The Public Water Supplies (Scotland) Amendment Regulations 2022

Regulation 16(a)

SCHEDULE 1 SUBSTITUTION OF TABLE B IN SCHEDULE 1 OF THE 2014 REGULATIONS

“TABLE B

CHEMICAL PARAMETERS

(1)	(2)	(3)	(4)	(5)	(6)
Notes—
Note 1: The parametric value of 0.10 μg/l refers to the residual monomer concentration in the water as calculated according to specifications of the maximum release from the corresponding polymer in contact with the water.
Note 2: A parametric value of 2.4 mgB/l must be applied when desalinated water is the predominant water source of the supply system concerned or in regions where geological conditions could lead to high levels of boron in groundwater.
Note 3: A parametric value of 0.70 mg/l must be applied where a disinfection method that generates this parameter, in particular chlorine dioxide, is used for disinfection of water intended for human consumption. This parametric value applies only if such disinfection methods are used.
Note 4: This parameter must be measured only when disinfection methods that can generate HAAs are used for the disinfection of water intended for human consumption.
Note 5: This parameter must be measured only in the event of potential blooms in source water (increasing cyanobacterial cell density or bloom forming potential).
Note 6: See also regulation 4(2)(c).
Note 7: The corresponding parametric value applies to each “other pesticide” individually.
Note 8: A parametric value of 30 μg/l must be applied for regions where geological conditions could lead to high levels of selenium in groundwater.
Note 9: The sum of concentrations of these two parameters.
Note 10: The parametric value of 0.50 μg/l refers to the residual monomer concentration in the water as calculated according to specifications of the maximum release from the corresponding polymer in contact with the water.”
Item	Parameter	Concentrat-ion or value (maximum)	Units of measurement	Point of compliance	Notes
Part 1
1.	Acrylamide	0.10	μg/l	Consumer’s tap	Note 1
2.	Antimony	10	μgSb/l	Consumer’s tap
3.	Arsenic	10	μgAs/l	Consumer’s tap
4.	Benzene	1.0	μg/l	Consumer’s tap
5.	Benzo(a)pyrene	0.010	μg/l	Consumer’s tap
6.	Bisphenol A	2.5	μg/l	Consumer’s tap
7.	Boron	1.5	mgB/l	Consumer’s tap	Note 2
8.	Bromate	10	μgBrO3/l	Consumer’s tap
9.	Cadmium	5.0	μgCd/l	Consumer’s tap
10.	Chlorate	0.25	mg/l	Consumer’s tap	Note 3
11.	Chlorite	0.25	mg/l	Consumer’s tap	Note 3
12.	Chromium	50	μgCr/l	Consumer’s tap
13.	Copper	2.0	mgCu/l	Consumer’s tap
14.	Cyanide	50	μgCN/l	Consumer’s tap
15.	1,2-dichloroethane	3.0	μg/l	Consumer’s tap
16.	Epichlorohydrin	0.10	μg/l	Consumer’s tap	Note 1
17.	Fluoride	1.5	mgF/l	Consumer’s tap
18.	HAAs	60	μg/l	Consumer’s tap	Note 4
19.	Lead	10	μgPb/l	Consumer’s tap
20.	Mercury	1.0	μgHg/l	Consumer’s tap
21.	Microcystin-LR	1.0	μg/l	Consumer’s tap	Note 5
22.	Nickel	20	μgNi/l	Consumer’s tap
23.	Nitrate	50	mgNO3/l	Consumer’s tap	Note 6
24.	Nitrite	0.50	mgNO2/l	Consumer’s tap	Note 6
		0.10	mgNO2/l	Treatment works
25.	Pesticides—
	Aldrin	0.030	μg/l	Consumer’s tap
	Dieldrin	0.030	μg/l	Consumer’s tap
	Heptachlor	0.030	μg/l	Consumer’s tap
	Heptachlor epoxide	0.030	μg/l	Consumers’ tap
	Other pesticide	0.10	μg/l	Consumer’s tap	Note 7
26.	Pesticides: total	0.50	μg/l	Consumer’s tap
27.	Sum of PFAS	0.1	μg/l	Consumer’s tap
28.	PAH Total	0.10	μg/l	Consumer’s tap
29.	Selenium	20	μgSe/l	Consumer’s tap	Note 8
30.	Tetrachloroethene and trichloroethene	10	μg/l	Consumer’s tap	Note 9
31.	THM: Total	100	μg/l	Consumer’s tap
32.	Uranium	30	μg/l	Consumer’s tap
33.	Vinyl chloride	0.50	μg/l		Note 10
Part 2
34.	Aluminium	200	μgAl/l	Consumer’s tap
35.	Colour	20	mg/1 Pt/Co	Consumer’s tap
36.	Iron	200	μgFe/l	Consumer’s tap
37.	Manganese	50	μgMn/l	Consumer’s tap
38.	Sodium	200	mgNa/1	Consumer’s tap
39.	Tetrachlorometh-ane	3	μg/l	Consumer’s tap
40.	Turbidity	4	NTU	Consumer’s tap

Regulation 16(b)

SCHEDULE 2 SUBSTITUTION OF TABLE C IN SCHEDULE 1 OF THE 2014 REGULATIONS

“TABLE C

Indicator Parameters

(1)	(2)	(3)	(4)	(5)	(6)
Notes—
Note 1: Water must not be aggressive or corrosive. This applies particularly to water undergoing treatment (demineralisation, softening, membrane treatment, reverse osmosis, etc.).
Note 2: Where water intended for human consumption is derived from treatment that significantly demineralises or softens water, calcium and magnesium salts could be added to condition the water in order to reduce any possible negative health impact, as well as to reduce the corrosiveness or aggressivity of water and to improve taste. Minimum concentrations of calcium and magnesium or total dissolved solids in softened or demineralised water could be established taking into account the characteristics of water that enters those processes.
Note 3: The water must not be corrosive.
Note 4: This parameter must be measured if a risk assessment under regulation 30(2) indicates that it is appropriate to do so.
Note 5: For water put into bottles or containers (which is not intended for sale for drinking by humans), the unit is number/250ml.
Note 6: The water must not be aggressive.
Note 7: For water put into bottles or containers (which is not intended for sale for drinking by humans), the minimum value is 4.5 pH units.
Note 8: This parameter need not be measured for supplies of less than 10,000 m³ a day.
Note 9: Remedial action is to be deemed justified on radiological protection grounds, without further consideration where radon concentrations exceed 1,000 Bq/l.
Note 10: If the concentration of tritium exceeds this value, an analysis of the presence of other artificial radionuclides must also be carried out by Scottish Water.”
Item	Parameter	Concentration or value (maximum) or state	Units of measurement	Point of monitoring	Notes
Part 1
1.	Ammonium	0.50	mgNH4/1	Consumer’s tap
2.	Chloride	250	mgCl/1	Supply point	Note 3
3.	Clostridium perfringens (including spores)	0	Number/100ml	Supply point	Note 4
4.	Coliform bacteria	0	Number/100ml	Consumer’s tap	Note 5
5.	Colony count	No abnormal change	Number/1ml at 22°C	Consumer’s tap, service reservoir and treatment works
6.	Colour	Acceptable to consumers and no abnormal change		Consumer’s tap
7.	Conductivity	2500	μS/cm at 20°C	Supply point	Note 6
8.	Hydrogen ion	9.5	pH value	Consumer’s tap	Notes 6 and 7
		6.5 (minimum)
9.	Odour	Acceptable to consumers and no abnormal change		Consumer’s tap
10.	Sulphate	250	mgSO4/l	Supply point	Note 3
11.	Taste	Acceptable to consumers and no abnormal change		Consumer’s tap
12.	Total organic carbon	No abnormal change	mgC/1	Supply point	Note 8
13.	Turbidity	1	NTU	Treatment works
Part 2
14.	Indicative dose	0.10	mSv	Supply point
15.	Radon	100	Bq/l	Supply point	Note 9
16.	Tritium	100	Bq/l	Supply point	Note 10

Regulation 18(4)(c)

SCHEDULE 3 SUBSTITUTION OF TABLE 1 IN SCHEDULE 3 OF THE 2014 REGULATIONS

“Minimum performance characteristic: uncertainty of measurement

Parameter	Uncertainty of measurement (% of prescribed concentration or value, except pH) (Note 1)	Notes
Notes—
Note 1: Uncertainty of measurement is a non-negative parameter characterising the dispersion of the quantity values being attributed to a measurand, based on the information used. The performance criterion for measurement uncertainty (k = 2) is the percentage of the parametric value stated in the table or any stricter value. The uncertainty of measurement must be estimated at the level of the parametric value, unless otherwise specified.
Note 2: If the value of uncertainty of measurement cannot be met, the best available technique must be selected (up to 60%).
Note 3: The method determines total cyanide in all forms.
Note 4: The value for the uncertainty of measurement is expressed in pH units.
Note 5: Reference method European standard EN ISO 8467:1995 entitled “Water quality - Determination of permanganate index (ISO 8467:1993)”(1).
Note 6: The performance characteristics for individual pesticides are given as an indication. Values for the uncertainty of measurement as low as 30 % can be achieved for several pesticides, higher values up to 80% may be allowed for a number of pesticides.
Note 7: The performance characteristics apply to individual substances, specified at 25% of the prescribed concentration or value for the corresponding parameter in Table B.
Note 8: The performance characteristics apply to individual substances, specified at 50% of the prescribed concentration or value for the corresponding parameter in Table B.
Note 9: The uncertainty of measurement must be estimated at the level of 3 mg/l of the total organic carbon in accordance with European standard EN 1484:1997 entitled “Water analysis - Guidelines for the determination of total organic carbon and dissolved organic carbon”(2).
Note 10: The uncertainty of measurement must be estimated at the level of 1.0 nephelometric turbidity units in accordance with European standard EN ISO 7027-1:2016 entitled “Water quality - Determination of turbidity - Part 1: Quantitative methods (ISO 7027-1:2016)”(3) or another equivalent standard method.”
Aluminium	25
Ammonium	40
Acrylamide	30
Antimony	40
Arsenic	30
Benzo(a)pyrene	50	Note 2
Benzene	40
Bisphenol A	50
Boron	25
Bromate	40
Cadmium	25
Chloride	15
Chlorate	40
Chlorite	40
Chromium	30
Conductivity	20
Copper	25
Cyanide	30	Note 3
1,2-dichloroethane	40
Epichlorohydrin	30
Fluoride	20
HAAs	50
Hydrogen ion concentration (in pH)	0.20	Note 4
Iron	30
Lead	30
Manganese	30
Mercury	30
Microcystin-LR	30
Nickel	25
Nitrate	15
Nitrite	20
Oxidisability	50	Note 5
Pesticides	30	Note 6
PFAS	50
Polycyclic aromatic hydrocarbons	40	Note 7
Selenium	40
Sodium	15
Sulphate	15
Tetrachloroethene	40	Note 8
Trichloroethene	40	Note 8
Trihalomethanes – total	40	Note 7
Total organic carbon	30	Note 9
Turbidity	30	Note 10
Uranium	30
Vinyl chloride	50

(1)

This standard was approved by the European Committee for Standardization (CEN) on 3rd November 1994. Under reference EN ISO 8467:1995, it is published as a UK standard by the British Standards Institution (ISBN 0 580 23435 5).

(2)

This standard has been approved by the International Organization for Standardization (ISO). Under reference BS ISO 5725-1 to BS ISO 5725-6, these are published as UK standards by the British Standards Institution.

(3)

This standard was approved by the European Committee for Standardization (CEN) on 15th April 2016. Under reference BS EN ISO 7027-1:2016, it is published as a UK standard by the British Standards Institution (ISBN 978 0 580 81961 2).