The biggest oil spills in history show exactly how an oil release harms people, water, and wildlife, and what your family can do to stay ahead of it. We rank ten major spills by size and by harm. Each entry gives the facts, then one practical preparedness lesson you can use at home.
You might live on a coast, near a pipeline right-of-way, or within sight of a drilling pad or refinery. You might simply buy Gulf shrimp and wonder what a spill means for your dinner. Either way, the facts below give you a clear picture and a short list of steps.
Start by picturing the oil infrastructure closest to your home: a pipeline marker by the road, a tanker lane offshore, or a pump jack in a nearby field. Keep that picture in mind as you read. Each lesson points back to it.
The Biggest Oil Spills in History: The Top of the List
Learn the upper limit of what an oil release can be, and you can judge any spill report with clear eyes. The biggest oil spills in history by volume came from war, a runaway land well, and two offshore blowouts. Each entry uses the same format, so you can compare them side by side. After the top four, the ranking continues with six more spills that shaped how oil moves today.
A barrel of oil holds 42 gallons. Nobody can meter a gushing well, so we give ranges where experts disagree.
1. The 1991 Gulf War Oil Spill
Year and Location: 1991, Kuwait and the Persian Gulf.
Oil Released: Roughly 4 to 11 million barrels, or about 168 to 462 million gallons. Estimates vary widely because the release happened in a war zone.
Cause: Deliberate wartime sabotage. Retreating Iraqi forces opened the valves at a Kuwaiti offshore oil terminal and dumped oil from tankers into the Gulf.
Impact on People, Water and Wildlife: Oil coated hundreds of miles of Kuwaiti and Saudi coastline, smothering salt marshes, mudflats, and coral. Tens of thousands of seabirds died, and fish and shrimp catches dropped. The slick also threatened desalination plants, which turn seawater into drinking water for millions of people.
Lesson for Families: A spill can threaten your tap as well as your beach. If your town draws water from a river, lake, or coast near oil traffic, officials may shut the intake during a spill. Store one gallon of water per person per day for three days, then build toward a one week supply.
2. The Lakeview Gusher
Year and Location: 1910 to 1911, Kern County, California, near the town of Maricopa.
Oil Released: About 9 million barrels, or roughly 378 million gallons, over about 18 months. It is the largest accidental spill on record.
Cause: A well blowout. A blowout is an uncontrolled rush of oil or gas from a well after drillers hit a high-pressure pocket. The Lakeview No. 1 well erupted in March 1910, and crews of the day had no way to shut it.
Impact on People, Water and Wildlife: Workers built earthen dams and sandbag walls to hold back a lake of crude. Crews piped some of it away for sale. Much of the rest soaked into the ground or evaporated. The field sat in thinly settled scrubland, so direct harm to people stayed limited.
Lesson for Families: Land spills spread by gravity. If you live near wells or pipelines on land, notice which way the ground slopes toward your home, private well, or creek. Know your low ground, and you know where spilled oil will pool.
3. Deepwater Horizon
Year and Location: 2010, Gulf of Mexico, about 40 miles off Louisiana.
Oil Released: About 134 million gallons, or roughly 3.2 million barrels, the figure a federal court accepted. The government's earlier estimate was higher, about 4.9 million barrels. Oil flowed for 87 days.
Cause: A well blowout. Gas shot up the Macondo well and exploded on the rig on April 20. The blowout preventer failed. A blowout preventer is a stack of heavy valves on the wellhead built to seal the well in an emergency.
Impact on People, Water and Wildlife: The explosion killed 11 workers. Oil reached more than 1,300 miles of shoreline from Texas to Florida. Officials closed more than a third of federal Gulf waters to fishing at the peak. Dolphins, sea turtles, and birds died in large numbers, and fishing and tourism towns lost a season or more of income.
Lesson for Families: For many families, the biggest cost was lost income. If your paycheck depends on fishing, charters, or beach tourism, keep tax returns, pay stubs, and booking records in one folder. Clear records make a damage claim faster to prove.
4. Ixtoc I
Year and Location: 1979, Bay of Campeche, off Mexico's Gulf coast.
Oil Released: Roughly 3.3 million barrels, or about 140 million gallons, over nearly ten months. Against the court figure for Deepwater Horizon, Ixtoc I is slightly larger. Against the government's higher estimate, it ranks just below.
Cause: A well blowout on an exploratory well run by Pemex, Mexico's state oil company. Drillers lost control of pressure, the oil caught fire, and the platform collapsed. Crews drilled relief wells, which are side wells that intercept and plug the original, and capped it in March 1980.
Impact on People, Water and Wildlife: Oil drifted hundreds of miles north and fouled Texas beaches. It threatened nesting grounds of the endangered Kemp's ridley sea turtle, and volunteers airlifted thousands of hatchlings to cleaner water. Mexican fishing communities lost catches.
Lesson for Families: A blowout can run for months, and oil crosses borders. Follow beach and seafood advisories for as long as they last, well past the first week of headlines.
More Major Spills That Made the Ranking
See the full range of how spills start, and you can spot the risks that apply to your own address. Numbers 5 through 10 among the biggest oil spills in history include collisions, groundings, wartime damage, a tanker fire, and an inland well blowout. The last entry, Exxon Valdez, sets up the most important idea in the ranking: where a spill happens matters as much as its size.
5. Atlantic Empress
Year and Location: 1979, Caribbean Sea, off Tobago.
Oil Released: About 287,000 metric tons, roughly 2.1 million barrels or 88 million gallons. It is the largest ship spill on record.
Cause: A collision with another loaded tanker during a tropical storm. Both ships caught fire.
Impact: Fire killed 26 crew members. The burning ship sank two weeks later far offshore. Most oil burned at sea, and Tobago's shores saw little damage.
Lesson for Families: Distance from shore buys time. During any spill, watch wind and current forecasts to see whether oil is headed your way.
6. Fergana Valley
Year and Location: 1992, Mingbulak oil field, Uzbekistan.
Oil Released: About 2 million barrels, or roughly 88 million gallons. Estimates vary.
Cause: An inland well blowout. The well caught fire and burned for about two months.
Impact: The Fergana Valley is a crowded farming region. Crews built dikes that penned the oil into ponds, which kept much of it from spreading. Smoke fouled the air for weeks.
Lesson for Families: Farm country carries oil risk too. If you live near wells, know two routes out that avoid the well site.
7. Nowruz Field
Year and Location: 1983, Persian Gulf, off Iran.
Oil Released: Roughly 1.9 million barrels, or about 80 million gallons. Estimates vary.
Cause: Wartime damage. During the Iran-Iraq War, a tanker struck a production platform, and attacks later set it ablaze. Fighting kept crews from capping the wells for months.
Impact: The slick spread across the Gulf, harming fish, seabirds, sea turtles, and dugongs, which are large sea mammals related to manatees.
Lesson for Families: Delayed repairs mean long leaks. Keep your basic supplies stocked so one emergency never drains you for the next.
8. Castillo de Bellver
Year and Location: 1983, off Saldanha Bay, northwest of Cape Town, South Africa.
Oil Released: About 252,000 metric tons, roughly 79 million gallons.
Cause: A fire. The tanker burned, broke in two, and the stern sank.
Impact: Winds pushed most of the slick out to sea. About 1,500 gannets were oiled. Oily soot that locals called black rain fell on wheat fields and sheep pasture.
Lesson for Families: Burning oil becomes an air problem. When oil-fire smoke drifts your way, stay indoors, close windows, and run an air purifier with a fresh filter.
9. Amoco Cadiz
Year and Location: 1978, Brittany, France.
Oil Released: About 223,000 metric tons, roughly 1.6 million barrels or 69 million gallons.
Cause: A grounding. The steering failed in a storm, and the tanker drifted onto rocks.
Impact: Oil fouled about 200 miles of coastline. Around 20,000 seabirds died, oyster beds were ruined, and towns lost tourism income.
Lesson for Families: Shellfish and fishing families face the most direct losses. Ask your insurer now whether your boat, gear, or business policy covers pollution.
10. Exxon Valdez
Year and Location: 1989, Prince William Sound, Alaska.
Oil Released: About 11 million gallons, or roughly 257,000 barrels. By volume, Exxon Valdez sits far below the other entries.
Cause: A grounding. The tanker left the shipping lane to avoid ice, failed to turn back in time, and struck Bligh Reef. Federal investigators cited a tired, short-handed crew, a captain absent from the bridge, and weak traffic monitoring.
Impact: The oil spread through a cold, rocky, enclosed sound. It fouled about 1,300 miles of coastline, with about 200 miles heavily oiled. Scientists estimate it killed about 250,000 seabirds, 2,800 sea otters, 300 harbor seals, and 250 bald eagles. The herring fishery collapsed a few years later and has never fully recovered. Native villages lost subsistence food for years, and pockets of oil still sit under some beaches.
Why It Changed the Rules: Congress passed the Oil Pollution Act of 1990 the next year. The law made spillers pay for cleanup and damages, created a federal fund to pay claims, and phased in double-hulled tankers in U.S. waters by 2015. A double hull is a second steel shell that holds oil in if the outer hull tears.
Lesson for Families: A smaller spill in the wrong place can do more harm than a giant one far offshore. If you harvest fish, shellfish, or game near the water, keep a backup food supply that does not depend on it.
Why Size Isn't Everything: What These Spills Teach Families
Understand what turns oil into harm, and you can size up your own risk in minutes. The biggest oil spills in history share a pattern: harm depends on where oil lands, how fast crews contain it, what lives in its path, and who lives nearby. After the lessons below come recent spills and a household checklist.
It is fair to assume a bigger spill means bigger damage, and volume does matter. Compare three cases, though. The Atlantic Empress lost eight times as much oil as Exxon Valdez, yet most of it burned at sea and Tobago's beaches were largely spared. Exxon Valdez spilled into a cold, closed sound where oil broke down slowly and washed onto 1,300 miles of shore. The Lakeview Gusher hit thinly settled scrubland, while Deepwater Horizon hit a coast full of fishing and tourism towns.
Fumes, Skin Contact, and Tainted Seafood
Fresh crude gives off vapors such as benzene, which can cause headaches, nausea, and sore eyes or throat. Wash oil off skin with soap and water or dish soap to prevent rashes. Officials test seafood before reopening fisheries, so buy from reopened areas and you get food that passed those tests.
Tainted Water Intakes
Spills near rivers or desalination plants can shut down drinking water intakes. A stored water supply bridges the gap. If you rely on a private well near a pipeline, test it after any nearby leak.
Lost Income and Property Value
Fishing, charter, and tourism income can vanish for a season or longer. Beach closures can cut rental income and property values for a time. Good records turn those losses into claims you can prove.
Long-Lived Oil in Ecosystems
Oil lingers in cold water, marshes, and under rocky beaches for decades. Prince William Sound herring show how a food chain stays damaged after beaches look clean. Expect advisories to outlast the news coverage.
New Rules After Disasters
The Oil Pollution Act of 1990 makes the responsible party pay for cleanup and for losses such as property damage, lost income, and lost subsistence food. If the company does not settle within 90 days, you can file with the federal Oil Spill Liability Trust Fund. Claims carry deadlines, often three years from when you discovered the loss, so file early.
Oil Spill Risk Today and How to Prepare
Build a household preparedness plan from recent spills, and you turn history into protection you can set up this weekend. None of the recent releases rank among the biggest oil spills in history. Aging pipelines, extreme weather, busy shipping lanes, and offshore drilling still cause real harm. A short checklist follows the examples.
Recent Spills Worth Knowing
Huntington Beach, California, 2021. An offshore pipeline leaked about 25,000 gallons. Investigators found ship anchors had dragged across the line during an earlier storm. Beaches closed, and fishing stayed shut for weeks.
Mauritius, 2020. The bulk carrier Wakashio grounded on a reef and leaked about 1,000 tons of fuel oil into a protected lagoon. Residents built floating barriers from sugarcane leaves and donated hair.
Kansas, 2022. The Keystone pipeline leaked nearly 13,000 barrels into a creek, the largest U.S. onshore crude spill in about a decade.
Weather adds to the risk. Prepper Life's On This Day look at Hurricane Katrina recalls the 2005 storm that flooded New Orleans, and that same storm damaged oil facilities that released millions of gallons across Louisiana.
Your Household Oil Spill Checklist
1. Locate nearby pipelines. Search your address in the National Pipeline Mapping System public viewer to see transmission lines and their operators. Call 811 before you dig, and you avoid hitting a buried line.
2. Sign up for local alerts. Register for county emergency alerts and turn on Wireless Emergency Alerts. You get evacuation and advisory notices the moment they go out.
3. Learn the warning signs. Watch for a petroleum or rotten-egg smell, a rainbow sheen on water, dead plants along a pipeline route, or hissing sounds. Early notice buys you time.
4. Know who to call. Walk away upwind first. Then call 911 and the National Response Center at 1-800-424-8802. Wait to use lighters, switches, or engines until you are well clear.
5. Keep clear of oiled water, sand, and wildlife. Report oiled animals to the posted hotline so trained responders can handle them. Keep pets leashed on affected beaches.
6. Follow seafood and beach advisories. Check state health notices before you fish, swim, or harvest shellfish.
7. Keep records and photos. Take dated photos of your home, boat, and business, and save income records. Good records speed up claims.
8. Review your insurance. Many homeowners policies exclude pollution damage. Ask your agent what is covered and what a rider would add.
If you live on the coast, start with items 2, 6, and 7. If you live near a pipeline or well, start with items 1, 3, and 4. Living close to oil infrastructure has an upside: you already know the risk exists, so you can plan ahead of it. The biggest oil spills in history prove that awareness and preparation reduce harm.
