Quick Answer
If sewage is backing up into your house, it's almost always a major clog in your main sewer line. First, stop using all water immediately – no flushing, no showering. Locate your main sewer cleanout, usually a capped pipe outside your house. If sewage is overflowing from the cleanout, the blockage is on your property, somewhere between the house and the street. If the cleanout is empty, the issue might be with the municipal sewer system, or a clog further down the line that isn't affecting your cleanout yet. This is typically not a DIY job. You'll need to call a professional plumber who can use a sewer camera to diagnose the problem and a powerful drain machine or hydro-jetter to clear it. Expect to pay a few hundred dollars just for the service call and initial clearing.

Common Symptoms
Possible Causes
Step-by-Step Diagnosis
Step 1
Immediately stop using all water in the house.
Step 2
Determine if the backup is affecting a single drain or multiple fixtures simultaneously.
Step 3
Locate the main line cleanout pipe in your yard or basement.
Step 4
Carefully open the cleanout cap to see if water is backed up there, which indicates a clog between the cleanout and the street.
Step 5
If the cleanout is dry but fixtures are backed up, the clog is between the house and the cleanout.
Step 6
If the cleanout is dry and fixtures are clear, but you suspect a problem, the issue could be with the municipal sewer system.
Step 7
Call a professional for a sewer camera inspection to definitively identify the cause and location of the problem.

DIY vs Professional Costs
| Repair Type | DIY Cost | Professional Cost | Time Required |
|---|---|---|---|
Main Line Clearing (Auger/Snake) | Not Recommended | $200-$600 | 2-4 hours |
Main Line Hydro Jetting | N/A | $400-$1000 | 3-5 hours |
Sewer Line Spot Repair (Excavation) | N/A | $2,000-$10,000+ | 1-3 days |
Sewage Cleanup & Sanitization | $100+ (for gear) | $1,000-$7,500+ | 2-5 days |
When to Call a Professional Water Damage
- When more than one plumbing fixture is backing up at the same time.
- As soon as you see raw sewage coming up from a drain, tub, or toilet.
- If you open your main line cleanout and it's overflowing.
- If you've tried to clear a single-drain clog with a plunger or small snake and it hasn't worked.
- If you have recurring backups, which indicates a bigger problem like tree roots or a damaged pipe that needs a camera inspection.
Prevention Tips
- Never pour grease or cooking oil down any drain; dispose of it in the trash.
- Do not flush anything other than human waste and toilet paper—especially not 'flushable' wipes, paper towels, or feminine hygiene products.
- Install mesh screens on all shower and tub drains to catch hair.
- If you have mature trees, schedule a preventative sewer line cleaning every 1-2 years to clear out encroaching roots.
- Consider having a backwater prevention valve installed, especially if you live in a low-lying area or one with frequent heavy rains.

Frequently Asked Questions
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