Coming off a record-breaking winter, Compass Minerals is investing millions of dollars into Goderich’s salt mine.

After selling the most deicing salt in years this past winter, Compass is embarking on a multi-million dollar project to re-line two underground shaft walls.

The company says the improvements will allow them to pull up to nine million tonnes of rock salt from underneath Lake Huron - improving efficiency and safety at the same time.

The existing concrete liners nearly 550 metres underground will either be overlaid with steel or removed and replaced.

The project is expected to take up to three years.