Rock Salt History

The UK's largest rock salt (halite) mine is at Winsford. It is one of only three places where rock salt is commercially mined in the UK, the others being at Boulby Mine, North Yorkshire, and Kilroot, near Carrickfergus, Northern Ireland.

Rock salt was laid down in this part of North West England 220 million years ago, during the Triassic geological period. Seawater moved inland from an open sea, creating a chain of shallow salt marshes across what is today the Cheshire basin. As the marshes evaporated, deep deposits of rock salt were formed.

Extraction began at Winsford in the 17th century. Initially it was used only as salt licks for animals, and to strengthen weak brine. In 1844 Winsford Rock Salt Mine was opened, and is claimed by its operator, Salt Union Ltd., to be "Britain's oldest working mine". Salt Union Ltd. is part of the US-owned group of companies Compass Minerals. Today, rock salt is quarried from a depth of more than 150 metres below ground, producing salt (commonly known as "grit") for use as a de-icing agent on roads. The mine produces 1 million tonnes of rock salt annually, and has a network of 135 miles (217 km) of tunnels over several square miles underneath the area between Winsford and Northwich.

A worked-out part of the mine is operated by DeepStore Ltd., a records management company offering a secure storage facility. Confidential government files, hospital patient records, historic archives belonging to The National Archives, and business data are stored in the mine, where the dry and stable atmosphere provides ideal conditions for long-term document storage.

The services we can provide to commercial customers include:

• Fixed contracts to supply a guaranteed quantity of de-icing rock salt over the winter months
• 30 day accounts. Particularly effective for larger businesses
• Neatly stacked Pallets of 25KG bags
• Secure required amount of de-icing salt before winter arrives and we will store and deliver the salt as and when you need it
• High quality pure white rock salt. The cleaner alternative to traditional brown rock salt
• No muddy surfaces and costly cleaning bills, often the case with brown rock salt
• Fast, efficient delivery anywhere in the UK