Orchard Wrong

Something just twigged today. I'm a bit slow I suppose.

You see when I described the noise of the Orchard Rite fans from Royce McKeans property up the Wairau Valley (and let's not forget the Hurunui). I referenced a report from Hegley Acoustics.

This report was completed in January 2006 from testing carried out in 2005.

In it Nevil Hegley records the noise levels of the model 2500D and 3000D Orchard Rite fans at 100 metres and calculates the levels that will be present at 300 metres.

They are as follows (all are L10 values by the way);

Wind Machine      @100m  @300m

2500D at 1850rpm  69dBA 59dBA

at 2000rpm 71dBA 61dBA

at 2270rpm 73dBA 63dBA

3000D at 1850rpm 64dBA 54dBA

at 2000rpm 67dBA 57dBA

at 2100rpm 67dBA 57dBA

at 2270rpm 69dBA 59dBA

Throughout the report Mr Hegley describes the noise as 'tonal' in other words it is exhibiting 'Special Audible Characteristics'. Now these characteristics mean that in accordance with the requirements of NZS 6801: 1991 (the noise standard almost universally used by District Councils) noise that exhibts them must include a 5dB penalty because of the intrusive nature of the noise. (in fairness to Orchard Rite, acoustics experts appear to universally agree that all frost fans running at their efficient speeds exhibit these characteristics).

This means that of all these readings only ONE actually meets the requirements of the Marlborough District Councils noise limit of 55dBA L10 at 300 metres (this figure includes the 5dB penalty for special audible characteristics).

So I presume that if Mr McKean is operating one of these models of fan (and he is certainly operating the 3000D according to the resource consent in Hurunui) then he can only operate them at 1850rpm in order to be compliant with the District Plan (in Marlborough).

Unless he has a resource consent to exceed the limit of course. 

So how do the council ensure compliance with the District Plan? I believe we've established that they don't do any measuring at all. Not before installation, and not after. 

Yet they're required to under the RMA.

Mr Maclean seems to think it can be done and done easily.

And yet they've done nothing.

     Nothing.

          Nothing.

              Nothing.

At least they've done it consistently.

Meanwhile no doubt Mr Mckean is lawfully operating his fans at the lowest setting to avoid making too much noise.