# The Private Water Supplies (Wales) Regulations 2017, Part 1: Wholesomeness

Extent: E+W

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
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
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
50
mg/l
Nitrite
0.5 (or 0.1 in the case of treatment works)
mg/l
Pesticides —
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
0.50
µg/1
Polycyclic aromatic hydrocarbons
0.10
µg/1
Selenium
10
µg/1
Tetrachloroethene and Trichloroethene
10
µg/1
Trihalomethanes: Total
100
µg/1
Vinyl chloride
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

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Source: https://www.legislation.gov.uk/wsi/2017/1041/schedule/1/part/1 (the official version)
Page: https://openlegislation.uk/private-water-supplies-wales-regulations-2017/schedule-1/part-1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.