Purification plants
Purification (or depuration) is a vital process used
to ensure that shellfish consumers are protected from the
risks associated with sewage-contaminated shellfish.
Purification entails placing shellfish in tanks of seawater for
a minimum of 42 hours to purge any microbiological contamination
they may have bio-accumulated while in the environment. Only
shellfish harvested from class B harvesting areas (and where deemed
necessary, class A areas) are permitted to be depurated.
Under EC Regulations EC 853/2004 (PDF, 154 KB),
the approval for shellfish purification plants to operate must be
given by the local enforcement authority (LEA). This
is subject to the conditions set out in the Regulations and
any additional conditions notified by the Food
Standards Agency.
In England and Wales, Cefas has the delegated
responsibility for setting the specific conditions under which the
system should operate. In addition, we are UKAS-accredited
against ISO 17020 for the purification system inspection
service.
For new systems, "Conditions of Approval" are set following a
technical inspection and, when necessary, a microbiological
challenge test. Following the approval process, responsibility
for ensuring that the system is maintained and operated correctly
is passed to the LEA.
Operators of depuration plants who wish to obtain approval or
modify a depuration plant or system should inform their local
food authority. The authority will then liaise directly with
us.
Specific advice about the design or running of purification
systems should be sought from Seafish or another
suitable consultancy.
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