Santa Barbara, California (CNN) Authorities have intensified their response to this week's Santa Barbara oil spill by announcing remedies and additional investigations.

The federal government on Friday ordered the firm, Plains All American Pipeline , to suspend operations and make safety improvements on the ruptured pipe, according to a corrective action order announced Friday by the U.S. Department of Transportation.

The California attorney general's office is working with local prosecutors as well as state and federal agencies in investigating Tuesday's spill that prompted a state-issued emergency in Santa Barbara County and the closing of two state beaches until June 4.

"California's coastline is one of the state's most precious natural treasures. This oil spill has scarred the scenic Santa Barbara coast, natural habitats and wildlife. My office is working closely with our state and federal partners on an investigation of this conduct to ensure we hold responsible parties accountable," Attorney General Kamala D. Harris said.

The cause of the oil spill remains under investigation.

Oil company's response

The oil firm, Plains All American Pipeline, has been actively participating in the cleanup and daily press conferences with federal and state officials.

"Our goal is zero (spills)," senior director Patrick Hodgins of Plains All American told reporters Friday. "Are we happy with this unfortunate event? Absolutely not.

"We're going to be here until it is taken care of," Hodgins added.

In a general statement Friday, the firm said it had "significantly increased" the size and spending of its safety program since 2008. The firm added that "releases from Plains pipelines have significantly decreased while throughput volume has increased since 2008."

The firm had taken measures that "exceeded the federal regulatory requirement" for the Santa Barbara pipeline that eventually ruptured this week, and had inspected it two times in the past three years.

In fact, the pipeline was examined May 5, and investigators will be reviewing those results, officials said.

The coastal town of Goleta on Friday declared its own state of emergency, citing the spill as an "extreme peril to the safety of persons and property."

Progress so far

As the cleanup entered its fourth day on Friday, vessels were "actually doing pretty well" recovering oil from the ocean, but "the harder part" will be cleaning the land -- the shoreline, the beaches, the cliffs and the hillside near U.S. Highway 101 where the pipe ruptured, said U.S. Coast Guard Capt. Jennifer Williams.

"It could take months," she said.

Officials provided a tally Friday of the cleanup and environmental damage:

• 10,000 gallons of oily water removed from the ocean;

• 91 cubic yards of oily solids and 800 cubic yards of oily soil removed from beaches;

• 9.5 square miles of ocean and 8.7 miles of coastline affected, from Arroyo Hondo beach to Refugio State Beach, near Goleta.

• Three brown pelicans were killed. Six more brown pelicans, two California sea lions and an elephant seal are being rehabilitated after oil coated them. A common dolphin was found dead without oil on its exterior, but it will be examined for signs of ingested oil.

Also called the Refugio oil spill, the incident began Tuesday when a 24-inch diameter pipeline ruptured near Goleta, California. It transports crude oil for 10.6 miles from Exxon Mobil's breakout storage tanks in Las Flores Canyon to Plains' pump station in Gaviota, said the federal Transportation Department's Pipeline and Hazardous Materials Safety Administration.

Environmentalists denounce oil firm

On Friday, environmentalists declared the spill "a wake-up call" on continued oil development. They urged state and federal politicians to refuse additional oil projects, especially in Santa Barbara County, and called upon the nation to usher in a "post-oil era" by embracing renewable energy.

"When we have a huge solar spill around here, we just call it a nice day," said Dave Davis, CEO and president of the Community Environmental Council.

The oil spill has hurt the area's $1.2 billion tourism economy, which employs more than 12,000 people, but tour operators such as Michael Cohen of Santa Barbara Adventure Company told potential visitors that only two state beaches are closed and other attractions remained open, including Channel Islands National Park.

The activists noted that a 1969 spill in Santa Barbara was so catastrophic it ignited the environmental movement and a host of federal and state laws to protect the natural world.

Putrid odor

The onshore pipeline behind this week's Santa Barbara oil spill leaked more than 100,000 gallons of crude on coastal lands and into the ocean, the oil company said.

At its worst, the smell burns your nostrils and gives you a little nagging headache.

Stones at Refugio State Beach lay splattered with a jet black tar, like goo, which can only be crude oil.

An industrial-size trash bin of oily vegetation sits next to the beach. Bikinis and surfboards on once pristine sandy shores have been replaced with people in hazmat suits, digging in the dirt and picking up oil-laden sticks and plants.

Among the worst violators

The underground oil pipeline was carrying 1,300 barrels an hour, below its maximum capacity of 2,000 barrels an hour, said Rick McMichael of Plains All American Pipeline

Photos: Oil spill off California coast Photos: Oil spill off California coast Workers clean oil off a brown pelican at the International Bird Rescue office in Los Angeles on Friday, May 22. More than 100,000 gallons of oil from a ruptured pipeline recently spilled onto coastal lands near Goleta, California, and into the Pacific Ocean. Hide Caption 1 of 15 Photos: Oil spill off California coast Workers prepare an oil containment boom at Refugio State Beach, north of Goleta, on Thursday, May 21. Hide Caption 2 of 15 Photos: Oil spill off California coast A pelican flies over an oil slick on the ocean surface near Refugio State Beach on May 21. Hide Caption 3 of 15 Photos: Oil spill off California coast A member of the Bureau of Land Management walks past rocks covered in oil on May 21. Hide Caption 4 of 15 Photos: Oil spill off California coast A crab and California mussels are covered in oil on May 21. Hide Caption 5 of 15 Photos: Oil spill off California coast A bird covered in oil flaps its wings on May 21. Hide Caption 6 of 15 Photos: Oil spill off California coast Plastic buckets are filled with oil collected from the beach on May 21. Hide Caption 7 of 15 Photos: Oil spill off California coast Workers clean up the site near Refugio State Beach on May 21. Hide Caption 8 of 15 Photos: Oil spill off California coast Oil flows toward the ocean on Wednesday, May 20. Hide Caption 9 of 15 Photos: Oil spill off California coast Crews clean up oil on May 20. Hide Caption 10 of 15 Photos: Oil spill off California coast Ships pulling booms attempt to collect oil from the spill on May 20. Hide Caption 11 of 15 Photos: Oil spill off California coast An octopus lies dead on May 20. Hide Caption 12 of 15 Photos: Oil spill off California coast Volunteers fill buckets with oil on May 20. Hide Caption 13 of 15 Photos: Oil spill off California coast Oil surrounds the feet of local resident Morgan Miller as he patrols the beach for affected wildlife on Tuesday, May 19. Hide Caption 14 of 15 Photos: Oil spill off California coast Miller and another local resident, Josh Marsh, look for distressed wildlife on May 19. Hide Caption 15 of 15

Plains All American is among the worst violators listed by the U.S. Pipeline and Hazardous Materials Administration.

It surpassed all but four of more than 1,700 operators in safety and maintenance infractions, the federal agency said.

Hodgins suggested the comparison wasn't fair because "we're also much larger than those companies that we were compared to."

"Most of the companies that we're compared to have half the amount of pipelines" that Plains All American has, Hodgins said Friday. "So therefore, with double the number of miles of pipelines, unfortunately incidents have occurred, (and) the larger and the more of those can be realized."

Plains has been committing money to safety improvements for the past seven years, said Pat Hutchins, the company's senior director of safety.

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Plains All American Pipeline violated federal environmental violations 10 times between 2004 and 2007, when about 273,420 gallons of crude oil were discharged into waters or shorelines in Texas, Louisiana, Oklahoma and Kansas, the Environmental Protection Agency said.

Most of the spills were caused by pipe corrosion, the EPA said.

The oil company agreed to pay a $3.25 million civil penalty and spend $41 million to upgrade 10,420 miles (16,770 kilometers) of crude oil pipeline operated in the United States, the EPA said in 2010

Lobsters killed, pelicans soaked in oil

Meanwhile, crews continued to clean beaches and coastal waters, and officials reported the leak killed an undisclosed number of lobsters, kelp bass and marine invertebrates. Six oil-soaked pelicans and one young sea lion were being rehabilitated.

As of Thursday night, vessels had skimmed 9,500 gallons of oily water from the ocean, McMichael said.

The cleanup could last months, officials said. For now, currents, tides and winds make the oil plume "a moving target" as it drifts offshore, said U.S. Coast Guard Capt. Jennifer Williams.

How it all started

Houston-based Plains All American Pipeline estimated up to 105,000 gallons may have spilled from a broken pipe, based on the typical flow rate of oil and the elevation of the pipeline.

Since the pipeline is underground, it will take a few days to determine how much crude oil was spilled, said McMichael, who estimated 21,000 gallons of crude had gone into the Pacific Ocean, with the rest spilled on land.

Not the first time

A spill in January 1969 became what was, at the time, the nation's worst offshore oil disaster. Though this week's spill is smaller, it still prompted California's governor to declare a state of emergency in Santa Barbara County.

The 1969 disaster was so catastrophic that it gave birth to an environmental movement, a host of regulations against the oil and gas industry, and a new commission to protect California's coast, experts said.

Santa Barbara Harbor after what was then the worst oil spill in U.S. history, in February 1969.

In all, about 3 million gallons of oil spewed from a Union Oil drilling rig 5 miles off the coast of nearby Summerland, California. The pipe blowout cracked the seafloor, and the oil plume killed thousands of seabirds and "innumerable fish," according to a 2002 paper by geographers at the University of California, Santa Barbara

Backlash and consequences

Subsequent U.S. oil spills were much larger, including the Exxon Valdez accident, which dumped 11 million gallons off Alaska's shores in 1989, and the Deepwater Horizon spill, which put 210 million gallons into the Gulf of Mexico in 2010.

But the 1969 Santa Barbara spill energized a movement that led to new federal and state environmental laws and helped establish the first Earth Day the next year.

The threat

The environment remains a major concern around Refugio State Beach, which was desolate Thursday, as were its campgrounds, which are normally packed for Memorial Day weekend. The only sounds were the waves and the helicopter above, a buzzing reminder of the oily mess below.