From USAToday (States tally oil spill toll to send BP their bills):
While the strategies differ, every state bordering the Gulf of Mexico is calculating the damage caused by an estimated 5 million barrels of oil spilled in the Gulf and the chemicals used to clean it up, and preparing to present BP with a bill. All of the states say they can back up their claims with a lawsuit if BP won't pay.
...Mississippi's state agencies and economists at its universities are calculating the state's economic damages, including sales tax revenue, Hood says. Another state agency is tallying the environmental toll. Once the state has solid numbers, he says it will seek quarterly or annual payments from BP.
