BP told its investors Monday that it has spent over $1.25 billion in costs since April 20 for the Deepwater Horizon oil spill disaster, and that rate of spending “is expected to continue for some time.”

While most of the money is going to containment and cleanup of the largest oil spill in U.S history, the amount probably includes the mere beginning of legal costs to prepare for the more than 130 lawsuits that have been filed so far. Legal experts say the spill presents complex issues far beyond any other U.S. environmental disaster.