The Water Supply (Water Quality) Regulations 2018

Regulations 2, 6, 12, 15 and 19

SCHEDULE 2 INDICATOR PARAMETERS

(1) The water should not be aggressive.
(2) Where treatment to reduce the level of radionuclides in water intended for human consumption has been taken, monitoring must be carried out to ensure the continued efficacy of the treatment.
(3) Remedial action may be taken by the Welsh Ministers on radiological protection grounds without further consideration and deemed to be justified where radon concentrates exceed 1,000 Bq/1.
(4) If tritium concentration exceeds its parametric value, an investigation (which may include analysis) of the presence of artificial radionuclides is required.
(5) May be monitored from samples of water leaving treatment works or other supply point, as no significant change during distribution.
Item Parameters	Specification	Concentration or Value (maximum unless otherwise stated) or State	Units of Measurement	Point of compliance
1	Ammonium	0.50	μgAl/l	Consumers’ taps
2	Chloride (1)	250	mgCl/l	Supply point (5)
3	Clostridium perfringens (including spores)	0	Number/100 ml	Supply point (5)
4	Coliform bacteria	0	Number/100 ml	Consumers’ taps
5	Colony counts	No abnormal change	Number/1 ml at 22°C	Consumers’ taps, service reservoirs and treatment works
6	Conductivity (1)	2500	μS/cm at 20°C	Supply point (5)
7	Hydrogen ion	9.5	pHvalue	Consumers’ taps
		6.5 (minimum)
8	Indicative dose (2)	0.10	mSv	Supply point (5)
	(a) gross alpha	0.1	Bq/l	Supply point (5)
	(b) gross beta	1	Bq/l	Supply point (5)
9	Radon (3)	100	Bq/l	Supply point
10	Sulphate 1	250	mgSO4/l	Supply point (5)
11	Total organic carbon (TOC)	No abnormal change	mgC/l	Supply point
12	Tritium (for radioactivity) (4)	100	Bq/l	Supply point
13	Turbidity	1	NTU	Treatment works
Notes: