Has Alberta oil sands development altered delivery of polycyclic aromatic compounds to the Peace-Athabasca Delta?

PLoS One. 2012;7(9):e46089. doi: 10.1371/journal.pone.0046089. Epub 2012 Sep 26.

Abstract

Background: The extent to which Alberta oil sands mining and upgrading operations have enhanced delivery of bitumen-derived contaminants via the Athabasca River and atmosphere to the Peace-Athabasca Delta (200 km to the north) is a pivotal question that has generated national and international concern. Accounts of rare health disorders in residents of Fort Chipewyan and deformed fish in downstream ecosystems provided impetus for several recent expert-panel assessments regarding the societal and environmental consequences of this multi-billion-dollar industry. Deciphering relative contributions of natural versus industrial processes on downstream supply of polycyclic aromatic compounds (PACs) has been identified as a critical knowledge gap. But, this remains a formidable scientific challenge because loading from natural processes remains unknown. And, industrial activity occurs in the same locations as the natural bitumen deposits, which potentially confounds contemporary upstream-downstream comparisons of contaminant levels.

Methods/principal findings: Based on analyses of lake sediment cores, we provide evidence that the Athabasca Delta has been a natural repository of PACs carried by the Athabasca River for at least the past two centuries. We detect no measureable increase in the concentration and proportion of river-transported bitumen-associated indicator PACs in sediments deposited in a flood-prone lake since onset of oil sands development. Results also reveal no evidence that industrial activity has contributed measurably to sedimentary concentration of PACs supplied by atmospheric transport.

Conclusions/significance: Findings suggest that natural erosion of exposed bitumen in banks of the Athabasca River and its tributaries is a major process delivering PACs to the Athabasca Delta, and the spring freshet is a key period for contaminant mobilization and transport. This baseline environmental information is essential for informed management of natural resources and human-health concerns by provincial and federal regulatory agencies and industry, and for designing effective long-term monitoring programs for the lower Athabasca River watershed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alberta
  • Environmental Monitoring
  • Oil and Gas Fields*
  • Polycyclic Aromatic Hydrocarbons / analysis*
  • Water Pollutants, Chemical / analysis

Substances

  • Polycyclic Aromatic Hydrocarbons
  • Water Pollutants, Chemical

Grants and funding

The research was supported by Suncor Energy Ltd. (http://www.suncor.com), an oil sands mining and production company. Dr. Jon Fennell (WorleyParsons Canada), a respected consultant to industry and government, and a scientific authority on water-related environmental issues in the oil sands industry, helped obtain the funding for the project. During periodic meetings, Dr. Fennell became familiar with the authors’ prior hydroecological research in the Peace-Athabasca Delta. And, the authors’ discussed with him the concepts and proposals for the project presented in this paper. He was also aware of challenges faced when trying to get the project funded by more traditional research funding routes. Dr. Fennell presented the concept of the research project the authors had developed to a manager at Suncor Energy Ltd., which provided an introduction that led to development of the funding for this project. During the project, Dr. Fennell acted as a liaison for communications between the authors and staff at Suncor Energy Ltd. The funder had no role in study design, data collection and analysis, or preparation of the manuscript. The agreement between the University of Waterloo and the funder allowed the funder an opportunity to delay publication by up to 18 months, which they did not execute.