( CNN ) -- BP showed up in court last week , finally , nearly three years after the Deepwater Horizon disaster and the hell it unleashed on the Gulf Coast . It 's a huge , high-stakes trial , and BP is taking the beating it 's earned . Here 's what 's at stake for America if there is a judgment : potentially tens of billions of dollars that will be used to create jobs while restoring some of our most productive and vulnerable natural places . Whether the trial results in a decision or a settlement , the outcome will send a signal about how serious this country is about enforcing its common-sense rules that guarantee clean air and waters . BP and its partners have already confessed to criminal negligence in the 2010 blowout that killed 11 men and gushed nearly 5 million barrels of oil . Every part of the Gulf of Mexico ecosystem , from the deep-sea corals to dolphins to migratory birds , was affected . Gulf Coast residents suffered billions of dollars in economic losses , with effects that rippled across the country . And despite those slick commercials that assure you all is well and then invite you to spend your tourism dollars on the Gulf Coast , the disaster is still unfolding . Last summer , scientists found traces of BP 's oil and dispersant in the eggs of migratory white pelicans nesting all the way up in Minnesota . Oil is still present on the Gulf 's beaches , in the marshes and under the water . It is working its way through the food chain , so it will be years before we understand the full extent of the disaster . BP 's billions at stake as courtroom showdown starts . Just Wednesday , in fact , the Gulf Restoration Network documented a fresh rash of tarballs on a Louisiana beach known as Elmer 's Island -- a spot that gets re-oiled every time a storm stirs up BP 's submerged goo . We 're nearly three years in , and there 's no end in sight . That 's why our justice system must hold BP and other polluters fully responsible under the law for the worst offshore oil disaster in history . How much could BP end up paying ? BP is liable for up to $ 17.6 billion in penalties under the Clean Water Act if it is found grossly negligent . ( And if this is n't gross negligence , it 's hard to imagine what is . ) Add to that figure the potential for tens of billions more in fines under the Oil Pollution Act . This much is clear : The rules were put in place to deter and , if needed , to penalize the offenders . The Deepwater Horizon was the kind of disaster that was envisioned when the full force of these penalties was contemplated . Those penalties -- and nothing short -- are the fair outcome . It was n't surprising to see BP 's stock rise when it agreed to an unprecedented $ 4.5 billion in criminal fines . The market was saying , in essence : Guys , it could have been a lot worse . BP claims it now leads the way on safety . So we know that some amount of penalties -- a staggering amount by normal standards -- has already been `` priced in '' to BP 's value . So , this is n't about whether BP will continue to be an ATM for shareholders . It will be . And we 're not saying that there should n't be drilling in the Gulf Coast . We 're saying that even megacorporations need to play by the rules . If Justice Department lawyers agree to a weak settlement , the burden of rebuilding from this disaster will be transferred from a foreign corporation to American taxpayers . Worse , it will send a message to polluters that we do n't take seriously our air , water , wildlife , communities or economic health . What 's the difference between a $ 15 billion settlement and a $ 35 billion dollar judgment ? The ability to rebuild the Louisiana wetlands -- America 's delta -- for generations to come . A healthy , productive Gulf Coast where people and wildlife thrive . The principle that if you break it , you buy it . Families of killed rig workers react to BP settlement . Under the terms of the RESTORE Act -- passed last year with historic bipartisan support -- 80 % of Clean Water Act civil penalties will go back to restore the environment and economies of the Gulf Coast states . That 's right and fair . We do n't love how the states want to spend every dollar . But this is what a grand political bargain looks like , in case we 've forgotten . Two weeks ago , we and our partners hand-delivered more than 133,000 petitions to the Department of Justice , calling for full and complete accountability under the law for BP and its partners . The point of the petitions was pretty straightforward : These rules matter to Americans , and everyone needs to play and -- in this case -- pay fully . The opinions expressed in this commentary are solely those of David Yarnold .
David Yarnold : BP is rightly on trial , potentially facing judgment in tens of billions . He says even if BP settles , it will send signal that U.S. enforces clean air , water rules . He says pollution of Gulf spill still present three years later ; BP must be accountable . Yarnold : Big judgment will fund Gulf coast restoration and send message .