On Tue, 12 May 2015 13:55:51 +0200,
Martin wrote:
Locally they pump water from the Rhine and spray it onto the dunes, where the
water works are located. The dunes act as a natural filter. Recently they have
skimmed the top off the dunes "to remove alien plants". It could be to remove
the nasty substances that were in the water from the Rhine.

They should rather consider covering the dunes with some of the plants
which serve as a host for water cleaning bacteria. We have Iris,
Salicaires, and Scirpes (I do not know their english, nor the latin
names) for that purpose. Common reed is okay and chosen more often,
while a combination of different species is best.

If the dunes were to be “cleaned”, they would have to be leveled
completely, or replaced, as their tops will not contain most of the
realy nasty stuff, if any. Maybe they just began to look ugly with the
decomposing sludge which should cover the sand after a wile. But chances
are, those workers just removed alien plants. ;-)

Michael

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