SCHEDULE 10Sampling and analysis for parameters other than radioactive substances in water bottled and labelled as “spring water” and bottled drinking water
PART 1General
Analysis of samples1
1
The district council must ensure that each sample is analysed in accordance with Annex III to Directive 98/83 and this Schedule.
2
For each parameter specified in the first column of Table 1 in Part 2 the method of analysis is specified in the second column of that table.
3
For each parameter specified in the first column of Table 2 in Part 2 the method of analysis is one that is capable of—
a
measuring concentrations and values with the trueness and precision specified in the second and third columns of that table; and
b
detecting the parameter at the limit of detection specified in the fourth column of that table.
4
For hydrogen ion, the method of analysis must be capable of measuring a value with a trueness of 0.2pH unit and a precision of 0.2 pH unit.
5
The method of analysis used for odour and taste parameters must be capable of measuring values equal to the parametric value with a precision of 1 dilution number at 25 ºC.
6
For the purpose of this paragraph—
“limit of detection” is—
- a
three times the relative within-batch standard deviation of a natural sample containing a low concentration of the parameter; or
- b
five times the relative within-batch standard deviation of a blank sample;
- a
“precision” (the random error) is twice the standard deviation (within a batch and between batches) of the spread of results about the mean;
“trueness” (the systematic error) is the difference between the mean value of the large number of repeated measurements and the true value.
Authorisation of alternative methods of analysis2
1
The Agency may authorise a method different from that set out in Part 2 if satisfied that it is at least as reliable.
2
An authorisation may be time-limited and may be revoked at any time.
Sampling and analysis by persons other than district councils3
1
A district council may enter into an arrangement for any person to take and analyse samples on its behalf.
2
A district council must not enter into an arrangement under paragraph (1) unless—
a
it is satisfied that the task will be carried out promptly by a person competent to perform it; and
b
it has made arrangements that ensure that any breach of these Regulations is communicated to it immediately, and any other result is communicated to it within 28 days.
PART 2Methods of analysis and performance characteristics
Parameter | Method |
---|---|
Clostridium perfringens (including spores) | Membrane filtration followed by anaerobic incubation of the membrane on m-CP agar1 at 44 ±1ºC for 21± 3 hours. Count opaque yellow colonies that turn pink or red after exposure to ammonium hydroxide vapours for 20 to 30 seconds. |
Coliform bacteria | BS-EN ISO 9308-1 |
Colony count 22ºC – enumeration of culturable microorganisms | BS-EN ISO 6222 |
Colony count 37ºC – enumeration of culturable microorganisms | BS-EN ISO 6222 |
Enterococci | BS-EN ISO 7899-2 |
Escherichia coli (E. Coli) | BS-EN ISO 9308-1 |
Pseudomonas aeruginosa | BS-EN ISO 12780 |
1 Use the following method to make m-CP agar: |
Make a basal medium consisting of—
Tryptose | 30.0g |
Yeast extract | 20.0g |
Sucrose | 5.0g |
L-cysteine hydrochloride | 1.0g |
MgSO4.7H2O | 0.1g |
Bromocresol purple | 40.0mg |
Agar | 15.0g |
Water | 1,000.0ml |
Dissolve the ingredients of basal medium, adjust pH to 7.6 and autoclave at 121ºC for 15 minutes. Allow the medium to cool. | |
Dissolve— | |
D-cycloserine | 400.0mg |
Polymyxine-B sulphate | 25.0mg |
Indoxl-β-D-glucoside | 60.0mg |
into 8ml sterile water and add it to the medium. | |
Add to the medium— | |
Filter-sterilised 0.5% phenolphthalein diphosphate solution | 20.0ml |
Filter-sterilised 4.5% FeCl3.6H2O | 2.0ml |
Parameters | Trueness % of prescribed concentration or value specification | Precision % of prescribed concentration or value or specification | Limit of detection % of prescribed concentration or value or specification |
---|---|---|---|
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 |
Conductivity | 10 | 10 | 10 |
Copper | 10 | 10 | 10 |
Cyanide1 | 10 | 10 | 10 |
1,2-dichloroethane | 25 | 25 | 10 |
Fluoride | 10 | 10 | 10 |
Iron | 10 | 10 | 10 |
Lead | 10 | 10 | 10 |
Manganese | 10 | 10 | 10 |
Mercury | 20 | 10 | 20 |
Nickel | 10 | 10 | 10 |
Nitrate | 10 | 10 | 10 |
Nititre | 10 | 10 | 10 |
Oxidisability2 | 25 | 25 | 10 |
Pesticides and related products3 | 25 | 25 | 25 |
Polycyclic aromatic hydrocarbons4 | 25 | 25 | 25 |
Selenium | 10 | 10 | 10 |
Sodium | 10 | 10 | 10 |
Sulphate | 10 | 10 | 10 |
Tetrachloroethene5 | 25 | 25 | 10 |
Tetrachloromethane | 20 | 20 | 20 |
Trichloroethene5 | 25 | 25 | 10 |
Trihalomethanes4 | 25 | 25 | 10 |
1 The method of analysis should determine total cyanide in all forms. | |||
2 Oxidation should be carried out for 10 minutes at 100ºC under acid conditions using permanganate. | |||
3 The performance characteristics apply to each individual pesticide and will depend on the pesticide concerned. | |||
4 The performance characteristics apply to the individual substances specified at 25% of the parametric value in Table B in Part 2, Schedule 7. | |||
5 The performance characteristics apply to the individual substance specified at 50% of the parametric value in Table B in Part 2, Schedule 7. |