What is trenchless water line replacement?

Your water service line is the buried pipe that runs from the city meter to your house. The City of Phoenix says: "Issues on the city's side (from the street to the water meter) are the responsibility of the City and issues after the water meter are the responsibility of the homeowner." So the line on your side is yours to replace when it fails, and that's where trenchless methods apply.

The EPA describes the idea in its pipe bursting fact sheet, written for sewer pipe but the same logic applies to any buried line: trenchless work happens "through smaller insertion pits, rather than through excavation along the entire length of pipe." It adds that these methods "provide a method of correcting pipe deficiencies with less disturbance, economic impact, and environmental degradation, and they require less restoration than the traditional dig-and-replace method."

Not sure yet whether your line needs replacing at all? What a main water line is and when it's replaced covers the signs.

Pipe bursting. A cone-shaped head is pulled through the old pipe. It breaks the old pipe outward into the surrounding soil while pulling the new pipe in right behind it. The American Water Works Association calls it "a well-established trenchless method for replacing an existing pipeline with a new pipeline that is the same or larger diameter." The crew digs a pit at each end of the run.

Directional drilling. A drill bores a new path underground and the new pipe is pulled through it. It's often used when the old line can't be followed, or when the new route has to avoid a tree, a slab or a pool. It follows a new path rather than the old pipe's.

### What happens on the job

The EPA lists the general steps for pipe bursting in its fact sheet. Adapted to a house water line, the sequence is:

1. 1Gather the history of the pipe and look at it if possible. The EPA's list starts with "obtain as much history as possible about the pipe's construction and repair."
2. 2Locate every buried utility and get the 811 ticket cleared.
3. 3Dig the access pits.
4. 4Disconnect the line at each end and clear anything in the way, such as valves or old repair fittings.
5. 5Burst the old pipe and pull the new pipe in behind it.
6. 6Pressure-test the new line. The EPA's steps include "pressure-test the pipe" and then "tie the pipe into the existing system."
7. 7Reconnect the house, restore the pits and turn the water back on.

Drilling follows a similar order, with a bored path in place of the burst.

For the sewer side of the story, see trenchless sewer repair vs digging and pipe bursting vs pipe lining.

### What you save and what you don't

You save the trench, and everything that goes with it: a torn-up lawn, a cut driveway or walkway, dead landscaping, and a long restoration job. The pits are small and get restored quickly.

You don't save the planning. Someone still has to locate every buried line, dig the pits safely, connect the new pipe to the meter side and the house side, and pressure-test it. A trenchless job also still needs a licensed contractor.

The EPA is direct about the limits of pipe bursting: "Difficulties can arise from expansive soils, close proximity of other service lines, a collapsed pipe along the pipeline, and other causes." It also says the "bursting operation also can cause ground heave or settlement above or at some distance from the pipe alignment." In practice that means:

• A collapsed or crushed line can stop the head, so that section has to be dug up.
• Other utilities close by get pushed by the burst. Gas, electric and irrigation lines all count.
• Shallow pipe or hard, compacted soil raises the risk of surface movement.
• A line that's badly out of alignment may be easier to replace with a new route.

If the pipe is only leaking at one spot, a spot repair by a small dig may cost you less disruption than replacing the whole run. A plumber should find the leak first, then decide. See what to do about a broken water line in your yard.

### Signs your water line may be failing

Trenchless replacement only comes up if the line has a problem. The usual signs are a meter that runs with everything off, a wet or sunken spot on the line's path, pressure that drops for no clear reason and a water bill that jumps. Phoenix Water Services notes that if pressure "is consistently low, it could be indicative of a larger problem with the City's or the customer's water system," so check whether neighbors are affected before you blame your own pipe. The meter test in how to detect leaks in your home tells you whether the leak is on your side.

Arizona law applies even to small pits. Arizona 811 says "Arizona law requires you to notify Arizona 811 at least two full working days before you start any project," and that contacting them is "easy and free." The utilities mark their own lines; Arizona 811 notes that they "mark only what they own and operate up to their point of sale, which is typically to the meter." Your private lines, such as a pool line or a gas line to a grill, may need a private locator.

Then check the license. The Registrar of Contractors says that if the entire cost of a project is over $1,000 "or requires a permit by the local municipality," you need a licensed contractor. Ask for the contractor's ROC license number and check it before you sign, and ask whether your city needs a permit for the work.

Keep in mind that a quote that says "trenchless" isn't automatically better. It's a method, and the right method depends on your site. A good plumber will tell you when digging is the better answer and explain why. Ask to see the plan for the pits and the path before you agree.

### Questions to ask

1. 1Is trenchless possible on my line, and how do you know?
2. 2Where will the pits go, and how will you restore them?
3. 3What pipe material will you use, and is it approved for drinking water?
4. 4Who pulls the permit, and who handles the locate ticket?
5. 5What happens if the old line turns out to be collapsed?

HQ Plumbing & Air handles water line and shutoff valve repair for Valley homes. If you're weighing options, ask for a free estimate: we're licensed and insured, and you get the price up front before work starts. If the line is actively leaking and you can't stop it, we answer emergency calls 24/7. Start by shutting the water off at the main; here's how to find your main shutoff.