In June 2012, City Staff responded to a reported spill in Centennial Park and found a tar-like substance breaking out at ground level at random locations in the park. Golder Associates was sole-sourced to investigate based on their experience with similar issues in Canatara Park. On-site meetings were held with representatives from the Ministry of the Environment and the Lambton Health Unit and Golder recommended that the City proceed with a Phase I Environmental Site Assessment (ESA).

The Phase I (ESA) was completed to review historical ownership and land uses on the site to determine potential contaminants. This report was submitted in November 2012 and Golder was retained to proceed with the Phase II ESA in May 2013 to conduct field work to identify and quantify contaminants.

During the Phase II ESA, contaminants (lead, hydrocarbons, asbestos, etc.) were discovered at varying depths and concentrations in the park (including in the topsoil layer), which led to fencing off the park, with adjustments made to the fencing as further analysis was conducted. Media releases were provided at these times with associated mapping.

During the Phase II investigation, the City proceeded with the Risk Assessment (RA) to address the potential health impacts, risk management measures and remediation options associated initially with the Legacy Project site and subsequently extended to the entire park. Work on the RA report commenced in July 2013.

On September 23, 2013, Golder Associates presented the initial findings of the Phase II ESA to City Council.

On November 8, 2013, City staff received the drafts of the Phase II Environmental Site Assessment (ESA) Report and the Risk Assessment (RA) Report which pertain to the entire Centennial Park Site. Staff is reviewing the draft reports; these reports are available on this web page for public reference.

On November 18, 2013 Golder Associates presented to Council the findings and available remedial measures determined through the environmental investigations on this site. The consultant responded to questions of Council. Council decided to consider next steps at their meeting of December 2, 2013.

On December 2, 2013, City Council approved moving forward with a third party review of the Risk Assessment Report. Council also approved City Staff proceeding with the Remedial Action Plan for Centennial Park.

On March 24, 2014, City Council received and released the remediation strategy plan and park concept plans for Cenntennial Park for public review and comment through the public engagement process.

On April 15, 2014, a public meeting was held in Council Chambers to present concepts and receive input.

On May 5, 2014, Council received the staff report for the finalization/presentation of the RAP document, which was presented for Council approval on June 30th, 2014.

On June 30, 2014, Staff presented the RAP report for Council approval to allow for the remedial works to commence in Centennial Park.

Following the approval of this plan by Council, Staff proceeded with grass cutting and a topographic survey of the entire park.  Golder Associates collected and submitted bulk samples of grass clippings as well as samples from the cabin air filter of the tractor following grass cutting activities.  As indicated in the report which is available on this web page, neither the grass samples nor the samples collected from the cabin air filter contained detectable concentrations of asbestos fibres.

Golder Associates also provided results of airborne fibre sample analysis collected during the grass cutting activities which took place over the course of two days at Centennial Park.  The samples were collected to evaluate the possible disturbance of asbestos in the soil resulting in the potential release of airborne fibres at the Site during the grass cutting activities.  Based on the results provided in the report, analyses determined that there were no detectable asbestos fibres in either of the samples collected.

On September 8, 2014, Council accepted the offer from Murray Demolition to demolish the H.G. MacLean Building in Centennial Park.  This building has been abandoned since March, 2011.  Murray Demolition has offered to demolish the building at no cost and demolition is expected to take place in October, 2014.

Concept Drawings

Council Meeting Minutes

Council Reports

Environmental Studies


Why will there be so much change in the park?

Through the Risk Assessment, required rehabilitation will involve the remediation of a large portion of the park, thus it will be necessary to reconstruct the site to re-establish park infrastructure for the public.

What initiated this project?

In June 2012 a black tar-like material was discovered coming to the ground surface on a portion of Centennial Park.

Originally speculated to be coal-tar, the material was tested and determined to be consistent with heavy fuel oil, such as bunker fuel or #6 fuel oil.

The discovery prompted a Phase 1 Environmental Site Assessment.

What were the results of the Phase 1 Environmental Site Assessment?

The Phase 1 Environmental Site Assessment completed by Golder Associates identified the following areas of potential environmental concern in the vicinity of Centennial Park:

Uncertainty regarding the disposal of chemicals and materials typically used in the salt and lumber industries previously located in the southern limits of the site.

The placement of dredged materials and imported fill material westward from Front Street.

Fill areas within the limits of the Park based on the review of historical information and aerial photographs.

The historical operation of a coal gasification plant east of the Park.

How was the Park tested during the Phase 2 Environmental Site Assessment ?

30 boreholes, 11 monitoring wells, 53 test pits, and 105 topsoil samples. In total, 607 soil analyses were completed for various parameters and 29 groundwater analyses were completed.

What contaminants were discovered?

Petroleum Hydrocarbons (PHCs), Polycyclic Aromatic Hydrocarbons (PAHs), Metals, and Asbestos were discovered. Soil quality issues were identified throughout the entire park site at varying depths within the approximate 2 metre depth of backfill material.

What remedial options were available?

Potential remedial options were evaluated by a team of experienced professionals including geo-environmental engineers, geoscientists, industrial hygienists, demolition/construction engineers, biologists, landscape architects and risk assessment specialists.

There were four remedial options presented to Council:

Shallow soil cover (0.5m thick).

Partial soil removal (to a depth of 0.5m) and replacement with clean soil.

Full soil removal.

Placement of a hard cap.

Cost estimates ranged from $3-5M for shallow soil cover to $30-40M for full soil removal.

Since there are no known standards or North American regulations for asbestos in soil, it is difficult to correlate concentration of asbestos fibers in soil to air. The human health risk associated with asbestos is through airborne exposure. The human health risk associated with other contaminates on site is through ingestion, inhalation, and absorption. Therefore, the Risk Assessment Report assumed that Risk Management Measures including removal or risk mitigation would be required to address the potential risk of exposure.

What remediation option did Sarnia City Council choose?

For the majority of park space, Council chose the shallow cap risk mitigation measure, which involves laying down a geotextile fabric, then covering that geotextile fabric with 0.5m of granular, and 0.1m of clean topsoil and re-vegetating by growing grass or planting native species.

The majority of the remediation work consisted of a soft cap (geotextile fabric + granular + top soil) and hard cap (concrete/asphalt) in the proper combination to adequately address public health, minimize cost and meet the future vision for the park.

Heavily impacted areas will be agitated as little as possible, and capped.

The playground area will require 1.0m of cap (whereas the other areas will be covered with approximately 0.6m of cap).

This Risk Management Measure was considered appropriate for the following reasons:

Given the use of the site (urban parkland), soil at a depth of 0.6 metres is not expected to be accessible to most human receptors.

The shallow soil cap would be re-vegetated. The plant community would consist mainly of grasses or other shallow rooting plants

For technical, environmental, and financial reasons, excavating all impacted material was not chosen by City Council.

What is the Risk Assessment?

The Risk Assessment determines safety measures moving forward. The Risk Assessment outlines remedial and risk mitigation measures to be used on the site. The Risk Assessment has been reviewed and approved by the provincial agencies involved.

View the Risk Assessment here:

What is the Remediation Action Plan?

The proposed strategy for remediating the site has been developed in conformance with the recommendations of the Risk Assessment prepared by Golder Associates, and a concept plan has been developed for the restoration of the surface level features.

Where would one look to learn of human health impacts?

Risk Assessment covers human health impacts and the Risk Mitigation Measures takes into consideration toxicology, pathways for exposure, and risk to human health, based on contaminants in topsoil and shallow soil.

View the Risk Assessment here:

Where was the asbestos in the park?

In the North portion, it is generally in the topsoil but not in the underlying fill. In the South portion, it is generally in the fill with limited areas in the topsoil.

Was the groundwater found to be contaminated?

There was no evidence of leachate or migration through groundwater discovered. One water test indicated high levels of sodium, which may be a result of previous uses on the site (salt mine).

What risks does asbestos in Centennial Park pose?

The human health risk associated with asbestos is through airborne exposure.

There are no known standards or North American regulations for asbestos in soil. Because of this, it is difficult to correlate concentration of asbestos fibers in soil to air. The level of management and protection was raised significantly due to presence of asbestos.

Samples taken revealed no airborne asbestos fibers.

Since contamination has been in place 50+ years, does it become inert or breakdown?

Metals and asbestos do not breakdown. Organics (Petroleum Hydrocarbons, Polycyclic Aromatic Hydrocarbons) could breakdown but only over a long period of time (hundreds of years for the PAH compounds).

Why was the boat launch required to be relocated?

Reason 1: Impact sediment in Sarnia Bay – sediment in the bay is impacted and dredging in the existing location would require extensive costs.

Reason 2: Contamination – the existing boat launch and parking lot area was identified as the most ideal location to permanently store impacted material.

Reason 3: Consolidation of boating activities.

Reason 4: Creating the most “green” space associated with waterfront property to enhance citizen experience.

Reason 5: The contaminated soil cannot be stored on land that is “clean,” limiting the locations where that amount of soil can be stored.

Will the new boat launch have sufficient parking?

Yes, the new boat launch will have a parking lot capacity equal to or greater than the existing boat launch parking.

Will the new boat launch have the same number of boat ramps?

Yes, the new boat launch will have the same number of boat ramps (four).

How was the public engaged?

Comments were received and presented to Council in a supplementary report following the November 18, 2013 City Council meeting.

Public was notified of engagement through: City’s website – all documents, plans, reports. Dedicated e-mail monitored by staff. Staff-led public meeting/open house held on April 15, 2014 to present the proposed remediation strategies and concept plans to promote discussion and seek feedback

Community invited to provide comment on the proposed concepts over the period of March 25th, 2014 – April 23rd, 2014

3 public consultation meetings were held in 2015 as part of the Environmental Assessment process.

Park Amenity Plan: City staff conducted a series of public consultations to develop the Park Amenity Plan. Three public meetings were held in May and June of 2015. Feedback was received through City’s Centennial Park e-mail account and City Facebook page.

What is happening to the Victims of Chemical Valley Memorial Sculpture?

The concrete pads that the Victims of Chemical Valley Memorial Sculpture reside on will be lifted and decontaminated, and replaced on the clean cap at grade, in a similar location that they are in now.

What is happening to the Footsteps Tribute to Courage?

The Footsteps Tribute to Courage memorial will be lifted and stored safely until the pathway adjacent to Harbour Road is constructed. At that time, the walking stones will be replaced adjacent and parallel to a walkway.

What is happening to the VON Memorial Wall and Garden?

The VON Memorial Wall and Garden will have new electrical and water tie-ins. The soft cap will come right up to the edge of the memorial, but otherwise the memorial will not change.

Will there be a beach?

Due to remediation requirements and the need to contain materials by the use of an armour stone wall, re-opening the beach will not be an option.

What is happening to existing memorial trees?

There is one existing memorial tree (located in Central Phase II/III area), which will be preserved to the best of the contractor’s ability. There is one other tree that is of local interest, adjacent to the eastern parking lot, which will be preserved as well.

Will the stage replacing the Dow People Place have a roof?

Yes. Concept drawings for the new building are available here, named “Activity Centre Design Drawing:”

What will happen to the children’s playground?

The new playground equipment chosen is representative of the harbor/Sarnia Bay, and shaped like a boat. It is aimed at children ages 18 months to 12 years and can accommodate approximately 60 children. The surface of the playground area will be 0.2m of wood carpet over a concrete pad and 0.8 metre of soft cap below the concrete.

What are the Phase II and III project costs? / Where did the money come from?

Centennial Park Site Remediation- Phase II and III cost $4,990,421.37

The majority of the monies were budgeted through capital projects approved by Council in each of the last 3 years, and kept in a reserve for this year’s project.

$150,000 donation by the Rotary Club Bluewaterland for playgroup equipment and the healing garden

$38,000 of donations through the Friends of Centennial Park Fund for park amenities

$1,000 from Warden Bev MacDougall

Harbour Road/Centennial Park Watermain Project cost $1,413,350.33

Funded from the “Watermain, Sanitary and Storm Sewer Replacement – Various Locations”


Media Releases

Non-Agenda Reports


Waterfront Master Plan