1.—(1) A monitoring programme established under Part 4 of these Regulations must—
(a)verify that—
(i)the measures in place to control risks to human health throughout the water supply chain (from the catchment area through abstraction, treatment and storage to distribution) are working effectively; and
(ii)water at the point of compliance is wholesome;
(b)provide information on the quality of water supplied to—
(i)demonstrate whether or not the water complies with prescribed concentrations and values for parameters in Schedule 1;
(ii)determine the organoleptic and microbiological quality of the water; and
(iii)establish the effectiveness of the treatment of the water, particularly of disinfection where it is used.
(c)identify the most appropriate means of mitigating any risk to human health; and
(d)have regard to Part 5.
(2) A monitoring programme must consist of either—
(a)the collection and analysis of discrete water samples; or
(b)measurement recorded by a continuous monitoring process; or
(c)a combination of both of the methods described in sub-paragraphs (a) and (b).
(3) In addition, monitoring programmes may consist of—
(a)inspections of records of the functionality and maintenance status of equipment; and/or
(b)inspections of the catchment area, water abstraction, treatment, storage and distribution infrastructure.
(4) The monitoring programme may be based on a risk assessment as set out in regulation 30.
(5) When choosing appropriate parameters and other micro-organisms, parasites or substances for monitoring programmes, local conditions for each water supply system must be taken into consideration.
| (1) Item | (2) Parameter | (3) Circumstances |
|---|---|---|
(1) A supply which consists of both groundwater and surface water is deemed to be a supply which consists only of surface water. | ||
| 1 | Aluminium | If used as water treatment chemicals or where the water originates from, or is influenced by, surface waters |
| 2 | Ammonium | Where chloramination is practised |
| 3 | Coliform bacteria | In all supplies |
| 4 | Colony Counts | In all supplies |
| 5 | Colour | In all supplies |
| 6 | Conductivity | In all supplies |
| 7 | Disinfectant residual | When disinfection treatment is practised |
| 8 | Escherichia coli (E. coli) | In all supplies |
| 9 | Indicative Dose | Where there is treatment in place to reduce the level of radionuclides in water intended for human consumption. |
| 10 | Iron(1) | If used as water treatment chemicals or where the water originates from, or is influenced by, surface waters |
| 11 | Manganese(1) | Where the water originates from, or is influenced by, surface waters |
| 12 | Nitrate | Where chloramination is practised |
| 13 | Nitrite | Where chloramination is practised |
| 14 | Odour | In all supplies |
| 15 | pH (Hydrogen ion) | In all supplies |
| 16 | Radon | Where there is treatment in place to reduce the level of radionuclides in water intended for human consumption. |
| 17 | Taste | In all supplies |
| 18 | Tritium | Where there is treatment in place to reduce the level of radionuclides in water intended for human consumption. |
| 19 | Turbidity | In all supplies |
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).
| (1) Substances and parameters subject to monitoring | (2) Estimated population of water supply zone(1) | (3) Number of samples per year |
|---|---|---|
(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 (5) and (6) below. | ||
(3) Group A monitoring in water supply zones is required only where chloramination is practised. In other circumstances Group B monitoring is required. | ||
(4) Group B monitoring in water supply zones is required only where sodium hypochlorite is added after water has left the treatment works. In other circumstances, Group B monitoring is required at supply points. | ||
(5) To monitor for indicative dose (for radioactivity). | ||
(6) In the event that a single sample is taken in a year, a further sample should be taken if there is any change in relation to that supply that could affect the concentration of radionuclides in the water supply. | ||
| Group A monitoring | ||
Escherichia coli (E. coli) | < 100 ≥ 100 | 4 12 per 5,000 population(1) |
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 | 2 4 12 24 36 52 76 |
| Ammonium | ||
Colony counts | ||
Colour | ||
Conductivity(2) | ||
Hydrogen ion | ||
Iron | ||
Manganese | ||
Nitrate(3) | ||
Nitrite(3) | ||
Odour | ||
Taste | ||
| Turbidity | ||
| Group B monitoring | ||
| Aluminium | <100 100–4,999 5,000–100,000 | 1 4 8 |
| Antimony | ||
| Arsenic | ||
| Benzene(2) | ||
| Benzo(a)pyrene | ||
| Boron(2) | ||
| Bromate(4) | ||
| Cadmium | ||
| Chromium | ||
| Clostridium perfringens (including spores) | ||
| Copper | ||
| Cyanide(2) | ||
| 1,2 dichloroethane(2) | ||
| Enterococci | ||
| Fluoride(2) | ||
| Gross alpha(2) (5) | ||
| Gross beta(2) (5) | ||
| Iron | ||
| Lead | ||
| Manganese | ||
| Mercury(2) | ||
| Nickel | ||
| Nitrate(3) | ||
| Nitrite(3) | ||
Pesticides and related products(2) | ||
| Polycyclic aromatic hydrocarbons | ||
| Radon(2) (6) | ||
| Selenium | ||
| Sodium | ||
Trichloroethene/ Tetrachloroethene(2) | ||
| Tetrachloromethane(2) | ||
| Trihalomethanes | ||
| Chloride(2) | ||
| Sulphate(2) | ||
| Total organic carbon(2) | ||
| Tritium(2) | ||
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 notes 2 and 3 to the Table below.
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).
| (1) Item | (2) Substances and parameters | (3) Volume of water supplied m3/d(1) | (4) Number of samples per year(2) |
|---|---|---|---|
(1) The water undertaker may use the number of inhabitants in a supply zone instead of the volume of water to determine the minimum frequency, assuming a water consumption of 200 l/day/capita. | |||
(2) The volumes are calculated as averages taken over a calendar year. | |||
(3) Sampling at treatment works when chloramination is practised. | |||
(4) Sampling at treatment works when chloramination is not practised. | |||
(5) Group B monitoring at supply points is required only where sodium hypochlorite is not added after water has left the treatment works. In other circumstances, Group B monitoring is required in water supply zones | |||
(6) To monitor for indicative dose (for radioactivity). | |||
| 1 | Escherichia coli (E. coli) | <20 20-1,999 2,000-5,999 6,000-11,999 ≥ 12,000 | 4 52 104 208 365 |
| 2 | Coliform bacteria | ||
| 3 | Colony counts | ||
| 4 | Nitrite(3) | ||
| 5 | Residual disinfectant | ||
| 6 | Turbidity | ||
| Group A monitoring | |||
| 7 | Conductivity | <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 4 12 24 36 52 104 156 208 260 312 365 730 1,460 2,190 |
| Group A monitoring | |||
| 8 | Gross alpha(6) | <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 |
| 9 | Gross beta(6) | ||
| 10 | Radon | ||
| 11 | Tritium | ||
| Group B monitoring | |||
| 12 | 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 |
| 13 | Boron | ||
| 14 | Bromate(5) | ||
| 15 | Clostridium perfringens (including spores) | ||
| 16 | Cyanide | ||
| 17 | 1,2,dichloroethane | ||
| 18 | Fluoride | ||
| 19 | Mercury | ||
| 20 | Nitrite(4) | ||
| 21 | Pesticides and related products | ||
| 22 | Trichloroethene/ Tetrachloroethene | ||
| 23 | Tetrachloromethane | ||
| 24 | Chloride | ||
| 25 | Sulphate | ||
| 26 | Total Organic Carbon | ||
| 27 | Radon | ||
| 28 | Tritium | ||
| 29 | Gross alpha(6) | ||
| 30 | Gross beta(6) | ||