Residential sewer lines are often buried about 1 to 3 feet deep where they leave the house and get deeper toward the street, commonly reaching around 4 to 6 feet or more at the connection to the city main. Depth varies with the slope needed, the depth of the main, the terrain and local codes, so the only way to know yours for sure is to locate it.
Depth matters for two reasons: it affects the cost of any repair, and it affects safety when digging. A shallow line near the house is a quick dig. A deep line near the street may need shoring to keep a trench from caving in.
Why Does Depth Change Along the Line?
Sewer lines work by gravity, so they have to slope downhill from the house to the main, commonly about a quarter inch per foot. Over a 60-foot run, that adds roughly 15 inches of depth. The line also has to meet the city main at whatever depth the main sits, which is set by the public system, not your house.
What Affects How Deep Your Line Is?
- Depth of the city main at your connection.
- Length of the run from house to street.
- Terrain. Homes above the street may have shallower lines; homes below may be deeper or need a pump.
- Freeze protection. Lines are kept below where the ground might freeze, which is shallow in south Arkansas.
- Foundation type. Slab, crawlspace and basement homes exit at different heights.
What About Pine Bluff?
Pine Bluff is mostly flat and rarely freezes deeply, so many local lines are not especially deep near the house. On flat lots, though, lines have little slope to spare, which is one reason bellies are common. Depth near the street depends on where the public main sits. We measure it on every job rather than guessing.
How Do You Find the Exact Depth?
Camera with transmitter
A camera inspection sends a small transmitter down the line inside the camera head.
Locate from above
A locator on the surface picks up the signal and reads both position and depth.
Mark the ground
Problem spots are marked with paint or flags, with the depth noted.
Why Depth Affects Repair Cost
| Depth | Typical impact |
|---|---|
| Shallow (a few feet) | Quick dig, often by hand |
| Moderate | Machine digging, more soil to move |
| Deep (around 5 feet or more) | Shoring for safety, more time and equipment |
That is part of why sewer repair costs vary so much.
Why Deep Trenches Need Extra Care
Soil can look solid and still give way. A cave-in in a trench just a few feet deep can trap a person, and safety rules generally require protection such as shoring, trench boxes or sloped walls once a trench reaches about 5 feet. That is one reason a deep repair takes longer and costs more than a shallow one. It is also why a deep line in good condition near the street is often a strong candidate for trenchless repair, which avoids the long open trench altogether.
Heavy clay soils, which are common across Jefferson County, hold water after rain and can make trench walls less stable. We plan each dig around the depth and the ground conditions we find that day.
Before You Dig Yourself
If you are planting a tree, building a fence or adding a patio, find the sewer line first and always call 811 so gas, water, power and communication lines are marked. Read why you call 811 before digging in Arkansas.
See how we approach sewer line repair in Pine Bluff, where every dig starts with an exact location and depth.
Call and my crew will camera and locate the line, marking its path and depth before anyone digs.
FAQ
Can a sewer line be too shallow?
Yes. Very shallow lines can be crushed by vehicles or damaged by digging. Codes set minimum cover depths.
Does my sewer line run under the house?
The drains inside do, and the main line exits through or under the foundation before heading to the street.
How far is the sewer line from the house?
It usually leaves the foundation near the main bathroom or kitchen and runs toward the street connection.