# Pipe Bursting in Denver

Pipe bursting replaces a sewer line end to end by pulling a bursting head through the old pipe, fracturing it outward, and drawing a new HDPE pipe into the same corridor behind it. It is full replacement without a full-length trench.

- New pipe, not a liner over an old one.
- Two access pits instead of a continuous trench.
- Can upsize diameter on the same path.
- Handles lines a liner cannot save.

## What Pipe Bursting Is

A cable or rod is run through the existing sewer line from an exit pit back to an entry pit. A conical bursting head is attached, along with the new pipe behind it. As the head is pulled through, it fractures the old pipe outward into the surrounding soil and the new pipe follows immediately into the void.

The result is a new continuous pipe, usually fused HDPE with no joints for roots to enter. Because the old pipe is displaced rather than removed, the new line follows the original path and grade.

Bursting is the trenchless method that handles the worst pipe. Where lining needs a host pipe in reasonable shape, bursting only needs a path it can follow.

- Clay tile, which fractures cleanly.
- Cast iron with corrosion and scale.
- Orangeburg and other failing fiber conduit.
- Thin wall PVC and ABS.
- Concrete in many, though not all, conditions.

## When Pipe Bursting Is the Right Method

Pipe bursting is the right method when the entire line needs replacing rather than one section, when the existing path and grade are correct, and when the surface above the line is a driveway, mature landscaping, or a finished area you do not want to lose.

It is also the right call when you need a larger diameter. Bursting can upsize a four inch line to six inches on the same route, which lining cannot do because a liner always reduces internal diameter.

It is the wrong method when the line is bellied and grade has to be corrected, when the pipe has already collapsed with no path to follow, or when surrounding utilities sit too close to absorb the ground displacement safely.

- Complete collapse leaving no continuous bore.
- Bellied or back-pitched line where grade must be reset.
- Utilities or foundations too close to the displacement zone.
- Rock, ductile iron, or pipe encased in concrete.
- Prior point repairs that leave an unburstable hard section.
- No room for an entry or exit pit at either end.

## How a Pipe Bursting Job Runs

1. **Inspect, Locate, Clear** Camera and locate confirm path, depth, material, and that a continuous bore exists. The line is cleaned so the cable can be run.
2. **Dig Two Pits** An entry pit at one end and a receiving pit at the other, sized for the pipe and the pulling rig rather than for the length of the run.
3. **Fuse and Pull** New HDPE is heat fused into one jointless length above ground, then the bursting head is pulled through, fracturing the old pipe and towing the new pipe in behind it.
4. **Tie In and Verify** Connections at each end are made, a camera pass confirms the finished line, then pits are backfilled and compacted and the surface is restored.

## Disruption, Timeline, and Cost Drivers

A typical residential burst is completed in one day on site, sometimes two when the tie-in is complicated or a street cut is involved. Disruption is concentrated at the two pits, so lawn, driveway, and trees between them are undisturbed.

Cost drivers are run length, depth of the pits, diameter and whether you are upsizing, soil conditions and shoring requirements, distance from the rig setup to the line, any permit and inspection requirements from the local jurisdiction, and restoration at the pit locations.

Bursting usually costs more per foot than lining and less than a full-length trench across a hard surface. On open lawn with a shallow line, open cut can be the cheaper answer.

## Frequently asked questions

**When is pipe bursting the right method?**

When the whole line needs replacing, the existing path and grade are correct, the surface above is expensive to restore, or you need to upsize the diameter.

**What rules pipe bursting out?**

A collapsed line with no path to follow, a belly that has to be regraded, nearby utilities inside the displacement zone, or a pipe material that will not fracture such as ductile iron or concrete encasement.

**Does pipe bursting damage nearby utilities?**

It can if they sit inside the displacement zone, which is why we locate every nearby utility before the pull and switch methods if clearances are too tight.

**Can pipe bursting increase the pipe size?**

Yes. Upsizing on the same route is one of the main advantages over lining, which always reduces internal diameter slightly.

**What pipe goes in?**

Typically HDPE, heat fused into one continuous length with no joints, which is why root intrusion at joints stops being a failure mode.

## Related Methods and Services

- [Trenchless Sewer Repair](https://www.denversewerandwater.com/methods/trenchless-sewer-repair) The umbrella page covering every no-dig and low-dig repair method we run.
- [CIPP Cured-In-Place Lining](https://www.denversewerandwater.com/methods/cipp-lining) A resin liner cured inside the host pipe to form a new jointless pipe wall.
- [Open Cut Excavation](https://www.denversewerandwater.com/methods/open-cut-excavation) Traditional trenching when the line has to be exposed and physically replaced.
- [Method Comparison and Cost Guide](https://www.denversewerandwater.com/methods/sewer-repair-method-comparison) Side by side comparison of every method, what drives cost, and what rules each out.

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Denver Sewer and Water is a privately owned, licensed and insured plumbing contractor. We are not affiliated with, endorsed by, or connected to Denver Water, the municipal water utility, or any government entity. To pay a municipal water bill or reach the public utility, visit denverwater.org.

Source: https://www.denversewerandwater.com/methods/pipe-bursting