The sewer words, in plain English

The pipe itself

Side sewer

Seattle's name for the privately owned sewer pipe that runs from a building to the public main — including the part under the sidewalk and street. The owner is responsible for it all the way to the connection at the main, which is why side-sewer repair is a homeowner cost, not a utility one.

Read: Side sewer, lateral, building drain, main: what do the words mean? Read: My sewer line is shared with a neighbor — who pays when it fails? Service: Sewer repair

Sewer lateral

The generic term for the same pipe Seattle calls a side sewer: the line carrying wastewater from one property to the public sewer main. Suburban cities and inspection reports usually say lateral; the ownership principle is the same — private up to the main.

Read: Side sewer, lateral, building drain, main: what do the words mean? Service: Sewer repair

Sewer main

The publicly owned pipe, usually under the street or an alley, that collects flow from every side sewer on the block and carries it toward the treatment plant. The utility maintains the main; a blockage in it is the utility's problem, a blockage before it is the homeowner's.

Read: Side sewer, lateral, building drain, main: what do the words mean? Read: Is my Seattle house on a combined sewer, and why does it matter? Service: Sewer camera inspection

Cleanout

A capped, accessible fitting on the sewer line — usually near the foundation or at the property line — that lets a technician put a cable, jetter or camera straight into the pipe without pulling a toilet. Many older Seattle houses have none; a repair permit is often when one is finally added.

Read: What actually happens when your sewer gets scoped? Read: Do I need a Seattle side sewer permit, and how does the process work? Service: Sewer camera inspection

Vitrified clay pipe

Fired-clay pipe in short sections with a joint every few feet. The clay itself lasts a very long time; the joints are the weak point — roots find them, soil movement offsets them, and the short sections let the line sag. Most pre-1950s Seattle side sewers are clay.

Read: How long does a clay sewer pipe last, and how does it fail? Read: What sewer pipe does my Seattle house probably have, by the year it was built? Service: Sewer lining

Concrete sewer pipe

Non-reinforced concrete pipe common in mid-century Seattle-area side sewers. Sewer gases and acidic soil slowly eat the cement, so the crown thins, cracks and eventually collapses — often while the bottom of the pipe still looks fine on camera.

Read: Why is my concrete sewer pipe cracking from the top down? Read: What sewer pipe does my Seattle house probably have, by the year it was built? Service: Sewer lining

Orangeburg pipe

Bituminized-fiber pipe — layers of wood pulp pressed with tar — installed widely from the 1940s into the early 1970s. It softens with age, deforms into an oval, and blisters on the inside. When a camera finds Orangeburg, the conversation is about replacement, not repair.

Read: Do I have Orangeburg sewer pipe, and how long does it last? Read: What sewer pipe does my Seattle house probably have, by the year it was built? Service: Sewer replacement

Cast iron drain pipe

The heavy black pipe used for the drains inside and under many older houses, often continuing under the slab before the line changes to clay or concrete outside. It rusts from the inside, scaling and channeling along the bottom until the wall is gone.

Read: Is my problem under the basement slab or in the side sewer? Service: Sewer camera inspection

Grade (fall)

The downhill slope of a sewer line. Enough grade keeps solids moving with the water; too little lets them settle, too much lets water outrun them. Code sets the minimum; an inspector checks it before backfill because a new pipe with bad grade fails like an old one.

Read: What is a sewer belly, and does it have to be dug up? Read: Do I need a Seattle side sewer permit, and how does the process work? Service: Sewer replacement

What goes wrong

Sewer belly (sag)

A low spot where the pipe has settled below its grade, so water and solids sit instead of flowing through. Bellies show on camera as standing water. They cannot be lined away — a liner follows the pipe's shape — so the sagged section is re-laid at proper grade.

Read: What is a sewer belly, and does it have to be dug up? Compare: Do I need the whole sewer line replaced, or just one section? Service: Sewer repair

Offset joint

A joint where one pipe section has shifted out of line with the next, leaving a step or gap. Soil movement, roots and settling cause it. Small offsets snag paper and roots; large ones let soil in and can be the start of a collapse.

Read: What does an “offset joint” on my sewer inspection mean? Compare: How do I read a sewer scope report? Service: Sewer lining

Root intrusion

Tree and shrub roots growing into the sewer through cracks and joints, drawn by the warmth and moisture inside. Cutting them restores flow for a season; they grow back through the same opening until the joint is sealed by lining or the pipe is replaced.

Read: Why are all my drains slow at the same time? Compare: Hydrojetting or snaking: which one does my sewer line actually need? Service: Sewer & drain cleaning

Infiltration

Groundwater leaking INTO a sewer pipe through cracks, joints and bad connections — the reverse of a leak out. It is why some side sewers back up only in heavy rain: the line is carrying rainwater it was never sized for, on top of the house's own flow.

Read: Why does my sewer back up only when it rains hard? Read: Is my Seattle house on a combined sewer, and why does it matter? Service: Sewer repair

Collapsed sewer line

A section where the pipe wall has failed and the surrounding soil has fallen in, leaving no open channel. A camera usually stops at a collapse. Depending on length and access, the fix is a spot repair or a full replacement; a liner needs a host pipe to hold its shape.

Compare: Can a collapsed sewer line be lined, or does it have to be dug up? Compare: Do I need the whole sewer line replaced, or just one section? Service: Sewer replacement

Diagnosis & cleaning

Sewer scope (camera inspection)

A waterproof camera pushed through the sewer line while a technician watches and records. It shows the pipe material, every joint, roots, cracks, bellies and the point of a blockage, and a locator on the camera head marks depth and position from above ground.

Read: What actually happens when your sewer gets scoped? Compare: How do I read a sewer scope report? Service: Sewer camera inspection

Line locating

Finding the exact path and depth of a buried sewer from the surface, using a transmitter on the camera head (a sonde) and a receiver above ground. Locating turns a camera finding into a spot in the yard that can be marked, priced and dug — or avoided with a trenchless method.

Read: How deep is my sewer line, and how do you find exactly where it runs? Service: Sewer camera inspection

Cabling (snaking)

Clearing a blockage with a rotating steel cable and cutting head. It punches a hole through roots, paper and grease so the line drains again. Cabling restores flow; it does not remove buildup from the pipe wall or tell you why the line clogged.

Compare: Hydrojetting or snaking: which one does my sewer line actually need? Read: My sewer is backing up right now — what do I do first? Service: Sewer & drain cleaning

Hydrojetting

Cleaning the sewer with high-pressure water from a nozzle that pulls itself down the pipe, scouring grease, scale and root mass off the walls and flushing it to the main. Jetting cleans the whole diameter; it is used before a camera inspection and before a liner is installed.

Compare: Hydrojetting or snaking: which one does my sewer line actually need? Read: Why are all my drains slow at the same time? Service: Sewer & drain cleaning

Repair & replacement methods

Trenchless sewer repair

Any method that repairs or replaces a sewer line through small access pits instead of a trench along its whole length — mainly lining and pipe bursting. Trenchless usually means far less digging, not none: access pits at each end are normal, and some defects still call for excavation.

Compare: What “trenchless” sewer repair does and does not mean Compare: Lining or pipe bursting: which trenchless method fits my sewer? Service: Trenchless sewer repair

CIPP lining (cured-in-place pipe)

A resin-soaked felt or fiberglass tube pulled or inverted into the existing pipe, inflated against the walls, and cured hard — leaving a new, jointless pipe inside the old one. It needs a host pipe that still holds its shape and cannot correct a belly or a collapse.

Compare: Lining or pipe bursting: which trenchless method fits my sewer? Compare: Can a collapsed sewer line be lined, or does it have to be dug up? Service: Sewer lining

UV-cured liner (BlueLight)

A CIPP liner cured with ultraviolet light from a lamp train pulled through the pipe, instead of hot water or steam. The resin stays workable until the light hits it and cures in a controlled pass. BlueLight is the UV lining system Pro Sewer Repair uses on qualifying lines.

Read: What is UV-cured (Bluelight) lining, and how is it different from steam-cured? Compare: Lining or pipe bursting: which trenchless method fits my sewer? Service: Sewer lining

Reinstatement

After a liner cures it covers every branch connection, so a robotic cutter goes back in and reopens each one. Reinstatement is checked on the post-lining video — a missed or ragged branch is a future blockage, which is why inspectors and good contractors look for it.

Read: What is UV-cured (Bluelight) lining, and how is it different from steam-cured? Read: Do I need a Seattle side sewer permit, and how does the process work? Service: Sewer lining

Pipe bursting

Trenchless replacement: a cone-shaped bursting head is pulled through the old pipe, breaking it outward into the soil while towing a new HDPE pipe into the same path. It replaces rather than relines, can go up a size, and handles collapsed or badly broken host pipe that a liner cannot.

Compare: Lining or pipe bursting: which trenchless method fits my sewer? Compare: What “trenchless” sewer repair does and does not mean Service: Pipe bursting

Spot repair (point repair)

Fixing one short section of the line — a broken joint, an offset, a root-damaged length — instead of the whole run, by excavating just that spot or installing a short sectional liner. Right when the rest of the pipe is sound; the wrong call when the camera shows the same defect every few feet.

Compare: Do I need the whole sewer line replaced, or just one section? Read: What is a sewer belly, and does it have to be dug up? Service: Sewer repair

Open-trench replacement

Replacing the sewer by excavating along its full length, removing the old pipe, and laying new pipe on fresh bedding at proper grade. The most disruptive method and still the right one when the line has bellies, multiple collapses, or needs a new route — and the only one that resets grade.

Compare: Do I need the whole sewer line replaced, or just one section? Compare: How do I compare sewer repair bids that all say something different? Service: Sewer replacement

Backwater valve

A one-way flap installed on the sewer line that lets flow leave the house but closes if the main surcharges and tries to push sewage back. Common protection for basements and daylight-basement homes on blocks that back up in heavy rain.

Read: Why does my sewer back up only when it rains hard? Read: Why is water coming up through my basement floor drain? Service: Sewer repair

Rules, permits & ownership

Side sewer permit

The permit a city requires before a side sewer is repaired, replaced, lined or burst, pulled by a contractor registered for that work. In Seattle, Seattle Public Utilities issues it (since October 1, 2025) and an inspector signs off the work before backfill. Cleaning and camera work do not need one.

Read: Do I need a Seattle side sewer permit, and how does the process work? Compare: What should I ask a sewer contractor before I let them dig up my yard? Service: Sewer repair

Public right-of-way

The strip of public land — sidewalk, planting strip and street — between the property line and the sewer main. The side sewer crosses it and is still the owner's pipe there, but working in it needs street-use permission from the city on top of the side sewer permit.

Read: Do I need a Seattle side sewer permit, and how does the process work? Read: How deep is my sewer line, and how do you find exactly where it runs? Service: Sewer replacement

Shared side sewer

One side sewer serving two or more properties before it reaches the main — common with older Seattle houses and townhomes. Each owner is responsible for the shared section; who pays for a repair depends on where the defect is, any recorded agreement, and what the neighbors work out.

Read: My sewer line is shared with a neighbor — who pays when it fails? Read: How do sewer lines work in a Seattle townhome, and what should I inspect? Service: Sewer camera inspection

Combined sewer

A sewer that carries both wastewater and stormwater in one pipe — how much of older Seattle was built. In heavy rain the pipe fills with runoff, which is why some houses back up only during storms. Separated systems carry storm and sanitary flow in different pipes.

Read: Is my Seattle house on a combined sewer, and why does it matter? Read: Why does my sewer back up only when it rains hard? Service: Sewer repair

Transferable lifetime warranty

A warranty that stays with the property when it sells rather than ending with the original owner. Pro Sewer Repair's transferable lifetime parts-and-labor warranty applies to full sewer replacements, subject to the written warranty terms — ask for the document, not the phrase.

Compare: What does a “lifetime” or “transferable” sewer warranty actually cover? Compare: How do I compare sewer repair bids that all say something different? Service: Sewer replacement

Sewer inspection contingency

A clause in a home-purchase offer that lets the buyer scope the sewer and renegotiate or walk away if it fails. In Seattle's older housing stock a sewer scope is a routine part of inspection week; sellers increasingly scope first so there is no surprise.

Compare: Should I scope my sewer before listing my Seattle house? Compare: How do I read a sewer scope report? Service: Sewer camera inspection