SCHEDULE 2Monitoring

PART 1Check monitoring

Sampling

1.

(1)

A local authority must undertake check monitoring in accordance with this Part.

(2)

Check monitoring means sampling for each parameter listed in Table 1 in the circumstances listed in that table in order—

(a)

to determine whether or not water complies with the concentrations or values in Schedule 1;

(b)

to provide information on the organoleptic and microbiological quality of the water; and

(c)

to establish the effectiveness of the treatment of the water, including disinfection.

Table 1Check monitoring

Parameter

Circumstances

Aluminium

When used as flocculant or where the water originates from, or is influenced by, surface waters

Ammonium

In all supplies

Clostridium perfringens (including spores) waters

Where the water originates from, or is influenced by, surface

Coliform bacteria

In all supplies

Colony counts

In all supplies

Colour

In all supplies

Conductivity

In all supplies

Escherichia coli (E. coli)

In all supplies

Hydrogen ion concentration

In all supplies

Iron

When used as flocculant or where the water originates from, or is influenced by, surface waters

Manganese

Where the water originates from, or is influenced by, surface waters

Nitrate

When chloramination is practised

Nitrite

When chloramination is practised

Odour

In all supplies

Pseudomonas aeruginosa

Only in the case of water in bottles or containers

Taste

In all supplies

Turbidity

In all supplies

Frequency of sampling

2.

(1)

Sampling must be carried out at frequencies specified in Table 2.

Table 2Sampling frequency for check monitoring

Volume m3/day

Sampling frequency per year

≤ 10

1

> 10 ≤ 100

2

> 100 ≤ 1,000

4

> 1,000 ≤ 2,000

10

> 2,000 ≤ 3,000

13

> 3,000 ≤ 4,000

16

> 4,000 ≤ 5,000

19

> 5,000 ≤ 6,000

22

> 6,000 ≤ 7,000

25

> 7,000 ≤ 8,000

28

> 8,000 ≤ 9,000

31

> 9,000 ≤ 10,000

34

> 10,000

4 + 3 for each 1,000 m3/day of the total volume (rounding up to the nearest multiple of 1,000 m3/day)

(2)

The local authority may reduce the frequency of sampling for a parameter to a frequency not less than half if—

(a)

the local authority is of the opinion that the quality of water in the supply is unlikely to deteriorate;

(b)

in the case of hydrogen ion the parameter has had a pH value that is not less than 6.5 and not more than 9.5; and

(c)

in all other cases, in each of two successive years the results of samples taken for the purposes of monitoring the parameter in question are constant and significantly lower than the concentrations or values laid down in Schedule 1.

(3)

The local authority may set a higher frequency for any parameter if it considers it appropriate taking into account the findings of any risk assessment, and in addition may monitor anything else identified in the risk assessment.

(4)

Notwithstanding the provisions in sub-paragraph (2) above, there must be a minimum of 1 sample per year.