The service line carrying water from the meter to your house is entirely buried — which means it can leak for months with no puddle, no stain, and no sound inside the home. The only early warnings are a climbing bill and subtle changes in the yard. Here's how to track one down.
Why underground leaks go unnoticed
Soil absorbs an enormous amount of water before anything surfaces. A small leak drains into the ground and disperses, and in Summerville's sandy Lowcountry soils it can travel laterally rather than pooling. By the time a wet spot appears, the leak may have been running for a season or more — which is why the bill, not the yard, is usually the first witness.
Signs in the yard
Walk the line's path from the meter to the house and look for anomalies: one patch of grass growing faster and greener than the rest, soil that stays soft or soggy days after rain, a sunken or spongy strip across the lawn, or water pooling where the ground should drain. In a dry spell, an inexplicably lush stripe is practically a map of the leak.
Heavy rain can mask the evidence
Summerville's summer downpours complicate the picture — after a storm, every yard is wet and every low spot holds water. Judge yard symptoms during dry stretches, not the day after a thunderstorm. Persistent wetness that outlasts the weather is the signal; storm puddles are noise.
The meter test
Shut off everything in the house — faucets, appliances, ice makers, irrigation — and watch the meter's low-flow indicator for 15 to 30 minutes. If the dial creeps or the indicator spins with zero water use, the system is losing water. This test catches leaks too small to show in the yard and too slow to hear.
The house shutoff isolation test
Next, narrow the location. Close the main shutoff valve at the house (leaving the meter side pressurized) and repeat the meter watch. If the meter stops, the leak is inside the house. If it keeps moving, the leak is in the buried service line between the meter and the house — and you've just eliminated half the property from the search.
Rule out irrigation first
Before calling in detection equipment, make sure the irrigation system isn't the culprit. A leaking zone valve or a cracked lateral line can mimic a service-line leak perfectly — same symptoms, same meter movement. Shut the irrigation supply off entirely and repeat the meter test; if the movement stops, the problem is in the sprinkler system, not the main line.
How professionals pinpoint it
Once the leak is confirmed in the buried line, professional detection takes over: acoustic listening traces the leak's sound through the soil, tracer gas pinpoints small leaks that are too quiet to hear, and electronic pipe locating maps the line's exact path so the search follows the pipe instead of guessing. The leak gets marked on the surface — one flag, one dig.
What the repair looks like once the leak is found
A located underground leak is a small, defined job — which is the entire payoff of detection. The typical repair exposes the line at the marked spot, cuts out the failed section, and splices in new pipe with proper fittings, then backfills and restores the surface. When the line is broadly deteriorated, replacing the full run from meter to house in one trench can be the saner long-term call. Either way, the excavation is measured in feet, not in exploratory trenches across the yard. The mark on the grass is what makes that possible.
Call 811 before any digging
South Carolina law requires calling 811 before you dig, and it's free. The service marks public utility lines so a repair excavation doesn't strike gas, electric, or communications. It doesn't mark your private water line — that's the locator's job — but it keeps the dig safe. Never let anyone excavate without those marks in place.
Underground leaks reward patience and punish guessing. Work the checklist in order — yard signs, dry-weather observation, meter test, house isolation, irrigation rule-out — and you'll either find the cause yourself or hand a technician a narrowed-down problem instead of a mystery. If your meter moves with everything off, or the yard keeps telling a story the weather can't explain, professional main water line leak detection finds the break without trenching the whole yard. Call +1 843-936-8115 — open 24 hours.