Urban waste water analysis. Waste water sample were take monthly during the period may 2010-November 2011, amounting to a total of 19 times. The sampling frequency was not bight because the main chemical, physical and mocrobiogical composition of the secondary effluent was highly constant and stable. Hourly sampling always occurred at the same time. This samples were collected at the inflow (0m) and at the out-flow(33m) of subunit. A litter of waste water was collected flow each of the two points for each of the subunits. The influent sample was taken close to the outflow pipe. The influent and effluent samples were instantaneous sample. The pH value, electrical conductivity ECw, temperature(T) and dissolved oxygen levels (DO) levels were determined directly on dissolved oxygen levels (DO) levels were determined directly on site the using a portable Universal meter (Multiline WTW P4), following the calibration protocol for each of four parameters being studied. Using Italian water analytical methods (IRSA-CNR,2004) total suspended solids (TSS), biochemical oxygen demand Chemical oxygen demand, total Kjeldahl nitrogen, ammonnia nitrogen and total phosphorus levels were determined. Total coliform , faecal streptococci