Potential issues of well water in domestic use in a retrospective study from 2014 to 2018.

Well water requires chemical, physical-chemical, and microbiological analysis to ensure that the water used for irrigation or for human consumption presents no specific risks. The aim of the present work was to determine the microbiological risk of samples taken from wells in south-central Sardinia. In this survey, 55 water samples were taken from private wells in the period from 2014 to 2018. Quality was assessed through the detection of the parameters required by national law. The analysis of the data showed that only 36.4% of the samples (20 wells) complied with legal limits for water for human consumption. The most isolated species was P. aeruginosa, present in 29.1%; its high concentration and recorded Coliforms suggest that the disinfection of the wells was insufficient or not performed properly if implemented. Such data suggest the need to pay more attention to the waters used not only for human consumption but also for irrigation, since the cultivated vegetables could become a vehicle for potentially pathogenic microorganisms. National legislation sets contamination limits only for water intended for human consumption and not for irrigation water. However, based on these considerations, it appears necessary to develop reference standards for irrigation water.