Environmental Standards Scotland (ESS) has published a new report which finds that action needs to be taken to improve monitoring, regulatory guidance and the operation of storm overflows in Scotland.

The report ‘Storm overflows: an assessment of spills, their impact on the water environment and the effectiveness of legislation and policy’ sets out that:

• there is no comprehensive, publicly available information on the scale and environmental impact of spills from storm overflows in Scotland

• where there is data, it is clear that some sites spill much more frequently than should be expected, some of them hundreds of times a ESS’ analysis of Scottish Water data reported to SEPA shows that in 2023, 49% of the 142 storm overflows and emergency overflows spilled over 50 times, 32% over 100 times and four spilled more than 500 times. As an example, one Combined Sewer Overflow (CSO) at the Meadowhead treatment works in North Ayrshire spilled waste water 365 times on 124 different days in 2023

• current Scottish guidance is outdated and it is not sufficiently clear that spills from storm overflows should only occur in exceptional circumstances. This limits the effective implementation and application of the Urban Waste Water Treatment (Scotland) Regulations 1994

• the system of identifying, reporting, classifying and addressing environmental pollution incidents (EPIs) is one of the key ways of protecting the environment from pollution from storm overflows. ESS has therefore begun investigatory work on the legislation governing EPIs and the responsibilities of the Scottish Environment Protection Agency (SEPA) and Scottish Water

Covered in The Guardian Sewage in Scotland’s rivers and beaches far more widespread than realised