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Interpreting the Results
During the bathing season
The results of each analysis are compared to the quality thresholds set for the microbiological criteria in the chart below:
- Water is of good quality when the results are below the guidance values,
- Water is of average quality when the results attained exceed the guidance values, but remain lower than the imperative value,
- Water is of poor quality when the results exceed the imperative value.
Total coliforms UFC/100mL
Guidance value = 500
Imperative value = 10 000 |
GOOD RESULTS |
AVERAGE RESULTS |
POOR RESULTS |
|
Escherichia coli UFC/100mL
Guidance value = 100
Imperative value = 2000 |
GOOD RESULTS |
AVERAGE RESULTS |
POOR RESULTS |
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Intestinal enterococci UFC/100mL
| Guidance value = 100 |
GOOD RESULTS |
AVERAGE RESULTS |
|
Should the imperative value be exceed, bathing may be prohibited by order of the prefect. An investigation is then carried out to identify the causes of pollution in the bathing area.
More information:
Complete bathing water quality criteria
- Council Directive 76-160 of 8 December 1975 concerning bathing water quality;
- Public Health Code: articles L.1332-1 to 4 and Articles D.1332-1 to D.1332-19;
- 29 November 1991 Order, issued to enforce Decree 91-980 of 20 September 1991 modifying Decree 81-324 of 7 April 1981 establishing the safety and hygiene rules applicable to swimming pools and organised bathing sites;
- 29 November 1991 Order, issued to enforce Decree 91-980 of 20 September 1991 modifying Decree 81-324 of 7 April 1981 establishing the safety and hygiene rules applicable to swimming pools and organised bathing sites, modified by 11 September 1995 Order.
Microbiological parameters (5):
parameter |
|
|
minimal sampling frequency
|
analysis or assessment method |
1 |
Total coliforms |
500 (100ml) |
10 000 (100ml) |
2/mois (a) |
NF EN ISO 9308-1 or NF T 90-413 standard
Membrane filtration and culture in appropriate environment (lactose tergitol agar, endo agar, 0.4% teepol broth); subculturing of suspicious colonies. Incubation temperature adjusted to find total coliforms. |
2 |
E. coli |
100 (100ml) |
2000 (100ml) |
2/mois (a) |
AFNOR standard T 90-433.
NF EN ISO 9308-3 |
3 |
Intestinal enterococci |
100 (100ml) |
- |
(b) |
AFNOR standard T 90-432.
NF EN ISO 7899-1 |
4 |
Salmonella |
- |
0 (1l) |
(b) |
Concentration using membrane filtration; inoculation in typical environment; enrichment and subculturing on isolation agar; identification et subculturing on isolation agar; identification. |
5 |
Enteroviruses |
- |
0 (10l) |
(b) |
Concentration through filtration, flocculation or centrifugation; confirmation. |
(a) When the sampling carried out in recent years yields markedly better results than those provided for in this appendix and when no condition likely to diminish water quality has arisen, the relevant authorities may reduce sampling frequency by a factor of 2.
(b) Concentration to be checked by relevant authorities when an investigation conducted in the bathing area shows the possible presence of pollutants or a decline in water quality.
| |
Measuring mandatory parameters |
Physico-chemical parameters (14):
parameter |
|
|
minimal sampling frequency
|
analysis or assessment method |
6 |
pH |
- |
6-9 (0) |
(c) |
Electrometry with calibration at pH 7 and 9. |
7 |
Colouring |
- |
No abnormal change in colour. |
2/months (c) |
Photometry with standards on the Pt/Co scale. |
8 |
Mineral oils |
- |
No film visible at water surface and no odour |
2/months (a) |
Inspection based on appearance and smell. |
<0.3 mg/l |
- |
(b) |
Extraction on sufficient, weighed volume of dry residue. |
9 |
Tensio-actives reacting to methylene blue |
- |
No persisting foam. |
2/months (a) |
Visual inspection. |
<0.3 mg/l |
- |
(b) |
Absorption spectrophotometry using methylene blue. |
10 |
Phenols
((phenols index)) |
- |
No special odour |
2/months (a) |
Check for lack of special odour due to phenol |
<0.005 |
< 0.05 |
(b) |
Absorption spectrophotometry. 4-aminoantipyrine (4-A.A.P.) method. |
11 |
Transparency |
2 m |
1 m (c) |
2/months (a) |
Secchi disk. |
12 |
Tar residues and floating matter |
Absence |
- |
2/months (a) |
Visual inspection. |
13 |
Dissolved O2 |
80-120 |
- |
(b) |
Winkler Method or electrometric method (oxygenometer). |
14 |
Ammonium NH4+ |
- |
- |
(d) |
Absorption spectrophotometry, Nessler reactant, or indophenol blue method. |
15 |
Kjeldhal nitrogen |
- |
- |
(d) |
Kjeldahl Method. |
16 |
Pesticides
(parathion, HCH, dieldrine) |
- |
- |
(b) |
Extraction using appropriate solvents and chromatographic determination. |
17 |
Heavy metals (As, Cd, Pb, Hg, Cr VI ) |
- |
- |
(b) |
Atomic absorption possibly preceded by extraction. |
18 |
Cyanides |
- |
- |
(b) |
Absorption spectrophotometry using specific reactant. |
19 |
Nitrates and phosphates |
- |
- |
(d) |
Absorption spectrophotometry using specific reactant. |
(a) When the sampling carried out in recent years yields markedly better results than those provided for in this appendix and when no condition likely to diminish water quality has arisen, the relevant authorities may reduce sampling frequency by a factor of 2.
(b) Concentration to be checked by relevant authorities when an investigation conducted in the bathing area shows the possible presence of pollutants or a decline in water quality.
(c) These parameters must be checked by the appropriate authorities when there is a tendency toward water eutrophication.
(d) Specified limits exceeded due to extraordinary geographic or meteorological conditions.
| |
Measuring mandatory parameters |
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At end of bathing season
At the end of the bathing season, each bathing site is classified based on the samples taken during the season. The classification takes into account the following six parameters:
- 3 microbiological parameters: total coliforms, Escherichia coli and intestinal enterococci.
- 3 physical/chemical parameters: mineral oils, tensioactive substances (foams) and phenols.
Pursuant to the provisions of Directive 76-160 regarding the quality of bathing water, incorporated into French law through the Public Health Code, the percentage of analysis results in line with the guidance values and imperative values for the 6 parameters, the waters are classified as either compliant or non-compliant. Bathing waters are deemed compliant if all of the results remain below the imperative values.
In France, bathing water is further classified into four quality categories:
- Waters deemed “compliant" under the European Directive are referred to as being of "good quality", in Category A (compliant with guidance values and imperative values under the European guidance values and imperative values) or as "average quality", in Category B (compliant with imperative values);
- Water deemed “non-compliant” are temporarily polluted, and fall either into Category C (5 to 33% of samples taken during any bathing season do not comply with the imperative values) and poor quality water, in Category D (over 33% of samples do not comply with imperative values).
Criteria for classifying bathing water in France
|
A |
Good-quality water |
B |
Average-quality water |
| |
At least 80% of Escherichia coli results are lower than or equal to the guidance figure
At least 95% of Escherichia coli results are lower than or equal to the imperative value
At least 90% of faecal streptococci results are lower than or equal to the guidance figure
At least 95% of total coliform results are lower than or equal to the imperative value
At least 80% of total coliform results are lower than or equal to the guidance figure
At least 95% of results are lower than or equal to the required thresholds on mineral oils, phenols and foams. |
|
At least 95% of samples are compliant with the imperative value on Escherichia coli and total coliforms;
At least 95% of the results are lower than or equal to the required thresholds on mineral oils, phenols and foams.
The conditions regarding guidance figures are not checked, either in full or in part. |
| Les eaux classées en catégories A ou B sont conformes à la réglementation européenne |
C |
Water that may be temporarily polluted |
D |
Poor-quality water |
| |
Imperative values are exceeded 5 to 33.3% of the time. |
|
The conditions on imperative values are exceeded at least one-third of the time. |
| In all areas classified in Category D one year, bathing must be prohibited the following year. |
| Waters classified in Categories C or D are not compliant with European standards. |
More information:
It should be noted that, if fewer than 20 samples are taken on a site during the bathing season, the threshold value may not be exceeded even one time; if it is, the beach may be classified as Category C.
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