Atlas of Contaminated Sites

Notable case, Fort McMurray, Alberta, Canada

Athabasca oil sands tailings ponds

The ponds where Alberta's oil sands mines store water, clays, residual bitumen, naphthenic acids and metals: nearly 1.5 billion cubic metres of fluid tailings in 2023.

Status
Not addressed
Area
22,000 ha in water1
Activity
since 1967
Media
surface water, groundwater, sediment, air, living organisms
Kind of site
oil, mining
  1. Area. About 220 km² of ponds in 2017 (77 km² in 2013 by another estimate); 1,486 million m³ of fluid tailings in 2023. The coordinates mark Fort McMurray, south of the mining area.

Contaminants

Metals

Metalloids

Organic compounds

Other inorganics

Status

Not addressed

The volume of fluid tailings keeps growing (1,441 million m³ in 2022, 1,486 in 2023). No tailings pond has yet been certified reclaimed; the financial security collected (C$1.4 billion) is a fraction of the estimated liability of C$130–260 billion.

Story

Extracting bitumen produces tailings that are about 75% water and 25% sand, silt and clay, with roughly 2% residual bitumen. The ponds, run by Syncrude, Suncor, Canadian Natural Resources and Shell, contain salts, naphthenic acids, polycyclic aromatic hydrocarbons, benzene and metals such as chromium, arsenic, nickel, cadmium, copper, lead and zinc.

In 2008, 1,606 ducks died after landing on a Syncrude pond whose deterrents were not operating. A 2013 Queen's University study found PAH levels in the region up to 23 times higher than before extraction began. The first pond declared reclaimed is Suncor's Pond One (1967–1997), 220 hectares now called Wapisiw Lookout: the fluid tailings were moved elsewhere, however, and environmental groups dispute that it counts as true reclamation.

Timeline

  1. 1967Suncor's Pond One comes into use.
  2. 20081,606 ducks die on a Syncrude pond.
  3. 2009Directive 074 on reducing fluid tailings.
  4. 2016Directive 085: tailings 'ready to reclaim' within ten years of mine closure.
  5. 2023Fluid tailings reach 1,486 million m³.

Remediation

  1. —pond reclamationWapisiw Lookout: Suncor's Pond One emptied and a planted landscape rebuilt on 220 hectares.

From the literature

Species that acted on one of this site's contaminants in at least one study. The list is automatic and takes no account of this site's soil, concentrations or climate.

Plants

Fungi

The rest are on the contaminant pages.

Sources

  1. Oil sands tailings ponds (Canada), Wikipedia, 2026
  2. Fort McMurray (coordinates), Wikipedia, 2026

Draft compiled from public sources, not yet reviewed.