Trenching nationally costs $5 to $12 per linear foot on HomeGuide's 2026 page, which puts 100 feet at $500 to $1,200. In Chicago, most trenches are sewer or water work to the street or the alley, in soft clay that needs shoring.
Each dollar figure below is a national range published by HomeGuide, and none of them is a quote from us. Chicago blue clay, alley access, buried debris from old buildings and the haul to a dump site are what really set the cost of a job here. We read every HomeGuide page used here in October 2026.
What does trenching cost in Chicago, and what about a 100-foot trench?
A 100-foot trench costs $500 to $1,200 at HomeGuide's national $5 to $12 a foot, with about $2 to $3 of each foot for equipment and $3 to $9 for labor. Labor alone is $35 to $65 an hour. Depth, shoring in soft clay and street or alley restoration are what raise trenching cost here.
| Trench length | HomeGuide national range |
|---|---|
| 50 ft | $250 to $600 |
| 100 ft | $500 to $1,200 |
| 200 ft | $1,000 to $2,400 |
Who do I call to replace an old or lead water line in Chicago, and what does it cost?
To replace an old or lead water line, call a licensed plumber; Illinois licenses plumbers through the Department of Public Health, and the plumber works with the city on the connection. HomeGuide puts main water line replacement at $2,000 to $5,000, around a $3,500 national average, or $50 to $200 a foot trenched and $70 to $250 trenchless.
How deep does a water line have to be buried so it does not freeze in Chicago?
A water line has to be buried below frost at the depth the plumbing code and the water utility set for your address, and the plumber confirms it before we dig. Lines under driveways and shoveled walks freeze first, because they lose the insulating snow cover.
What does it cost to dig up and replace a clay sewer line in Chicago?
Replacing a clay sewer line costs $50 to $250 a foot, or $2,000 to $10,000 for 40 feet, on HomeGuide's sewer page; bursting is $60 to $200 a foot and lining $90 to $250. A camera inspection at $125 to $500 shows whether the old pipe can be lined or must be dug. Many Chicago laterals run deep to the main, which adds shoring.
What does it cost to trench an electric line to a detached garage?
Trenching an electric line to a detached garage costs the same $5 to $12 a foot as other trenching in HomeGuide's figures. A licensed electrician installs the conduit and sets the depth, and in Chicago electrical work is licensed by the city. We dig and backfill after the inspection.
What does it cost to run a gas line underground to a grill, heater or garage?
An underground gas line runs $12 to $25 a foot, or $350 to $1,000 or more, on HomeGuide's trenching page. The pipe goes in under a licensed plumber or gas fitter, who also pressure-tests it. Propane is uncommon in the city but used on some rural parcels at the edge of the metro.
Can you bore under a driveway, sidewalk or parkway instead of trenching?
Yes, boring under a driveway, sidewalk or parkway avoids cutting it. Directional boring costs $10 to $30 a foot, or $1,000 to $9,000 for a typical job, in HomeGuide's figures, with 100 feet at $1,000 to $3,000. It saves concrete and parkway trees but costs more per foot.
Can the water service and the sewer lateral share the same trench?
The water service and the sewer lateral can share the same trench only when the plumbing code's separation between them is met, and the licensed plumber decides the layout. When it works, one trench to the street saves digging and restoration.
Can you trench near tree roots or close to the house and the neighbor's foundation?
Yes, trenching near tree roots or close to a house is done carefully: we shore the trench in soft clay, stay clear of footings and backfill the same day. Parkway trees belong to the city, so trenches near them are routed or bored to protect the roots.
For a number on your own Chicago-area property, call or text (872) 201-3760. We look at the lot, then send the scope and the price in writing.