On Friday, Miami Mayor, Francis Suarez, shared some details about his ‘wonderful’ phone call with Elon Musk about a two-mile tunnel. What would normally be around $1 billion for this kind of project, Musk told Suarez that the Boring Company can do it for just $30 million instead.

In a video posted via Twitter, he explains that Elon Musk wanted the tunnel to have maximum utility for the most affordable price. He also told him that the tunnel could take about 6 months.

During the video, Suarez shares what he thinks of the tunnel’s potential:

“I think we have a unique opportunity to create a signature project not just for Miami but for the world that will bring from across the world to see this solution and allow it to scale to more transportation solutions throughout the city and more throughout the world.”

Just had my call w/ @elonmusk regarding @boringcompany tunnels coming to MIA

DETAILS BELOW?? pic.twitter.com/NsJFYcvGeQ

— Mayor Francis Suarez (@FrancisSuarez) February 5, 2021

The ball for this idea started rolling in January. Elon Musk tweeted that Boring Company tunnels would solve traffic in Miami and for the rest of the world.

Cars & trucks stuck in traffic generate megatons of toxic gases & particulate, but @boringcompany road tunnels under Miami would solve traffic & be an example to the world.

Spoke with @RonDeSantisFL about tunnels last week. If Governor & Mayor want this done, we will do it.

— Elon Musk (@elonmusk) January 18, 2021

So what’s the catch? Well, according to the Miami Herald, the construction of the tunnel could lead to some big problems. Firstly, South Florida is composed of porous limestone bedrock. This kind of limestone has holes in it that allow water to pass through. This means that a high sea level can cause water to l go over the coast as well as underground. This would make the tunneling process a nightmare with constant water filling up the tunneling site. The Miami Herald did report that this issue was brought up during the 30-minute phone call, but it was not clear as to how much the topic was discussed.

Secondly, Conrad Felice, a professor of civil engineering at the University of Florida informed CBS Miami that the 4,200 foot Port Miami tunnel that runs 120 feet down was completed earlier this decade. That tunnel cost $668.5 million. So it’s safe to say that tunnels are not cheap in Miami.

But, he also brings up that there is a safe way for the Boring Company to complete the project. Tunnels that have a larger diameter are possible if measures are taken to ensure safety.

With all of this in mind, it will be interesting to see how the Boring Company could deal with saltwater intrusion and the possible inflation of cost.