"Rate of Oil Leak, Still Not Clear, Puts Doubt on BP"
"On Monday, BP said a cap was capturing 11,000 barrels of oil a day from the well. The official government estimate of the flow rate is 12,000 to 19,000 barrels a day, which means the new device should be capturing the bulk of the oil. But is it? With no consensus among experts on how much oil is pouring from the wellhead, it is difficult -- if not impossible -- to assess the containment cap’s effectiveness."