Environmental health officers investigating complaints about a low-frequency humming from the Wester Balblair Sub-station near Beauly have found a “statutory nuisance” does exist.
It has served SSE with an “abatement notice” by Highland Council, telling the company to deal with the noise, by removing entirely or reducing to an acceptable level, within six months.
Failure to comply with the terms of an abatement notice without reasonable excuse may result in prosecution in the sheriff court.
The company said they were treating the matter “very seriously” and there was “a programme in place to resolve the issue”.
An SSE spokesman said installation of acoustic barriers at the substation would start during Februarybut the timescale was dependent on whether its SHE Transmission division has to seek permission from National Grid to switch off some equipment in order to allow work to be carried out safely.
Residents in the small rural community around the sub-station near complained they were being woken up at night by the noise, while being unable to sit outside during the day.
Highland Council sent in environmental health officers last summer following “an increasing number of complaints” of a recurring loud buzz.
Residents believe it is linked to the expansion of the sub-station at the start of the 137-mile overhead power line which is being upgraded to 400,000 volts to carry renewable energy generated in the Highlands and Islands to the south.
The first section between Beauly and Fort Augustus went live last year.
Highland Council has confirmed that following its investigation into noise emitting from the sub-station, officials had “concluded a statutory nuisance exists”.
A statement issued today said: “After establishing the extent of the problem and with an increasing number of complaints, the Council has taken the decision to serve an abatement notice in terms of the Environmental Protection 1990 on Scottish Hydro Electric Transmission PLC which is part of the SSE energy company.”
Steve Byford, chairman of Kilmorack Community Council, has been woken up several times in the early hours at his home in Broallan, about a mile-and-a-half away from the site.
On one occasion, he registered 43 decibels using a downloaded app, whereas Department of the Environment guidelines suggest 30 decibels are an acceptable sound level in a bedroom at night.
He said: “It is very distracting and upsetting. The trouble is with the nice weather when you want to open the windows and let in the breeze at night, the noise has been so loud you are not able to do that.”
Highland Council officials said the noise had become apparent since the commissioning of new equipment installed at the site as part of the Beauly Denny upgrading works.
Environmental Health officers carried out detailed noise monitoring at various locations since receipt of the complaints and has been discussing the problem with SSE.
Councillor Graham Phillips, chair of the council’s TECS Committee, said: ‘The council appreciates the ongoing patience of the residents as this complex investigation progresses to the next stage.
“We would also acknowledge the steps SSE have taken to investigate the source of the noise and their stated commitment to resolving the issue.”
Alan Yates, Highland Council’s Environmental Health Manager, said: “Our officers have reached the stage of the investigation where they feel it is appropriate to serve an abatement notice to ensure the nuisance is resolved and to provide some reassurance to local residents.”
The notice gives SSE six months to deal with the noise problem.
Mr Yates added: “The time scale is reasonable given the complexities of finding and implementing suitable solutions for a live substation of the size at Wester Balblair.”
Alastair Brand, the Beauly-Denny Project Director, said: “We are taking this matter extremely seriously and are disappointed that the Highland Council has felt it necessary to serve a noise abatement notice as we have been working closely with the council and the local community to address their concerns.
“We have made a significant amount of progress and there is now a programme in place to resolve the issue.
“This is a complex technical issue and it takes time to design the correct solutions and procure the appropriate equipment in order to deliver the most effective solution.”
Mr Brand said the SHE Transmission arm of SSE had been working with environmental health officers and the local community since the issue was reported by local residents in July.
He insisted a considerable amount of work has already been undertaken including the appointment of expert consultants and extensive noise monitoring at and around the substation.
They have also established a noise map to identify the causes of the increased noise and had discussions with equipment manufacturers.
A dedicated project team has been set up to oversee the handling and resolution of the issue.
Following analysis of the monitoring data, proposals were put forward to install specially designed acoustic barriers at the substation. A contractor has been appointed to carry out the work required at the substation.