Drilling & boring
Water main directional drilling
Water mains are the most-bored pressure pipe in the country. Here is how new mains, replacements and service lines are installed by directional drilling and what the water utility will require.
Why water work suits HDD
Water flows under pressure, so a main can follow the gentle curve of a directional bore without any effect on service. That makes HDD the natural method for new mains along existing streets, for crossings of creeks, highways and railroads, and for replacing an old main while it stays in service beside the new one. Service lines from the main to a meter are bored under driveways and yards every day.
Pipe and standards
Most utilities specify HDPE (AWWA C906) or fusible PVC (AWWA C900) for bored water mains, with restrained-joint ductile iron where a utility stays with iron. Pipe is fused on site by a certified operator and pulled in one continuous length. The utility sets the cover, commonly 36 to 48 inches plus local frost depth in cold states, the minimum separation from sewer, and the tracer wire, valves and fittings required. Tie-ins at each end are made by open cut in a small pit.
Crossings
A creek or river crossing is bored well below the scour depth with the pipe protected from the bed; the permit from the state environmental agency or the Corps of Engineers sets depth, fluid-control measures and the season in which work is allowed. Highway and railroad crossings are bored at the owner's required depth and often inside a steel casing. Long bores for large mains use larger rigs and detailed geotechnical borings.
Replacing a main under a live street
The new main is bored alongside or beneath the old one with the street open to traffic, services are transferred one at a time, the new main is pressure-tested and disinfected, and the old main is abandoned in place. Pits at the tie-ins and at each service are the only cuts in the pavement.
Contractors by area
Water main drilling contractors are listed here by state and city. In the Southeast the listed contractor is Davis Underground Solutions, which installs mains, services and crossings for utilities and developers across the region. Elsewhere, the national line routes your project to a contractor working your area. Estimates are free.
Estimates are free. Call now: (855) 804-1434 — or pick your state below to reach the contractor covering your area.
Find a water main drilling contractor by state
Other drilling and boring services
Directional Drilling
Horizontal directional drilling (HDD) for new underground utilities: steered bores under roads, driveways, parking lots, creeks and landscaping with no open trench.
Horizontal Boring
Horizontal boring for conduit, casing and carrier pipe where digging across a surface is not an option.
Auger Boring
Steel-cased auger bores for road, rail and railroad crossings that need a straight, on-grade casing.
Pipe Boring
Boring and pulling in HDPE or steel product pipe from a few inches up to large-diameter casings.
Fiber Optic Drilling
Directional drilling for fiber and communications duct: long bores, multiple ducts in one pull, tight easements.
Electrical Conduit Drilling
Bores for primary and secondary power conduit, lighting circuits and site electrical feeds.
Utility Drilling
Multi-utility installs for developers and utilities: power, gas, water, sewer and telecom on one site plan.
Sewer Line Drilling
Directional drilling and boring for new gravity-adjusted force mains, laterals and sewer crossings.
Gas Line Drilling
Bores for new natural gas mains and services, coordinated with the utility and its operator-qualification rules.
Questions about water main drilling
What size water main can be installed by directional drilling?+
Service lines from 1 inch and mains from 4 inches through 24 inches are routine for mid-size rigs; large rigs install 36-inch and larger transmission mains under rivers and highways.
How deep is a bored water main?+
Below the utility's minimum cover, typically 36 to 48 inches, plus frost depth in northern states, and deeper under roads, railroads and streams where the permit requires it.
How is a bored water main tested?+
Pressure-tested and disinfected to the utility's standard, with bacteriological samples cleared before it is put in service. Tracer wire is tested where required. Testing is part of a complete quote.
Can a water main be replaced without shutting down the street?+
Yes. The new main is bored beside the old one while the old one stays in service, services are switched over, and the old main is abandoned. Only the tie-in and service pits are cut.
What permits does a water main creek crossing need?+
A state environmental permit and often a Corps of Engineers nationwide permit for the crossing, plus the right-of-way permit for the approach. Depth below scour and drilling-fluid controls are standard conditions.