Bob Humbert and Son

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.

Paving preparation is the earthwork under asphalt or concrete: cutting the subgrade to plan, undercutting and replacing soft spots, placing and compacting aggregate base in lifts, and proof rolling with a loaded truck to find anything that pumps before the paving crew shows up. Asphalt is only as good as what is under it, and most premature cracking and rutting traces back to a thin or poorly compacted base rather than the mix. Base thickness runs from about four to six inches of crushed stone under a residential driveway to eight to twelve inches or more under a commercial lot or a road, compacted to 95 percent or better of maximum density, with the surface held to within a fraction of an inch of grade so the asphalt lift is uniform. Prep contractors often also handle the curb subgrade, drainage structures and the connection to existing pavement.

Septic contractors install and replace the tank, distribution box and drain field that treat wastewater on properties without sewer. Nothing goes in the ground until a soil evaluation or percolation test has been done and the county or state health department has approved a system design; the installer builds to that design and the inspector looks at the open trenches before they are covered. Conventional gravel-and-pipe drain fields are the least expensive where soil drains well, but heavy clay, high water tables and small lots push jobs toward chambers, sand mounds, drip dispersal or an aerobic treatment unit, each with a different price and maintenance schedule. Most states license septic installers separately from general contractors, and many require a pumping and inspection record at property sale.