Mechanical containment and recovery is considered the primary or preferred response strategy in many regions of the world. Containment booms are normally used in combination with a skimmer to remove oil from the water’s surface where it is temporarily stored before further treatment.
The main challenge presented to mechanical recovery in ice is the difficulty of accessing the oil and, therefore, low skimmer encounter rates. Additional challenges include the need for the skimmer to process the ice in such a way that the flow of oil into the skimmer is not restricted as well as the ability of skimmers to function effectively at very low temperatures.
Depending on the time of year, responders in the Arctic can face a spill in open water and with varying amounts of ice cover. Most mechanical containment and recovery systems are technologies developed for open water; however several types of skimmers have been developed specifically for recovering oil in ice.
- Containment booms, ice, and snow provide barriers against the spread of oil and result in a thicker layer of oil available for recovery.
- Several types of skimmers and vessels have been developed specifically for recovering oil in ice covered regions. The skimmers are often brush belts, drums, or ropes rotating through the slick and capable of recovering oil while processing small ice pieces. Some skimming units are equipped with heating systems, ice deflection frames, and advanced systems for pumping viscous oil/water/ice mixtures.
- Environmental conditions and the oil’s physical properties should all be taken into account when determining what type of mechanical recovery device is best suited for oil recovery in each particular situation.