Standard view

SCHEDULE 2

Page 9 of 11

Previous Next

First page 1 2 3 4 5 6 7 8 9 10 11 Last page

Regulations 2 and 4

SCHEDULE 2 INDICATOR PARAMETERS

(*)

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) or State Units of Measurement Point of monitoring
1 Ammonium 0.50 mgNH4/l Consumers’ taps
2 Chloride (i) 250 mgCl/l Supply point(*)
3 Clostridium perfringens (including spores) 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 Conductivity (i) 2500 µS/cm at 20°C Supply point(*)
7 Hydrogen ion 9.5 pH value Consumers’ taps
8 Sulphate (i) 250 mgSO4/l Supply point(*)
9 Total indicative dose (for radioactivity) (ii) 0.10 mSv/year Supply point(*)
10 Total organic carbon (TOC) No abnormal change mgC/l Supply point(*)
11 Tritium (for radioactivity) 100 Bq/l Supply point(*)
12 Turbidity 1 NTU Treatment works

Notes:

(i)

The water should not be aggressive.

(ii)

Excluding tritium, potassium-40, radon and radon decay products.

SCHEDULE 3 MONITORING

TABLE 1: PARAMETERS AND CIRCUMSTANCES FOR CHECK MONITORING

(1) (2) (3)
Item Parameter Circumstances
1 Aluminium When used as flocculant or where the water originates from, or is influenced by, surface waters
2 Ammonium
3 Clostridium perfringens (including spores) Where the water originates from, or is influenced by, surface waters
4 Coliform bacteria
5 Colony Counts
6 Colour
7 Conductivity
8 Escherichia coli (E. coli)
9 Hydrogen ion
10 Iron When used as flocculant or where the water originates from, or is influenced by, surface waters
11 Manganese Where the water originates from, or is influenced by, surface waters
12 Nitrate When chloramination is practised
13 Nitrite When chloramination is practised
14 Odour
15 Taste
16 Turbidity

Table 2: ANNUAL SAMPLING FREQUENCIES: WATER SUPPLY ZONES

(*)

Sampling for these parameters may be within water supply zones or at supply points as specified in Table 3, subject to notes (ii) and (iii) below.
(1) (2) (3) (4)
Substances and parameters subject to check monitoring Estimated population of water supply zone Reduced Standard
E. coli <100 4
Coliform bacteria ≥100 12 per 5,000 population (i)
Residual disinfectant
Aluminium
Ammonium
Clostridium perfringens
(including spores)*
Colony counts
Colour <100 1 2
Conductivity* 100-4,999 2 4
Hydrogen ion 5,000-9,999 6 12
Iron 10,000-29,999 12 24
Manganese 30,000-49,999 18 36
Nitrate (ii) 50,000-79,999 26 52
Nitrite (ii) 80,000-100,000 38 76
Odour
Taste
Turbidity
(1) (2) (3) (4)
Substances and parameters subject to audit monitoring Estimated population of water supply zone Reduced Standard
Aluminium
Antimony
Arsenic
Benzene(*)
Benzo(a)pyrene
Boron(*)
Bromate (iii)
Cadmium
Chromium
Copper
Cyanide(*)
1,2 dichloroethane(*) <100 1
Enterococci 100-4,999 4
Fluoride(*) 5,000-100,000 8
Iron
Lead
Manganese
Mercury(*)
Nickel
Nitrate (ii)
Nitrite (ii)
Pesticides and related products(*)
Polycyclic aromatic hydrocarbons
Selenium
Sodium
Trichloroethene/Tetrachloroethene(*)
Tetrachloromethane(*)
Trihalomethanes <100 1
Chloride(*) 100-4,999 4
Sulphate(*) 5,000-100,000 8
Total organic carbon(*)
Tritium(*)
Gross alpha(*) (iv)
Gross beta(*) (iv)

Notes:

(i)

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.

(ii)

Check monitoring in water supply zones is required only where chloramination is practised. In other circumstances audit monitoring is required.

(iii)

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.

(iv)

To monitor for total indicative dose (for radioactivity).

TABLE 3: ANNUAL SAMPLING FREQUENCIES: TREATMENT WORKS OR SUPPLY POINTS*

(1) (2) (3) (4) (5)
Item Substances and parameters Volume of water supplied m3/d Reduced Standard
1 E. coli <20 4
2 Coliform bacteria 20-1,999 12 52
3 Colony counts 2,000-5,999 52 104
4 Nitrite (ii) 6,000-11,999 104 208
5 Residual disinfectant ≥12,000 104 365
6 Turbidity
Subject to check monitoring
7 Clostridium perfringens (i) <20 2
20-999 2 4
8 Conductivity 1,000-1,999 6 12
2,000-5,999 12 24
6,000-9,999 18 36
10,000-15,999 26 52
16,000-32,999 52 104
33,000-49,999 78 156
50,000-67,999 104 208
68,000-84,999 130 260
85,000-101,999 156 312
102,000-119,999 183 365
120,000-241,999 365 730
242,000-484,999 730 1,460
485,000-728,999 1,095 2,190
Subject to audit monitoring
9 Benzene
10 Boron
11 Bromate (iv)
12 Cyanide
13 1,2 dichloroethane <20 1
14 Fluoride 20-999 4
15 Mercury 1,000-49,999 8
16 Nitrite (iii) 50,000-89,999 12
17 Pesticides and 90,000-299,999 24
related products 300,000-649,999 36
18 Trichloroethene ≥650,000 48
Tetrachloroethene
19 Tetrachloromethane
20 Chloride
21 Sulphate
22 Total organic carbon
23 Tritium
24 Gross alpha (v)
25 Gross beta (v)

(*) 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 (ii) and (iii);

(i) Check monitoring is required only in respect of surface waters (see regulation 6(2) and Table 1 in Schedule 3).

(ii) Sampling at treatment works when chloramination is practised.

(iii) Sampling at treatment works when chloromination is not practised.

(iv) 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.

(v) To monitor for total indicative dose (for radioactivity).

Page 9 of 11

Previous Next

First page 1 2 3 4 5 6 7 8 9 10 11 Last page