Water quality
[GRI - 103-1],
[GRI - 103-3],
[GRI - 417-1],
[GRI - 416-1],
[GRI - 303-2],
[GRI - 303-4],
Water quality is monitored by all the companies in the operating segment (see chart no. 55). The analytical checks, in addition to those performed by the Local Water Authorities, are performed on a scheduled, ongoing basis and regard both drinking water issued to users, essential due to the associated health effects, and water returned to the environment following treatment. The results of drinking water analyses are compliant for all Companies, at around 99%.
Chart no. 55 – Analytical checks on drinking water, total and by Company (2021)
N.B.: for Acea Ato 2 analysis data does not include analyses performed by Acea Elabori.
Water quality is monitored by all the companies in the operating segment (see chart no. 55). The analytical checks, in addition to those performed by the Local Water Authorities, are performed on a scheduled, ongoing basis and regard both drinking water issued to users, essential due to the associated health effects, and water returned to the environment following treatment. The results of drinking water analyses are compliant for all Companies, at around 99%.
In Rome, the qualitative characteristics of the water collected and distributed are monitored through continuous testing, with instruments located along the water systems and through daily sampling at the collection points and in the distribution network. In Latium there are areas of volcanic origin where the water has potability issues linked to the natural presence of some substances in greater concentrations compared to those indicated by regulations. In these areas, Acea Ato 2 continues to take action aimed at resolving these problems, e.g. increasing the number of drinking water plants capable of removing unwanted substances and reducing them to concentrations well within legal limits. Monitoring of the chemical/ biological parameters of the water in the distribution network of the water system allows a high quality and safety level to be achieved.
Overall, in 2021, 346,164 analyses were conducted in the area managed by ATO 2, for a total of 11,926 drinking-water samples. In addition to the analyses conducted to check water quality, per- formed by Acea Ato 2, with the support of Acea Elabori, another 840 analyses were performed by Acea Elabori for study and research purposes aimed at continuous improvement of monitoring of the drinking-water system.
Acea Elabori, accredited pursuant to the ISO/IEC 17025 stand- ard, performs and certifies chemical and microbiological analyses in different substrates, including water (see Table no. 54 for the analyses performed on Rome drinking water). AdF, which outsources analyses to Publiacqua SpA, took 4,757 samples, identifying representative withdrawal points in the context of districts, with equivalent characteristics, into which the entire network of the aqueduct is divided. All withdrawal points are georeferenced using the GPS system and area available in WebGis. In 2020, AdF launched works for creation of an in-house laboratory and in 2021 it carried out a tender procedure for the purchase of instrumentation. The labo- ratory will be subject to accreditation in compliance with standard ISO IEC 17025:2018.
Table no. 54 – Analyses in Rome (2019-2021) and main quality parameters of the drinking water distributed in Latium, in Campania and in Tuscany (2021)
| ANALYSES PERFORMED BY ACEA ELABORI ON DRINKING WATER – ROME HISTORICAL NETWORK (2019-2021) | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| withdrawal area | no. withdrawal points | no. samples | no. analyses | ||||||||||||
| 2021 | 2019 | 2020 | 2021 | 2019 | 2020 | 2021 | |||||||||
| collection | 57 | 329 | 227 | 344 | 11.968 | 13.579 | 15.267 | ||||||||
| water system and water feed pipes | 22 | 164 | 135 | 104 | 5.617 | 4.950 | 3.997 | ||||||||
| tanks/water centres | 22 | 203 | 85 | 198 | 7.096 | 3.048 | 7441 | ||||||||
| distribution networks | 405 | 3.095 | 3.619 | 3.379 | 99.835 | 120.372 | 107.709 | ||||||||
| total | 532 | 3.791 | 4.066 | 4.025 | 124.516 | 141.949 | 134.414 | ||||||||
| MAIN AVERAGE CHEMICAL AND MICROBIOLOGICAL CHARACTERISTICS OF THE DRINKING WATER DISTRIBUTED IN LAZIO IN CAMPANIA AND IN TUSCANY (2021) | |||||||||||||||
| parameters | measurement unit | average value Acea Ato 2 | average value Acea Ato 5 | average value GORI | average value Gesesa | average value AdF | parameter Legislative Decree no. 31/01 | ||||||||
| chlorides | mg/l Cl | 7,8 | 6,7 | 43 | 21 | 27 | <250 | ||||||||
| sulphates | mg/l SO4 | 11 | 7,7 | 24 | 24 | 41 | <250 | ||||||||
| calcium | mg/l Ca | 80,1 | 87,5 | 113 | exempt (*) | 61 | not applicable | ||||||||
| magnesium | mg/l Mg | 14,9 | 15,6 | 28 | exempt (*) | 11 | not applicable | ||||||||
| sodium | mg/l Na | 7,3 | 4,3 | 29 | 45 | 17 | <200 | ||||||||
| potassium | mg/l K | 4,3 | 1,1 | 14 | exempt (*) | 2,3 | not applicable | ||||||||
| calculated fixed residue | mg/l | 347 | 347,7 | 548 | 299 | 302 | (**) | ||||||||
| nitrates | mg/l NO3 | 3,6 | 3,8 | 18 | 8 | 4,1 | <50 | ||||||||
| fluorides | mg/l F | 0,13 | 0,12 | 0,53 | 0,2 | 0,14 | <1,50 | ||||||||
| bicarbonates | mg/l HCO3 | 326,5 | 343,3 | 470 | exempt (*) | 223 | not applicable | ||||||||
(*) In accordance with Legislative Decree no. 31/01 and in agreement with the health authority, Gesesa is exempted from supplying the parameter.
(**) maximum value recommended: 1,500 mg/l.
FILTRATION OF DRINKING WATER: GESESA LAUNCHES PROJECT IN PEZZAPIANA
In 2021, Gesesa launched a project for the creation of an activated-carbon filtration system for treatment of drinking water for the water plant in Benevento, in the Pezzapiana area. The filtration plant will provide adequate water resources for the city of Benevento, maintaining the values for the substances tetrachloroethylene and trichloroethylene below the Contamination Concentration Limits (CCL) defined by Italian Legislative Decree 152/2006.
In addition, the project promotes circularity criteria, with the plant-based activated carbon used as adsorbent, once no longer functional, rather than being disposed of, are subject to thermal regeneration by specialised companies.
Once fully functional, therefore, the filtration system will improve management of water resources upstream and will promote the reuse of the adsorbent material downstream. The project is aimed at efficient management of water resources through technological innovation, minimising environmental impacts.
During 2021, Acea Ato 2 designed, created and commissioned an innovative experimental plant for processing water destined for human consumption capable of removing arsenic. The plant uses an innovative filtration medium made with amyloid proteins from dairy-industry waste (ß-Lactoglobulin), capable of capturing not only arsenic but also vanadium and lead. It has a treatment capacity of approximately 5 l/s (18 m3/h), corresponding to the drinking-wa- ter requirements of a small settlement of around 600 families (2,000 people).
With regard to the processing of drinking water, at the Grottarossa and Montanciano plants, monitoring and analysis activity continued on treatment processes (chemical conditioning/pre-oxidisation, clariflocculation, sand filtration, granular activated carbon (GAC) filtration, post-oxidisation/disinfection), evaluating the efficiency of the removal of pollutants, specialised parameters for emerging organic species, both microbiological and sub-products of disinfection, in relation to the main management parameters of the plant. In addition, with reference to forecasting the availability of water resources, Acea Ato 2 has implemented a machine-learning algorithm based on the random forest technique to identify meteoro- logical proxies (temperature and/or precipitation) or management proxies (volumes drawn) correlated to the variability of the state of preservation of the resource, with reference to the different collection sources (springs, well fields, etc.)