Lessons From the Exxon Valdez Oil Spill Exxon Valdez: In the Wake of Disaster: In 1989, a tanker ran aground off the coast of Alaska, causing one of the worst oil spills in United States history. Nearly 25 years later, the lessons of the Exxon Valdez continue to resonate. On a cold March night in 1989, the tanker Exxon Valdez ran aground off the coast of Alaska, spilling 11 million gallons of crude oil into the waters of Prince William Sound and creating one of the worst oil spills in American history. This week's Retro Report examines how that spill happened and follows its impact over the past twenty-five years. Watch the video above for the complete story. Below, a Times reporter who covered the BP oil disaster of 2010 writes about how containment and cleanup evolved. As oil disasters go, the 1989 Exxon Valdez grounding and the 2010 Deepwater Horizon blowout were about as different as two spills could be. One wasn't even technically a spill. When the Deepwater Horizon exploded and sank in the Gulf of Mexico, it uncorked a gusher, a mile down at the seabed. This subsea torrent of oil turned out to be far greater than the amount of crude that leaked from the damaged Exxon Valdez onto the surface of Prince William Sound - about 200 million gallons compared with 11 million - and it posed a different set of problems for BP and government officials. In cleaning up an oil spill, a main goal is to separate the oil from the water - like skimming the fat off a bowl of gravy. In the gulf disaster, it didn't help that cleanup technologies like booms and skimmers had changed little over two decades. But the fact that the oil spewed into the deep gulf waters and spread out over a wide area before it reached the surface made containing and collecting the oil even harder. As a result, the government allowed BP to try something new: injecting chemical dispersants into the plume of oil at the seabed. Ordinarily, dispersants help break surface oil into tiny droplets that sink into the water column, where they can be degraded by bacteria. That was the goal in Prince William Sound. In the gulf, the hope was that the chemicals would keep the oil from reaching the surface. It is unclear how effective the technique was, and subsequent studies have suggested that the large amount of dispersants - close to two million gallons in all, far more than in any other spill - might have left their own detrimental environmental effects. For BP, the cleanup was only half the battle. The Exxon Valdez carried a huge but finite amount of oil, while the gulf well could have continued gushing for months or years if it wasn't stopped. That is where BP, the rest of the industry and the government were really unprepared. They had no experience in trying to control a deepwater blowout. The well was only 5,000 feet away, but because no human could reach it, it might as well have been on Mars. Technology had failed BP's engineers. The subsea blowout preventer - the enormous array of pipes and valves that sat atop the well at the seabed - had not done its job during the initial emergency, and in the first few days of the disaster all the remotely operated submersibles in the world could not get it to shut the gusher down. That left the engineers and well-control specialists to attempt jury-rigged solutions. For months none of these efforts - with nicknames like "junk shot," "top kill" and "top hat" - worked. What eventually did tame the well was a large "capping stack" that fit snugly atop the blowout preventer. To the engineers" credit, they had thought of this early on. When I met with some of them at BP in Houston two weeks into the disaster, the idea of such a device was mentioned, but it took two months to design and build it. After that experience, most of the major companies that drill in the gulf, including BP, formed an independent company to come up with equipment and procedures for dealing with future spills. The company, Marine Well Containment, has built an all-purpose capping stack and other equipment, and more work is planned. The idea is to have the equipment ready, along with people trained to use it, should another deep-sea blowout occur. Then again, the next disaster may be completely different, just as the Deepwater Horizon disaster was from the Exxon Valdez. This week's Retro Report is the 23rd in a documentary series.