Choice of techniques
Different techniques used.
The choice of techniques not only depends on the coast’s
sensitivity, but also on the extent of the pollution, the
nature of the pollutant and the type of coast.
No technique is universal. Some techniques
can be used with certain variations for different substrates
and pollutants. Others, dedicated to certain precise pollutant,
pollution and substrate conditions, have a far more limited
range of use. Finally, some techniques are more suited to
the Mediterranean coastline for example, with its small
tidal range, than the tidal coasts of the Channel and the
Atlantic. Due to the extremely wide range of techniques
and pollution scenarios, it would be impossible to identify
all the solutions which could be used to deal with each
situation.
Nonetheless, certain elements will be provided
here to assist in the choice of techniques to be implemented.
Thus, a number of choice matrices are presented below, which
have been designed to help select one or more response techniques
according to the type of pollutant and substrate, for each
of the two phases of response.
Choice matrices
The choice matrices presented below were designed for the Atlantic and Channel coastline, however others also exist for the Mediterranean. They aim to illustrate typical pollution scenarios, resulting from the combination of characteristics of the pollution, pollutant and substrate. These characteristics are classified as follows:
- two types of pollution: heavy pollution and light (or residual) pollution, corresponding respectively to phase one and phase two
- two types of pollutant: fluid to slightly viscous pollutant and viscous pollutant
- around twenty typical environments defined according to the substrates and their exposure to wave energy (exposed or sheltered).
| Pollution | Pollutant | Matrix |
|---|---|---|
| Heavy
pollution/ phase 1 |
Fluid | Matrix
1  |
| Viscous | Matrix
2 |
|
| Light
or residual pollution/ phase 2 |
Fluid | Matrix
3 |
| Viscous | Matrix
4 |
In the matrices, the clean-up techniques are ranked according to their relative usefulness using the following symbols:
Before implementing any technique, a technical datasheet should systematically be referred to in order to determine relevant procedures and restrictions.Synopsis by substrate
Cleaning a site can require several complementary techniques, which may not necessarily be able to be implemented at the same time. This means that the different stages must be well defined and the potential implications of each stage considered prior to any action being taken. In order to facilitate this process, two summary sheets (phase 1 and phase 2) have been prepared for each category of substrates.
These
synopsis sheets summarise the sequence of possible operations,
the procedures involved and the various factors to take
into consideration at the different stages in the process
(with reference to the relevant datasheets).