Sand Filters Bottomless
Bottomless Sand Filters have been developed from the result of over one hundred years of successful wastewater treatment using sand media. Bottomless Sand Filters are intended to be used as a drainfield option, following an advanced treatment system, where conventional or shallow narrow drainfields are not viable due to ground water, impervious layers, soil, or other site conditions.
A typical bottomless sand filter consists of a Liner covering the side walls, manifold kit, and control panel. Wastewater, having received secondary or better treatment in advanced treatment unit(s), is intermittently pressure dosed using a programmable timer to a bed of specified sand media. Wastewater is dispersed over the bottomless sand filter surface in a PVC pipe distribution network surrounded in peastone. Wastewater trickles down in unsaturated thin film-flow through the sand media, where physical and biological treatment occurs. The small size of particle media promotes straining and subsequent removal of pathogenic organisms. The treated wastewater (bottomless sand filter effluent) infiltrates into the underlying native soil, where it may receive additional treatment as it percolates down through air-filled soil pore space, before entering the saturated zone.