Learn about all the factors, including sewer line length and excavation, that determine how much trenchless sewer line replacement costs in Seattle, WA.
Cost to Install a Sewer Line in Seattle
Septic tank service costs depend on your project and location. Check with a local pro for your specific job.
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Highlights
Side sewers are the sewer lines that run from your home to the public sewer system in Seattle.
You’ll need to obtain the proper permits from the Seattle Department of Construction & Inspections before beginning installation.
A plumber or sewer service in Seattle can provide a quote and help you navigate the process.
On average, homeowners pay $4,682 for the cost to install a sewer line in Seattle, Washington. Depending on factors like materials, length, and labor, the cost can fall between $2,209 and $7,347. Homeowners are responsible for keeping side sewers in good condition and replacing them when necessary. Break down the cost factors below as you plan your sewer line budget.
Sewer Line Installation Cost Factors
Various factors impact the cost your sewer pro will quote you in Seattle, Washington. Consider the linear footage, type of pipe, demolition, and prep.
Sewer Line Cost per Linear Foot
The average cost to install a sewer line ranges from $50 to $250 per linear foot. Sewer line pipes are about 5 inches in diameter and run underneath your yard from your house to the main sewer drain. See the table below for cost averages based on the linear footage.
| Length (Feet) | Average Cost |
|---|---|
| 25 | $1,250–$6,250 |
| 50 | $2,500–$12,500 |
| 75 | $3,750–$18,750 |
| 100 | $5,000–$25,000 |
Materials
To install a sewer line, you’ll need to purchase the pipes that connect the main sewer drain to your home. New pipes cost around $3 to $20 per linear foot. Factor in the type of piping material to gain a closer estimate as to how much you’ll pay per linear foot by referencing the following chart:
| Type of Pipe | Average Cost (Per Linear Foot) | Pros | Cons |
|---|---|---|---|
| Clay | $50–$60 | Durable, resistant to corrosion, long-lasting | Common in older homes, likely needs to be replaced, prone to cracking |
| PVC | $0.50–$5 | Most affordable, good fit for mild temperatures | Doesn’t stand up well in extreme cold |
| Cast iron | $2–$10 | Highly durable, performs well in areas with heavy surface traffic | Prone to rust and corrosion, heavy material makes labor more intensive |
| Copper | $20–$30 | High quality, long-lasting | Prone to corrosion, can freeze in cold temperatures |
| HDPE | $4–$6 | High quality, long-lasting $4–$6 Used with trenchless methods, resistant to corrosion, tree root intrusion, and chemical damage | Flammable, higher cost for skilled labor and specialized techniques |
Demolition and Prep
Trenching: $800 per 100 linear feet
Boulder removal cost: $650–$1,200 per boulder
Tree removal cost: $200–$2,000 per tree
Pavement removal cost: $8–$15 per square foot
Sewer Line Installation Pro Costs
Before finalizing your sewer line installation project, weigh the costs of hiring a skilled pro and the permits you’ll need in Seattle.
Permits and Regulations
If you live in Seattle, you will likely need to coordinate with Seattle Public Utilities, and possibly King County, to determine necessary permits and follow regulations specific to the city and county.
The Seattle Department of Construction & Inspections requires a side sewer permit to make repairs or alterations, relocate or remove a pipe, or install a new sewer line. A sanitary permit for a side sewer in new construction costs $375, and a storm system permit also costs $375—for a total of $750 if you need both. Additional fees may be required if you’re working in a public right-of-way. Your sewer service will help you navigate the permitting process.
Labor
Labor to install a sewer line in Seattle depends on the sewer service or plumber you hire and the scope of the project. Pros charge between $30 and $247 per linear foot or $50 to $250 per hour for labor. Because the cost of living in Seattle is 45% higher than the national average, labor rates can be higher than in other areas.
Speak with your sewer line repair pro in Seattle, Washington, so you know the hourly rate and get an estimate for the total cost of materials and labor.
Does Sewer Line Installation Increase Home Value?
Installing a new sewer line doesn’t necessarily raise a home’s value, but a broken sewage line or a system in need of repairs can lower it. If you’re selling your home, prospective home buyers may request a sewer inspection, and a well-maintained sewer line can ease their mind. Properly maintaining your sewer line, taking care of repairs in a timely manner, and replacing it when necessary is a worthwhile investment.
How Angi Gets Its Cost Data
Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We survey real Angi customers about their project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.
Want to help us improve our cost data? Send us a recent project quote to [email protected]. Quotes and personal information will not be shared publicly.
Septic tank services reviews from real Angi homeowners in Seattle, WA
4.3★ avg. • 36 total reviews
- Xicheng W.
Hired Chris Pluming and paid 3000 for a motor replacement for my septic tank, the work is 2 hours.... but never fixed my alarm. I kept calling them and no response.
Chris's Plumbing, Inc. - Terrence R.
Perfect! My house is old... and the drains can be 'cranky'. Bobby T was able to come right out and take care of it! Prompt, professional and knowledgeable... Bobby also advised me on another issue (with my hot water tank) and gave me very specific information, without any 'sales pressure'....
- Roger O.
It went very well. I always worry about damage when companies come into my home to do work but they were great. They removed two tanks across my
Fast Water Heater Company - Todd L.
they pumped septic and spent extra time trying to unclog one of my sewer lines. Will have to get ahold of a rotor-rooter type service. But he was patient, knowledgible, committed to solving the problem.
- Sharon E.
Plumber called and was able to come earlier than expected. He pointed out that faucet was one that could be expected to fail repeatedly in the future due to a defective part and so I decided to get it replaced. After doing that I asked him to look at toilet which seems to take a long time to...
Drain Pro Plumbing Inc - M C.
Excellent. Straight forward and professional bid process. They were happy to answer my questions and then decommissioned the tank quickly and professionally after I decided what I wanted to do.
Filco Company Inc - Sharon B.
I spoke with Scott over the phone and we talked about replacing the hot water tank. My husband followed up with his thoughts. We had tentative plan a and plan b. He gave me a verbal quote to replace the tank and suggested I compare prices with other companies. I already had 2 sources and knew...
Greenwood Hardware - Emilio B.
We had an 80 gallon electric water heater from 1991 that we wanted to replace, so we solicited bids to replace it with a tank-less gas system. Durant was able to come out right away and walked us through all our options, explaining the different tank-less options they use as well as where...
Greenwood Heating and Home Services - Randal W.
When heavy rain floods your drain field and your septic tank, you want someone to come out fast! That's what Dano's Septic Service does. They have new, modern pump trucks and professional service. Adam did a thorough job and was very professional. <br />
- Davene W.
Kevin came out to give me a quote on a tankless water heater. He was so helpful explaining all the differences between tank and tankless and different tankless models. I was considering a tankless because the space (attic) is so difficult to access but after Kevin told me I could set up a...
Brennan Heating & Air Conditioning
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