Wastewater coming up through a shower drain, a basement floor drain or the lowest toilet in the house is an emergency. Stop running water everywhere, do not flush, keep children and pets out of the wet area, and call (503) 974-3329. Our 24/7 dispatch sends a licensed plumber to open the main line, and you get a clear price before work starts.
A main line backup is different from a slow sink. Every fixture in the house empties into one pipe, so when that pipe stops, the lowest opening takes the overflow. Below you will find what to do in the first few minutes, how a plumber finds the blockage, and how to tell whether the problem is yours or the public system's.
Sewage Is Backing Up Right Now: First Steps
Speed matters because every flush, shower and load of laundry adds more water to a line that cannot take it. Shut off appliances that drain and stay out of wet rooms. Raw sewage carries bacteria, so wear rubber gloves and boots if you must walk through it.
Do not use the toilets, sinks, shower or washer until a plumber has opened the line. Use the main shutoff valve at the house if water is still running into a flooded room. Never shut off water at the city meter. Call Public Works at 503-992-3258 if the house valve will not close.
Open windows if the smell is strong. If you see standing sewage, photograph it before any cleanup, since your insurer will want pictures. Then call, even after hours, and tell dispatch which fixtures are backing up and which are not.
Whose Pipe Is Stopped? Lateral, City Main and Trunk Line
Three sets of pipe sit between your toilet and the treatment plant. The private sewer lateral runs from the house all the way to the connection at the public sewer. In Forest Grove that lateral is the property owner's responsibility under City Ordinance 52.03.
The City maintains collection lines smaller than 24 inches and all manholes. Clean Water Services handles trunk lines, lift stations and the Fernhill Treatment Facility. If the blockage is out in the street main, neither a cable nor a jetter inside your property will fix it, which is why a plumber starts by figuring out where the stoppage is.
| Pipe | Who is responsible | Who to call |
|---|---|---|
| House drain to the public connection. | Property owner | A licensed plumber. |
| City collection lines under 24 inches and manholes. | City of Forest Grove. | After hours sewer line 503-412-2444. |
| Trunk lines, lift stations, treatment. | Clean Water Services | CWS Field Operations 503-547-8100. |
| Defects in a lateral inside the public right of way. | CWS may repair structural defects. | CWS with a plumber's video. |
Not sure whether the stoppage is yours or the street's? Call and we will sort it out with you.
Call (503) 974-3329Find the Cleanout Before the Plumber Does
A cleanout is a capped pipe, usually four inches across, that gives direct access to the sewer line. It may sit outside near the foundation, in a crawlspace, in a basement or garage, or at the property line. Knowing where it is saves time, since the plumber can feed a cable straight in instead of pulling a toilet.
If you cannot find one, say so on the call. Older homes sometimes have none.
Why Main Lines Stop in Forest Grove Homes
Roots lead the list. About 48 percent of local homes were built before 1980, and older clay and cast iron lines have more joints for roots to find. A hair-thin root enters, snags paper and grows into a plug. Wet winters keep soil damp and roots hungry.
Grease, wipes and paper towels are the next group. CWS asks residents not to flush wipes, including ones sold as flushable, and not to pour grease down drains. Then there are structural causes: a sag where waste settles, a joint that has shifted, or a collapsed section. Those return no matter how often you clean, and a camera inspection of the sewer finds them.
How a Plumber Clears a Main Line
The usual first tool is a large cable machine with a cutting head sized for four-inch pipe. If the line is coated or has fine roots at many joints, the plumber follows with a high-pressure jetter, then runs a camera to confirm the pipe is clear.
A good plumber does not leave once the water drains. They flush the line to prove it moves. If it backs up again in seconds, the clog was not the whole story.
| Method | Strongest use | Limit |
|---|---|---|
| Cable with cutting head. | Roots, packed paper, soft blockages. | Leaves a ragged channel. |
| Hydro jetting | Grease, scale, fine roots. | Not for broken pipe. |
| Camera pass | Confirming the line, finding defects. | Shows but does not clean. |
What Sewer Line Cleaning Costs
Angi reports a 2026 national average of $380 for a main sewer clog, with most jobs between $187 and $572. Its Portland average is $994 with a range from $259 to $1,785. HomeGuide lists $175 to $800 for a main line and $600 to $1,400 when jetting is needed. These are guide numbers. We give you our price first.
Cleanout access
An outdoor cleanout is the cheapest way in. Pulling a toilet adds time.
Distance to the blockage
A plug at the house is quicker than one at the property line.
Method
Angi puts snaking at roughly $100 to $250 and jetting at about $350 to $600.
Cause
Roots and collapsed pipe need follow-up work that a simple clog does not.
Standard homeowners policies often exclude sewer backup unless you added a water backup endorsement. If you have one, call your insurer early and keep photographs, receipts and any recordings the plumber makes.
Call (503) 974-3329 for the price on your situation before anyone starts.
When the Cleaning Does Not Hold
If the line backs up again within a few months, a cleaning removed the symptom, not the cause. Ask for a recording of the pipe and a plain description of what was seen. If the camera finds a crack, an offset joint or roots entering at one seam, repairing the damaged section is often the lasting fix.
CWS may repair structural defects in a lateral inside the public right of way, including cracked pipe, offset joints and root intrusion. A sag is not a structural defect. A plumber, homeowner or realtor can send CWS a video to ask. Digging for repair means calling 811 first, and the plumber may need plumbing and erosion control permits.
Living With a Lateral You Own
Because the private lateral belongs to the owner, small habits matter. Keep wipes and grease out of the system, do not plant trees over the line and know where your cleanout is. Owners in Banks and North Plains are in the same position, with Clean Water Services handling sewer service.
Once the line is open, plan a follow-up camera look rather than wait for the next emergency. For small clogs that stop at one sink, our page on clearing household drains covers the lighter options. Same-day appointments are available when the schedule allows, and nights and weekends are covered by dispatch.
Sewage coming up or a drain gurgling in the lowest part of the house? Call now.
Call (503) 974-3329