Where the highways braid together above the river, Waterbury never entirely goes quiet, and neither does the business of keeping its properties in shape. NCL Services LLC covers both halves of that calendar — mowing, trimming and edging while the grass is running, plowing and shoveling once the weather turns white. Storm nights mean driveways opened and front walks cleared while most of the city is still asleep; July means a steady weekly circuit and lawns that stay ahead of the heat. It is the kind of service noticed mostly by its absence, when a walk is slick or a yard has gotten away from somebody. Here, neither one happens.