The U.S. government has finally entered the litigation fray over the catastrophic Deepwater Horizon oil spill. Eight months after oil began spewing into the Gulf of Mexico, Attorney General Eric Holder announced Wednesday that the Department of Justice has filed civil claims against BP, Transocean, and seven other defendants over the disaster.

The government’s 27-page complaint, filed in New Orleans federal district court, alleges that BP and the other defendants failed to ensure the safety of the well, and seeks compensation for clean-up costs and damages under the Clean Water Act, the Oil Pollution Act, and other federal environmental laws. The complaint notes that federal laws subject each defendant to a penalty of up to $4,300 for each barrel of oil spilled if the spill was the result of gross negligence or misconduct. And considering that government scientists estimated in August that about 4.9 million barrels of oil were released as a result of the Deepwater Horizon blowout, we’re talking about more than $20 billion in potential exposure — for each defendant.