Italy · Comune

Drinking water in Rocca Santo Stefano

One supply zone, published by ACEA ATO 2 S.p.A.. The values come from the publications of the Italian water suppliers (gestori), which D.Lgs. 18/2023 requires of them from 12 January 2026. Italian parametric values apply: trihalomethanes 30 instead of 50 µg/l, chromium 25 µg/l, uranium 30 instead of 10 µg/l; for hardness there is no maximum value, it is given in French degrees (°F).

ZONA 1

ACEA ATO 2 S.p.A.

Water hardness

9.6 °dH

Key values ZONA 1
Parameter	Value	Parametric value	Share of the parametric value	Reference
Sum of PFAS	<0,10 µg/L below limit of quantification	0.1 µg/l	< 100 % *	Median
Nitrate	1,40 mg/L NO3	50 mg/l	3 %	Median
Lead	0,20 µg/L Pb	10 µg/l	—	Median
Escherichia coli (E. coli)	Conforme MPN/100 mL	0/100 ml	—	Median
Sulphate	2,205 mg/L SO4	250 mg/l	0.9 %	Median
Sodium	2,2 mg/L Na	200 mg/l	1 %	Median

* Value below the limit of quantification: the actual share of the parametric value is not known; it lies somewhere below the stated upper bound. The marker shows where the limit of quantification of the measurement lies relative to the parametric value.

Show all recorded parameters (61 — most recent value per parameter)

Microbiology (2)

Microbiology – ZONA 1
Parameter	Value	Parametric value	Share of the parametric value	Reference
Escherichia coli (E. coli)	Conforme MPN/100 mL	0/100 ml	—	Median
Intestinal enterococci	Conforme N/100 mL	0/100 ml	—	Median

Chemical parameters (28)

Chemical parameters – ZONA 1
Parameter	Value	Parametric value	Share of the parametric value	Reference
1,2-dichloroethane	<0,1 µg/L below limit of quantification	3 µg/l	< 3 % *	Median
Acrylamide	<0,03 µg/L below limit of quantification	0.1 µg/l	< 30 % *	Median
Antimony	<1,0 µg/L Sb below limit of quantification	10 µg/l	—	Median
Arsenic	<1,0 µg/L As below limit of quantification	10 µg/l	< 10 % *	Median
Bisphenol A	<0,25 µg/L below limit of quantification	2.5 µg/l	< 10 % *	Median
Boron	<0,02 mg/L B below limit of quantification	1.5 mg/l	—	Median
Cadmium	<0,2 µg/L Cd below limit of quantification	5 µg/l	—	Median
Chlorate	<0,05 mg/L ClO3 below limit of quantification	0,25 — bzw. 0,70 bei Desinfektion mit Chlordioxid	—	Median
Chlorite	<0,05 mg/L ClO2 below limit of quantification	0,25 — bzw. 0,70 bei Desinfektion mit Chlordioxid	—	Median
Chromium	<5,0 µg/L Cr below limit of quantification	25 µg/l	—	Median
Copper	<0,001 mg/L Cu below limit of quantification	2 mg/l	—	Median
Cyanide	<10 µg/L CN below limit of quantification	50 µg/l	—	Median
Epichlorohydrin	<0,05 µg/L below limit of quantification	0.1 µg/l	< 50 % *	Median
Fluoride	<0,10 mg/L below limit of quantification	1.5 mg/l	< 7 % *	Median
Haloacetic acids (HAA)	- µg/L not determined	60 µg/l	—	Median
Lead	0,20 µg/L Pb	10 µg/l	—	Median
Mercury	<0,2 µg/L Hg below limit of quantification	1 µg/l	—	Median
Nickel	<2,0 µg/L Ni below limit of quantification	20 µg/l	—	Median
Nitrate	1,40 mg/L NO3	50 mg/l	3 %	Median
Nitrite	<0,05 mg/L NO2 below limit of quantification	0.5 mg/l	< 10 % *	Median
Pesticides — Total	- µg/L not determined	0.5 µg/l	—	Median
Polycyclic aromatic hydrocarbons	- µg/L not determined	0.1 µg/l	—	Median
Selenium	<1,0 µg/L Se below limit of quantification	20 µg/l	—	Median
Tetrachloroethene	<1,0 µg/L below limit of quantification	—	—	Median
Trichloroethene	<1,0 µg/L below limit of quantification	—	—	Median
Trihalomethanes — Total	<1,0 µg/L below limit of quantification	30 µg/l	< 3 % *	Median
Uranium	0,75 µg/L U	30 µg/l	—	Median
Vinyl chloride	<0,1 µg/L below limit of quantification	0.5 µg/l	< 20 % *	Median

PFAS (1)

PFAS – ZONA 1
Parameter	Value	Parametric value	Share of the parametric value	Reference
Sum of PFAS	<0,10 µg/L below limit of quantification	0.1 µg/l	< 100 % *	Median

Indicator parameters (16)

Indicator parameters – ZONA 1
Parameter	Value	Parametric value	Share of the parametric value	Reference
Aluminium	5,9 µg/L Al	0.2 mg/l	—	Median
Ammonium	<0,1 mg/L NH4 below limit of quantification	0.5 mg/l	< 20 % *	Median
Chloride	4,1 mg/L Cl	250 mg/l	2 %	Median
Coliform bacteria	Conforme MPN/100 mL	0/100 ml	—	Median
Colour	Incolore Scala Pt/C	accettabile per i consumatori, senza variazioni anomale	—	Median
Conductivity (25 °C)	299 µS/cm	2,500 µS/cm	—	Median
Iron	<5,0 µg/L Fe below limit of quantification	0.2 mg/l	—	Median
Manganese	0,20 µg/L Mn	50 µg/l	—	Median
Odour	0 Diluiz. 25	accettabile per i consumatori, senza variazioni anomale	—	Median
pH	7,90 pH	6,5–9,5	—	Median
Sodium	2,2 mg/L Na	200 mg/l	1 %	Median
Sulphate	2,205 mg/L SO4	250 mg/l	0.9 %	Median
Taste	0 tasso diluz.	accettabile per i consumatori, senza variazioni anomale	—	Median
Temperature	11,0 °C	—	—	Median
Total organic carbon (TOC)	0,65 mg/L C	senza variazioni anomale	—	Median
Turbidity	<0,5 NTU below limit of quantification	accettabile per i consumatori, senza variazioni anomale	—	Median

Treatment substances (1)

Treatment substances – ZONA 1
Parameter	Value	Parametric value	Share of the parametric value	Reference
Free chlorine	0,21 mg/L Cl2	—	—	Median

Further parameters (13)

Further parameters – ZONA 1
Parameter	Value	Parametric value	Share of the parametric value	Reference
Acid capacity to pH 4.3	183 mg/L CaCO3	—	—	Median
Beryllium	<0,2 µg/L Be below limit of quantification	—	—	Median
Bromide	<50 µg/L Br below limit of quantification	—	—	Median
Calcium	54,00 mg/L Ca	—	—	Median
Dry residue	229,5 mg/L	—	—	Median
Hydrogen carbonate	223 mg/L HCO3	—	—	Median
Magnesium	8,85 mg/L Mg	—	—	Median
Phosphate	<50 µg/L P2O5 below limit of quantification	—	—	Median
Potassium	0,47 mg/L K	—	—	Median
Silicate / silicic acid	2,3 mg/L SiO2	—	—	Median
Thallium	<0,2 µg/L Tl below limit of quantification	—	—	Median
Total hardness	17,1 °F	—	—	Median
Vanadium	<1,0 µg/L V below limit of quantification	0.14 mg/l	—	Median

Values taken unchanged from the publications linked below — for each parameter the most recent recorded value. „—" in the parametric value column: no currently valid legal parametric value is stored in our database for this parameter; the parameter register with all parametric values is being expanded continuously.

Source: https://www.aceaato2.a-acqua.it/content/dam/acea-ato2/pdf/it/mappe-qualita/rocca_s._stefano_zona_1.pdf · luglio 2026 · luglio 2026 · retrieved on 08/07/2026

How to read the share of the parametric value

12 % Share of the parametric value. The proportion of the permitted maximum that the measured value uses — here 12 %, so just over an eighth.

< 10 % * Below the limit of quantification. The substance was not detectable. The mark shows where the detection limit lies relative to the parametric value — the actual share of the parametric value is below that.

Several samples per year: for chemical parameters the mean value is given, for microbiological ones the highest measured value. There the parametric value is zero — a single finding would disappear in the average, and it is precisely that finding which is the information. Which reference applies is stated in the last column of the table.

Legal basis: Art. 18 D.Lgs. 18/2023 as amended by D.Lgs. 102/2025 (transposition of EU Directive 2020/2184). The values are not official — the publication of the Gestore, to which every row links, remains authoritative. Assignment of the comune: information in the analysis document, resolved against the municipality list of ISTAT (territorial status 01.01.2026, CC BY 4.0).