Open-cut excavation

Digging along the line to expose and replace pipe directly.

Excavation is often presented as the outdated option. It is not: it is the only method that lets someone look directly at what is there, and there are situations where that is exactly what is needed.

What this page cannot establish

SewerOwner cannot establish whether traditional excavation is appropriate for your property
this approach cannot establish the condition of any section outside the excavation
this approach cannot establish that no further conditions exist elsewhere
this approach cannot establish that the new installation will perform for any stated period

What it attempts to do

Expose the line so that pipe can be removed and replaced, and so that what is uncovered can be observed directly.

When contractors may discuss it

These are circumstances in which the approach comes up, not a checklist that makes it correct. There is no situation in which one method is universally right.

when the line must be seen directly
when conditions or configuration make trenchless methods impractical
when connections, transitions, or obstructions need direct access

What has to be known before applicability can be judged

If a proposal for this work is priced without these, it is priced against assumptions. That is not necessarily wrong — but the assumptions should be written down.

the route and approximate depth of the line
what surfaces and features sit above it
what other buried services are present
the length involved

Access and site considerations

disturbs surfaces along the excavated route
requires utility locating
requires equipment access to the work area
may require permits and inspections

What to clarify in a proposal for this work

These are the details that most often differ between two proposals for what sounds like the same job.

the excavation limits, stated as start and end points
assumptions about depth, soil, and groundwater
which surfaces will be removed and which will be restored
restoration standard for each surface type
what happens if obstructions are encountered
the change-order process

What to keep afterwards

photographs of the open excavation before backfill
the permit and inspection record
post-work footage
warranty terms as written

Alternatives worth asking about

Asking why one approach is proposed rather than another is a reasonable question, and the answer tells you what the contractor believes about your line.

Pipe bursting

Pulling a new pipe along the existing route while displacing the old one.

Replace the pipe along its existing route by drawing new pipe through while the existing pipe is displaced outward, using pits rather than a full-length trench.

Cannot establish: that the route is suitable without site-specific assessment; the position of other buried services; that this method is preferable to any other for a given property.

Cured-in-place lining

Installing a liner inside the existing pipe that hardens in place.

Create a new pipe wall inside the existing line, using the existing pipe as the host, without excavating the full route.

Cannot establish: that lining is appropriate for a given line without inspection; the condition of the ground around the host pipe; that the host pipe’s surroundings are unaffected; that this method is preferable to any other for a given property.

Spot repair

Repairing a defined length of the line rather than the whole run.

Address a condition at one identified location, leaving the remainder of the line as it is.

Cannot establish: the condition of the rest of the line; that no further work will be needed; that the identified condition was the cause of a symptom.

Rerouting

Installing the line along a different path rather than the existing one.

Establish a new route for the line where the existing route presents difficulties that a same-route method would not resolve.

Cannot establish: that a new route is permissible without checking; that the new route avoids all obstructions.

What would change the answer

the route and approximate depth of the line
what surfaces and features sit above it
what other buried services are present
the length involved

What to do next

Depth, soil, groundwater, and obstructions are the assumptions that move an excavation price after work begins.

Check the assumptions the price depends on

If your situation is different

You are comparing this against a no-dig option: Trenchless and excavation methods

Restoration
Excavation and restoration scope are the same conversation.