A poor ranking is bad for
the image. Feared by tourist resorts, the European Commission's
annual bathing water report, issued at the beginning of the summer,
is awaited with bated breath. The latest edition (for 1999) notes
a constant improvement in water quality for both coastal and river
bathing water. In 1992, 84.9% of European beaches met the quality
criteria laid down by the 1976 directive, in particular from a microbiological
point of view. In 1999, the figure had climbed to 95.6%. For fresh
water sites, the progress has been even more spectacular: up from
47.5% in 1992 to 90.5% in 1999.
This optimistic picture
is the result of constant efforts by the Member States and research
carried out by laboratories with the aid of the Commission. But
it remains open to debate. There is no standardised method for carrying
out microbiological measurements in bathing zones - measurements
designed to reveal possible faecal contamination. 'The 1976 directive
remains vague on the methods of analysis, the result being that
laboratories use very different methods. The measurements are not
fully comparable,' explains Bert Van Maele of the Environment Directorate-General.
Disparities and limits
Since the early 1990s, the Union has therefore
supported a number of research projects designed, first of all,
to assess the disparities between the various methods used and,
subsequently, to identify a standard method which all laboratories
can adopt for their analyses.
Another drawback of the present system of monitoring
bathing waters is that it is basically a retrospective method. Traditional
microbiological tests take about 36 hours to give a quantified result.
It is not therefore possible to envisage a day-to-day management
of beaches on such a basis. The Commission's annual pre-summer report
on bathing water quality is based on the average measurement taken
every two weeks during the previous season.
It is therefore only general trends which are
picked up, the effects of particular incidents often remaining undetected.
A big storm, for example, can cause the drains in a coastal town
to overflow for several hours with large quantities of dirty water
flowing into the sea. The two or three days which follow could see
a very sharp increase in the faecal microbe content of the bathing
waters. If no measurement is taken during this relatively short
period this increase could well pass totally unnoticed. Besides,
at the present time we do not have the technical means at our disposal
to deal instantly with the problems of microbiological contamination,"
explains Tristan Simonart, a researcher at the Pasteur Institute
in Lille (FR). "The tests do not yet exist. We will have to
wait for a number of years."
Forecasts and variables
A number of studies are being carried out
at present to develop computer models that can forecast water quality
on the basis of a wide range of possible influences, such as hydrography,
weather, capacity of purification stations, population, drain design,
etc. 'The purpose of these computer models is to predict a deterioration
in bathing water quality so that, if necessary, certain beaches
can be closed as a preventive measure,' explains Eddie Maier, a
scientific officer with the Research DG.
The European Commission held a scientific
workshop on this subject at Sitges (Spain) in June 1997. The experts
concluded that a more proactive approach was 'technically possible'
and would provide 'a valuable and inexpensive instrument in many
cases' in support of a directive on bathing water quality.
In its recent communication entitled Developing
a new bathing water policy, the Commission notes that this research
has given quite good results in the case of models for hydrographic
basins which are small in size or only exposed to a small number
of potential sources of pollution. But more extensive bathing areas
with multiple potential sources of contamination require sophisticated
forecasting models. Realistically, such models will probably be
used only for the main bathing resorts.
Choosing your microbes
The Microbath project (1996-1999), coordinated
by the Institut Pasteur (Lille), set its sights on developing
a standard method for analysing bathing water quality which
could be used by all European laboratories charged with this
task of protecting public health. 'It was first necessary
to redefine the microbes selected as the best indicators of
faecal contamination of the water,' explains coordinator Jean-Marie
According to the 1976 directive, two families
of bacteria are 'good indicators': heat-tolerant coliforms
and total coliforms. 'The problem,' continues Jean-Marie Delattre,
'is that these families are much too big. They include many
bacteria which have never seen an intestine in their lives.
Today, everybody agrees that the best indicators are E.
coli bacteria, and a group of four intestinal enterococci
for recreational waters.' This selection is in line with the
WHO proposal in its draft guidelines on recreational waters.
Sixteen European laboratories cooperated
on the Microbath project which validated two microbiological
reference analysis procedures for these two microbial indicators.
The methods chosen allow a maximum margin of error of 5% and
were tested on a samples of natural fresh water and sea water.
During one season, the laboratories then compared their own
methods with the new standardised methods. Today, the procedures
adopted by the Microbath project are candidates for the status
of CEN (European Standardisation Centre) standards.
The next Commission bathing water directive
could make an explicit reference to a CEN or ISO standard.
'This means that the Member States should preferably use an
ISO or CEN method,' points out Bert Van Maele (Environment
DG), 'but they can also use other methods provided they show