# operation

| Option | Description     |
| ------ | --------------- |
| 0      | Not operational |
| 1      | Active          |
| 2      | Failing         |

An active system automatically becomes failing as the biozone layer gets clogged over time. A failing system turns to an active system after the user specified number of days for rehabilitation defined by [t\_fail](https://swatplus.gitbook.io/io-docs/introduction-1/structural-practices/septic.str/t_fail).