SCHEDULE 2Indicator parameters
(1) | (2) | (3) | (4) | (5) |
|---|---|---|---|---|
Item | Parameters | Specification concentration or value (maximum unless otherwise stated) or state | Units of measurement | Point of compliance |
1. | Ammonium | 0.50 | mgNH4/1 | Consumers' taps |
2. | Chloride1 | 250 | mgC1/ | Supply point5 |
3. | Clostridium | 0 | Number/100ml | Supply point5 |
Perfringens (including spores) | ||||
4. | Coliform bacteria | 0 | Number/100ml | Consumers' taps |
5. | Colony counts | No abnormal change | Number/1ml at 22°C | Consumers' taps, service reservoirs and treatment works |
6. | Conductivity1 | 2500 | μS/cm at 20°C | Supply point5 |
7. | Hydrogen ion | 9.5 (maximum) 6.5 (minimum) | pH value | Consumers' taps |
8. | Indicative dose2 | 0.10 | mSv | Supply point5 |
(a) gross alpha | 0.1 | Bq/1 | Supply point5 | |
(b) gross beta | 1 | Bq/1 | Supply point5 | |
9. | Radon3 | 100 | Bq/1 | Supply point |
10. | Sulphate1 | 250 | mgSO4/l | Supply point5 |
11. | Total organic carbon (TOC) | No abnormal change | mgC/l | Supply point |
12. | Tritium (for radioactivity)4 | 100 | Bq/l | Supply point5 |
13. | Turbidity | 1 | NTU | Treatment works |
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 Secretary of State 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. | ||||