Because the service line is under soil, concrete or lawn, its failures rarely announce themselves. In Fullerton's dry months a leak can even hide well: water soaks down into the soil rather than pooling. What you usually notice is a combination of small clues, and the more of them you see together, the more likely the buried line is involved.
Signs and what they can mean
| What you notice | Where | What it may point to |
|---|---|---|
| A strip of lawn that stays wet or unusually green | Between meter and house | Water escaping along the line's route |
| Ground that dips or feels spongy | Over the line route | Soil washing out around a leak |
| Meter leak indicator turning with everything off | Meter box | Water being lost somewhere on the property |
| Water bill rising with no change in habits | Your bill | Steady loss, possibly underground |
| Lower pressure at every fixture | Throughout the house | A large leak or a narrowed pipe |
| Rusty or discolored water at several taps | Throughout the house | Corroding galvanized pipe |
| Hissing near the house shutoff | Outside wall | Flow when nothing is on |
| Water seeping from a driveway crack | Hardscape over the line | Leak under concrete |
Rule out these first
Many signs that look like a service line leak come from something simpler.
How a typical leak progresses
Not every leak follows this path, but this is a common pattern.
- Early
- The meter creeps slowly. There is no visible water and the bill change is small.
- Weeks later
- One patch of grass looks greener or stays damp. The bill climbs.
- Later
- Soil softens or sinks, pressure drops noticeably and water may surface.
- If ignored
- Washed-out soil can undermine walkways or driveway sections, and the leak can grow suddenly.
Why older Fullerton homes see these more often
Much of the city was built in the 1950s through the 1970s, when galvanized steel and copper were the usual service line materials. After decades in the ground, galvanized pipe corrodes and copper can pit, particularly with hard water. Joints, old repairs and spots where tree roots press on the line tend to be where leaks start.
Common questions
Can a main line leak happen without any wet spot?
Yes. In sandy or well-drained soil, water can drain downward without surfacing. A moving meter and a rising bill may be the only clues.
Is rusty water always a sign of a leak?
No. It often points to corrosion inside galvanized pipe, which may not be leaking yet. It is still a reason to have the line and interior piping checked.
How quickly should I act on these signs?
Run the meter test as soon as you notice them. If it confirms a leak, have it located and repaired promptly to limit water loss and soil damage.
General information for Fullerton, not a quote or professional advice. In an emergency, call 911.