
Granite State Services
Contoocook, NHMerrimack County
demolition, driveways, excavation, foundations, grading, hauling trucking
14 years in business

Trenching / Underground in New Hampshire
Water, sewer, gas, electric, irrigation and drainage lines put in the ground to spec, with 811 locates, shoring and bedding handled right.
Project guide
Trenching and underground utility contractors open the ground for pipe and conduit, bed and backfill it, and put the surface back. What looks like a straight line on a plan is governed by a few hard numbers: 811 locates before any digging, a minimum cover depth that varies by utility (commonly 18 to 24 inches for electric and gas service, and below the frost line for water), and OSHA's requirement that any trench five feet or deeper have a protective system such as a trench box, shoring or a sloped wall, with a competent person on site. Bedding material under the pipe, compaction of the backfill in lifts and tracer wire on non-metallic pipe are the details that separate a line that lasts fifty years from one that settles and cracks the driveway above it.
GradeLine lists 35 trenching / underground contractors that serve New Hampshire.Compare their work and equipment, then confirm availability and service area before requesting a quote.
Listed businesses are based in Contoocook, Manchester, Whitefield, Boscawen, Bethlehem, Sanbornton, though most crews travel well beyond their home city.
Simple trenching in soft soil is often priced per linear foot, roughly $4 to $12 for shallow runs and $10 to $30 or more when depth, rock or shoring come into play. A residential water or sewer service replacement typically runs $3,000 to $12,000 depending on length, depth and how much pavement has to be cut. Directional boring under driveways and roads is priced separately, often $10 to $30 per foot.
Ranges are national and approximate; regional labor rates, material prices and site conditions move them in both directions.
Simple trenching in soft soil is often priced per linear foot, roughly $4 to $12 for shallow runs and $10 to $30 or more when depth, rock or shoring come into play. A residential water or sewer service replacement typically runs $3,000 to $12,000 depending on length, depth and how much pavement has to be cut. Directional boring under driveways and roads is priced separately, often $10 to $30 per foot.
Send the route on a plot plan, the pipe or conduit size, the connection points at both ends, target depth if the utility has told you one, and how you want the surface restored.
The main cost items are trench length, depth and width, and whether the route crosses pavement, tree roots or other utilities; soil, rock and groundwater, which decide whether a trencher, an excavator or dewatering is needed, and whether shoring is required; bedding stone, compacted backfill, pipe material, and restoration of grass, gravel or concrete over the top. A site visit helps the crew see which ones apply.
Utility work in the public right-of-way needs a road opening permit and often a bond. Sewer, water and gas connections require plumbing or utility permits with an open-trench inspection, and gas lines must be pressure tested before backfill. 811 is required by law in every state and locates are free.
Directory
35 contractors found

Contoocook, NHMerrimack County
demolition, driveways, excavation, foundations, grading, hauling trucking
14 years in business

Manchester, NHHillsborough County
driveways, excavation, grading, hauling trucking, land clearing, pond water management

Whitefield, NHCoos County
demolition, driveways, excavation, foundations, grading, hauling trucking

Boscawen, NHMerrimack County
demolition, erosion control, excavation, foundations, grading, hauling trucking
20 years in business

Bethlehem, NHCoos County
driveways, excavation, foundations, grading, land clearing, retaining walls

Sanbornton, NHBelknap County
driveways, excavation, foundations, grading, hauling trucking, land clearing

Pelham, NHHillsborough County
demolition, driveways, erosion control, excavation, foundations, grading

Temple, NHHillsborough County
driveways, excavation, foundations, grading, land clearing, site prep
30 years in business

Madison, NHCarroll County
demolition, driveways, erosion control, excavation, foundations, grading

Hollis, NHHillsborough County
demolition, excavation, foundations, grading, hauling trucking, paving prep
42 years in business

Milford, NHHillsborough County
excavation, site prep, trenching underground
48 years in business

Alton, NHBelknap County
demolition, driveways, excavation, foundations, grading, site prep

Lebanon, NHGrafton County
driveways, excavation, retaining walls, site prep, trenching underground
45 years in business

Meredith, NHBelknap County
demolition, driveways, erosion control, excavation, foundations, grading

Lee, NHStrafford County
excavation, foundations, land clearing, septic systems, site prep, trenching underground

Center Ossipee, NHCarroll County
demolition, driveways, excavation, foundations, grading, land clearing

Newmarket, NHRockingham County
demolition, excavation, foundations, grading, septic systems, site prep
25 years in business

Sanbornville, NHCarroll County
driveways, excavation, foundations, retaining walls, septic systems, site prep
20 years in business

Greenland, NHRockingham County
demolition, excavation, grading, land clearing, pond water management, septic systems

Pittsfield, NHMerrimack County
demolition, erosion control, excavation, grading, land clearing, paving prep
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