The Private Water Supplies (Wales) Regulations 2017

PART 1 Wholesomeness

TABLE A:

MICROBIOLOGICAL PARAMETERS

Prescribed concentrations or values Parameters	Maximum concentration or value	Units of Measurement
Escherichia coli (E. coli)	0	Number/100ml
Enterococci	0	Number/100ml
In the case of water in bottles or containers:
Escherichia coli (E.coli)	0	Number/250ml
Enterococci		Number/250ml
Pseudomonas aeruginosa	0	Number/250ml
Colony count 22ºC	100	Number/ml

TABLE B:

CHEMICAL PARAMETERS

Prescribed concentrations or values Parameters		Maximum concentration or value	Units of Measurement
(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. This is controlled by product specification.
(2) See also the nitrate-nitrite formula in regulation 4(1)(c).
(3) For these purposes “Pesticides” means: organic insecticides organic herbicides organic fungicides organic nematocides organic acaricides organic algicides organic rodenticides organic slimicides related products (inter alia, growth regulators) and their relevant metabolites, degradation and reaction products. Only those pesticides likely to be present in a given supply need be monitored.
(4) “Pesticides total” means the sum of the concentrations of the individual pesticides detected and quantified in the monitoring process.
(5) The specified compounds are: benzo(b)fluoranthene benzo(k)fluoranthene benzo(ghi)perylene indeno(1,2,3-cd)pyrene. The parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.
The parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.
(6) The parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.
(7) The specified compounds are: chloroform bromoform dibromochloromethane bromodichloromethane. The parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.
The parametric value applies to the sum of the concentrations of the individual compounds detected and quantified in the monitoring process.
Acrylamide (1)		0.10	µg/1
Antimony		5.0	µg/1
Arsenic		10	µg/1
Benzene		1.0	µg/1
Benzo(a)pyrene		0.010	µg/1
Boron		1.0	mg/1
Bromate		10	µg/1
Cadmium		5.0	µg/1
Chromium		50	µg/1
Copper		2.0	mg/1
Cyanide		50	µg/1
1.2 dichloroethane		3.0	µg/1
Epichlorohydrin(1)		0.10	µg/1
Fluoride		1.5	mg/1
Lead		10	µg/1 µg/1
Mercury		1.0	µg/1
Nickel		20	µg/1
Nitrate (2)		50	mg/l
Nitrite (2)		0.5 (or 0.1 in the case of treatment works)	mg/l
Pesticides (3)—	Aldrin	0.030	µg/1
	Dieldrin	0.030	µg/1
	Heptachlor	0.030	µg/1
	Heptachlor epoxide	0.030	µg/1
	Other pesticides	0.10	µg/1
	Pesticides total (4)	0.50	µg/1
Polycyclic aromatic hydrocarbons (5)		0.10	µg/1
Selenium		10	µg/1
Tetrachloroethene and Trichloroethene(6)		10	µg/1
Trihalomethanes: Total(7)		100	µg/1
Vinyl chloride(1)		0.50	µg/1

National requirements – Prescribed concentrations or values

Parameters	Maximum concentration or value	Units of Measurement
Aluminium	200	µg/1
Colour	20	mg/l Pt/Co
Iron	200	µg/1
Manganese	50	µg/1
Odour	Acceptable to consumers and no abnormal change
Sodium	200	mg/l
Taste	Acceptable to consumers and no abnormal change
Tetrachloromethane	3	µg/1
Turbidity	4	NTU