Two white PVC risers rising from a trench beside a brick house at a backwater valve install

09 · Backwater Valve Installation

A backwater valve is a one-way door on your sewer

A backwater valve sits on the main sewer line. It lets your wastewater out, and its flap closes when the city sewer pushes back. For a house with a finished basement or floor drains below the street, that is the difference between a storm and a cleanup.

Call (618) 444-9976 Book Service

Why the Metro-East needs them

Parts of the region still run on combined sewers, where storm water and sewage share one pipe. Belleville’s system dates to 1912 and is combined; Wood River’s has an overflow straight to the Mississippi. When a heavy rain fills those pipes, the water looks for the lowest opening it can find, and that can be a basement floor drain.

Downspouts make it worse. Belleville’s wastewater department calls downspouts and sump pumps tied into the sanitary sewer incorrect and illegal connections, and a major contributor to backups.

What the Illinois plumbing code says about them

Illinois repealed its plumbing code section on backwater valves in February 2004, so there is no statewide rule that a house must have one. A town may still require or recommend one, and so may an insurer; your public works office can tell you where your town stands. We fit each valve to the plumbing layout, the depth of the line and the local code.

We’ll provide solutions that make sense – not upsells.

Dig N Drain

Signs you may need one

Your basement has backed up before
Floor drains sit below street level
Drains gurgle during heavy rain
The house is older and on a city sewer
Your town recommends or requires one

Talk to the crew

(618) 444-9976

Answered 24/7. Scope and price before any work starts.

Book Service

How the job goes

What to expect, step by step

01Inspect and evaluate
Camera the line, find the depth, pick the valve and its spot.
02Install to code
Fitted to your layout and your town’s rules.
03Test
Confirm it flows out and closes against backflow.
04Clean up and show you
The area restored, and how to check and clean the valve.

Our work

Photos from our own jobs

Answers

Questions about backwater valve installation

How much does a backwater valve cost to install?

It depends on how deep the main line runs, whether the valve goes inside on the building drain or outside in the yard, and what the floor or ground on top is made of. The camera inspection tells us all three, and you get the price before any work begins.

Are backwater valves required in Illinois?

Not statewide. Illinois repealed its plumbing code section on backwater valves effective February 18, 2004, so no state rule requires one. Your town may still require or recommend one, especially in older areas on combined sewers, so ask your public works office, or ask us when we camera the line.

Where is a backwater valve installed?

On the main sewer line where it leaves the building, below the lowest fixtures it protects, with an access cover so it can be opened and cleaned. The exact spot depends on the plumbing layout and the depth of the line, which is why every installation starts with an inspection.

How do I know if I already have a backwater valve?

Look for an access cover or a short riser on the main line, inside near where the sewer leaves the basement, or outside close to the foundation. If you cannot find one, a camera run from the clean-out will show whether a valve is in the line and whether its flap still moves.

Do backwater valves need maintenance?

Yes. The flap has to swing freely, and grease or debris can hold it open or shut. When we install a valve we show you how it works and how to check and clean it; a look every so often, and after any big storm, keeps it ready for the next one.

Book it

Book service or ask a question

Your name Phone

Email Property address

City State ZIP

What do you need? How did you hear about us? What are the drains doing?

Where your message goes and what the site keeps: our privacy policy.