by Heather Jennings, PE
. . . the lagoon sludge layer, that is. I’ve seen many lagoons full of sludge, and the general attitude I find in the water industry is that the sludge layer is inert and really can only be mechanically dredged. To a certain point, that is correct: sand, soil, grit, plastics—basically inorganics—do need to be mechanically dredged. The organics, on the other hand, don’t, and they are easily removed with bioremediation. Continue Reading