Coast Guard Commander Adm. Thad W. Allen warned this weekend that even if the flow of crude was completely stopped by summer, it could take well into fall, or even much longer, to cleanup the slick spreading through the Gulf of Mexico.  Mitigating the damage done to beaches, marshes, and wildlife will take years.

Allen also said this weekend on CBS’s “Face the Nation” that the only solution to the problem would be the successful completion of relief wells, which are currently being drilled. The wells will not be completed until August at the earliest.

This assessment comes after the sheer volume of the oil spewing from the well forced British Petroleum to halt its efforts to close all four vents on a capping device placed over the wellhead last week. Even with three vents open, the cap is capturing so much oil that BP does not have adequate equipment on hand to process more. BP has reported that the cap is currently capturing 10,000 barrels of oil a day from the leaking well, but it is impossible to gauge what fraction of the total spill flow that represents.

The British oil giant also said Monday that it has already spent $1.25 billion to contain the Gulf oil spill. With possibly months still ahead in the cleanup effort, the costs will only continue to rise.