Sewer problems are stressful, especially when you’re worried about backups inside your home. At this South Hill home in Spokane, our Mainstream drain install team was called in to replace a failing exterior sewer line. By excavating the old line, installing a new, code-compliant drain system, and adding a cleanout for easier access, we helped this homeowner get reliable drainage again and peace of mind for the future.

Job Overview

Location – South Hill, Spokane, WA
Client Type – Single-family homeowner
Scope – Exterior drain and sewer line replacement with excavation and permit
Equipment Installed – New exterior sewer/drain line and outdoor cleanout in a protective box
Additional Work – Floor drain cleared and inspected inside the home
Why It Mattered – The existing line was restricting flow and at risk of backing up into the house, which could cause water damage, mess, and future repair costs

What We Found

When our team arrived, the homeowner was worried about slow drainage and the risk of sewage backing up into the home. During our diagnostics, we found that the exterior sewer line was in poor condition and not draining the way it should.

Our inspection showed:

Sections of the exterior line had poor slope, causing waste and water to sit in the pipe instead of flowing away.
The existing piping and fittings were aging and no longer reliable for long-term use.
Inside the home, the floor drain line had a small “belly” (low spot) that can slightly restrict flow when a large amount of water is run at once.

While the interior floor drain was still usable after clearing, the exterior line needed a full replacement to protect the home from future backups and to meet current code requirements under the City of Spokane sewer permit.

The Solution

For this project, our team fully replaced the failing exterior sewer line with a new, long-lasting system designed to drain smoothly and protect the home. We carefully excavated the yard to expose the old pipe, removed the damaged sections, and installed a new, code-compliant sewer line with the correct slope so waste and water flow away from the house like they should.

We also added an outdoor cleanout in a small garden-style box, which makes any future maintenance much easier and keeps most work outside instead of inside the home. Inside, our drain technician cleared the floor drain to restore flow and explained the small low spot in that line so the homeowner knows what to watch for and what their options are down the road.

Once the new line was in place, we tested everything, coordinated inspection with the City of Spokane, and then carefully backfilled and cleaned up the yard. The homeowner was left with a stronger, more reliable sewer system and a clear understanding of the work that was done.

Photo Highlights

The safety precautions taken around the excavation site in the customer’s yard
Digging deep required additional bracing to ensure the safety of our plumbers and the pipes

The Results

With the new exterior sewer line in place, this Spokane home now has smoother, more reliable drainage. The line is properly sloped, supported, and tied into the existing system to help prevent future clogs and messy backups.

The added outdoor cleanout makes any future maintenance faster and less invasive. Inside, the floor drain is flowing again, and the homeowner understands the condition of that line and the options if they ever want to upgrade it. Overall, the home is better protected against surprise sewer issues and expensive water damage.

Trusted Local Experts Closing Paragraph

If you live in Spokane or the surrounding area and are worried about your drains, sewer line, or floor drains, the team at Mainstream Electric, Heating, Cooling & Plumbing is here to help. Our Spokane drain repair specialists handle everything from diagnostics and permits to excavation, installation, and cleanup. Schedule a quote today, and let us help you protect your home from sewer backups and plumbing headaches.

Understanding Sewer Line Responsibility

For most single-family homes, the responsibility for a broken sewer line falls on the homeowner. This usually includes the entire sewer pipe that runs from the house to the point where it connects to the municipal sewer main. Even if the break occurs under a sidewalk or near the street, that portion of the line is often still considered part of the homeowner’s system.

The city or municipality is generally responsible only for the main sewer line itself — not the private lateral that serves your home. This setup is common throughout the Spokane area and Northern Idaho, though exact boundaries can vary depending on local regulations and property layouts.

In multi-unit or shared properties, responsibility may be split among owners based on local rules or HOA agreements. Homeowners insurance may help cover sewer line repairs in some situations, but coverage varies by policy and often requires optional endorsements.

Because responsibility isn’t always obvious, a sewer camera inspection is often the fastest way to confirm where the problem lies and who is responsible for the repair. At Mainstream Electric, Heating, Cooling & Plumbing, licensed plumbers help homeowners understand their sewer systems, identify issues early, and navigate repair options before damage — and costs — escalate.