Schedule 2 INDICATOR PARAMETERS

(1) Item	(2) Parameters	(3) Specification Concentration or Value (maximum unless otherwise stated) or State	(4) Units of Measurement	(5) Point of monitoring
¹ May be monitored from samples of water leaving treatment works or other supply point, as no significant change during distribution.
² The water should not be aggressive.
³ Where radon concentrations exceed 1000Bq/l, remedial action must be carried out on radiological protection grounds without further consideration.
⁴ Excluding tritium, potassium-40, radon and radon decay products.
⁵ Elevated levels of tritium may indicate the presence of other artificial radionuclides. If the tritium concentration exceeds its parametric value, an analysis of the presence of other radionuclides is required.
⁶ 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.
⁷ If the gross alpha activity exceeds 0.1Bq/l or gross beta activity exceeds 1.0Bq/l, analysis for specific radionuclides is required.
1	Ammonium	0.50	mg/l	Consumers' taps
2	Chloride¹²	250	mg/l	Supply point
3	Clostridium perfringens (including spores)¹	0	Number/100ml	Supply point
4	Coliform bacteria	0	Number/100ml	Consumers' taps
5	Colony counts	No abnormal change	Number/1ml at 22°C Number/1ml at 37°C	Consumers' taps, service reservoirs and treatment works
6	Conductivity¹²	2500	µS/cm at 20°C	Supply point
7	Hydrogen ion²	9.5	pH units	Consumers' taps
7	Hydrogen ion²	6.5 (minimum)	pH units	Consumers' taps
8	Radon (for radioactivity)¹³⁶	100	Bq/l	Supply point
9	Sulphate¹²	250	mg/l	Supply point
10	Indicative dose (for radioactivity)¹⁴⁶⁷	0.10	mSv	Supply point
11	Total organic carbon (TOC)¹	No abnormal change	mg/l	Supply point
12	Tritium (for radioactivity)¹⁵⁶	100	Bq/l	Supply point
13	Turbidity	1	NTU	Treatment works