The NewsHour and NPR interviewed Choy last May. He, his wife Monica and attorney Steve Gordon spoke with Hari Sreenivasan on Monday from Houston.

Last year, Choy said he was having nightmares and suffered mental anguish from the experience. Since then, "things seem to be improving slowly," Choy said this week. "But I can tell that my attitude is different than it used to be."

Gordon said he's seeking "a reasonable amount" in damages for Choy for loss of earnings, medical expenses and pain and suffering.

The NewsHour contacted BP, Transocean, Cameron and Halliburton for comment about Gordon's comments in this interview. Transocean and Cameron declined to comment. BP and Halliburton did not respond.

Watch last year's interview with the Choys:

NewsHour interview filmed by and video edited by Justin Scuiletti. Houston interview filmed by Jeff Horton

Click on the image below to access a timeline in which we look back on how the NewsHour covered the story from the beginning to present day. We built the timeline using ProPublica's TimelineSetter, an open source media tool.

With Wednesday marking the first anniversary of the Deepwater Horizon explosion and the start of the massive environmental disaster, we spoke with Washington Post reporter Joel Achenbach about this new book, "A Hole at the Bottom of the Sea: The Race to Kill the BP Oil Gusher."

Follow Hari on Twitter.

Researchers collect water samples to study bacteria and methane gas. Photo by Elizabeth Crapo/NOAA

As soon as oil began spewing into Gulf of Mexico waters, bacteria went to work, gobbling up mass amounts of methane. And as the oil continued to spill, the bacteria bloomed swiftly to consume the growing quantities of gas.

The rate at which the bacteria broke down methane in the Gulf may be the fastest ever recorded in ocean waters, said David Valentine, professor of microbial geochemistry at the University of California, Santa Barbara, and one of the lead authors of the study published online Thursday in the journal, Science.

"Whether or not it's the fastest ever observed, it's the fastest I've either observed myself or seen published," Valentine said.

Methane is a dangerous greenhouse gas, more potent than carbon dioxide, and scientists worry about it escaping from the oceans into the atmosphere. This study indicates that the ocean can rapidly filter out methane fast enough to prevent this from happening, Valentine said.

Methane made up about 20 percent -- some 200,000 tons -- of that material. After studying natural gases released by the spill in June, Valentine's team returned on the NOAA ship Pisces in August to track how quickly methane was degrading.

Their research before the spill had focused on methane that bubbles up naturally from the bottom of the ocean. The seafloor is a massive reservoir of methane, and the gas typically gets consumed rather slowly, said John Kessler, lead author and professor of oceanography at Texas A&M University. But the post-oil spill data told an entirely different story, one that took them by surprise.

"We anticipated that the Deepwater Horizon methane would be in the Gulf for years based on that information," Kessler said. "When we went back in September to get a timepoint, lo and behold, we saw an endpoint."

The team collected thousands of samples in the water and atmosphere, spanning an area of 36,000 square miles around the wellhead. They analyzed the water for methane and bacteria. By extracting DNA from trapped bacteria, they discovered that many of the microscopic critters were methane-specific, specialized to attack and degrade the stuff. But methane was absent from the water.

"It's like the cat that ate the canary sitting by the birdcage with the feathers sticking out of its mouth," Valentine said.

Within four months, their study concludes, bacteria had consumed nearly all of the methane released from the well's initial blowout.

Kessler says the results provide a snapshot of how the ocean might handle large releases of methane. "This shows the capability of the natural system to respond to these types of events ... and as the world's energy demands increase, this is potentially not the last time we'll see an event like this."

The oil spill allowed for what Valentine calls "a forbidden experiment," with oil and natural gases at levels that scientists could never replicate on their own. "It provided an opportunity for us to ask what happens in these large-scale methane events. And given this sort of emission, the ocean has a capacity, a very rapid capacity, to filter out that methane before it reaches the atmosphere, where it's a potent greenhouse gas."

However, they caution, this is only part of the story. "The methane," Valentine said, "is not the compound of greatest concern in terms of toxicity." Of most concern, he said, are the aromatic hydrocarbons, which exist in liquid oil and dissolve into water.

While these findings give insight into methane degradation, they tell us little about the oil remaining in the Gulf.

Attorney General Eric Holder and EPA Administrator Lisa P. Jackson announced a major lawsuit against BP, Transocean and other companies the Department of Justice says are responsible for the massive oil spill in the Gulf of Mexico in April of this year.

Holder said they will seek damages from nine defendants without limitation under the Clean Water Act and the Oil Pollution Act, which could total billions of dollars.

"I have seen the devastation that this oil spill caused throughout the region," Holder said.

"We intend to prove that these defendants are responsible for government removal costs, economic losses and environmental damages without limitation," he said.

Jackson said the government is seeking a "fair deal" for the region that would help those whose livelihoods were affected by the oil spill.

The AP reports that the other defendants in the case are Anadarko Exploration & Production LP and Anadarko Petroleum Corp.; MOEX Offshore 2007 LLC; Triton Asset Leasing GMBH; Transocean Holdings LLC and Transocean Offshore Deepwater Drilling Inc. and Transocean Deepwater Inc.; and BP's insurer, QBE Underwriting Ltd./Lloyd's Syndicate 1036.

We'll have more on the lawsuit on Wednesday's NewsHour. Stay tuned.

Watch a live stream here:

The commission's findings will be formally released on Jan. 11. You can read some of the panel's preliminary conclusions here.

The past decade was one of rapid growth for BP, a company that now dominates the oil industry. Mergers expanded the BP empire and cost-cutting helped keep shareholders happy. The newest collaboration between Frontline and ProPublica is an hour-long documentary called "The Spill". It looks into whether that profits-first kind of corporate culture contributed to the explosion on the Deepwater Horizon last spring.

Correspondent Martin Smith and investigator Abrahm Lustgarten have joined forces to report on BP's poor safety record and the signals missed by the company and government along the way leading up to the Gulf oil disaster. From a Texas plant explosion in 2005 that killed 15 workers to the 2006 oil spill on Alaska's North Slope, BP's recent track record may have warned of a deeper problem.

Smith spoke with Hari Sreenivasan about the documentary airing tonight on most PBS stations.

Six months after oil began flowing into the Gulf of Mexico, BP's blown-out well is long capped but the effects of the spill are still being felt. Hari Sreenivasan spoke to Bob Marshall, who covers the environment and outdoors for the New Orleans Times-Picayune, about life in the Gulf six months after the spill.

Fresh oil no longer washes ashore, Marshall reported recently, but because of erosion and beach retreat, buried patches still reappear in some of the "hot spot" areas that were hardest hit.

Meanwhile, money from BP has introduced a new word into the Louisiana lexicon -- "Spillionaires." But even people who have received substantial payments from the company worry about what will happen when that money dries up, and whether they'll be able to go back to their livelihoods of fishing and shrimping next year, Marshall says.

The administration has been under pressure from business leaders and others to lift the six-month ban due to its economic impact. The moratorium was set to expire Nov. 30.

Drilling is not expected to resume immediately. Michael Bromwich, head of the Bureau of Ocean Energy Management, Regulation and Enforcement, said it would take "at least a couple of weeks" after the ban is lifted before permits are approved, the AP reports.

The New York Times quotes Ken Salazar on the announcement:

"We have made and continue to make significant progress in reducing the risks associated with deepwater drilling," Interior Secretary Ken Salazar told reporters on a conference call. Therefore, he said, "I have decided that it is now appropriate to lift the suspension on deepwater drilling for those operators that are able to clear the higher bar that we have set."

In June, the NewsHour explored the debate over the offshore drilling ban - who's for it, who's against it, and why.

According to the National Oil Spill Commission investigating the Deepwater Horizon disaster in the Gulf, the White House blocked efforts by federal scientists to tell the public the worst-case estimates of the leak in late April or early May. That revelation and others were contained in new set of reports released Wednesday by the panel.

The panel says that the White House Office of Management and Budget denied a request by National Oceanic and Atmospheric Administration scientists to release to the public its worst-case oil-flow estimates.

Throughout the summer, the amount of oil gushing from the well was a slippery number to estimate, and part of why the NewsHour created its Gulf Leak Tracker widget.

Over the course of several months after the rig exploded on April 22, the federal government slowly raised its public estimate of the oil flow rate -- always a step or two behind independent and government scientists measuring the spill. And at one point the White House appears to have blocked efforts by federal scientists at NOAA to release to the public their worst-case spill rate estimates, the report finds.

In its findings, the commission said:

By initially underestimating the amount of oil flow and then, at the end of the summer, appearing to underestimate the amount of oil remaining in the Gulf, the federal government created the impression that it was either not fully competent to handle the spill or not fully candid with the American people about the scope of the problem.

Amount and Fate.for Release

After leaks were first discovered on April 24, Coast Guard Adm. Mary Landry said that up to 1,000 barrels (42,000 gallons) of oil per day were flowing from the well. In its report, the commission found that that figure came directly from BP without supporting evidence.

Four days later, the government upped its estimate to 5,000 barrels (210,000 gallons) per day. According to the report, that number was based on "an unsolicited, one-page document e-mailed to Admiral Landry's Scientific Support Coordinator on April 26, 2010, by a NOAA scientist," -- a scientist who did not have extensive background in estimating oil flow, who acknowledged that his estimate was "very rough" and who only intended to make it clear that the 1,000 barrel estimate was too low.

Despite those caveats, the 5,000-barrel-per-day estimate remained the only number released by the government for a month, until May 27. At one point, the commission found, the White House turned down a request to make other numbers public:

In late April or early May 2010, NOAA wanted to make public some of its long-term, worst-case discharge models for the Deepwater Horizon spill, and requested approval to do so from the White House's Office of Management and Budget. Staff was told that the Office of Management and Budget denied NOAA's request.

Meanwhile, outside scientists began to question the 5,000 barrel estimate and to come up with their own estimates up to an order of magnitude higher -- estimates that in the end were much closer to the final estimate of 62,000 barrels per day.

Just days after the government released the 5,000-barrel estimate, Florida State University oceanographer Ian MacDonald reported that based on satellite images of the slick, oil was leaking at the rate of about 26,000 barrels per day.

Then, when BP released a 30 second-video of oil gushing from the broken pipe in mid-May, independent scientists analyzed the video for news outlets including the NewsHour and NPR and put the flow rate in the range of 70,000 barrels per day.

The government soon convened a "Flow Rate Technical Group" of outside and government scientists. That group released a series of estimates between mid-May and August, each higher than the last. That ever-rising numbers also contributed to public distrust. The commission reports:

The initial success of the Flow Rate Group is questionable given that it did not release an arguably accurate flow-rate estimate until mid-June [...] The Group's estimates may also have suffered from a failure to disclose enough information to enable other experts to assess the group's methodologies and findings. If more of the Group's data had been made public, its estimates may have evolved more rapidly with input from the broader scientific community.

And in fact, as we first reported, the government was at first slow to release the upper boundaries of some of the Flow Rate Technical Group's own estimates.

On Aug. 2, the government released the current estimate of 62,000 barrels of oil per day -- produced by the Flow Rate Technical Group and a team working with Energy Secretary Steven Chu.

Overall, the presidential commission report states, "the national response may have benefited early on from a greater sense of urgency, which public discussion of worst-case discharge figures may have generated." And even if not, it adds:

Federal government responders may be correct in stating that low flow-rate estimates did not negatively affect their operations. Even if responders are correct, however, loss of the public 's trust during a disaster is not an incidental public relations problem. The absence of trust fuels public fears, and those fears in turn can cause major harm.

In a statement Wednesday, National Oceanic and Atmospheric Administration chief Jane Lubchenco and White House budget director Jeffrey Zients pointed out that in early May, Interior Secretary Ken Salazar and Coast Guard Adm. Thad Allen told the public that the worst-case scenario could be more than 100,000 barrels, or 4.2 million gallons, a day, according to The Associated Press.

Hari Sreenivasan contributed to this report.

On Friday, Ken Feinberg, who's overseeing the administration of the compensation fund, told us that he was leaning toward proximity as a factor in making his decisions, noting that he was getting sharp disagreement from state officials in Florida.

But Feinberg said Monday that distance from the affected spill area will not prevent claimants from applying for or receiving money if they can document their losses. Proximity has been a particularly difficult question in Florida since Feinberg has been receiving claims from the state's Panhandle down to the Keys. A number of hotels have filed a claim for canceled reservations in locations like Tampa, for example, even though they were not especially close to the impacted area.

"I have heard from elected officials in Florida, including Governor Crist, Attorney General McCollum, CFO Sink and others, about their concerns regarding Floridians' proximity to the spill and how, regardless of distance, there has been economic impact beyond the areas closest to the spill," Feinberg said in a statement. "After listening to these concerns, I have concluded that a geographic test to determine eligibility regarding economic harm due to the oil spill is unwarranted."

So far, the Gulf Coast Claims Facility, as Feinberg's group is called, has paid nearly $1 billion to roughly 50,000 individuals and businesses.

Five weeks after taking over as the administrator of BP's $20 billion oil claims fund and facing criticism for the pace of his decisions, Ken Feinberg told the NewsHour in a telephone interview that he believes he has made good progress on awarding payments in a more timely manner to individuals and businesses along the Gulf Coast.

"We've paid approximately 50,000 claims to the tune of about $825 million so far," Feinberg said. "Now that's in five weeks since I took over. BP paid $400 million in four months.

"This program has been subject to a good number of mid-course corrections in the last five weeks, leading to sea change of the way we handle payments," he said.

Feinberg had been criticized by residents and local officials for failing to deliver on promises to provide emergency payments within 48 hours for up to six months of lost wages. That pledge also included a promise of emergency payments to businesses for losses they've suffered within a week of receiving claims and proper documentation.

There are still at least 25,000 claims that have not been paid yet. Roughly 2,000 of those claims are in Florida, which Feinberg contends are tough calls because of questions of proximity.

The lawyer, who oversaw the 9/11 compensation fund and served as the Obama administration's pay czar for recipients of bailout money, apologized for the delay and said part of the problem was that he was too optimistic about the timing.

"What happened was that I oversold the program," Feinberg said. "In some cases, because the documentation was so weak, and it took so much longer to review a claim than I thought, people were frustrated. There are virtually no delays now."

Not everyone agrees.

Marcia Mandel, who filed a claim in late August for lost income on behalf of her hotel, the Marco Island Lakeside Inn, told ProPublica a few days ago that her application was still under review.

"Saying the backlog is gone is nonsense," she said.

Still, roughly 32,000 individuals and 18,000 businesses have received emergency payments. The range has varied from $1,000 for an individual to as much as $1 million for a company that documented major damages when it couldn't secure enough fish during the spill. The largest number of claims have come from Florida and Louisiana.

But in total there are still at least 25,000 claims that have not been paid yet. Roughly 2,000 of those claims are in Florida, which Feinberg contends are tough calls because of questions of proximity. Should a hotel along the Keys -- or in Tampa -- be eligible because reservations were canceled in connection with the oil disaster?

In Florida, several state officials including Gov. Charlie Crist and Alex Sink, the Democratic candidate running to succeed him, have spoken harshly about a number of Feinberg's decisions.

Attorney General Bill McCollum has also been critical.

"This is ridiculous. It's not just ridiculous, it hurts people," he said earlier this week. "There are people hurting out there who will go out of business because they're not getting their claims paid."

Most of the immediate claims throughout the region that haven't been resolved yet -- maybe 20,000 or so -- are cases where Feinberg says he needs some basic documentation to prove losses. Local businesses and fishermen say they ran a cash operation that never had that kind of paper trail.

"They say, 'I run a cash business, thank you.' It's a more serious problem than I thought," he says. "I need something to go on."

Feinberg also says he believes his team -- known formally as the Gulf Coast Claims Facility -- is finding more examples of fraud or scams than he expected. He is suspicious of 1,000 claims already and BP is questioning the validity of 800 they already paid.

Then there's what he calls an outright scam.

"I've got 4,000 claims from one parish in Louisiana," he said. "They read, 'I used to live off the sea and eat fish every day. Now I have go to the grocery store.' It's a ridiculous scam and these claims all have the exact same paragraph. There's no difference between them."

What lies ahead may be more daunting.

After the deadline for immediate and emergency claims passes on Nov. 23, Feinberg will have to determine what will be the criteria to decide long-term claims.

That decision is fraught with questions.

Again, the question of geography might loom. But there's also the question of what kinds of conditions Feinberg might oppose if a claimant receives a major payment, something that he hopes to decide within the next 30 days.

"I'm inclined to say to the plaintiff, 'I'll give you a check for, say, $100,000 for your full loss, but first you've got to sign a document that you won't sue anybody -- BP, Halliburton, Transocean,'" he explained.

"The second issue is to say, 'I'll give you $100,000, but you can't come back a year from now and tell me you didn't realize you wouldn't be able to fish for a second year.'"

Of course, that begs the question: How can he possibly make decisions about fishing conditions, for example, when scientists are still trying to study the impact of the hydrocarbons in the water and on the fishing areas that were hit?

Feinberg says he plans to consult with top officials at NOAA, Fish and Wildlife Services and Woods Hole, who can in turn help him make educated decisions.

"I will be guided by what they tell me," he said. But "if it's not resolved by then and people are having to decide on a hunch, it may make sense to take an interim payment for the moment" without forfeiting their legal rights.

This post was updated on Oct. 1.

As spring turned to summer and the oil kept flowing, the government revised its calculations. And then revised them again -- each estimate higher than the last.

First, it was 42,000 gallons a day. Then 210,000. Then 504,000 to 798,000. Finally, in early August, a team appointed by the government produced the highest estimate yet: 2.2 million to 2.6 million gallons leaking per day from the broken wellhead.

But on Thursday in the journal Science, Timothy Crone, a marine geophysicist from Columbia University's Lamont-Doherty Earth Observatory, released another estimate. His study analyzed the oil from the time the rig exploded, until the well was finally crammed with mud and a mile of cement, sealing it for good.

Crone's calculations show that about 2.4 million gallons of oil gushed into the gulf every day until the riser was cut on June 3, after which the rate swelled to 2.9 million gallons daily. And the total escaped oil: 4.4 million barrels, or 184.8 million gallons.

"I think his numbers and our numbers are statistically indistinguishable. And the reality is that it could have been even higher or it could have been lower."

It was in May when Crone first got his hands on an underwater video that was high enough in quality that he could apply his own technique to measure the flow rate. At the time, the government had estimated that the flow rate was at least 504,000 to 798,000 gallons a day. Using a method he'd developed to study underwater volcanoes, Crone provided estimate three times that size: 2.1 million to 2.9 million gallons a day. This latest estimate narrows his earlier numbers, he says.

"My estimate had come out in May, and their estimate slowly changed and became closer and closer to mine, until theirs in effect confirmed mine," Crone said. "They really confirmed each other."

To measure the spill, Crone and coauthor Maya Tolstoy, also a marine geophysicist from Lamont, relied on a technique called optical plume velocimetry that they normally use to measure hydrothermal vents: superhot jets of water, heated by magma, that gush from cracks in the seafloor. By using a computational algorithm that breaks the video image down pixel by pixel, they were able to determine the velocity of the oil.

"You're measuring the velocity times the area of the opening," Tolstoy said. "That gives you a flow rate. And the flow rate will give you barrels per second."

Liefer says that estimates taken from these video images still lack vital information. "Basically, no measurements were made of what happened interior to the plume," he says. "So you only know the surface. Then you have to make educate guesses or assumptions about what happens inside." The degree of uncertainty, he adds, reinforces the need for monitoring equipment to be installed around deepwater oil wells.

Crone said he addressed these questions in his paper. Namely, he says, they were unable to measure how the rate might have changed over time due to variations in pressure and changes in the shape of the wellhead.

"I think this paper should be viewed as sort of a proof of concept and a preliminary estimate, essentially showing this can be done," Crone said. "Future work can narrow the uncertainties."

After a weekend of final sealing and testing, the federal government on Sunday declared the Macondo oil well officially dead. The announcement came nearly five months after the Deepwater Horizon oil rig exploded in the Gulf of Mexico, setting off the largest offshore oil spill in U.S. history.

The "well-kill" is an end to one chapter of the Deepwater Horizon story, but other chapters are just beginning. Here's a roundup of stories to watch:

The Legal Battle | Just last week, Judge Carl Barbier held the first hearing in what's likely to be a years-long legal fight for the more than 300 lawsuits already filed against BP and others likely to come. The Wall Street Journal explains the legal process that governs these suits:

The idea is to roll numerous suits of similar nature filed in U.S. district courts into one case before one judge, for efficiency's sake. The 1968 law that created the process stemmed from a price-fixing case that gummed up federal courts involving more than 25,600 claims against electrical-equipment manufacturers. But critics of the consolidation say these cases become so unwieldy they sometimes drag on for years.

BP could also face penalties under the Clean Water Act -- $1,100 or $4,300 per barrel of oil spilled, depending on whether the company is found to have been "grossly negligent" in its actions. That could mean a fine of potentially $21 billion, although many experts say that BP and the government are likely to settle for less than that in the end.

BP has estimated that the spill will cost $32 billion, including $20 billion to compensate individuals and businesses hurt by the spill. It has announced plans to sell $30 billion in assets over the next 18 months to help pay for it.

The Future of Deepwater Drilling | The six-month moratorium on deepwater oil drilling imposed by the Obama administration in the wake of the spill is set to expire Nov. 30. Michael Bromwich, the nation's chief drilling regulator, told reporters in a conference call last week that it's "highly unlikely" the moratorium will be extended beyond that date. Bromwich also said that he expects to complete a report by the end of September with recommendations of how and when to end the drilling ban, including new mandates governing deepwater drilling.

The Houston Chronicle reports:

Even when the ban is lifted, drilling won't begin immediately. Bromwich said Tuesday "it will be up to industry when deep-water drilling can resume, because they will only be able to resume once they're in compliance with the existing rules" and coming mandates.

Industry analysts say it could take weeks -- or longer -- for the offshore energy bureau to sign off on new deep-water well applications, given the current slowdown in permitting shallow projects that are not blocked by the moratorium. Confusion about the scope of new requirements has held up some of those approvals. Bromwich said he hoped to prevent a repeat whenever the deep-water drilling ban is lifted.

"We fully understand that with new rules coming down the pike, there is the risk of confusion and uncertainty," he said. "And I really don't want that to extend the point where drilling can resume."

The Ongoing Cleanup and Environmental Effects | The well has been capped since mid-July, but along parts of the Gulf Coast, the oil has not disappeared. On Saturday, Coast Guard Adm. Thad Allen told CNN that the cleanup effort is going to go on "as long as it takes to get the marshes and the beaches clean."

The New Orleans Times Picayune reports that about 500 miles of Louisiana's 7,700 miles of tidal coastline were oiled:

That seems a small toll -- unless, like [property manager Forrest] Travirca, you manage some of those 500 miles. Then you find yourself in a place where the bullets are still flying and battle is still going on, a battle experts say you could be fighting for years to come.

"There might not be fresh oil coming ashore, but there's a lot of residual oil that will continue to show up, especially in those places that were hard-hit," said Ed Overton, an LSU professor who has been studying and fighting oil spills for 30 years. "This is a well-known and common occurrence in spills."

"I'd say those folks are probably going to be dealing with this certainly for the next year, and very possibly beyond in these hot spots."

The New York Times reports that many scientists believe that through "a combination of luck (a fortunate shift in ocean currents that kept much of the oil away from shore) and ecological circumstance (the relatively warm waters that increased the breakdown rate of the oil), the gulf region appears to have escaped the direst predictions of the spring."

But the scientific debate continues about how much oil remains in the Gulf -- suspended in the water column or sitting on the sea floor -- and what long-term environmental effects it might have.

Last week, for example, University of Georgia researcher Samantha Joye said that her team found a layer of oil on the sea floor up to 80 miles from the well.

NOAA head Jane Lubchenco said last week that the federal government is organizing a long-term monitoring effort to better understand the fate of the leaked oil.