Blocked Drain Emergency: What to Do Right Now

A sewage backup or drain flooding is a health emergency as well as a property problem. Raw sewage contains E. coli, hepatitis viruses, and other serious pathogens. The first priority is stopping the spread; the second is getting a drainage engineer there quickly. Here’s the immediate action sequence.

Right now: stop using water

Every litre that goes down a drain in your property when the drainage system is blocked adds to the backup. Stop immediately:

• Don’t flush toilets
• Don’t run taps
• Don’t use the dishwasher or washing machine
• Don’t shower or bathe

If the blockage is in the main underground drain (the most common scenario when multiple outlets are affected), all water usage adds to the problem until the blockage is cleared.

Identify the extent

Is it one fixture or multiple?

• One toilet or sink blocked: The blockage is likely in the individual waste pipe for that fixture. Use the other facilities while you arrange a plumber. Not an immediate health emergency (assuming the blocked fixture isn’t overflowing).

• Multiple fixtures backed up, toilets unusable: The blockage is in the main underground drain serving the property. This is the more serious scenario — no water can be drained until cleared.

• Inspection chamber cover rising or sewage at ground level: The drain is surcharging (completely full). Don’t go near any ground-level sewage without PPE. Keep children and pets away.

What sewage backup looks like and the health risks

Raw sewage (what comes out of a completely blocked drain) is a Category 3 biohazard (the same as human waste contamination). It contains:

• E. coli and other bacteria
• Hepatitis A and E viruses
• Norovirus
• Campylobacter
• In some cases, Weil’s disease (Leptospirosis — from rat-contaminated sewers)

Do not attempt to clear a sewage backup with your hands, and do not let children or pets into the affected area. If sewage has entered the property (not just outside), restrict access to the contaminated area.

Before the engineer arrives: containment

You can’t fix the blockage yourself (not if the main drain is backing up). What you can do is limit the damage:

Outside: If a manhole cover is rising or lifting, weigh it down if you can do so without contact with sewage — an open manhole releases gas and creates a hazard. Note: if the cover has already lifted, the chamber may be at risk of overflowing.

Inside: If sewage has entered the property via a drain gully or floor drain, close the toilet lids. Stuff damp towels around any floor drain that’s at risk of backing up. Don’t put towels down the drain.

Document everything: Take photographs of the damage before any clean-up. You will need this for your insurance claim.

Calling an emergency drainage engineer

When you call, tell them:

1. Whether it’s inside the property (sewage inside) or outside
2. Whether multiple outlets are affected or just one
3. How long it’s been blocked
4. Whether there’s been any recent tree work or garden excavation near the drain
5. The age of the property (useful context for likely drain material)
6. Your exact address and any access constraints

A legitimate emergency drainage company should be able to give you:

• An estimated arrival time
• A call-out price before they travel (this might be a fixed call-out fee that covers attendance and assessment; the clearance price should be quoted on site)

What the engineer will do

Access: The engineer needs access to an inspection chamber to introduce the jetting nozzle. Most residential drainage has at least one chamber — often under or near a manhole cover in the garden. If there’s no accessible chamber, the engineer may access via a downpipe connection or a toilet connection.

Clearance: High-pressure jetting clears virtually all organic blockages within minutes. The engineer will confirm the blockage is fully cleared with a downstream flush check and ideally a camera pass.

Investigation: If the drain has backed up without obvious cause (no known build-up, no visible foreign objects), the engineer should camera the drain after clearing to establish what caused the blockage. Root ingress, a collapsed section, or a displaced joint can cause a sudden blockage that will recur if not addressed.

After the drain is cleared: clean-up

If sewage has entered the property:

Do not clean up without protection: Disposable gloves, eye protection, and if in an enclosed space, a mask. Dedicated wellies or disposable overshoes if you’re walking in the affected area.

Disinfect thoroughly: Hard surfaces should be cleaned with a disinfectant solution, then rinsed, then disinfected again. Sewage on soft materials (carpets, upholstered furniture) cannot be adequately decontaminated at home — specialist remediation or disposal is required.

Bag and seal all waste: Any material that came into contact with sewage (towels, cleaning materials, soft furnishings) should be sealed in heavy-duty plastic bags for disposal as contaminated waste.

Professional remediation: For significant internal sewage flooding, professional biohazard remediation is the appropriate response. Your insurer’s emergency line may arrange this — check before you start cleaning.

Wash thoroughly: After any work in a sewage-affected area, wash hands with soap and water for at least 20 seconds. Shower before eating or drinking. Seek medical advice if you develop any gastrointestinal symptoms in the days following.

Is it the water company’s problem?

If the drain that backed up is a public sewer (check your water company’s map), report it to the water company. They are obligated to respond and clear public sewer blockages without charge.

However, in a sewage-backed-up emergency with sewage actively entering the property, you need someone there now — not after the water company’s response time. Get the drain cleared first; if the blockage turns out to be in the public sewer, you can seek reimbursement from the water company.