More than 76,000 sewage spills have been recorded at waste overflow sites in Scotland following the installation of new monitoring equipment, BBC analysis suggests. The addition of 1,009 sewer monitors in 2024 expanded the proportion of the Scottish Water network being monitored from 6% to 30%.
These latest figures have uncovered tens of thousands of spills that would have previously gone unrecorded, including hundreds at scenic locations such as Loch Lomond. Scottish Water indicated that most of these spills were not environmentally harmful, and that the increased monitoring has enhanced understanding of the sewer network.
Last year, over 100,000 spills were recorded, totalling almost 277,000 hours, averaging about 274 spills per day. Glasgow's River Clyde was significantly affected, receiving almost 6,150 spills, or approximately 17 daily. When including the Clyde Estuary, Firth of Clyde, and other tributaries, this figure nearly doubles to almost 14,200 spills, or 39 per day.
Simon Parsons, director for wastewater at Scottish Water, explained that most overflows function as designed, primarily draining rainwater from the sewer system. He stated that 99% of spills consisted of rainwater, surface water, road run-off, 'grey' water from households, groundwater infiltration, and trade effluent. Parsons added that the improved monitoring helps identify areas needing investment and improvements.