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description: Time until failing systems gets fixed
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# t\_fail

An active system becomes failing as the biozone gets clogged and hydraulic failure occurs. A failing system automatically turns active during the simulation and septic parameters are re-initialized to default values after the specified number of days for rehabilitation. For testing long term failure, _t\_fail_ can be increased as per the failing duration. The parameter [operation](operation) should be set to 2 for simulating failing conditions.
