Sewage Backup

Understanding Sewage Backup

Sewer backups are one of the most hazardous and costly water damage events a Philadelphia homeowner can face. When the city's sewer system is overwhelmed — by heavy rain, combined sewer overflow, or blockage — sewage can reverse direction and enter homes through basement floor drains, toilets, and shower drains. This water is classified as Category 3 (black water), the most contaminated and dangerous category, containing human waste, bacteria, viruses, and chemical contaminants. Philadelphia's combined sewer system, which serves approximately 60% of the city, mixes stormwater runoff with sanitary sewage in the same pipes. During heavy rain events, this system regularly overflows — discharging an average of 14 billion gallons of mixed sewage and stormwater annually. For homeowners, this means basement sewer backups are not rare events but a recurring risk.

What to Do Right Now

1. Do NOT enter the flooded area — sewage is a serious biohazard⚡ Time-Critical✓ DIY Safe

   Category 3 water contains human waste, bacteria, viruses, and parasites. Contact can cause serious illness including gastroenteritis, hepatitis, and skin infections.

2. Call PGW (215-235-1212) to shut off gas if basement is flooded⚡ Time-Critical✓ DIY Safe

   Gas appliances in flooded basements create explosion risk. Do NOT use electrical devices or open flames near flooded areas. Do NOT enter to shut off gas yourself.

3. Shut off electricity at the breaker panel (if panel is NOT in the flooded area)⚡ Time-Critical✓ DIY Safe

   Electrocution risk from submerged outlets, wiring, and appliances. If the breaker panel is in the flooded basement, call PECO (1-800-841-4141) to disconnect power.

4. Call a professional restoration company immediately⚡ Time-Critical

   Category 3 water requires professional remediation with proper PPE, antimicrobial treatment, and disposal protocols. This is not a DIY situation.

5. Document damage from outside the flooded area — do not wade in✓ DIY Safe

   Use a phone camera from doorways or stairs. Insurance will need documentation but not at the cost of your health.

6. Report the backup to Philadelphia Water Department: (215) 685-6300✓ DIY Safe

   PWD needs to know about sewer system issues. If the backup is caused by a municipal system failure, you may have additional recovery options.

Insurance Coverage

Standard homeowner's insurance does NOT cover sewer backup. You need a separate sewer backup endorsement (rider) on your policy. This costs $50-250 per year and typically covers $5,000-$25,000 per event. Given Philadelphia's combined sewer system and recurring overflow problems, this endorsement is essential. If you don't have it, you're paying for the entire cleanup out of pocket. Even with the endorsement, coverage limits may not cover a severe event in a finished basement. Check your policy limits and consider increasing them if you have a finished basement.

Philadelphia-Specific Information

Philadelphia's combined sewer system serves approximately 60% of the city and has 164 discharge points that overflow during wet weather. The system averages 14 billion gallons of combined sewage/stormwater overflow annually. Germantown is particularly affected due to the encapsulated Wingohocking Creek — an old creek bed converted to sewer pipe in the late 1800s that is drastically undersized for modern storm volume ($8.72M annual property damage). A $93.5 million capacity doubling project is underway. Kensington, Northern Liberties, South Philadelphia, Center City, and West Philadelphia are all in combined sewer zones. Philadelphia's Basement Backup Protection Program offers free backwater valve installation to qualifying residents — contact PWD for eligibility.

Cost Estimate — Philadelphia Metro Area

When to Call a Professional

Always call a professional for sewage backup — no exceptions. Sewage is classified as Category 3 (black water) and is a serious biohazard. Professional remediation companies have proper PPE (Tyvek suits, respirators, rubber boots), antimicrobial treatment chemicals, and disposal protocols. All porous materials that contacted sewage — drywall, carpet, pad, insulation, cardboard, clothing — must be removed and properly disposed of as biohazardous waste. Do not attempt to clean up sewage yourself. The health risks (bacterial infections, viral infections, parasitic infections) far outweigh any cost savings.

Sewage Backup — Frequently Asked Questions

Sources & References

• According to IICRC S500, sewage backups are classified as Category 3 (grossly contaminated) water containing pathogenic agents — all affected porous materials must be removed, and non-porous surfaces require antimicrobial treatment.
• Per IICRC S520, the combination of organic nutrients in sewage and moisture creates ideal conditions for rapid mold colonization — remediation must begin within 24 hours to prevent widespread fungal contamination.
• According to EPA biohazard guidelines, sewage contains bacteria (E. coli, Salmonella), viruses (Hepatitis A, Norovirus), and parasites that pose serious health risks — personal protective equipment including respirators, waterproof boots, and chemical-resistant gloves is required for any contact.
• Per the Philadelphia Water Department, the Basement Backup Protection Program provides free backwater valve installation for qualifying homeowners who have experienced sewer backups — contact PWD at (215) 685-6300 to check eligibility.