Setting sediment standards

Many industry experts believe it’s only a matter of time before sediment assessment and remediation becomes the next European‑wide hot topic. Environmental consultant Simon Morten investigates what this means for oil and gas companies.

Historically, the majority of oil terminals and refineries in Europe were supplied by ship or barge. As a result, petroleum distribution and refining facilities are often located adjacent to seas, estuaries or rivers. The combined effects of the less stringent standards and practices of our predecessors, extended operation periods and bomb damage caused during the World Wars, have left a complicated contaminated land legacy, which often extends into the adjacent waterways and sediments.

Complicated contaminants

The complication doesn’t end there. Terminals and refineries were built in locations to serve ports and industry. Industrial hubs, including petrochemical plants, later grew around these coastal refineries and ports and were fuelled by the same petroleum-based products, often creating a mix of co-mingled petroleum hydrocarbon, and other contaminant plumes, from multiple sources. Ports can also receive pollution from agricultural runoff, and urban and wastewater treatment discharge from surrounding catchment areas, leading to a concoction of contamination.

Whose responsibility?

The challenge within the dynamic water environment is to understand where contamination originated, and hence who should pay for any assessment and remediation. Oil companies are typically the only company still operating and often take on this burden.

Sediment remediation, compared to terrestrial (land-based) remediation, is a relatively underdeveloped field in Europe. We are yet to see large scale environmental resource-driven whole catchment remediation projects, as are common in the US. That said, sediment is increasingly mentioned in European legislation as part of the Water Framework and Marine Framework, among others. Legislation is in place locally and clean‑up case studies, including projects undertaken by AECOM in Norway and Italy, in addition to navigation-driven dredging projects, are available. However, as yet, many countries are slow to implement defined sediment remediation legislation and enforce clean‑up.

A sustainable approach

Many in the industry believe it’s only a matter of time before sediment assessment and remediation becomes the next European-wide hot topic. The challenge facing the oil and gas industry is to ensure that legislation and developing best practices incorporate the right experience from contaminated land management, resulting in a holistic and sustainable approach to managing the risks posed by contaminated sediments, so that the benefits of undertaking remediation are greater than its impact.

Integrated models

Applying an integrated model will ensure that any financial expenditure is correctly targeted towards improving the environment, rather than blindly chasing targets for little or no improvement in the resource value of our lakes, rivers and seas. We’re already helping clients explore options in this emerging area though the use of assessment tools based on environmental, economic and social indicators to select the best, practical approach.