Ty Nant Natural Mineral Water has unique characteristics. This is not surprising from a hydrogeological perspective, due to the unique character of the region's underlying geology. Although the geology of Wales is both interesting and complex, it may for simplicity be generalised into two main formations: metamorphic and igneous, both very old geologically. These two types make up the vast majority of subterranean rock found in Wales, each of which form very poor aquifers in terms of transmissivity. However, within these formations are to be found units of high permeability rock, making them ideal for water extraction. One such subterranean rock stratum forms the source aquifer for Ty Nant. Effectively surrounded by rocks of very low transmissivity, the water contained in the Ty Nant aquifer will primarily consist of recharge directly through the surface of the ground above. Lateral flows into the aquifer from the surrounding, relatively low permeability rock is insignificant, allowing for the isolation of the aquifer. As the rocks forming the Ty Nant aquifer unit are of high transmissivity, residence times for the water are low, producing the characteristically low mineral content of Ty Nant Natural Mineral Water. Furthermore, recharge to the aquifer is rapid, allowing for a high water yield to be drawn without over exploiting the available capacity of the aquifer. Ty Nant prides itself as being the custodian of this very precious and essential resource. Having created a successful international distribution network for the water drawn from the aquifer at Bethania, Ty Nant is totally committed to ensuring the long-term preservation of what truly is a marvellous and worthy resource: the production of pure spring water from solid rock!