We take numerous precautions to reduce the risk of a spill, proactively work to minimize opportunities for spills and continually evaluate spill risks across our operations. Design, operation and maintenance of our facilities play a key role in protecting the environment where we operate. We are also focused on strengthening our oil spill response capability through our systematic, multi-tiered approach to emergency preparedness and crisis management.
Hydrocarbon spills impacting a sensitive area and spills greater than 100 barrels are immediately reported to our corporate office. In 2019, we experienced two spills greater than 100 barrels. Both spills were to land in the Lower 48. The two events resulted in approximately 1,100 barrels being released with an 84% recovery rate which was higher than 2018.
The number of spills greater than one barrel was also reduced in 2019, although the spilled volume was higher. We had 89 spills that were greater than one barrel, with 70 of those being between one and 10 barrels. All spills were to land. Two-thirds of the volume of our spilled material was fully recovered.
Our investment in spill response technologies includes membership in Oil Spill Removal Organizations (OSROs) across the globe, which affords us access to substantial inventories of, and the latest advances in, proven response equipment.
In the Gulf of Mexico, we are members of two OSROs, Marine Spill Response Corporation (MSRC) and Clean Gulf Associates (CGA). Our Alaska business unit has memberships in two large OSROs, including Alaska Clean Seas (ACS) and Ship Escort/Response Vessel System (SERVS) for our exploration and production operations on the North Slope and our Polar Tanker operations in Prince William Sound, respectively. Our membership in MSRC, as well as a contract with the National Response Corporation (NRC), provides coverage for our Polar Tankers operations along the U.S. west coast.
In addition to our U.S.-based OSRO memberships, the company also belongs to the Oil Spill Response Limited (OSRL) and Norwegian Clean Seas Association for Operating Companies (NOFO). OSRL provides global substantial response resources staged at various locations around the world, whereas NOFO, also with significant resources, provides regional OSRO support for our Norway operations. We are also members in other, somewhat smaller, local OSROs associated with many of our global operations.
Read more about our Emergency Preparedness.