Sewage backups on Cavalero Hillon a slope, in a newer home

Slope generally helps a sewer line drain, and a newer home has younger pipes. Neither is a guarantee. Yard work, fences, sprinkler trenches and later utility work can all damage a side sewer. Trees planted when a subdivision was new have now grown large enough for their roots to look for joints. Soil movement can produce a belly where solids settle, and a home with a daylight basement or lower bathroom may have fixtures not far above the level where the line can back up.

Inside the house, the usual suspects still apply: wipes, grease, and things children flush. One slow sink is usually a local clog. If several fixtures are slow, a toilet gurgles when a sink drains or water rises in the lower tub, then the problem is further down, and you should stop using water until the line has been cleared. Our main sewage backup cleanup page explains the cleanup steps. This page looks at what is different for a house on a slope.

On sloped lots, lower-level rooms are often finished as family rooms or bedrooms, and these are the rooms a backup reaches first. Carpet and pad are common here, and Washington's sewage guidance is clear that saturated wall-to-wall carpet and pad usually cannot be adequately cleaned. ^[2] Plasterboard that is soaked and soft to the touch needs to be removed and replaced. For hard surfaces, it describes cleaning with detergent and then rinsing with a solution of one tablespoon of unscented household bleach per gallon of water. Never mix it with ammonia.

Furniture and stored belongings are harder. Hard furniture can often be cleaned. Upholstery, mattresses and soft toys soaked by sewage are usually discarded, and it is especially important to be careful with items used by babies and small children. Photograph them, and list what you discard, as you will need that for any claim. A lower-level room may also be someone's bedroom, in which case they will need somewhere else to sleep for a while. Our safety guide can help you think that through.

Your side sewer runs from the house to the public main, and responsibility generally shifts somewhere along that line. Ask your utility where that point is for your home. If neighbors have problems at the same time, call the sewer utility first. If it is only your home, call a plumber. Many people in the area are served by the Lake Stevens Sewer District, and the relationship between the district and the city has been the subject of litigation, so confirm the current contact for your address.

A camera inspection is useful after any backup. It can show you the pipe material, joints, root intrusion and any sags. Some subdivisions also have shared lines or private pump arrangements, so check your plat or ask your association if you are unsure about yours. If your home relies on a grinder or lift pump to send waste uphill, an alarm or a power failure may be the cause, so mention it on the call.

Ground movement is one thing to keep in mind on a hillside. A pipe can shift if the slope is moving, and repeated breaks in the same place are a reason to look at the ground as well as the pipe. Water from a leaking sewer line can also saturate a slope, so a wet patch or smell downhill of your house deserves attention. If you see cracks in the ground, a leaning wall or wet spots that appear suddenly, ask for professional advice before you dig.

Digging up a side sewer on a slope has its own complications, including shoring, utilities and possibly permits. Ask your plumber about those, and check with the Lake Stevens permit center if you have any questions about what needs a permit. Trenchless repair may be an option, depending on the condition of the pipe.