Garbage Disposals & Septic Systems
Updated February 20, 2026
Key Takeaway
Using a garbage disposal with septic is possible but adds 30-50% more solids to the tank. Septic-safe disposals inject enzymes to help break down food. Either way, be conservative about what goes in.
Overview
Using a garbage disposal with septic is possible but adds 30-50% more solids to the tank. Septic-safe disposals inject enzymes to help break down food. Either way, be conservative about what goes in.
What to Know
Comparison
| Standard disposal on septic: works but increases solids 30-50% |
| Septic-safe disposal: enzyme injection reduces impact, $20-40/year cartridge cost |
| No disposal (composting): zero septic impact, safest for stressed systems |
Buying Tips
- Get your septic assessed before installing any disposal.
- Be extra conservative -- soft scraps only, no grease, no fibrous vegetables.
- Increase pumping frequency by 1 year after installing a disposal.
- Avoid bleach and anti-bacterial soap down the disposal drain.
Common Mistakes
- Installing on an old or failing septic system.
- Treating septic-safe as permission to grind everything.
- Forgetting to replace enzyme cartridges on schedule.
- Not adjusting the pumping schedule.
Bottom Line
Healthy septic system plus septic-safe disposal plus conservative use equals fine. Stressed system equals compost instead.