RISCHIO DI CONTAMINAZIONE PATOGENA PER APPROVVIGIONAMENTO DA POZZI DOMESTICI DELLA FALDA DEL SALENTO

The Salento groundwater supplies over 70% (=4000 l/s) of drinking water requirements. The Puglia carbonate aquifer is an important water reservoir but presents also high vulnerability to wastewater injections. Under these conditions, hazardous pathogens could affect drinking water quality even at long distance from pollution sources. Recent epidemiological studies focused that the population on the Salento Coast (Puglia, Southern Italy) have an higher exposure to gastroenteritis in comparison to Italian population. The quantitative estimation of the pathogens effects on contaminated wells water has been carried out in the Nardò aquifer, where a channel (Asso) outflows raw water in a natural sinkhole. The systematic monitoring of groundwater quality in the wells was carried out during Winter 2002 and allowed the evaluation of the natural inactivation of pathogen injected in the fractured subsoil. This estimation was supported by mathematical model simulations of the groundwater flow and pathogens migration in fractures. Moreover on water samples derived from a wells affected by injected wastes at 500 m of distance, has been tested the impossibility of total inactivation of some viral indicators (Clostridi perfringens e somatic phages anti-E. coli) by hypochlorination.