with Modern Challenges

Hamilton’s water and wastewater system has served the community for more than 150 years.

Like other historic cities in Ontario, Hamilton faces challenges related to aging infrastructure, including the presence of combined sewer systems that require continuous maintenance and strategic upgrades to reduce overflows and protect water quality. The City is actively addressing these issues through ongoing capital reinvestment and modernization efforts.

Provincial and Global Leadership in Wastewater Innovation

The Woodward Avenue Wastewater Treatment Plant is the largest tertiary treatment plant in Ontario and hosts the largest tertiary disk filtration system in the world. This advanced treatment system significantly improves effluent quality, contributing to the environmental health of Hamilton Harbour and Lake Ontario.

Sustainability through Biogas and Energy Recovery

Hamilton has invested in renewable energy solutions through its biogas cogeneration system, which produces 1.6 MW of electricity annually, helping offset energy use by the City’s water and wastewater treatment plants on Woodward Ave and reduce greenhouse gas emissions.

The City also operates a Biogas Purification System, which allows purified biogas to be injected into the Enbridge natural gas grid, creating a closed-loop system that reuses waste as energy.

Recognition for Resilience and Proactive Monitoring

Hamilton has earned awards for its innovative approaches, including:Proactive leak detection to reduce water loss and extend infrastructure lifespan.Stormwater pond drone bathymetry surveys to better understand sediment build-up in stormwater ponds and improve flooding resilience.Sewer Inspection and Sampling Program, an industry-leading initiative that uses water quality indicators (such as caffeine) to find and fix issues in our combined sewer system.