Appendix 5
NORTH NORFOLK DISTRICT COUNCIL
Environmental Health
Memorandum
To:
Geoff Lyon - Planning
From:
Sally Nicholson - Environmental Protection Team
Extension:
01263 516085
Our Ref:
WK/110019795
Date:
23 April 2012
_____________________________________________________________________
Re: PF/11/0983 - Erection of wind-turbine maximum hub height 60m, maximum
tip height 86.5m.
On the 3rd October 2011 I sent my initial comments to planning regarding this turbine, I
had several areas of concern and highlighted them and recommended refusals due to
my concerns see the memo attached.
In response to this memo I had discussions with the applicant and the noise consultant
regarding my concerns. The noise consultant then produced an Addendum to the noise
report which reviewed the original assessment; see document “Addendum to noise
assessment for a proposed wind turbine at Pond farm, Bodham.” Project number
0910285 produced 21st October 2011.
The addendum answered the queries we had in our initial memo:
1. We have serious concerns due to the low background noise in the areas
monitored around the turbine; and we are not satisfied that the
projected noise levels from the turbine would not give rise to noise
complaints at the nearby residential properties.
The noise consultant responded that the majority of wind farms and wind turbine
installations take place in areas with low background noise. The ETSU guidance
recognises this and makes the following comment:
“The recommendation of the Noise Working Group is that, generally, the
noise limits should be set relative to the existing background noise at
nearest noise-sensitive properties and that the limits should reflect the
variation in both turbine noise source and background noise with wind
speed. We have considered whether the low noise limits which this could
imply in particularly quiet areas are appropriate and have concluded that
it is not necessary to use a margin above background approach in such
5.1
low-noise environments. This would be unduly restrictive on
developments which are recognised as having wider national and global
benefits. Such low limits are, in any event, not necessary in order to offer
a reasonable degree of protection to the wind farm neighbour.”
(Paragraph 11, of the Executive Summary)
The consultant went on to say:
“In the light of this guidance (and the detailed recommendations within the body
of the document), it is clear that Government policy (which specifically
recommends the use of this guidance) backs the use of the limits which we have
used, and that this includes areas where there are low background levels.”
With further consideration to the report in line with the ETSU guidance and the
review carried out in the addendum, along with the discussions with the noise
consultant we agreed that the noise consultant had followed the correct procedures
and that we are now satisfied that although the background noise levels are low this
assessment has been carried out with this in mind.
During our discussions we decided that a condition should be attached in the event
that when the turbine was installed and if noise were to be experienced then this can
be implemented:
“At the request of the Local Planning Authority (LPA) following a justified noise
complaint the wind turbine operator shall, at its expense, employ a suitably qualified
noise consultant approved by the LPA, to undertake an appropriate noise
assessment of the noise emissions from the wind turbine at the complainant’s
property following the procedures agreed by the LPA. A report of the assessment
shall be provided in writing to the LPA within X days of the request under this
condition unless this period is extended by the LPA in writing.
If the findings of this report identify that the wind turbine is causing noise levels
considered to be of a detriment to the amenity to the nearby residential properties, a
scheme shall be included in the report detailing remedial works, and these works
shall be implemented in full.”
2. There is no clear justification to the proposed daytime noise fixed limit
proposed by the consultant in table 4.2, and as to why the upper noise
limit of the criteria (detailed in 2.5) is acceptable?
Through discussions with the noise consultant and the addendum to the report it
became clear that environmental protection had misunderstood the limits, and in fact
the upper limit was not used. The consultant had produced a variable limit using the
methodology laid out in ETSU. This was determined with reference to background
levels and subject to a lower limiting value (which is at the lower end of the specified
range).
We subsequently had a meeting with the acoustic consultant and he talked us
through the workings, and how he calculated the target level. This answered our
above query.
5.2
3. It has not been confirmed which wind turbine shall be installed,
therefore I feel it is not possible to carry out an adequate assessment to
the impact on residential properties.
The acoustic consultant confirmed that there are two wind turbines being considered
(the Enercon E-53 and the Enercon E-48) and the original assessment looked at
only one (the E-53). The noise characteristics for each are slightly different. He
produced a table that gives the sound power levels for each wind turbine.
Manufacturer’s data for wind speed at 10m against sound power levels:
Due to our concerns the noise consultant reviewed the original report and re ran it
using the E-48. The table above shows that the E-48 noise levels are generally a
little higher than for the E-53.
The original assessment looked at the E-53, so the addendum includes a re-run the
model using the E-48 sound power levels. Table 3.2 in the addendum and table 4.2
of the main report show the noise readings at the varying wind speeds:
Table 3.2 Predicted sound pressure levels at the Pylons as a result of
operation of the proposed turbine (E-48)
Table 4.2 Predicted sound pressure levels at the Pylons as a result of
operation of the proposed turbine (E-53)
5.3
This shows that the predicted noise readings at the pylons are similar and actually
slightly lower at the lower wind speeds.
We discussed that we would condition the planning permission appropriately to
reflect this issue.
“The Enercon E53/E48 800 kW 60 metre turbine shall be installed and maintained in
accordance with the manufacturers specifications;
If a different model turbine is to be used the turbine details should be submitted to
and approved in writing by the LPA prior to the commencement of the development.”
4. Has the applicant given consideration to the effects of wind shear?
The addendum details the procedure in which wind shear is calculated, I myself also
read the article in the Acoustics Bulletin published in March 2009. The acoustic
consultant then revised the assessment to use the derived values to take account of
windshear, which still showed the results as being complaint with ETSU.
Conclusion
Through discussions and the further information supplied to myself and my colleagues,
we were now satisfied that the assessment has been carried out following ETSU-R-97,
on assessing noise from wind turbines, which is the recognised current guidance and
that sufficient noise monitoring had been undertaken and that we now had enough
information to make an informed decision.
In conjunction with this addendum myself, my colleagues Paul Clarke and Mark
Whitmore met with the noise consultant and the applicants to go through the noise
report and addendum to discuss it further and so any queries could be discussed.
We decided that as ETSU is the recognised guidance and that this has been followed
and that the proposed wind turbine has met these criteria. Therefore, we had no further
objection to the installation of this turbine.
We are now satisfied that we have sufficient information to make a decision on this
proposed turbine and we have no further objection, provided that the following
conditions are applied:
5.4
The conditions we decided upon are as follows (see memo 2):
1. Type of Turbine
“The Enercon E53/E48 800 kW 60 metre turbine shall be installed and
maintained in accordance with the manufacturers specifications;
If a different model turbine is to be used the turbine details should be submitted to
and approved in writing by the LPA prior to the commencement of the
development.”
2. Condition
“At the request of the Local Planning Authority (LPA) following a justified noise
complaint the wind turbine operator shall, at its expense, employ a suitably
qualified noise consultant approved by the LPA, to undertake an appropriate
noise assessment of the noise emissions from the wind turbine at the
complainant’s property following the procedures agreed by the LPA. A report of
the assessment shall be provided in writing to the LPA within X days of the
request under this condition unless this period is extended by the LPA in writing.
If the findings of this report identify that the wind turbine is causing noise levels
considered to be of a detriment to the amenity to the nearby residential
properties, a scheme shall be included in the report detailing remedial works, and
these works shall be implemented in full.”
We feel these conditions are workable and measurable to address the concerns of the
residents and ensure that if as ETSU indicates the turbine shall not be detrimental to
the amenity in relation to noise, if there is a subsequent problem when the turbine is
installed this matter can be addressed by enforcing these conditions.
If you have any further queries please contact me.
Regards
Sally Nicholson
Environmental Protection Team
5.5
NORTH NORFOLK DISTRICT COUNCIL
Environmental Health
Memorandum
To:
Geoff Lyon - Planning
From:
Sally Nicholson - Environmental Protection Team
Extension:
01263 516181
Our Ref:
WK/110019795
Date:
3rd October 2011
_____________________________________________________________________
Re: PF/11/0983 - Erection of wind-turbine maximum hub height 60m, maximum
tip height 86.5m, associated infrastructure, single-storey substation building,
access tracks and crane hard standing
Further to the receipt of the noise report produced by Sharps Redmore Partnership
“Noise Assessment for a proposed wind turbine at Pond Farm, West Beckham,
North Norfolk” dated 7 January 2011 and the additional information submitted on 20
September 2011.
The Environmental Protection Team has considered this report against the ETSU-97
guidance and the World Health Organisation guidance along with consideration of
the residential amenity of the nearest properties.
On assessing the above noise report the following issues have been identified:
•
We have serious concerns due to the low background noise in the areas
monitored around the turbine; and we are not satisfied that the projected
noise levels from the turbine would not give rise to noise complaints at the
nearby residential properties.
•
There is no clear justification to the proposed daytime noise fixed limit
proposed by the consultant in table 4.2, and as to why the upper noise limit of
the criteria (detailed in 2.5) is acceptable?
•
It has not been confirmed which wind turbine shall be installed, therefore I feel
it is not possible to carry out an adequate assessment to the impact on
residential properties.
•
The applicant appears not to have given consideration to the affects of wind
shear.
5.6
Therefore, on the current information we have we recommend refusal.
If you have any queries please contact me.
Regards
Sally Nicholson
Environmental Protection Officer
5.7