The U.S. Coast Guard estimated that spill covered 8,320 acres (3,370 ha) of the ocean's surface as they monitored it several times daily from the air.

Investigations found a 17.7-mile (28.5 km) pipeline connecting offshore oil platforms with the shore had been displaced by being dragged by a ship's anchor.

A consortium led by Royal Dutch Shell discovered the Beta field in 1976 in San Pedro Bay[1] and built the platforms Elly and Ellen in 1980.

Connected by pipelines, Ellen and Eureka have dozens of wells while Elly separates the water and natural gas from the crude oil.

In 2000, the shipping lanes were relocated about one mile (1.6 km) west of the platforms as the newer deep draft vessels required significant room to maneuver.

Beta Offshore, a subsidiary of Amplify Energy and current owner, pays royalties to the government in exchange for the lease on federal property as do other oil and gas companies.

[6] As these wells were no longer producing as much oil, the company received a $20-million “end of life” royalty discount for two years starting in July 2016.

Believing that the system was providing false alarms for a leak at the platform, they began a series of restarting and stopping the flow of oil throughout the night.

Multiple calls concerning a possible spill north of the Huntington Beach Pier came in over a marine radio emergency channel from boats leaving the Pacific Airshow.

[10] In the evening, a foreign ship anchored off the coast reported a possible oil slick about 5 miles (8.0 km) west of Huntington Beach.

A satellite image from the European Space Agency was reviewed by a National Oceanic and Atmospheric Administration analyst which confirmed a substance on the water which was most likely petroleum.

[12] The National Response Center, staffed by United States Coast Guard officers and marine science technicians, is the sole federal point of contact for reporting all hazardous substances releases and oil spills.

They forwarded the information to the Office of Spill Prevention and Response (OSPR), a division of the California Department of Fish and Wildlife charged with handling such emergencies.

The Coast Guard and Orange County Sheriff's Department flew out once the fog had lifted to the reported leak location to investigate.

[17] The US Coast Guard estimated that spill covered 8,320 acres (3,370 ha) of the ocean's surface as they monitored it several times daily from the air.

[19] The ocean currents pushed the plumes of oil south without large amounts entering the surf zone and fouling the beaches.

[20] During the days, workers in hazmat gear scoured the beaches to find and remove tar balls and any traces of damage from the spill.

[11] Contract divers and remotely-operated vehicles found a 4,000-foot (1,200 m) section of the pipeline had been pulled like a bowstring so that it was about 105 feet (32 m) out of place at its widest point with a 13-inch split (33 cm) aligned with the length of the pipe.

[25] Initial investigations were of ships anchored closest to the pipeline the week before the spill such as the MV Rotterdam Express which was boarded by the Coast Guard.

[26] The investigation continued with particular interest in ships that were waiting to get into port and anchored outside an assigned anchorage or too close to a pipeline that was marked on nautical charts.

[32] Birds that gather in and around Huntington State Beach include gulls, willet, long-billed fletcher, Elegant terns and reddish egret.

[34] Significant impacts can still occur to birds and marine life from the exposure that they get subtly through their diet or because of physical contact later on which might affect their physiology, their health and translate into a lower reproductive success.

[37] By November 6, about a third of the shoreline was nearing final cleanup approval as crews continued to collect tar balls along with sand, seaweed and driftwood tainted with oil.

[50] Actions advocated by some lawmakers and environmentalists include prohibiting all future offshore drilling and extending the ban to companies already operating in state and federal waters.

[45] In August 2022, Amplify announced it would plead guilty to one count of misdemeanor negligent discharge of oil related to the leak in federal court.

[54] Amplify Energy and two of its subsidiaries agreed to enter no contest pleas to killing birds and water pollution in a settlement with the county and state officials in September.

[55] In 2022, a proposed claim settlement of $956,352 by Amplify was accepted by the Orange County Board of Supervisors over the costs of dealing with the oil spill.

[58] Amplify announced it had reached an agreement in principle to resolve all civil claims with more than a dozen businesses and residents that brought a class-action suit with payment through their insurance company.