Quality standards stipulated in the Shellfish Waters
Directive
|
Parameter
|
Unit
|
G
|
I
|
| A.
GENERAL PHYSIO-CHEMICAL PARAMETERS |
| Colour |
|
|
(a)
|
| Dissolved
oxygen |
% sat
|
>80 T95
|
>70 TAA(b)
|
| pH |
|
|
7-9 T75
|
| Salinity |
g/kg
|
12-38 T95
|
40 T95(c)
|
| Suspended
solids |
|
|
(d)
|
| Tainting
substances |
|
|
(e)
|
| Temperature |
|
(f)
|
|
| B.
METALS AND INORGANIC ANIONS |
| Arsenic |
|
(g)
|
(h)
|
| Cadmium |
|
(g)
|
(h)
|
| Chromium |
|
(g)
|
(h)
|
| Copper |
|
(g)
|
(h)
|
| Lead |
|
(g)
|
(h)
|
| Mercury |
|
(g)
|
(h)
|
| Nickel |
|
(g)
|
(h)
|
| Silver |
|
(g)
|
(h)
|
| Zinc |
|
(g)
|
(h)
|
| C.
ORGANIC SUBSTANCES |
| Hydrocarbons |
|
|
(i)
|
| Organohalogens |
|
(g)
|
(h)
|
| D.
MICROBIOLOGICAL PARAMETER |
| Faecal
coliforms |
per 100 ml
|
300 T75(j)
|
|
Notes:
G guide value
I imperative (mandatory) value
T total concentration (ie without filtration)
D dissolved concentration ie usually involving
filtration through a 0.45-µm membrane filter before
analysis
AA standard defined as annual average
75 standard defined as 75-percentile
95 standard defined as 95-percentile
MA maximum allowable concentration
Pt/l concentration of platinum (Pt) determined
photometrically on the Platinum/Cobalt scale
as a measure of colour in water
A discharge affecting shellfish waters must not
cause an increase in colouration of more than 10
mg Pt/l compared to the waters not so affected (waters
filtered in both cases). This standard is expressed
as a 75-percentile.
If an individual result indicates a value lower
than 70% of saturation, the measurement must be
repeated. Concentrations below 60% of saturation
are not allowed, unless there are no harmful consequences
for the development of shellfish colonies.
A discharge affecting shellfish waters must not
cause an increase in salinity of more than 10% compared
to the water not so affected. This standard is expressed
as a 75-percentile.
A discharge affecting shellfish waters must not
cause an increase in the concentration of suspended
solids by more than 30% compared to the water not
so affected. This standard is expressed as a 75-percentile.
The concentration of substances affecting the taste
of shellfish must be lower than that liable to impair
the taste of the shellfish.
A discharge affecting shellfish waters must not
cause an increase in temperature of more than 2
°C compared to the water
not so affected. This standard is expressed as a
75-percentile.
The concentration of this substance or group of
substances in shellfish flesh must be so limited
that it contributes to the high quality of shellfish
products.
The concentration of this substance or group of
substances in water or in shellfish flesh must not
exceed a level which gives rise to harmful effects
in the shellfish or their larvae. Synergistic effects
must also be taken into account in the case of metal
ions.
Hydrocarbons must not be present in water in such
quantities as to produce a visible film on the surface
of the water and/or a deposit on the shellfish,
or to have harmful effects on the shellfish.
In shellfish flesh and intervalvular fluid. However,
pending the adoption of a directive on the protection
of consumers of shellfish products, it is essential
that this value be observed in waters from which
shellfish are taken for direct human consumption.
References
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