SCHEDULE 4ANALYTICAL METHODOLOGY

Regulation 18

TABLE AParameters for which, subject to regulation 18(12), methods of analysis are prescribed

(1) Parameter

(2) Method

Clostridium perfringens (including spores)

EN ISO 14189

Coliform bacteria

EN ISO 9308-1 or EN ISO 9308-2

Colony count 22°C-enumeration of culturable microorganisms

ENISO 6222

Colony count 36°C-enumeration of culturable microoganisms

EN ISO 6222

Enterococci

EN ISO 7899-2

Escherichia coli (E. coli)

EN ISO 9308-1 or EN ISO 9308-2

Pseudomonas aeruginosa

EN ISO 16266

TABLE BMinimum performance characteristic: “uncertainty of measurement”

(1) Parameter(1)

(2) Uncertainty of measurement (% of parametric value, except pH)(2)

Aluminium

25

Ammonium

40

Antimony

40

Arsenic

30

Benzo(a)pyrene(3)

50

Benzene

40

Boron

25

Bromate

40

Cadmium

25

Chloride

15

Chromium

30

Conductivity

20

Copper

25

Cyanide(4)

30

1,2-dichloroethane

40

Fluoride

20

Hydrogen ion concentration pH (expressed in pH units)(5)

0.2

Iron

30

Lead

25

Manganese

30

Mercury

30

Nickel

25

Nitrate

15

Nitrite

20

Oxidisability(6)

50

Pesticides(7)

30

Polycyclic aromatic hydrocarbons(8)

50

Selenium

40

Sodium

15

Sulphate

15

Tetrachloroethene(9)

30

Tetrachloromethane

30

Trichloroethene(9)

40

Trihalomethanes: total(8)

40

Total organic carbon(10)

30

Turbidity(11)

30

(1)

Acrylamide, epichlorohydrin and vinyl chloride to be controlled by product specification.

(2)

Uncertainty of measurement is a non-negative parameter characterising the dispersion of the quantity values being attributed to a measurand, based on the information used. The performance criterion for measurement uncertainty (k = 2) is the percentage of the parametric value stated in the table or better. Measurement uncertainty must be estimated at the level of the parametric value, unless otherwise specified.

(3)

If the value of uncertainty of measurement cannot be met, the best available technique should be selected (up to 60%).

(4)

The method determines total cyanide in all forms.

(5)

Values for trueness, precision and uncertainty of measurement are expressed in pH units.

(6)

Reference method EN ISO 8467.

(7)

The performance characteristics for individual pesticides are given as an indication. Values for the uncertainty of measurement as low as 30 % can be achieved for several pesticides, higher values up to 80 % may be allowed for a number of pesticides

(8)

The performance characteristics apply to individual substances, specified at 25% of the parametric value in Table B in Schedule 1.

(9)

The performance characteristics apply to individual substances, specified at 50% of the parametric value in Table B in Schedule 1.

(10)

The uncertainty of measurement should be estimated at the level of 3 mg/l of the total organic carbon. CEN 1484 Guidelines for the determination of total organic carbon and dissolved organic carbon must be used.

(11)

The uncertainty of measurement must be estimated at the level of 1.0 NTU (nephelometric turbidity units) in accordance with EN ISO 7027.

TABLE CMinimum performance characteristics: trueness, precision and limit of detection- may be used until 31 December 2019

(1) Parameter(1)

(2) Trueness(2)

(3) Precision(3)

(4) Limit of detection(4)

Aluminium

10

10

10

Ammonium

10

10

10

Antimony

25

25

25

Arsenic

10

10

10

Benzene

25

25

25

Benzo(a)pyrene

25

25

25

Boron

10

10

10

Bromate

25

25

25

Cadmium

10

10

10

Chloride

10

10

10

Chromium

10

10

10

Colour

10

10

10

Conductivity

10

10

10

Copper

10

10

10

Cyanide(5)

10

10

10

1,2-dichloroethane

25

25

10

Fluoride

10

10

10

Hydrogen ion concentration pH (expressed in pH units)(6)

0.2

0.2

Iron

10

10

10

Lead

10

10

10

Manganese

10

10

10

Mercury

20

10

20

Nickel

10

10

10

Nitrate

10

10

10

Nitrite

10

10

10

Oxidisability(7)

25

25

25

Pesticides(8)

25

25

25

Polycyclic aromatic hydrocarbons(9)

25

25

25

Selenium

10

10

10

Sodium

10

10

10

Sulphate

10

10

10

Tetrachloroethene(10)

25

25

10

Tetrachloromethane

20

20

20

Trichloroethene(10)

25

25

10

Trihalomethanes: total(9)

25

25

10

Turbidity(11)

10

10

10

Turbidity(12)

25

25

25

(1)

Acrylamide, epichlorohydrin and vinyl chloride to be controlled by product specification.

(2)

Trueness is a measure of systematic error, i.e. the difference between the mean value of the large number of repeated measurements and the true value. Further specifications are those set out in ISO 5725.

(3)

Precision is a measure of random error and is usually expressed as the standard deviation (within and between batches) of the spread of results from the mean. Acceptable precision is twice the relative standard deviation. This term is further specified in ISO 5725.

(4)

Limit of detection is either three times the standard deviation within a batch of a natural sample containing a low concentration of the parameter; or five times the standard deviation of a blank sample (within a batch).

(5)

The method determines total cyanide in all forms.

(6)

Values for trueness, precision and uncertainty of measurement are expressed in pH units.

(7)

Reference method EN ISO 8467 1995.

(8)

The performance characteristics for individual pesticides are given as an indication. Values for the uncertainty of measurement as low as 30% can be achieved for several pesticides, higher values up to 80% may be allowed for a number of pesticides

(9)

The performance characteristics apply to individual substances, specified at 25% of the parametric value in Table B in Schedule 1.

(10)

The performance characteristics apply to individual substances, specified at 50% of the parametric value in Table B in Schedule 1.

(11)

The performance characteristics apply to prescribed value 4 NTU.

(12)

The performance characteristics apply to prescribed value 1 NTU for water leaving surface water treatment works.