Oil and gas activities generate many different types of waste, ranging from ordinary household waste to various hazardous waste fractions. The rules for dealing with waste vary, depending both on its properties and on the risk of environmental damage.
Drilling generates most waste
Well drilling is the offshore activity that generates the largest quantities of waste. About 465 000 tons of hazardous waste was taken ashore in 2015, which is 38 000 tons more than in 2014. The largest fraction consisted of drilling waste.
About 37 000 tons of non-hazardous waste was generated on the Norwegian shelf in 2015. The different waste fractions are shown in the figure below.
Hazardous waste on the rise
The quantity of hazardous waste from the offshore sector has increased considerably since 2009, mostly because more drilling waste has been taken ashore and treated as hazardous waste. This is largely due to the difficulties the industry has experienced in injecting drill cuttings into the underground on several fields on the continental shelf.
Pollution from drilling waste
Transporting drill cuttings to land and treating drilling waste result in emissions of greenhouse gases and acidifying substances. There is also a risk that soils, rivers and lakes, and coastal waters may be polluted by releases from waste treatment facilities and landfills.
Drill cuttings require special treatment
The Departments of Environmental Affairs at the County Governor's Office decide which waste treatment facilities are authorised to receive waste from offshore activities for intermediate storage.
Non-hazardous waste is treated together with household waste.
Hazardous waste is transported to authorised treatment facilities. Drill cuttings sent onshore can only be treated by facilities that have been approved by the Norwegian Environment Agency.
The offshore sector is obliged to report all generated hazardous waste and trade waste.