POLIOVIRUS MOVEMENT DURING HIGH-RATE LAND FILTRATION OF SEWAGE WATER

Research with soil columns that are good models of a field ground water recharge system showed that most polioviruses are held near the soil surface. Secondary sewage effluent seeded with poliovirus type 1 (LSc) was filtered through 250-cm columns packed with calcareous sand from an area in the Salt River bed that is used for ground water recharging of secondary sewage effluent. When the concentration of poliovirus added to the sewage water was increased from 0. 9 multiplied by 10**2 to 2. 6 multiplied by 10**4 PFU/ml, the number of viruses detected at each soil depth increased with the increasing virus concentration in the sewage water. However, the percentage of added viruses that remained at each depth was about the same for each concentration. Increasing the flow rate from 0. 6 to 1. 2 m/day caused a virus breakthrough of less than 1% of the added virus. The velocity of water movement through the soil may be the single most important factor affecting the depth of virus penetration.