Regulation 9
Note: This table sets out the annual sampling frequencies for all the substances and parameters in column 1. These are determined for each water supply zone according to its estimated population (column 2). The number of samples is either the standard number in column 4 or the reduced number in column 3 (if one is given). Regulation 9 provides for the circumstances in which the reduced number of samples may be taken.
1 Where the population is not an exact multiple of 5,000, the population figure should be rounded up to the nearest multiple of 5,000. | ||||
2 Sampling for these parameters may be within water supply zones or at supply points as specified in Table 3, subject to notes (iii) and (iv) below. | ||||
3 Check monitoring in water supply zones is required only where chloramination is practised. In other circumstances audit monitoring is required. | ||||
4 Audit monitoring in water supply zones is required only where sodium hypochlorite is added after water has left the treatment works. In other circumstances, audit monitoring is required at supply points. | ||||
5 To monitor for total indicative dose (for radioactivity).” | ||||
(1) Substances and parameters subject to monitoring | (2) Estimated population of water supply zone | (3) Reduced | (4) Standard | |
---|---|---|---|---|
Subject to check monitoring | ||||
E. coli | < 100 ≥ 100 | 4 12 per 5,000 population1 | ||
Coliform bacteria | ||||
Residual disinfectant | ||||
Aluminium | <100 100–4,999 5,000–9,999 10,000–29,999 30,000–49,999 50,000–79,999 80,000–100,000 | 1 2 6 12 18 26 38 | 2 4 12 24 36 52 76 | |
Ammonium | ||||
Clostridium perfringens (including spores)2 | ||||
Colony counts | ||||
Colour | ||||
Conductivity2 | ||||
Hydrogen ion | ||||
Iron | ||||
Manganese | ||||
Nitrate3 | ||||
Nitrite3 | ||||
Odour | ||||
Taste | ||||
Turbidity | ||||
Subject to audit monitoring | ||||
Aluminium | <100 100–4,999 5,000–100,000 | 1 4 8 | ||
Antimony | ||||
Arsenic | ||||
Benzene2 | ||||
Benzo(a)pyrene | ||||
Boron2 | ||||
Bromate4 | ||||
Cadmium | ||||
Chromium | ||||
Clostridium perfringens (including spores) | ||||
Copper | ||||
Cyanide2 | ||||
1,2 dichloroethane2 | ||||
Enterococci | ||||
Fluoride2 | ||||
Iron | ||||
Lead | ||||
Manganese | ||||
Mercury2 | ||||
Nickel | ||||
Nitrate3 | ||||
Nitrite3 | ||||
Pesticides and related products2 | ||||
Polycyclic aromatic hydrocarbons | ||||
Selenium | ||||
Sodium | ||||
Trichloroethene/ | ||||
Tetrachloroethene2 | ||||
Tetrachloromethane2 | ||||
Trihalomethanes | ||||
Chloride2 | ||||
Sulphate2 | ||||
Total organic carbon2 | ||||
Tritium2 | ||||
Gross alpha25 | ||||
Gross beta25 |
Regulation 9
Note 1: Sampling is at treatment works for the substances and parameters shown in column (1) of the Table as items (1) to (6) and at supply points for the other substances and parameters, except nitrite subject to footnotes (i) and (iv) to the Table below.
Note 2: This table sets out the annual sampling frequencies for all the substances and parameters in column 2 at treatment works or supply points. The frequencies are determined according to the volume of water supplied at each treatment works or supply point (column 3). The number of samples is either the standard number in column 5 or the reduced number in column 4 (if one is given). Regulation 9 provides for the circumstances in which the reduced number of samples may be taken.
1 Sampling at treatment works when chloramination is practised. | ||||
2 Check monitoring is required only in respect of surface waters (see regulation 6(2) and Table 1 in Schedule 3). | ||||
3 Audit monitoring at supply points is required only where sodium hypochlorite is not added after water has left the treatment works. In other circumstances, audit monitoring is required in water supply zones. | ||||
4 Sampling at treatment works when chloramination is not practised. | ||||
5 To monitor for total indicative dose (for radioactivity).” | ||||
(1) Item | (2) Substances and parameters | (3) Volume of water supplied m3/d | (4) Reduced | (5) Standard |
---|---|---|---|---|
1. | E. coli | <20 20–1,999 2,000–5,999 6,000–11,999 ≥12,000 | - 12 52 104 104 | 4 52 104 208 365 |
2. | Coliform bacteria | |||
3. | Colony counts | |||
4. | Nitrite1 | |||
5. | Residual disinfectant | |||
6. | Turbidity | |||
Subject to check monitoring | ||||
7. | Clostridium perfringens 2 | <20 20–999 1,000–1,999 2,000–5,999 6,000–9,999 10,000–15,999 16,000–32,999 33,000–49,999 50,000–67,999 68,000–84,999 85,000–101,999 102,000–119,999 120,000–241,999 242,000–484,999 485,000–728,999 | - 2 6 12 18 26 52 78 104 130 156 183 365 730 1,095 | 2 4 12 24 36 52 104 156 208 260 312 365 730 1,460 2,190 |
8. | Conductivity | |||
Subject to audit monitoring | ||||
9. | Benzene | <20 20–999 1,000–49,999 50,000–89,999 90,000–299,999 300,000–649,999 ≥650,000 | 1 4 8 12 24 36 48 | |
10. | Boron | |||
11. | Bromate3 | |||
11A. | Clostridium Perfringens (including spores) | |||
12. | Cyanide | |||
13. | 1,2 dichloroethane | |||
14. | Fluoride | |||
15. | Mercury | |||
16. | Nitrite4 | |||
17. | Pesticides and related products | |||
18. | Trichloroethene/ Tetrachloroethene | |||
19. | Tetrachloromethane | |||
20. | Chloride | |||
21. | Sulphate | |||
22. | Total organic carbon | |||
23. | Tritium | |||
24. | Gross alpha5 | |||
25. | Gross beta5 |