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MONITORING
BATHING WATER QUALITY
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QUALITY
OF BATHING WATER IN THE LIGURIAN SEA
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Legislation.
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Bathing
water standards (fresh and sea water) are governed by the terms of Presidential Decree N°. 470/82
entitled "Implementation of Directive
76/160/EEC concerning the quality of bathing water".
In compliance with
Article 4 of Presidential Decree N°. 470/82, the Liguria Region has
identified 450 areas along its 350 km of coastline.
The 405 of these areas considered
suitable for bathing are covered by the monitoring programme; since they are
used for specific activities (marine parks, ports, airports, military
zones), the remaining 45 carry a permanent ban on bathing and are therefore
excluded from monitoring.
The Liguria Region has selected a
specific sampling point in each of the 405 designated areas.
Prior to the start of every bathing
season, the Liguria Region assesses the bathing water standards in each
area by analysing the results of samples taken during the previous year
(statistics are processed as set out in Presidential Decree N°. 470/82).
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Bathing Season &
Sampling Requirements.
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In Italy the
bathing season starts on 1st May and ends on 30th
September.
ARPAL (Regional
Agency for the Protection of the Environment in Liguria) takes samples to
monitor the quality of bathing water twice a month from 1st
April onwards; sampling continues throughout the bathing season using the
methods and criteria set out in Presidential Decree N°. 470/82.
Sampling and analysis are carried out
by ARPAL's local organisations (Provincial Departments) using standard
procedures.
This involves taking at least two
samples per month from each stretch of coastline designated for bathing at
average distances of approximately 750 m ; a total of at least 4632 samples
are taken every year.
 previous
section
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Data Set.
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The quality
of each bathing water sample is tested for the following: Total coliforms,
Faecal coliforms, Faecal streptococci, Colour and Transparency, Dissolved
oxygen, pH, Mineral oils, Phenols and Surface-active substances.
Tests for Salmonellae are also carried
out in special circumstances.
An explanation and upper limits for
each parameter are given in the Table below.
previous section
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Terms of European Directive
and Upper Limits set out in Italian legislation.
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The European Directive sets standards
for the parameters mentioned above ("guide values", Column G) along with the upper limits for
the same ("imperative values", Column I of Table attached to Directive).
Italian legislation only sets
out the upper limits adopted as a precautionary measure for European
"guide values". The exception is the limit for Total coliforms
which is 2,000 UFC/100 ml under Presidential Decree 470/82, midway between
the Directive's "guide value" of 500 UFC/100 ml and the
"imperative value" of 10,000 UFC/100 ml.
previous
section
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Quality of seawater in
designated bathing areas.
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Various
types of information are shown on this page.
Maps in the form of graphics (visible
instantly) and satellite pictures (requiring more time to download) are
used to show the current
standard of designated bathing areas, as determined by samples gathered by
ARPAL's Regional Organisations during the year.
The maps are a snapshot of the
current status of the Ligurian Sea in designated bathing areas.
Symbols and colours (4) are used to define
the following:
1.
Compliance with
Italian legislation - (blue strip of sea).
2.
Temporary non-compliance with Italian legislation - (red
strip of sea).
3.
Temporary ban on bathing as a result of precautionary
measures issued by Mayors of Communes involved, where accidental
occurrences have led to a possible deterioration in the quality of the
water (yellow strip of sea).
4.
Areas in which
there is a permanent ban on bathing for reasons other than pollution (e.g.:
ports, airports, military zones, marine parks and reserves) - (black strip
of sea).
previous section
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Meaning of parameters
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Parameters
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Physico-chemical
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Upper limits
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explanation
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Aesthetic qualities of primary importance; affected both by
natural factors and pollution
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Absence of abnormal colour variations
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1 metre
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Measure of the acidity or alkalinity of bathing water; the result
of the chemical balances which it contains. Provides useful information
on water quality, particularly in the case of freshwater. pH fluctuations
may result from natural conditions (natural soil degradation) or human
activities (mining processes, airborne pollutants which may cause acid
rain, etc.)
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6 - 9
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Low values may
indicate organic pollution; high values may point to eutrophication (the
process which causes the aquatic ecosystem to "suffocate": in
the presence of large quantities of nutrients such as nitrogen and
phosphorous, algae reproduce rapidly - algae blooms - thereby reducing
levels of dissolved oxygen in the water).
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70 - 120 % O2
saturation
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An important
quality indicator. The presence of mineral oils is particularly
detrimental to the aesthetic quality of bathing water.Mineral oils may be
released into the sea by boats or as the by-product of industrial
activities.
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Absence of visible film on surface of water;
absence of odour.=< 0.5 mg/l (in case of borderline sampling results,
the upper limit must be applied)
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Chemical
substances, mostly of industrial origin (they are used to make rubber,
plastics, pharmaceutical products, etc.), with an unpleasant taste and
odour.Compounds containing chlorine (chlorophenols) pose health risks;
they are corrosive and cause irritation to the skin, eyes and mucous
membranes.
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No particular odour=< 0,05 mg/l (in case of borderline sampling
results, the upper limit must be applied)
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- Surface-active substances methylene
blue-reactive
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These substances
- the main component of detergents - are found commonly in water.As well
as increasing the toxicity of other contaminants, they reduce oxygen
levels in the water.They are a source of phosphorous, a nutrient for
aquatic micro-organisms, which is one of the causes of eutrophication.
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Absence of lasting foam=<0,5 mg/l (in case of borderline
sampling results, the upper limit must be applied)
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Microbiological substances
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These
micro-organisms are useful microbiological indicators of sewage pollution
in bathing water samples; by analysing these parameters it is possible to
produce a quantisable assessment of biological contamination and, as a
result, the risks of pathogens (Salmonellae, Vibrios, etc.) being present
in the water; since these pathogens are found inconsistently and in
varying quantities, they can only be monitored directly through ongoing
testing - practically impossible on a large scale.The presence of faecal
coliforms indicates sewage pollution.Indicative of an acute risk of
infection for bathers; by monitoring this parameter regularly it is
possible to maintain high environmental and health standards.
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2.000/100 ml
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100/100 ml
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100/100 ml
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These pathogenic
enterobacteria indicate a real risk of infection for bathers.For the real
risk to become an actual risk, the bacteria must be found in sufficient
numbers to produce the pathology.
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0 / litre
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previous
section
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