Right now
- Stop using water. Everywhere in the building. No flushing, no laundry, no dishwasher. Every additional gallon pushes more sewage into the house.
- Keep people and pets out of the affected area. Close the door if there is one.
- Cut the power to that area at the breaker if you can reach the panel without stepping in the water.
- Do not touch it without gloves, rubber boots, eye protection and a respirator.
- Photograph from the doorway for the claim, without entering.
- Call a plumber and a restoration contractor. The plumber clears the blockage; the restoration contractor deals with the contamination. Both are needed.
What a backup means
Sewage entering the building through a floor drain, a basement toilet, a tub or a laundry standpipe means the wastewater line is blocked or surcharged somewhere between you and the main.
Common causes on the Front Range:
Root intrusion in clay laterals. Any pre-1960 neighborhood — Denver's older core, Olde Town Arvada, downtown Littleton, Old Town Longmont, east Greeley. Roots find the joints and the blockage builds over years.
Storm surcharge. Monsoon downpours load the system faster than it carries, and the volume backs up into the lowest fixture in the lowest house.
Grease and wipes. The most preventable cause. Nothing labeled flushable is flushable.
Collapsed or broken lines in older properties where the lateral has reached the end of its life.
Warning signs before it happens
Several drains running slow at the same time. Gurgling from a toilet when the washing machine drains. A sewer smell near a floor drain. Water appearing at a basement drain when a fixture upstairs is used. Any of those means the line is partly blocked and the full backup is coming.
A camera inspection at that point costs a small fraction of a cleanup.
Why professionals handle this
Sewage is IICRC Category 3 — grossly contaminated water carrying pathogenic agents. The classification is not a judgment call and it dictates the method.
Containment is established with plastic barriers and negative air pressure so the work does not push contamination through the rest of the building and the HVAC system. Crews work in full PPE. Porous materials come out and are disposed of: carpet, pad, drywall cut well above the contamination line, insulation, particleboard cabinetry, anything upholstered. Hard surfaces are cleaned mechanically and disinfected with an EPA-registered antimicrobial. Only then does drying start.
Exposure routes are ingestion, inhalation of aerosols and contact through broken skin. Gastrointestinal illness, skin infection and respiratory irritation are the common outcomes. If anyone develops symptoms, that is a doctor conversation.
Afterwards
Get the lateral camera-inspected to find out why it happened. Consider rodding, relining or replacement depending on what the camera shows. On a low-lying property, a backwater valve stops street-side surcharge entering the house at all.
And check your policy for a water backup endorsement before the next one. Most Colorado homeowners do not have it and most assume they do.
Related: sewage cleanup in Colorado, the insurance claims guide, and the cost guide.
Frequently asked questions
What is the very first thing to do?
Stop using every water fixture in the building — no flushing, no washing machine, no dishwasher, no showers. Every gallon you send down the drain makes the backup worse. Then keep people and pets out of the affected area and cut power to it at the breaker if you can do that safely.
Can I clean it up myself with bleach?
Not safely, and not effectively. Sewage carries bacteria, viruses, parasites and chemicals. Bleach on a porous surface sanitizes the surface and leaves the material underneath contaminated, and mopping aerosolizes pathogens. Carpet, pad, drywall and particleboard that took sewage get removed, not cleaned.
Is a sewer backup covered by my homeowners policy?
Usually only if you carry a water backup or sewer backup endorsement. Base policies commonly exclude it. The endorsement is typically inexpensive relative to a $2,000 to $10,000 cleanup, which makes it one of the better-value add-ons available.
Do we need to move out?
Consider it if the smell is strong, a large area is affected, or there are infants, elderly or immunocompromised people in the household. Containment reduces spread but the work is disruptive and the space is not safe to occupy while it is under way.