Ancient spring waters still emerging and accessible in the Roman Forum area. Chemical–physical and microbiological characterization

The presence of abundant surface and underground waters and, consequently, fertile and flat soils favored the birth and expansion of Rome. Before the construction of the first aqueduct, the “springs” were probably the only source of drinking water in Rome. At the same time, today, many of them are only scarce outcrops that, anyway, constitute an important heritage for their hydrogeological, archaeological, and monumental significance. In the present study, a multiparametric analytical approach is reported to highlight possible differences among the still emerging and accessible sources in the area of the Roman Forum and to exclude infiltrations from the water and/or sewage network. Temperature, conductivity, pH, dissolved oxygen, and redox potential were measured in situ, while the salt and bicarbonate content, the fixed residue, some UV-Vis indices, and the volatile organic compounds were determined in the laboratory. The microbiological water quality was evaluated by assaying Escherichia coli, intestinal Enterococci, and Salmonella, with the total bacterial count at 22 and 37°C. As expected, all samples are non-potable. Nevertheless, the comparison of data on standpipes close to the springs allowed us to exclude important infiltrations from the water network and the microbiological analysis of those from the sewer network.