It is cool that they don't disturb the surface vegetation or topsoil by simply dumping dredge tailings on the surface. Their method reminds me of injecting expa

It is cool that they don't disturb the surface vegetation or topsoil by simply dumping dredge tailings on the surface. Their method reminds me of injecting expanding foam underneath concrete slabs to lift and level them. "Flood-prone terrain is then elevated by injecting a wood-based slurry 15–300 feet underground" This is the part that's odd to me. A wood-based slurry? If there's high organic content in the pump material, won't that decompose (and settle down) over time? I would think that they would want to use something less organic (such as dredge tailings) as their fill material. They say it's compact within a few hours and doesn't need much time to settle before it's ready to be built on -- but how long does it last?