Hera's commitment beyond quality
In 2020, Hera has continued to investigate the field of Emerging Contaminants. These are biologically active substances of anthropic origin such as medicines, psychoactive substances associated with drug dependency and relative metabolites, and personal treatment products. Their presence in water is a key environmental issue. Drinking water standards (Italian Legislative Decree 31/2001) do not set limits for these substances. Therefore, these parameters are not regulated and monitored as per art. 4 of Italian Legislative Decree no. 31/2001 which states that water must not contain micro-organisms, parasites or other substances in such quantities that endanger human health and that the most recent scientific knowledge of product quality and risk to human health, were no specific legal requirements are in place.
At the Pontelagoscuro drinking water treatment plant in Ferrara, monitoring of 22 substances considered to be of “priority” interest - belonging to the categories of polyalkylphenols, oestrogens and perfluorinated acids (PFAS) - continues; among these PFAS, research into two further active ingredients has been integrated in 2019: perfluorotetradecanoic acid (PFTEDA) and perfluorotridecanoic acid (PFTRDA).
The analyses carried out on the outlet water from the Pontelagoscuro plant in Ferrara in 2020 showed the presence of these substances in very low concentrations, as listed in the following table.
As already explained, at the moment there are no regulatory limits for these parameters. For perfluorinated acids (PFAS) only, the Ministry of Health recommends “adequate water contamination prevention measures at source and, at plant level, implementation of adsorption and/or filtration via membranes proven to be effective for PFAS removal along drinking water production/distribution lines since the application of such technology is believed to ensure the following performance (target) levels in treated waters: PFOA: ≤500 nanograms per litre, PFOS: ≤30 nanograms per litre, other PFAS: ≤500 nanograms per litre".
The Italian National Health Institute (prot. 11/08/2015-0024565) has defined supplemental performance levels, attributing PFBA and PFBS with a value of 500 nanograms per litre.
The European Food Safety Authority (EFSA) has established tolerable daily doses (estimates of the quantity of substance that can be ingested over a lifetime without appreciable health risks) of 150 nanograms per kilogram of body weight per day for PFOS and 1,500 nanograms per kilogram of body weight per day for PFOA. Therefore, according to the EFSA a person of 50 kilograms could ingest 7,500 nanograms of PFOS and 75,000 nanograms of PFOA. These quantities could be ingested by drinking 250 litres and 150 litres of tap water per day respectively with concentrations equal to the limit recommended by the Ministry of Health. However, the average measured concentrations of PFOA substances in the water leaving the Pontelagoscuro plant are 99% lower than the level recommended by the Ministry of Health, while concentrationsof PFOS have not been detected. Therefore, it would take almost 12,500 litres of tap water a day to reach the maximum tolerable daily intake according to EFSA.
Analysis performed on emerging pollutants in water to be treated and water which was treated (not required by Legislative Decree 31/2001) in 2020
| Substance | No. of analyses carried out | No. of analyses in which the substance was detected | Average value measured (ng/L) |
Indication of the Ministry of Health and/or the Italian National Health Institute (ng/L) | |
| polyalckylphenols | 4-n-nonylphenol (NP) | 8 | 0 | <1 | |
| 4-t-octylphenol (t-OP) | 8 | 0 | <5 | ||
| bisphenol A (BPA) | 8 | 1 | <5 | ||
| 4-octylphenol (OP) | 8 | 0 | <1 | ||
| estrogens | 17-a-etinylestradiol (EE2) | 8 | 0 | <1 | |
| b-estradiol (E2) | 8 | 0 | <1 | ||
| estriol (E3) | 8 | 0 | <1 | ||
| extron (E1) | 8 | 0 | <1 | ||
| perfluorinated acids (PFAS) | Perfluorobutyric acid (PFBA) | 57 | 18 | <5 | |
| Perfluorooctanoic acid (PFOA) | 57 | 2 | <5 | ≤500 ng/L | |
| Perfluorohexane sulfonic acid (PFHxS) | 57 | 0 | <5 | ||
| Perfluorodecanoic acid (PFDA) | 57 | 11 | <5 | ||
| Perfluorodecanoic acid (PFDoA) | 57 | 0 | <5 | ||
| Perfluoroheptanoic acid (PFHpA) | 57 | 0 | <5 | ||
| Perfluorohexanoic acid (PFHxA) | 57 | 0 | <5 | ||
| Perfluorononanoic acid (PFNA) | 57 | 0 | <5 | ||
| Perfluorooctanoicosulfonate acid (PFOS) | 57 | 0 | <5 | ≤30 ng/L | |
| Perfluoroheptanoic acid (PFPeA) | 57 | 1 | <5 | ||
| Perfluorotetradecanoic acid (PFTEDA) | 57 | 0 | <5 | ||
| Perfluorotridecanoic acid (PFTRDA) | 57 | 0 | <5 | ||
| Acido perfluoroundecanoic acid (PFUnA) | 57 | 0 | <5 | ||
| Perfluoro butane sulfonate (PFBS) | 57 | 0 | <5 | ||
| Sum of other perfluorinated compounds (other PFAS)* | 57 | 18 | <5 | ≤500 ng/L |
* The total parameter of other PFASs includes at least the following compounds: PFPeA, PFxA, PFpA, PFxS, PFNA, PFDeA, PFUnA, PFDoA (Italian National Health Institute’s opinion for Veneto Region of 11/08/2015).
AcegasApsAmga continued monitoring for emerging contaminants in the Padua and Trieste areas as well.
22 substances considered of "priority" interest belonging to the categories of polyalkylphenols, estrogens and perfluoroalkyl substances (PFAS) were monitored in this case as well.
Concerning in particular the presence of per-fluorinated acids (PFAS) in the aqueducts of Veneto Region operated by AcegasApsAmga, the results of the monthly controls carried out relative to 15 parameters in 2020 - available also on the website www.acegasapsamga.it - found values lower than the "performance levels" (target) defined by the ISS (Italian National Health Institute) at national level (less than or equal to 530 nanograms per litre for PFOA and 30 nanograms for PFOS and less than or equal to 500 nanograms per litre for the sum of the other PFAS) and the limits set by the Veneto Region with the Resolution of the Regional Council no. 1590 of 3/10/2017 (90 nanograms or less per litre for PFOA and PFOS of which PFOS does not exceed 30 nanograms per litre and 300 nanograms or less per litre for the sum of the other PFAS).