Santa Clarita Sewer Repair: Project example: a 40-foot sewer lateral replaced by open trench, including the broken section under the street to the county main, in a Castaic tract — what it involves and what it costs

The scenario

The house is a tract home in one of the sewered neighborhoods of Castaic, served by a public sewer main under the street. Some outlying parcels in the Castaic area are not on the public sewer; septic systems are outside the scope of this site. Here the lateral runs about 40 feet from the house across the front yard to the property line, and continues under the sidewalk, the curb and part of the street to the main.

After a backup has been cleared, a camera inspection finds the lateral broken in two places: a crushed section under the front lawn, and a separated, broken section under the street near the main. This site does not provide emergency service; the example describes the planned replacement that follows. In Los Angeles County, the property owner is typically responsible for the house sewer lateral from the house to the connection at the public main, which can include the part under the sidewalk or street; the agency that maintains the main confirms where the owner's part ends for a specific address. Here the street section is work in the public right of way, which typically means an excavation permit from the agency that owns the street, traffic control and an inspection at the main connection.

The findings in short:

• Yard section: crushed under the front lawn
• Street section: separated and broken near the main
• Length on the property: about 40 feet
• Right of way: sidewalk, curb and part of a residential street
• Permits: LA County Building & Safety for the plumbing work in this unincorporated area, plus an excavation permit from the agency that owns the street

What the job involves

1. The lateral is scoped from the house cleanout to the main, both breaks are located with a sonde and a locator, and the depth at the main is confirmed from the video and the surface trace.
2. The plumbing permit and an excavation permit with a traffic control plan for the street section are applied for, underground utilities are marked, and the work is scheduled to the permit's conditions.
3. The yard section is trenched from the house to the property line, the old pipe is removed, and new PVC is laid on compacted bedding on a steady slope, with a two-way cleanout near the house.
4. On the permitted day, traffic control is set, the sidewalk, curb and street are saw-cut along the trench line, and the trench is excavated to the main with shoring as required.
5. The broken street section is removed, new pipe is laid from the property line to the main, and the connection at the main is made with the fitting the agency specifies, then inspected before backfill.
6. The street trench is backfilled and compacted to the agency's specification, the asphalt, curb and sidewalk are restored, the yard is backfilled, and the whole line is scoped from the cleanout to the main.

Hardware and materials

• New PVC sewer pipe and fittings for the yard and street sections
• Connection fitting at the main as specified by the agency
• Sand or fine gravel bedding; compacted backfill to the agency's specification in the street
• Two-way cleanout near the house
• Traffic control devices per the permit; saw-cutting and asphalt, curb and sidewalk restoration
• Excavator, shoring and compaction equipment; push camera with a sonde and locator

Add-ons often paired with this job

• New two-way cleanout — +$800–$2,000. A two-way cleanout near the house is usually added during the replacement so the new line can be inspected in both directions.
• Hydro jetting and root cutting — +$400–$800. After a backup, cleaning the house side of the system clears debris that collected while the lateral was blocked.
• Camera inspection with video — +$150–$400. A follow-up inspection after the street trench has settled confirms the line stays on grade.

Why it is done this way

Both breaks need fixing for the line to work, and the street section cannot be reached from the yard, so the job spans private property and the public right of way. The street work is the larger and more regulated part: it requires a permit, traffic control, restoration of the street to the agency's standard and an inspected connection at the main. Its cost is shown as a separate item in the estimator for that reason.

Open trench is used for both sections because the yard break is a crushed pipe, which rules out lining and makes bursting uncertain, and because the street section has to be excavated anyway to make a new connection at the main.

What would change the price

• The main is deeper than expected — a deeper street trench and more shoring add cost.
• Traffic control requirements are heavier on a busier street — more equipment and staff.
• The connection at the main needs a different fitting or the main itself shows damage — the agency directs that work.
• The yard section passes under a driveway — the hardscape rate applies to that stretch.
• Permit fees and inspections for the right-of-way work — fees, where they apply, are outside the estimator's ranges.