America has a new word to learn: Dilbit.

Dilbit, short for diluted bitumen, is a combination of tar sands crude (bitumen) and dangerous liquid chemicals like benzene (the dilutant) used to thin crude so it can be piped to refineries.

And there is a lot of it being piped into America — in some cases through the backyards of communities that don’t even know it’s there.

The U.S. imports around half a million barrels of bitumen a day from Canada’s tar sands. According to the Sierra Club, if Keystone XL backers get their way, that number may grow to 1.5 million barrels per day.

A must-read investigation released this week by Inside Climate News illustrates why that could be a potential nightmare for communities located near pipeline infrastructure.

The story follows the complicated clean-up of a tar sands oil spill that most people haven’t even heard of — a 2010 pipeline rupture in southwestern Michigan that resulted in more than one million gallons of dilbit fouling a local waterway close to the Kalamazoo River.

The three-part narrative is detailed and extremely well-researched. It features a blow-by-blow account of how the pipeline ruptured, how officials acted (or, in the case of the pipeline owner, Enbridge, how it failed to act) and why dilbit represents a double threat to the environment and public health. It also shows why having an Environmental Protection Agency is so important when crisis hits.

This investigation is a must-read for any public official or resident from a community located near the proposed route of the Keystone XL pipeline.

Here’s why, nearly two years after the spill, residents are still finding tar balls in the local waterway:

Instead of remaining on top of the water, as most conventional crude oil does, the bitumen gradually sank to the river’s bottom, where normal cleanup techniques and equipment were of little use. Meanwhile, the benzene and other chemicals that had been added to liquefy the bitumen evaporated into the air.

InsideClimate News also learned that federal and local officials didn’t discover until more than a week after the spill that 6B was carrying dilbit, not conventional oil. Federal regulations do not require pipeline operators to disclose that information. And Enbridge officials did not volunteer it.

Mark Durno, an EPA deputy incident commander who is still involved in the cleanup in Marshall, is among those who were surprised by what they found.

“Submerged oil is what makes this thing more unique than even the Gulf of Mexico situation,” Durno told InsideClimate News. “Yes, that was huge—but they knew the beast they were dealing with. This experience was brand new for us. It would have been brand new for anyone in the United States.”

One of the most compelling pieces of the investigation comes when the reporters examine the safety record of America’s pipeline infrastructure. The results are shocking:

When corrosion rises above a certain threshold, PHMSA requires that it be repaired within 180 days. But the rules are flexible, and companies can easily negotiate for more time.

Records show that 6B had a history of corrosion problems.

In 2008, Enbridge identified 140 corrosion defects on 6B as serious enough to fall into the 180-day category. But the company repaired just 26 of them during that period.

In 2009, Enbridge self-reported a separate set of 250 defects to PHMSA. The company fixed only 35 of them within 180 days.

Instead of immediately addressing the 329 defects that now remained, Enbridge got a one-year extension from PHMSA by exercising its legal option to reduce pumping pressure on 6B while it decided whether to repair or replace the line.

A defect on 6B near John LaForge’s house, where the pipeline eventually ruptured, didn’t appear on any of the 180-day repair lists.

That defect, at mile marker 608, was detected at least three times before the pipeline ruptured, in 2005, 2007 and 2009, according to documents Enbridge filed with PHMSA over the years. But each time, Enbridge decided it wasn’t significant enough to require repairs within 180 days.

Ten days before 6B ruptured, Enbridge applied to PHMSA for another extension. It asked for an additional two and a half years to decide whether 6B should be repaired or replaced.

Does this sound familiar?

In January, we wrote about a pipeline inspector for the original Keystone pipeline who raised some very serious questions about the integrity of work being done for TransCanada, the company overseeing the project. After being built, the Keystone pipeline saw 12 spills in its first year in operation. The inspector, Mike Klink, warned that “people along the Keystone XL pathway have a lot more to lose if this project moves forward with the same shoddy work”:

What did I see? Cheap foreign steel that cracked when workers tried to weld it, foundations for pump stations that you would never consider using in your own home, fudged safety tests, Bechtel staffers explaining away leaks during pressure tests as “not too bad,” shortcuts on the steel and rebar that are essential for safe pipeline operation and siting of facilities on completely inappropriate spots like wetlands.

I shared these concerns with my bosses, who communicated them to the bigwigs at TransCanada, but nothing changed. TransCanada didn’t appear to care. That is why I was not surprised to hear about the big spill in Ludden, N.D., where a 60-foot plume of crude spewed tens of thousands of gallons of toxic tar sands oil and fouled neighboring fields.

TransCanada says that the performance has been OK. Fourteen spills is not so bad. And that the pump stations don’t really count. That is all bunk. This thing shouldn’t be leaking like a sieve in its first year — what do you think happens decades from now after moving billions of barrels of the most corrosive oil on the planet?

Let’s be clear — I am an engineer; I am not telling you we shouldn’t build pipelines. We just should not build this one.

Let’s remember: The Keystone XL pipeline will be built right on top of the Ogallala Aquifer, a massive source of fresh water that provides almost one third of the water used for irrigation in the U.S.

As the debate over Keystone XL rages on, proponents of Canadian tar sands are attempting to brand the resource as a “safe” alternative that will make America more secure.

As we have detailed over and over, those security arguments don’t hold up. The Keystone XL pipeline is a way to pipe dilbit across America to service refineries that will then sell the final product into a global market.

Plus, if you care about a maintaining a liveable climate, sticking a massive straw into one of the largest pools of carbon on the planet isn’t exactly how you make the country more secure.

But more than any of that, people really care about keeping their local environment clean. And this investigative piece from Inside Climate News shows us that we’re dealing with a fundamentally different product than conventional oil — and Americans need to know more about it.