The Private Water Supplies (Wales) Regulations 2017

Regulations 2, 11, 12, 13, 18 and 19

SCHEDULE 1E+WConcentrations or Values

PART 1E+WWholesomeness

Commencement Information

I1Sch. 1 Pt. 1 in force at 20.11.2017, see reg. 1

TABLE A:

MICROBIOLOGICAL PARAMETERS

Prescribed concentrations or values

Parameters

Maximum concentration or value

Units of Measurement

Escherichia coli (E. coli)0Number/100ml
Enterococci0Number/100ml
In the case of water in bottles or containers:
Escherichia coli (E.coli)0Number/250ml
EnterococciNumber/250ml
Pseudomonas aeruginosa0Number/250ml
Colony count 22ºC100Number/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)0.10µg/1
Antimony5.0µg/1
Arsenic10µg/1
Benzene1.0µg/1
Benzo(a)pyrene0.010µg/1
Boron1.0mg/1
Bromate10µg/1
Cadmium5.0µg/1
Chromium50µg/1
Copper2.0mg/1
Cyanide50µg/1
1.2 dichloroethane3.0µg/1
Epichlorohydrin(1)0.10µg/1
Fluoride1.5mg/1
Lead10

µg/1

µg/1

Mercury1.0µg/1
Nickel20µg/1
Nitrate (2)50mg/l
Nitrite (2)0.5 (or 0.1 in the case of treatment works)mg/l
Pesticides (3)Aldrin0.030µg/1
Dieldrin0.030µg/1
Heptachlor0.030µg/1
Heptachlor epoxide0.030µg/1
Other pesticides0.10µg/1
Pesticides total (4)0.50µg/1
Polycyclic aromatic hydrocarbons (5)0.10µg/1
Selenium10µg/1
Tetrachloroethene and Trichloroethene(6)10µg/1
Trihalomethanes: Total(7)100µg/1
Vinyl chloride(1)0.50µg/1

National requirements – Prescribed concentrations or values

Parameters

Maximum concentration or value

Units of Measurement

Aluminium200µg/1
Colour20mg/l Pt/Co
Iron200µg/1
Manganese50µg/1
OdourAcceptable to consumers and no abnormal change
Sodium200mg/l
TasteAcceptable to consumers and no abnormal change
Tetrachloromethane3µg/1
Turbidity4NTU

PART 2E+WIndicator Parameters

Commencement Information

I2Sch. 1 Pt. 2 in force at 20.11.2017, see reg. 1

TABLE C:

Prescribed concentrations, values or states

Parameters

Maximum concentration or value

Units of Measurement

(1)

The water should not be aggressive.

(2)

Only in the case of surface water or groundwater that has been influenced by surface water.

Ammonium0.50mg/l
Chloride(1)250mg/l
Clostridium perfringens (including spores)0Number/100ml
Coliform bacteria0Number/100ml (Number/250ml in the case of water put into bottles or containers)
Colony countsNo abnormal changeNumber/ml at 22ºC
Conductivity(1)2500µS/cm at 20ºC
Hydrogen ion9.5 (maximum)pH value

6.5 (minimum) (in the case of still

water put into bottles or containers the minimum is 4.5)

pH value
Sulphate(1)250mg/l
Total organic carbon (TOC)No abnormal changemgC/l
Turbidity(2)1NTU

PART 3E+WRadioactive substances parameters

Commencement Information

I3Sch. 1 Pt. 3 in force at 20.11.2017, see reg. 1

TABLE D:

Prescribed values for radon, tritium and indicative dose of water intended for human consumption

Parameters

Maximum concentration or value

Units of Measurement

(1)

Enforcement action by the local authority is deemed justified on radiological protection grounds without further consideration where radon concentrations exceed 1,000 Bq/1.

(2)

If tritium concentration exceeds its parametric value, an investigation (which may include analysis) of the presence of artificial radionuclides must be carried out.

Indicative dose (for radioactivity)0.10mSv
Radon(1)100Bq/l
Tritium (for radioactivity)(2)100Bq/l