HDD outfall for whisky distillery on Scottish isle
In August 2025, Brownline UK assisted in an HDD project on the Scottish isle of Islay. For a whisky distillery, a wastewater pipeline was installed using horizontal directional drilling. To ensure perfect accuracy while drilling through the hard rock layers, the pilot bore was surveyed using the Drillguide Gyro Steering Tool.
Drilling to minimize disturbance
Islay is home to several world-famous whisky distilleries. A new facility, the Portintruan Distillery, is under construction on the southern coast of Islay. This project required the installation of a wastewater pipeline to safely and efficiently dispose of waste after the distilling process.
To minimize disturbance to the seabed and coastline, the pipeline was installed using horizontal directional drilling. Contractor Nicol of Skene Ltd. carried out the drilling operations.
Accurate drilling through rock layers
The 258 m / 846 ft HDD trajectory crossed rock layers of varying hardness, including phyllite, limestone and quartzite. Accurate positional measurements were necessary to navigate along the planned trajectory without deviations. For this reason, the client trusted the proven accuracy of the Drillguide Gyro Steering Tool to survey the pilot bore.
The Drillguide Gyro Steering Tool is tested to the extreme to ensure it maintains its accuracy in all environments. This accuracy makes it very suitable to survey HDD projects in rocky conditions.
Nearly half of the total length was drilled below the seabed. The drill punched out as planned, at a depth of 5 m / 16 ft below sea level. The successful pilot bore enabled an efficient installation of the wastewater pipeline from the seabed to the Portintruan Distillery. The distillery is expected to start production in 2026.
See below for several great photos as well as a video taken on the drill site and nearby.
