Green Earthworks

Excavation contractors dig and move earth for foundations, basements, utilities, pools and site cuts. Most residential jobs run on a mini or mid-size excavator paired with a skid steer and a dump truck; larger cuts bring in a dozer or scraper. The price depends less on the size of the hole than on what is in the ground: clay, ledge rock, high groundwater and buried utilities all slow the machine down and change the hauling math. Before the bucket touches dirt the site needs an 811 utility locate, and any trench deeper than five feet needs a protective system under OSHA rules.

Grading is the shaping of ground to a designed elevation and slope. Rough grading moves the bulk of the earth to bring a site close to plan; finish grading dials in the last few inches so a pad is level and a yard sheds water. The number that matters is fall: building codes call for the ground to drop at least six inches in the first ten feet away from a foundation, and a lawn or gravel area needs roughly a two percent slope to drain. Crews do this with a dozer, a skid steer with a grading bar, or a motor grader on larger lots, checked against a laser or GPS grade stake rather than by eye.

Retaining walls hold back soil where a grade change is too steep to slope, and they fail for one reason far more than any other: water. A wall that lasts has a compacted crushed-stone base, a perforated drain pipe at the heel, clean gravel backfill behind the wall face, and geogrid layers tied into the backfill on anything tall. Segmental concrete block is the most common residential system and can be built by a landscape contractor up to about four feet; above that, or wherever a driveway, slope or structure sits above the wall, an engineer's design is required by most codes and the wall becomes structural work. Poured concrete and reinforced masonry walls are used for tall cuts and tight sites, boulder walls for rural and natural-look projects, and pressure-treated timber for budget walls with a shorter life.