pcs 38 which fills the treatment cell 12 treatment water infiltration system 16 includes a plurality of perforated pipes laid along the high density liner 32 and encased in the pea gravel layer 36 these pipes 40 provide the means for collecting the infiltrating treatment water and supplying it via a cell recovery well 52 for further processing the details of the infiltration treatment water system and the air oxygen distribution system are shown in more detail in fig3 the equipment components for both the systems are preferably housed within a suitable structure 42 see fig1 for purposes of protection thereof and security infiltrating treatment water system 16 operates to circulate naturally supplied water such as rain water through the pcs 38 in the treatment cell 12 the initial distribution of treatment water over the surface of the pcs 38 is accomplished by means of suitable sprinkler nozzles 50 which evenly distribute the treatment water over the entire surface of the pcs this treatment water percolates naturally through the pcs until it reaches the bottom of treatment cell 12 where it is recovered primarily by means of a cell recovery well or wells designated generally as 52 which collects the treatment water from the pea gravel layer 36 by means of perforated pipes 40 which extend generally outwardly.