Council Directive 98/83/EC on the quality of water intended for human consumption establishes a high level of protection for the consumer and requires Member States to ensure that substances and materials used in preparation and distribution of drinking water do not reduce that level of protection. The Directive's point of compliance is at consumers’ taps. This implies a need for control of all drinking water construction products, including pipes and fittings within consumers’ premises. Most of the metals used in metallic construction products are controlled as parameters by the Drinking Water Directive. The stricter requirements that have been imposed by the 98/83/EC Directive indicate a need for a stricter scrutiny of the leaching characteristics of currently available metallic products. In the light of the above report, a scientific study aiming at the determination of variations in drinking water quality as an effect of interactions with metallic materials in distribution systems was conducted. In Italy, 15 main water suppliers and 13 state laboratories homogeneously distributed over the country, except for Sardinia, were involved in the research. 6000 samples were taken from 3800 sampling sites selected according to specific criteria and following specific sampling procedures. The samples were analyzed for Cr, Cu, Fe, Ni, Pb, and Zn and these experimental data were completed with information on buildings, pipes, etc. The major problems with respect to the metals originated from Fe, Ni, and Pb. High Fe concentrations could be related to corrosion processes, Ni outliers to tap materials and Pb levels to lead pipes in old buildings. With respect to the sampling procedures (random without flushing, migration for 30 min or 240 min, both after 5 min of flushing) the statistical analysis showed that random sampling without flushing gave results similar to those ensuing from 4 h migration time, and this for all types of metals.

In this study, we have investigated arsenic occurrence and distribution in ground waters of a large volcanic area in the central part of Italy. Samples were collected from 100 springs and wells currently supplying drinking water to the province of Viterbo. A complete chemical and physicochemical characterization of the samples was carried out. The concentration of the target element was greater than 10 µg L⁻¹ in 37% of the analyzed samples and greater than three times the legal limit in 12% of the sites (in the south-east area of the Vico lake). A 48% of the concentration values were in the range 0.0–5.0 µg L⁻¹. The presence of arsenic is most likely due to the volcanic origin of the monitored area. Cluster analysis of the whole data set showed the existence of a significant correlation between arsenic and fluoride concentrations.

This study concerns the occurrence of arsenic in the groundwater system of the Cimino-Vico volcanic area (central Italy), different parts of which are currently widely used for local drinking water supply and for irrigation. The system shows a complex groundwater circulation, including a continuous basal aquifer, discontinuous perched aquifers, groundwater flows at high altitude, and local interactions with rising thermal fluids. Data on arsenic contents in 250 water samples from springs and wells and in 68 samples from rock outcrops were measured and combined with already existing information. Results highlight that arsenic concentrations of groundwater are influenced by type of aquifer, groundwater flow path, arsenic content of the aquifer rocks, and interaction with fluids rising from depth. Waters circulating in the Vico volcanics, one of the prominent rock units of the area, have high concentrations of arsenic, both for the basal and the perched aquifers. A large fraction of the waters associated with this rock unit have arsenic contents higher than 10 μg/L (82 percent for basal, 40 percent for perched). In contrast, waters circulating in the Cimino volcanics have lower arsenic contents: 30 percent of the basal and 10 percent of the perched aquifers have arsenic concentrations greater than 10 μg/L. Through an integrated approach, including leaching tests to investigate the arsenic behavior concerning the water-rock interaction and a geostatistical modeling of data, it has been possible to identify and tentatively quantify suitable water resources that have arsenic content not exceeding the quality standards for human consumption.

The reuse of Pteris vittata plants for multiple phytofiltration cycles is a main issue to allow an efficient phytoremediation of arsenic (As)-contaminated groundwater. Here, we assessed the capacity of phytofiltration of P. vittata plants grown for two cycles on naturally As-contaminated drinking water (collected in Central Italy), spaced by a growth cycle on non-contaminated water (N cycle). P. vittata young plants, with extensive frond and root development, were suspended individually in 15 L of water with initial As of 59 µg/L, without any additional treatment or water refilling. During cycle 1, in 45 days P. vittata plants reduced As concentration below 10 µg/L, the allowed EU limits for drinking water. During the subsequent 30 day-N cycle on non-contaminated water, no leaching of As from the roots was observed, while the water pH increased 0.9 Units, but is within the allowed limits. During cycle 2, under the same conditions as cycle 1, As concentration decreased below 10 µg/L in less than seven days. These results show that P. vittata young plants, previously used for the phytofiltration of As, do not extrude As and, when reused, remove As much more rapidly. No additional treatments were required during phytofiltration and thus this represents a sustainable, efficient, and scalable strategy.