The Water Intended for Human Consumption (Private Supplies) (Scotland) Regulations 2017

Regulation 3(1)

SCHEDULE 2 PARAMETERS AND PARAMETRIC VALUES

PART A Microbiological parameters

Parameter	Parametric value (number/volume)
Enterococci	0/100 ml
Escherichia coli	0/100 ml

PART B Chemical parameters

Parameter	Parametric value	Unit	Notes
Acrylamide	0.10	μg/l	Note 1
Antimony	5.0	μg/l
Arsenic	10	μg/l
Benzene	1.0	μg/l
Benzo(a)pyrene	0.010	μg/l
Boron	1.0	mg/l
Bromate	10	μg/l	Note 2
Cadmium	5.0	μg/l
Chromium	50	μg/l
Copper	2.0	mg/l	Note 3
Cyanide	50	μg/l
1,2-dichloroethane	3.0	μg/l
Epichlorohydrin	0.10	μg/l	Note 1
Fluoride	1.5	mg/l
Lead	10	μg/l	Note 3 and 4
Mercury	1.0	μg/l
Nickel	20	μg/l	Note 3
Nitrate	50	mg/l
Nitrite	0.50	mg/l
	0.10	mg/l	Note 5
Pesticides—			Note 6
Aldrin	0.030	μg/l
Dieldrin	0.030	μg/l
Heptachlor	0.030	μg/l
Heptachlor epoxide	0.030	μg/l
Other pesticide	0.10	μg/l	Note 7
Pesticides: total	0.50	μg/l	Notes 6 and 8
Polycyclic aromatic hydrocarbons	0.10	μg/l	Note 9
Selenium	10	μg/l
Tetrachloroethene and trichloroethene	10	μg/l	Note 10
Trihalomethanes: total	100	μg/l	Notes 2 and 11
Vinyl chloride	0.50	μg/l	Note 1

Note 1: The parametric value 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: Where possible, without compromising disinfection, an enforcing authority (in relation a supply of water) must strive for a lower value.

Note 3: The parametric value applies to a sample of water obtained by an adequate sampling method at the tap and taken so as to be representative of a weekly average value ingested by consumers of the water. Where appropriate the sampling and monitoring methods must be applied in accordance with any guidelines under Article 7(4) of Council Directive 98/83/EC on the quality of water intended for human consumption(1). Each enforcing authority in relation to the water must take account of the occurrence of peak levels that may cause adverse effects on human health.

Note 4: When implementing measures to achieve compliance with this parametric value, each enforcing authority (in relation supplies of water to premises) must progressively give priority where lead concentrations in the water are highest.

Note 5: The additional parametric value of 0.10 mg/l applies only if the water is subject to treatment to improve its quality. The point of compliance for this additional parametric value is the point at which the water flows out from the treatment works.

Note 6: “Pesticide” means an organic insecticide, organic herbicide, organic fungicide, organic nematocide, organic acaricide, organic algicide, organic rodenticide, organic slimicide, a related product (including growth regulator) and any relevant metabolite, degradation or reaction product. Only those pesticides which are likely to be present in a supply of water need to be monitored.

Note 7: “Other pesticide” means a pesticide other than aldrin, dieldrin, heptachlor and heptachlor epoxide. The parametric value applies to each “other pesticide” individually.

Note 8: The parametric value for this parameter is the sum of all individual pesticides detected and quantified in the monitoring procedure.

Note 9: The parametric value for this parameter is the sum of the concentrations of benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(ghi)perylene and indeno(1,2,3-cd)pyrene.

Note 10: The parametric value for this parameter is the sum of the concentrations of tetrachloroethene and trichloroethene.

Note 11: The parametric value for this parameter is the sum of chloroform, bromoform, dibromochloromethane and bromodichloromethane.

PART C Indicator parameters

Parameter	Parametric value	Unit	Notes
Aluminium	200	μg/l
Ammonium	0.50	mg/l
Chloride	250	mg/l	Note 1
Clostridium perfringens (including spores)	0	number/100 ml
Colour	Acceptable to consumers and no abnormal change
Colour	20	mg/l Pt/Co
Conductivity	2500	μS/cm at 20 °C	Note 1
Hydrogen ion concentration	≥ 6.5 and ≤ 9.5	pH units	Notes 1 and 3
Iron	200	μg/l	Note 2
Manganese	50	μg/l	Note 2
Odour	Acceptable to consumers and no abnormal change
Oxidisability	5.0	mg/l O2	Note 4
Sulphate	250	mg/l	Note 1
Sodium	200	mg/l
Taste	Acceptable to consumers and no abnormal change
Colony count 22 °C	No abnormal change
Coliform bacteria	0	number/100 ml	Note 5
Total organic carbon	No abnormal change		Note 6
Turbidity	Acceptable to consumers and no abnormal change		Note 7

Parametric values for radon, tritium and indicative dose—

Parameter	Parametric value	Unit	Notes
Radon	100	Bq/l	Note 8
Tritium	100	Bq/l	Note 9
Indicative dose	0.10	mSv
Note 1: The water must not be aggressive.
Note 2: This parameter must be measured if the water originates from, or is influenced by, surface water.
Note 3: For still water put into bottles or containers, the minimum value may be reduced to 4.5 pH units. For water put into bottles or containers which is naturally rich in or artificially enriched with carbon dioxide, the minimum value may be lower.
Note 4: This parameter need not be measured if total organic carbon is analysed.
Note 5: For water put into bottles or containers the unit is number/250 ml.
Note 6: This parameter need not be measured for supplies of less than 10,000 m3 of water a day.
Note 7: If the water is subject to treatment to improve its quality, each enforcing authority in relation to the water must strive to ensure that the water, at the point at which it flows out from the treatment works, does not exceed 1.0 nephelometric turbidity units.
Note 8: Remedial action is to be deemed justified on radiological protection grounds, without further consideration, where radon concentrations exceed 1,000 Bq/l.
Note 9: Elevated levels of tritium may indicate the presence of other artificial radionuclides. If the tritium concentration exceeds its parametric value, each enforcing authority in relation to the water must also carry out an analysis of the presence of other artificial radionuclides.

(1)

OJ L 330, 5.12.1998, p.32, as amended by Regulation (EC) No 1882/2003 of the European Parliament and of the Council (OJ L 284, 31.10.2003, p.1), Regulation (EC) No 596/2009 of the European Parliament and of the Council (OJ L 188, 18.7.2009, p.14), Commission Directive (EU) 2015/1787 (OJ L 260, 7.10.2015, p.6) and Corrigendum (OJ L 111, 20.4.2001, p.31).