Up to 500 new jobs are set to be created at a Ross-shire engineering firm developing new ways to treat water.
RSE in Muir of Ord plans to take on 100 new apprentices in each of the next five years under its expansion.
The firm wants to make it quicker, greener and cheaper to replace Victorian-era treatment works, making systems fit to withstand modern-day demands.
It said it was spending £14m on a research and development programme.
Jordan Miller is among the first wave of apprentices, having started at RSE as a trainee project engineer.
She said: “Everyone will always need water – so we need to make ourselves the best that we can in the industry.”
RSE managing partner Iain MacGregor said innovative ideas were needed as it was becoming harder to provide clean water.
He said: “There are huge water quality challenges in the UK, we are seeing that in the treatment required for us to consume water without becoming ill.”
Highlands and Islands Enterprise (HIE) has provided £2m funding for the programme.
James Gibbs, from HIE, said: “If you look at what we ask for from larger companies, there are really three things that drive it; helping them innovate, creating really good jobs and helping our progress towards low carbon.”