This report explains the waste generation implications of different oil spill clean-up techniques and describes best practice options for oiled waste management, which in many countries is strictly regulated.
The importance of waste management
There is a constant risk of oil spills in almost every environment worldwide. If a spill occurs at sea, the action of currents, winds and tides will often result in the spilt oil impacting a shoreline. This has many implications but one of the most difficult problems to deal with is the quantity of waste generated in a very short period.
Historical data show that oil spills impacting the shoreline can, in extreme cases, produce up to 30 times more waste than the volume of oil originally spilt. Although there may be different reasons for the amount of waste generated, it is also evident that a significant number of smaller spills have created large amounts of waste. The management of all waste in any spill should be regarded as a high priority.
Waste management considerations
The waste hierarchy
A useful model when dealing with a waste stream originating from any source is the ‘waste hierarchy’. This concept uses principles of waste reduction, reuse and recycling to minimise the amount of waste produced, thus reducing environmental and economic costs and ensuring that legislative requirements are met. It provides a tool for structuring a waste management strategy and can be used as a model for all operations.
In the event of a spill and the subsequent clean-up operation, oil and oiled debris collected becomes a waste that should be segregated, stored, treated, recycled or disposed of. Assuming segregated disposal routes are available, an important process in the first stages of an oil spill response is to classify and segregate waste streams at source. Waste should be channelled into separate storage dependent upon type, taking into consideration the most suitable containment for that material.
Minimisation is a method of reducing the amount of waste entering the waste stream. This is essential to reduce the amount of waste for final disposal, thus limiting environmental and economic impacts.
Secondary contamination is the spread of oil via people, transport and equipment to otherwise unpolluted areas. This should be avoided to control the overall impact of the spill, and can be achieved in a number of ways.
Health and safety
All hydrocarbons potentially pose some degree of health risk and it is therefore essential that a health and safety plan is drawn up before any activity commences. Risks from physical hazards, e.g. storage pits, should not be overlooked. Each stage of the management process should be assessed to establish any potential health and safety risks together with appropriate mitigating methods.