Comparison
Repair vs. replace: a side-by-side
When each option makes sense, and what each one really costs over five years.
| Repair | Replace drainfield | Full replacement | |
|---|---|---|---|
| Best when | A single component has failed | The drainfield itself is failing | Both tank and field are at end of life |
| Typical cost | $200–$1,200 | $6,000–$15,000+ | $10,000–$25,000+ |
| Permits required | Sometimes | Yes | Yes |
| Disruption | Low | Moderate (yard work, design time) | High |
| Expected lifespan added | 1–5 years on a stopgap; full life on a real fix | 15–25 years | 20–30+ years |
| Risk | May only buy time | Tank may still fail next | Higher upfront, but resets the clock |
The honest version: repeated repairs add up fast. If you're on your second drainfield-adjacent repair in three years, run the math on replacement before committing to a third.