38

Part  B  -  Technical  instructions

Table  4.3:  Survey  of  waterborne  noise  emissions  and  immissions.

Baseline  study

Construction  phase

Operation  phase

Objectives

Prediction  of  noise  immissions
  and  propagation  in  the
construction  and  operation
phases  for  the  efficient  design ­
  of  noise-mitigating
measures.
Measurement  of  waterborne ­
  background  noise  in
the  project  area  prior  to
construction.

Monitoring  of  waterborne
noise  emission  and  immission.

Efficiency  control  of  noisemitigating
  measures.

Monitoring  of  waterborne
noise  emission  and  immission
  near  the  wind  turbines.

Scope

The  expected  levels  of  waterborne ­
  noise  due  to  the
construction  and  operation
of  the  planned  offshore
wind  farm  have  to  be  determined ­
  by  means  of  forecast
computations.  The  existing
noise  level  by  potentially
existing  wind  turbines  must
be  taken  into  account  (immission
  forecast).
Ambient  noise  measurement ­
  shall  be  made  in  each
target  area  prior  to  the  start
of  construction  activities.

During  noise-intensive
construction  work  (e.  g.
pile  driving),  underwater
noise  measurements  must
be  carried  out  in  the  area
around  the  construction
site.  In  particular,  the  efficiency ­
  of  noise-mitigating
measures  must  be
assessed  (according  to
incidential  provision  14
and  20).
The  underwater  noise
measurements  must  be
carried  out  for  each  pile
driving  site  or  at  least  until
proof  has  been  provided
of  continuous,  reliable
adherence  to  the  noise
prevention  value.
Randomised  separate
measurements  from  vibration ­
  pile  driving  must  be
carried  out  in  co-ordination
with  the  BSH.

After  commissioning  of  all
wind  turbines,  waterborne
operating  noise  must  be
measured.

Timing

One  time  only.

Throughout  the  entire  construction ­
  phase.

During  the  first  year  of  the
operation  phase.

The  “Measuring  instruction  for  underwater  sound  measurements”  (BSH  2011)  applies.

Method

Immission  forecast:
•  The  forecast  quality  depends ­
  on  the  accuracy  of
the  input  data  and  the
used  models.  The  quality
of  input  data  and  the  parameters ­
  forming  the  basis ­
  for  modelling  must  be
documented.
•  The  German  language
guideline  ‘Prognosen  für
Unterwasserschall  -  Mindestmaß ­
  an  Dokumentation’ ­
  (BSH  2013a)  applies. ­


The  efficiency  of  a  noise
reduction  system  must  be
assessed  by  suitable  underwater ­
  noise  measurements. ­
  The  German  language ­
  guideline  “Anleitung
für  die  quantitative  Bestimmung ­
  der  Wirksamkeit  von
Schalldämmmaßnahmen”
(BSH  2013b)  applies.

The  measurements  shall
capture  the  three  performance ­
  ranges  “low”,  “medium” ­
  and  “rated  output”.