The cost of silencing the humming noise produced by electricity sub stations in Inverness-shire has spiralled to £3.5million.
About £2.5million is being spent on noise screening work at the Wester Balblair sub station near Beauly, with a further £1million being used for acoustic barriers at the Auchterawe site near Fort Augustus.
Scottish and Southern Energy was given a six-month abatement notice in February this year, requiring it to reduce the low-frequency noise to an “acceptable” level.
The order was made after Kilmorack community council and some residents complained about equipment installed as part of the Beauly-Denny pylon upgrading.
The work was due to start in April with an initial deadline of October, but this was moved back to December.
This week, David Gardner, SSE’s transmission director, admitted the problem threatened to tarnish the company’s name but said finding a solution was difficult because of the complex nature of the issue.
Kilmorack Community Council chairman, Steve Byford, said the high costs of repair were a problem of SSE’s own making.