Construction on the seawall project, right next to the viaduct. Kelly O

The first thing that came to my mind while walking the length of the waterfront between the viaduct and Elliott Bay the other day was the Department of Homeland Security terror drill that happened in Sodo in 2003. The theater of post-9/11 mayhem on the streets of Seattle, with bloody bodies, burning buses, bashed cars, and emergency professionals in protective gear that made them look like spacemen among the ruins of a dirty-bombed city—those images blend in effortlessly with the mayhem on the waterfront right now. Not only is there Bertha and all that surrounds it, there is also the Elliott Bay Seawall Project simultaneously under way, the $330 million replacement of our 100-year-old seawall. Our old seawall was made of landfill, concrete, and the remains of 20,000 trees, and the project right now appears as debris of tree trunks, muddy pools of water, concrete rubble, and rising dust. This is a moment when the productive activities of construction resemble the chaos of destruction.

And as you walk between the seawall construction site and what is effectively the ghost of the Alaskan Way Viaduct (it has no future to speak of), you come across tourists who are unable to reach the ice cream shops and fish-and-chips places on the piers, some of which are closed during this stage (especially those between the Seattle Ferry Terminal and Pier 57). You and the tourists stand transfixed by the movement of heavy-duty vehicles. It is, after all, something fun to watch. Humans doing their civil thing.

It's also unusually cold down here, and it's not because you're on the waterfront. It's not the wind over the bay. There is another very good reason for the coldness. A part of the soil has been frozen solid by large machines that hum inside of white containers, on either side of which extend pipes with ice-capped sections that plunge into the earth. What is this all about? Why and how is the ground being frozen? The answer, oddly enough, begins in 1945 with the mushroom cloud that rose over Nagasaki. Stay with me. The plutonium used in that world-historical explosion was manufactured at the Hanford Site, a production facility in Washington State that went into operation in 1943 and was fully decommissioned in 1987 (its reactors are now entombed like the pharaohs of the atomic age). Hanford Site contains 54 million gallons of radioactive waste that threatens to poison the life of the great Columbia River that once cooled its reactors. In the early 1990s, Ron Krieg, a Washington researcher and entrepreneur, held seven patents of technologies that concerned the management and containment of nuclear waste. One of these technologies involved freezing the ground beneath the deteriorating tanks that contain radioactive waste. Nothing came of this idea, but Larry Applegate, a construction manager by profession, helped transfer Krieg's ground-freezing technology to the civil construction market. In 1998, the company SoilFreeze was born and began the curious business of freezing the earth for companies that build the world we humans live in.

Why do they need to freeze the ground along the Seattle waterfront? As Applegate, who is now president of the Seattle-based company, explained to me over the phone, freezing the ground provides a temporary solid wall to deal with water. "People always think of the water in the bay," explained Applegate, "but there is also water in the land. And as you have to block water from the bay, you have to block water from the land. By freezing the ground, we create that wall, a wall of ice."

And what are the advantages of dealing with groundwater in this way? "For one, it's environmentally friendly. Once the construction is done, nothing has changed. Everything is the same as before. No impact." They turn off the machines, and the ground thaws. "Also, if you don't do it this way, then you have to mechanically pump out the water, and what that does is it basically dries the ground. This dryness compromises the stability of nearby structures... What happens is this: The water in the ground adds weight to it [the ground], and the loss of water is also a loss of that weight. Bertha is using pumps and so is having this kind of problem with structures near the site."

The wall of ice goes down 35 feet. The tourists along the waterfront are actually standing on a wall of frozen soil as they look at the workers in the hard hats, the piers beyond the exposed seawall, the Great Wheel, which is open during the construction, the silently magnificent waters of the bay, and the cargo ships, which on the day I visited the waterfront area were covered in a mist that rolled down from West Seattle. recommended