a bed of gravel media over which pretreated wastewater is sprayed
a bed of gravel or pebble media through which clarified effluent percolates and microbial activity removes BOD, suspended solids and ammoniacal nitrogen
The process of having the wastewater pass thru a filter to hold back and digest any remaining solid materials or paper. This protects the drainage filed or dispersal site from accumulation of solids and prevents clogging of the drain pipes.