Understanding Randle Reef
Hamilton Harbour is home to the largest and
most contaminated site within the Canadian
side of the Great Lakes – Randle Reef.
Hamilton Harbour is the western tip of Lake Ontario, separated naturally from the lake by a sandbar known as the Beach Strip. It is the largest naturally protected harbour on western Lake Ontario. Industry, commerce and residential areas, along with private and public open spaces share its 45 kilometre shoreline. The Harbour’s watershed covers more than 500 square kilometres and is drained by three major tributaries – Grindstone, Spencer and Red Hill creeks. The cities of Hamilton and Burlington, with a combined population of 750,000 people, are located within and around the watershed. In 1985, the Harbour was identified as an Area of Concern under the Canada–United States Great Lakes Water Quality Agreement due to significant impairment of water quality, loss of fish and wildlife habitat, and contaminated sediment and fish and wildlife populations. While many improvements have been made to reduce pollution in the Harbour, the legacy problem of contaminated sediment remains.
Located in the southwest corner of Hamilton Habour, the Randle Reef site is approximately 60 hectares (or about 120 football fields) in size. The site contains approximately 695,000 cubic metres of sediment contaminated with polycyclic aromatic hydrocarbons (PAHs) and other toxic chemicals. It is the largest PAH-contaminated sediment site on the Canadian Great Lakes. The contamination is often described as “a spill in slow motion” due to the continuing slow spread of contaminants across the Harbour floor and uptake into the food chain of the Harbour ecosystem. PAH contamination at Randle Reef is a legacy of a variety of past industrial processes dating back to the 1800s. There were multiple sources of contamination including coal gasification, petroleum refining, steel making, municipal waste, sewage and overland drainage.
The site was identified as a principal target of Harbour restoration objectives in the late 1980s. Studies were conducted over several years to determine possible options for cleaning up the site. In 2002, a Project Advisory Group reached an agreement to explore the idea of containing and capping the sediment. An environmental assessment, project designs, and the quest to secure funding soon followed.
The Randle Reef sediment remediation project involves constructing a 6.2 hectare engineered containment facility (ECF) on top of a portion of the most contaminated sediment, then dredging and placing the remaining contaminated sediment in the facility. The facility will be made of double steel sheet pile walls with the outer walls being driven to depths of up to 24 metres into the underlying sediment. The inner and outer walls will be sealed creating an impermeable barrier. The sediment will then be covered by a multi-layered environmental cap.
Cleaning up Randle Reef is one of the most significant steps remaining to remediate Hamilton Harbour and remove it from the list of Areas of Concern. The project will reduce the amount and spread of contaminants through the Harbour, significantly improving water quality and fish and wildlife habitat. The Harbour will also experience economic and social benefits: enhancement of shipping and port facilities, increased recreational opportunities and the promotion of the Harbour community as a clean and progressive place to live and work.
Randle Reef Newsletter
Check out BARC's latest What's Up @ Randle Reef newsletter with updates on the contaminated sediment contaiment project.
Read the December 2022 Newsletter
Have a Question?
The Bay Area Restoration Council (BARC) maintains this website to promote and provide updates on the Randle Reef project. For more about BARC’s role in the Hamilton Harbour Remedial Action Plan, visit the BARC website.
You can contact Environment and Climate Change Canada, the project lead agency responsible for the construction of the Randle Reef contaminated sediment contaiment project, at email@example.com
The remediation plan involves the construction of a 6.2 hectare engineered containment facility (ECF) on top of 140,000 m3 of sediment highly contaminated with polycyclic aromatic hydrocarbons (PAHs) and heavy metals. Building the facility in this location ensures that the most toxic sediment will not be disturbed. Up to 550,000 m3 of contaminated sediment surrounding the ECF will be dredged and placed inside the ECF for a total containment of 690,000 m3. This total volume of sediment would fill Hamilton’s First Ontario Centre (formerly Copps Coliseum) three times! An additional 5,000 m3 of sediment (located in the channel between the ECF and Stelco) has been managed with an engineered isolation cap. If the ECF reaches capacity prior to the completion of dredging, any remaining marginally contaminated sediment (located in the outlying areas) will be capped with a thin layer of sand.
STAGE 1, Construction of the ECF structure and dredging between the double sheet pile walls [COMPLETE]
- The seawall at Pier 15, at the foot of Sherman Avenue, was over 100 years old and in a state of disrepair. It was rebuilt in 2015 as part of this project to allow dredging to occur adjacent the wall without compromising its integrity.
- Double steel sheet pile walls were installed during 2016 and 2017 to create the perimeter of the ECF structure. Construction was completed prior to dredging activities. The outer wall provides structural stability, and the inner wall provides isolation of the contaminated sediment from the surrounding Harbour environment. The interlocks between sheet piles on the inner wall were sealed creating an impermeable barrier.
- The sediment between the ECF’s inner and outer walls was mechanically dredged and moved inside the ECF. The space between the walls was sampled to confirm contaminant removal and then filled with clean crushed rock to provide structural stability.
- Before closing out Stage 1, the ECF was tested to verify the integrity of the seals on the inner wall.
STAGE 2, Dredging of the contaminated sediment located outside of the ECF, 2018-2021 [COMPLETE]
- Production dredging (of sediment beyond the footprint of the ECF). A cutter suction hydraulic dredge made multiple passes along the bottom of the Harbour to reduce the possibility of leaving behind contaminants. Areas that exceeded a predetermined PAH value after dredging were managed by a second pass of dredging and/or covered by a thin layer of sand. A discharge pipeline carried the dredged sediment from the dredge pump into the EFC. The pipeline was submerged under water in the EFC to reduce the possibility of toxins transferring from the sediment into the air.
- As the ECF filled with sediment, the excess contaminated water was treated by an on-site water treatment system to remove any remaining sediment or dissolved contaminants. Treated water was thoroughly tested and safely discharged into Hamilton Harbour.
- The channel between the ECF and the Stelco property required an environmental cap to contain highly contaminated sediment that cannot be fully removed by dredging. A 65cm thick cap consisting of sand with a minimum organic carbon content of 3% was layered above the sediment. The organic carbon is important to bind the contaminants. Reactive core mats were used to enhance the effectiveness of the sand isolation cap in areas where the height of the cap is limited by the presence of a water intake or where there are elevated contaminant levels in the underlying slag. The cap is protected from underwater erosive forces by armour stone.
STAGE 3, Capping of the contaminated sediment in the ECF, 2021-2023
- The first part of Stage 3 involves the installation of aggregate and synthetic layers to form a base for the cap. A drainage layer will then be added to collect and remove water from the contaminated sediment. The collected water will be treated prior to being discharged back into the harbour. This layer is then covered by a synthetic impermeable barrier designed to isolate the contaminated sediment from the clean cap layers that will be placed overtop.
- The second part will consolidate and further de-water the contaminated sediment in the ECF. This is achieved by the placement of large aggregate materials (pre-load) on top of the dredged sediment to squeeze out all water. The pre-load will remain on the ECF for a period of up to 6 months. After the completion of consolidation, the pre-load will be removed and the final capping of the ECF can begin.
- The last part is the installation of the EFC cap consisting of several layers of materials which include aggregates of various sizes and topped by surface asphalt.
Upon completion of the project, the Hamilton Oshawa Port Authority (HOPA) will accept ownership of the facility and be responsible for monitoring, maintaining, and developing the site as port facilities. The facility is expected to have a 200-year life span.
Hamilton Spectator, March 30, 2005
1986 to 1992The Canadian and Ontario governments lead the Remedial Action Plan (RAP) preparation for Hamilton Harbour and submit it to the International Joint Commission (IJC).
1992ECCC demonstrated new technologies to manage contaminated sediment at the Randle Reef site. 150m3 of PAH contaminated sediment was removed by an environmental mechanical bucket and treated on land...
Early 1995Randle Reef Remediation Steering Committee, which includes Environment Canada (EC), Ontario Ministry of the Environment (MOE) and Hamilton Port Authority (HPA) is formed...
Mid 1997Stelco suggests forming a not-for-profit corporation to manage the Randle Reef clean-up, including the use of the Stelco plant for part of the treatment process.
December 1999The option of using a Stelco plant is presented at a public open house. Based on public feedback it is concluded it is not a viable clean-up option.
2000EC establishes a Technical Steering Committee (later re-named the Project Advisory Group), to further explore options for cleaning-up the sediment at Randle Reef.
April 2002EC-led Project Advisory Group reaches a consensus on a “contain and cap” solution for cleaning-up Randle Reef.
May 2003EC-led Project Advisory Group reaches a consensus on a “contain and cap” solution for cleaning-up Randle Reef
August 2003HPA receives seven proposals from engineering consulting firms in response to the Request for Proposals for design of the Randle Reef Sediment Remediation Project.
December 2012“Today, I am delighted to announce $46.3 million in Government of Canada funding to clean up Randle Reef in Hamilton Harbour...
June 2013Canada’s Environment Minister, Peter Kent, signs off on the federal Environmental Assessment.
September 2013A very important and final Randle Reef Remediation Project milestone is reached: all legal agreements to fund and start the clean-up project have been reached.
May 2015Federal Government issues tender for Stage 1 Construction of the Engineered Containment Facility (ECF).
September 2015Pile driving the new sheet wall at Pier 15 with the vibratory hammer. Rebuilding the Pier will provide the base of operations for the entire Randle Reef containment project.
October 2015Anchors for the new sheet pile wall during reconstruction of Pier 15. Rebuilding the Pier will provide the base of operations for the entire Randle Reef containment project.
April 2016The first loads of interlocking steel sheet piles are delivered, possibly the most famous and anticipated cargo shipment in or out of Hamilton Harbour in last 100 years!
June 2016Turbidity monitoring buoy inside the ECF structure. Environment Canada and Climate Change will be monitoring water and air quality throughout construction and dredging.
August 2016Phase 1 of the Randle Reef Environmental Containment Facility involves the in-water construction of the double steel walls. The second half of this initial phase of the project will occur in the summer of 2017.
April 2018Site visit by federal environment minister Catherine McKenna, posing with members of the construction team and several Remedial Action Plan agencies in the project’s water treatment facility.
May 2018Aerial view of the site showing the water treatment plant. Piping to the ECF is not yet connected in this photo.
July 2018Inside the water treatment facility constructed at Pier 15 specifically for the Randle Reef ECF project.
July 2018The view looking north up the channel created between Stelco on the right and the ECF on the left. The scale of the project is difficult to grasp from the ground.
July 2018The view looking northeast across the ECF, with a close-up of the sheet piles that form the double steel wall around the perimeter of the ECF and through the middle splitting the ECF into two cells.
July 2018Members of partner agencies of the Hamilton Harbour Remedial Action Plan are provided a tour around the ECF on the fill between the double steel walled perimeter.
July 2018Looking down at interlocking steel sections of the ECF, many of which extend down more than 100 feet.
August 2018The first dredging of contaminated sediment at Randle Reef outside the steel containment structure begins! The photo shows the dredge pump in use prior to the cutter suction head dredging.
November 2018Stage 2 aerial photo of the ECF project and the surrounding landscape.
November 2018Dredge being launched. The wheelhouse and some other components were attached once the dredge was in the water.
October 2019Overflow weir on the ECF that allows the extraction of water from either half of the ECF as part of the water treatment process. Water is drawn from the half of the ECF that is not being filled with dredged sediments to allow for gravity settling of sediments. This is switched periodically to evenly fill the ECF.
October 2019Close-ups of the diffuser used at the end of the dredge pipeline. It is used to smooth and spread out the discharge of sediments pumped from the dredge into the ECF.
December 2019Contractor filling in the double steel walls of the ECF with crushed stone. This area being filled, on the northeast portion of the ECF, was previously left open from Stage 1 in case the contactor needed to use the space between the walls as part of their water treatment operations. They did not and so the area was filled in Stage 2.
May 2021Hydraulic dredge in the water in May 2021. The spuds (long dark brown pole-like components) are extended to the harbour bottom and hold the dredge in place while slowly advancing the barge during dredging.
June 2021Overhead of the Randle Reef ECF at the end of hydraulic dredging. The remaining surface water will be pumped-off and treated in preparation for the multi-layer environmental cover in Stage 3.
June 2021Drawing of the isolation cap placed over contaminated sediment in the channel between the ECF and Stelco. The remaining work consists of the placement of rip rap for erosional protection.
June 2021Celebration of the last day of hydraulic dredging on June 2, 2021. The overall project completion date is now expected to be Fall 2023.
November 2021Overhead view of the ECF at Randle Reef in early winter after most of the precipitation had been removed.
March 2022Pictured above (left) from L to R: Sujit Sanyal, Chief Operating Officer, Stelco; Ian Hamilton, President and CEO, HOPA Ports; Jason Farr, Deputy Mayor, City of Hamilton;
June 2022Aerial view of location of unloading additional navigational dredge spoils for Hamilton-Oshawa Port Authority into the Randle Reef ECF.
June 2022Aerial view of the Randle Reef ECF, the capping project at top right, the deposition of Hamilton-Oshawa Port Authority navigational dredge at bottom left.
June 2022Precipitation accumulated and was removed in through an agreement with the City of Hamilton to use its sanitary sewer
Randle Reef Resources
Randle Reef contaminated sediment remediation project, stage 2 update: completion of dredging the harbour, November 2022
Randle Reef contaminated sediment remediation project overview: looking ahead at what to expect, October 2018.
Frequently Asked Questions
Located in the southwest corner of Hamilton Harbour, the Randle Reef site is approximately 60 hectares (120 football fields) in size. The site contains approximately 695,000 cubic metres of sediment contaminated with highly toxic polycyclic aromatic hydrocarbons (PAH) and heavy metals. PAH contamination at Randle Reef is a legacy of various past industrial processes dating back to the 1800s.
The Randle Reef sediment remediation project involves constructing an engineered containment facility (EFC) around and on top of a portion of the most contaminated sediment in the Harbour. The remaining contaminated sediment surrounding the ECF is currently being dredged (suctioned out) and placed inside the structure. The ECF was constructed with double steel sheet pile walls to fortify the structure and to prevent toxins from leaching out into the Harbour.
Environment and Climate Change Canada, the Ontario Ministry of Environment, Conservation and Parks, the City of Hamilton, the Hamilton Oshawa Port Authority, Stelco, the City of Burlington, and the Regional Municipality of Halton are all working together on the Randle Reef sediment remediation project.
The Government of Canada: $46.3 million
The Province of Ontario: $46.3 million
The City of Hamilton: $14 million
Stelco: $14 million
Hamilton Oshawa Port Authority: $14 million
The City of Burlington: $2.3 million
Halton Region: $2 million
Total Project Budget: $138.9 million
Environment and Climate Change Canada is the lead agency on the Randle Reef project, while contracts are being managed by Public Services and Procurement Canada.
Stage 1 started in 2015 with the re-construction of adjacent Pier 15. This was necessary to permit dredging of the contaminated sediment in the vicinity of Randle Reef. This was followed in 2016 through 2017 by the construction of an engineered containment facility (ECF) – the “steel box” – on top of the most highly contaminated sediment. Stage 2 involves dredging as much as 550,000 cubic metres of contaminated sediment and placing it within the ECF. Stage 2 began in 2018 and is expected to be completed in 2021. Stage 3 will involve placing an environmental cap on the ECF to isolate the contaminants. Once Stage 3 is completed in 2023, the ECF will be handed over to the Hamilton Oshawa Port Authority for use as a port facility.
Stage 2 is expected to be completed by the fall of 2021. Stage 2 timelines have been extended due to delays experienced by the contractor with the delivery of the dredge in 2018, record-high water levels across the Great Lakes in 2019, and workplace limitations related to COVID-19 in 2020. Timelines have also been extended because two factors have allowed for more contaminated sediment to be dredged and contained than was initially expected: the consolidation rate of contaminated material in the ECF has been higher than expected, and contaminated sediment in some dredge areas did not extend as deep as originally estimated and therefore the ECF can hold more contaminated sediment than was originally planned.
Stage 3 is expected to start in the spring of 2022.
The project will involve the use of a completely sealed engineered containment facility (ECF) to isolate the contaminated sediment from the surrounding ecosystem. While other confined disposal facilities for contaminated sediment exist in Canada, those facilities are not designed to contain contaminants with concentrations as high as those found at Randle Reef, nor are they designed to completely seal the contamination from the surrounding ecosystem. The Randle Reef ECF will be utilized as a port facility once it is filled with contaminated sediment and capped with a solid surface. This approach to managing contaminated sediment in an engineered structure and creating a port facility is a first in Canada.
The contamination of sediment at Randle Reef is the result of multiple historical sources over a period of more than 150 years, including coal gasification, petroleum refining, steel making and associated coking, municipal waste, sewage effluent and overland drainage.
Polycyclic Aromatic Hydrocarbons (PAHs) are a class of organic compounds that are present in oil, coal and tar and are produced during the burning of these fuels. PAHs are also formed by the process of incomplete combustion of such products as wood tobacco smoke and diesel fuel. There are several known PAH carcinogens (directly involved in causing cancer) and several others are suspected carcinogens.
Real-time environmental monitoring systems are being used to measure air and water quality in the vicinity of construction at each stage. Air and water quality criteria have been established to ensure that human health and the environment are protected. In addition, a water treatment plant is being used to treat all water displaced from the containment facility during Stage 2 and 3.
The completion of the Randle Reef engineered containment facility (ECF) in 2023 will be one of the most significant milestones in the restoration of Hamilton Harbour and its eventual delisting as a Great Lakes Area of Concern. Delisting of Hamilton Harbour cannot occur until remediation of contaminated sediment at Randle Reef has been successfully addressed, and the Randle Reef ECF is the signature Remedial Action Plan project to address the issue of legacy contaminated sediment. Unrelated goals such as restoring shoreline and wetland habitat and improving water quality through phosphorus reductions are also significant, however, and ongoing RAP projects to address those issues must also be successful before delisting is achieved.