Relay to the pit wastewater treatment (such as backwash water-rich liquid) is more than the size of the largest tank effluent to be discharged in a batch or if more than one hour residence time,
Relay pit to wastewater treatment time more than the maximum drain tank size or discharged in batches at least one hour (reverse rinsing water; concentrated liquid) is a
relay to the wastewater treatment pit dwell time 1 hours or more or if the emissions in the batch (concentrated liquid and backwash water, etc. ) is the largest drainage basin in size, more than