there's really no end in sight to this. even if it hasn't done exxon valdez numbers yet, it will within a few days anyway.
it already has passed that point if you do simple math to check it:
The coast guard map from april 28th identified areas with relative heavy thickness and areas with relative light thickness (
http://1.bp.blogspot.com/_edvxM1dkF...X2N9-D1BY/s1600/CG_spill_map_28apr10_1330.jpg ).
The vast majority of the spill (~89%) is extremely light (.5 microns thick), but somewhere around 1% of the spill is estimated to be very thick (200 microns thick), around 4% of the spill is estimated to be fairly thick (100 microns thick), and another 5% was estimated to be around 10 microns thick.
The estimated concentration per acre for each of those levels (based on ranges given in
http://3.bp.blogspot.com/_edvxM1dkF...UjIY/s1600/April+28+volume+BOAC+chart+Ian.jpg ):
.5: .0128 barrels per acre
10: .282 barrels per acre acre
100: 2.54 barrels per acre
200: 5.1 barrels per acre
If we multiply the concentration by the reported proportion and convert barrels to gallons, the expected spill size should be 7.48 times the reported area of the spill: (.0128*.89+.282*.05+2.54*.04+5.1*.01)*42 = 7.479864
On April 28th, the estimated size was 1786 square miles aka 1.1 million acres. Using the proportions above and the size of the oil slick, the estimated size would be 8.2 million gallons
The estimated size hit roughly 2600 square miles aka 1.6 million acres on May 1st. Using the same proportions as described above, the estimated spill size would have been around 11.9 million gallons as of May 1st
Now the area of spill is being estimated at 4-5 thousand square miles (aka 2.5-3.2 million acres). With the same proportions again, the estimated amount of oil spilled is in the range of 18.7-23.9 million gallons of oil.
I presume it is also becoming obvious that based on the growth of the spill area and total spill, clearly there is a lot more being leaked than 200k gallons a day.