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One of Donald Trump's flashiest campaign promises was to build a wall along the U.S.-Mexico border. Well, Noel King from our Planet Money podcast found that some construction and concrete firms have already been thinking about what that would entail.
NOEL KING, BYLINE: Building the wall would be a massive logistical challenge, but Todd Sternfeld thinks he's up to the task.
TODD STERNFELD: I'm the owner and CEO of Superior Concrete Products.
KING: Todd makes concrete, and he builds walls. He's built walls all over the U.S., and his company is based in Texas. So when candidate Trump first proposed the idea of a wall, Todd wrote him a letter, told Trump what he could do wall-wise.
STERNFELD: I sent it to Eric, Don and Ivanka, all three of them. (Reading) Dear Mr. Trump, I have stayed at the Trump Hotel for the last several years while exhibiting my products and services at the World of Concrete show in Las Vegas. Your staff and the accommodation have always been superb.
KING: He hasn't gotten a response back yet. Still, Todd spent a lot of time thinking about what it would take to get this wall built. The first problem is a legal one. There are landowners along the border. Not all of them might want a wall on their property.
STERNFELD: That's an eminent domain situation. The federal government has eminent domain over property.
KING: Seizing people's land wouldn't be a popular option, but it's an option. Then there would be a massive surveying operation. Todd says you got to know the terrain you're building on. He thinks that would take a couple months.
Then the building, the concrete - this is the part Todd does best. A thousand-mile-long, 40- to-50-foot-high wall - how much concrete are we talking about?
STERNFELD: OK - times a thousand.
KING: Todd pulled out a calculator and tapped in some numbers and muttered under his breath for a while.
STERNFELD: It would be about 250,000 truckloads of - you know the concrete trucks? It would be about 250,000 of those trucks just to make the product.
KING: Just to make the wall - plus tons and tons - literal tons of steel reinforcement bars. Todd says, no problem. He's got a steel supplier. What's the longest wall you've ever built?
STERNFELD: The longest wall that I've ever built was about four miles.
KING: Four miles, but the border wall is a thousand miles.
STERNFELD: I understand.
KING: But you think you could do it?
STERNFELD: Yeah, I think I could do it.
KING: But Todd seemed to hesitate when I asked him the big question. How much is all this going to cost?
STERNFELD: Put it this way. If it's done, the amount of money that it would cost would just be astronomical.
KING: How much is astronomical?
STERNFELD: Now, he's talking about having Mexico pay for it. So if he's having Mexico pay for it, he might have Mexico build it.
KING: But that wouldn't help you, would it?
STERNFELD: No. Look; I have my business. I mean I'm not going to, you know - I have a business I'm very successful at, so...
KING: You have other walls to build.
STERNFELD: You bet.
KING: Many estimates, by the way, put Donald Trump's wall in the $15 to $25 billion range. Maybe that's partly why Trump in his first televised interview as president-elect told "60 Minutes" that he'd consider swapping some parts of the wall for a fence instead. Noel King, NPR News. Transcript provided by NPR, Copyright NPR.