Garston Water Hardness & Quality Report (2026)

United Utilities supplies Garston residents with a blend of water from two distinct sources. The primary source is Thirlmere, known for its naturally soft water. This is then mixed with groundwater drawn from the Permo-Triassic Sherwood Sandstone and Keuper Marl aquifer. This combination forms the south Liverpool Triassic-blend supply sub-zone, aiming to balance the characteristics of both inputs before distribution.

The geology contributing to this water supply is quite varied. The soft component originates from the upland catchment feeding Thirlmere, where the bedrock is typically ancient, hard, and less soluble. In contrast, the groundwater component is sourced from the Permo-Triassic Sherwood Sandstone and Keuper Marl formations. These sedimentary rocks, particularly the marl layers, contain minerals that dissolve more readily into water, contributing to increased hardness.

This moderately hard water, measuring around 11.3° Clark, means you might notice some scale buildup over time, particularly in kettles and on shower heads. While not excessively hard, it can affect how much soap or detergent you need for laundry and washing. To combat scale, occasional descaling of appliances is a good idea. For areas prone to significant buildup, a water softener could be considered, though many find this level of hardness manageable for everyday use.