Nearly 20 kilometres off the Louisiana coast, an oil leak continues to spew thousands of gallons of oil into the ocean, every single day.

The Taylor Energy offshore spill began in 2004. By now, it has gone on for so long that it is now set to surpass the Deepwater disaster as the largest oil catastrophe in U.S. history.

For years, the public wasn't told about the leak. Now we know, but that knowledge isn't power — because the company, and the authorities, have no idea how to plug it for good.

As It Happens guest host Megan Williams spoke to Cynthia Sarthou, executive director of the Gulf Restoration Network, which is one of the conservation groups who uncovered the incident.

Here is part of their conversation.

How is it that this spill managed to go on for so long without the public knowing about it?

There is no requirement under law of the United States that actually the agencies or the industry put you on notice of a continuing spill.

And so what happened is you have an offshore area that is not actually seen by most people unless you're flying over it, and most organizations can't afford to fly over it.

It just went under the radar until there was a need to fly over, which was the BP disaster, when people started noticing that there was something wrong.

When they asked the federal government, the federal government admitted, "Yeah, there's a problem."

A support ship related to the collection of oil from over the site of the BP Deepwater Horizon oil well leak. (Saul Loeb/AFP/Getty Images)

So how did the Gulf Restoration Network actually discover the leaks then?

We had staff who was flying out to monitor the BP response to the disaster and the federal government's response to the disaster.

We kept seeing a slick, as did other people that were flying the Gulf. It wasn't anywhere close to where the BP disaster was so it started raising questions.

Then the federal government released a lot of satellite data and one of our partners, SkyTruth, did an analysis of the satellite data and realized that there was a 10-mile slick, and that again, it had nothing to do with BP.

What do you know about what happened to the Taylor Energy platform during that hurricane?

It's my understanding that the platform was actually associated with 26 smaller rigs or wells. That the platform toppled and when it toppled and was turned over, it buried not only the platform, but all the wells, or most of the wells.

Taylor Energy was only able to plug nine of those wells. Representatives of Taylor Energy say it's just a plume that exists in the sediment. But the federal government is saying no, that there's a continuing release from one or more of those unplugged wells.

Since 2004, an oil-production platform owned by Taylor Energy that sank as a result of Hurricane Ivan has leaked 300 - 700 barrels of oil per day into the Gulf. <a href="https://twitter.com/hashtag/Volunteer?src=hash&ref_src=twsrc%5Etfw">#Volunteer</a> Erin S. flew <a href="https://twitter.com/washingtonpost?ref_src=twsrc%5Etfw">@washingtonpost</a> journalist Darryl Fears and <a href="https://twitter.com/HealthyGulf?ref_src=twsrc%5Etfw">@HealthyGulf</a> for the story <a href="https://t.co/oYKl2fURv9">https://t.co/oYKl2fURv9</a> —@SouthWings

Do we have a sense of how much is being leaked now?

In 2018, they're now estimating that there is between 10,000 and 30,000 gallons a day and that's about 10 times the earlier estimate, which was given in 2011.

If, in fact, that level of oil is being released and has been released from the site since the beginning of the disaster ... will rival BP.

How has Taylor Energy responded to try to stop the leak?

They did try to cap the well, but it was not effective.

So they've essentially now thrown up their hands and said, "It was an act of God. We have spent what we can to do what we can. We can't do anymore. You need to give us back our money."

So they're now seeking to get $450 million back from a trust fund that they had established to address this spill.

A dead sea turtle is seen laying on a beach. (Joe Raedle/Getty Images)

And whose responsibility is it now to try to clean up the mess?

Well, I guess it would the federal government's. But the federal government generally gets money from the polluter to do the clean-up. So it's really unclear whether there would be any money to continue to take action to try to stop the leak.

What legal responsibilities does an oil company have to report an incident like this to the authorities?

They actually did report it to the Coast Guard. The difference is that that was not released to the public. So they reported it to the Coast Guard and the Coast Guard worked with them to respond and put together this trust fund.

It was just the public that was largely kept in the dark.

As this mess plays out in the Gulf of Mexico, the Trump administration is talking about offering federal offshore drilling licenses on the Atlantic coast. What do you think the industry can learn from this incident as they look into setting up drills in that part of the country?

I think what they need to be looking into is ensuring that technology for exploration is equal to your technology for response.

I think response and shut down has to be as important as exploration itself, or you get into this type of situation, and that's what the problem is here. They don't have technological expertise sufficient to shut down this spill.

Written by Ashley Mak and John McGill. Produced by Ashley Mak. Q&A has been edited for length and clarity.