Noise generated by a proposed shale gas drilling rig would cause annoyance and sleep disturbance to residents in the area, an acoustics expert has said.
Speaking on day 15 of the public inquiry into Cuadrilla’s applications to drill and test frack for gas at two sites on the Fylde, Mike Stigwood, gave evidence on behalf of the Preston New Road Action Group (PNRAG).
Mr Stigwood, an environmental health officer, gave detailed evidence to say that Cuadrilla’s environmental impact assessment carried out by Arup was ‘flawed’ and had underestimated the effects of noise by the proposed fracking drilling rig at Preston New Road.
He said the study had failed to accurately assess the true low level of background noise near the site and failed to take into account non-acoustic factors, and the effects of low frequency noise generated by a drilling site.
He said noise levels could be as high as between 51 to 52 decibels when the nightime noise level cited by Cuadrilla was not to exceed 42db.
He said his studies had shown the nightime background noise level was in the region of 19db.
He said : “This is patently lower than considered by the appellant.
“Even if it was 35db it would be double the background for a substantial portion of the night.”
Questioned by PNRAG’s counsel, Mr Ashley Bowes, about whether the level of 42db proposed by Cuadrilla for the site was suitable or would cause sleep loss, Mr Stigwood said awakening can come well below the level of 42db.
Mr Bowes asked if the World Health Organisation recommended maximum level of 42db, which Cuadrilla’s noise expert Mr Hiller had referred to, was pertinent.
Mr Stigwood said that it was an upper ceiling noise level and the real level should be much lower. He also said that it should be much lower if low frequency noise was involved.
He said: “Arup had discounted the effects of low frequency noise at an early stage – taking that view was simply wrong.” He said low frequency noise had capacity to be more noticeable and could cause adverse effects on health.
Mr Bowes asked: “The $64,000 question is, of course, would noise in this case, at or below 42db, cause sleep disturbance?
Mr Stigwood replied: “Yes it will absolutely cause it.
“Because of character of noise and because throughout the night when the background drops during core sleep hours. Added to that, you have low frequency noise and vulnerable groups in the area.
“This area has a high proportion of elderly people and they suffer from a number of sleep effects others do not.”
Cuadrilla’s counsel, Nathalie Lieven, cross-examined Mr Stigwood.
She questioned the sources of his data on which he based his noise estimates for a fracking rig, and whether they came from shale gas or potash extraction.
She defended Arup’s acoustic evidence saying its estimates and those of Lancashire County Council’s own noise consultants Jacobs came to a similar conclusion within 1db.
She went on to contest his assertion background noise levels had to be taken into account when assessing how much noise could be allowed from the fracking site.
She said: “It would not be possible to describe this as a quiet noise area during the night.”
She said the A585 and the M55 motorway were both already noisy in the area – and in any case nowhere in World Health Organisation guidelines did it say noise levels should be related to background noise.
Mr Stigwood replied that it was illogical not to do so, and that the WHO level applied to transport noise not industrial.