A new report published by Environmental Standards Scotland (ESS) has founds 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 year. 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- current Scottish guidance is outdated and it is not sufficiently clear that spills from storm overflows should only occur in exceptional circumstances.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
Storm overflows are part of the sewerage system and are designed to reduce the risk of sewers flooding homes and businesses. However, spills from storm overflows can pose a risk to the environment and to human health. The Scottish Government, Scottish Water and the Scottish Environment Protection Agency (SEPA) all have responsibilities in relation to storm overflows in Scotland.
ESS finds that in 2023, data was publicly available for only 8% of storm overflows and emergency overflows. Furthermore, the guidance for the regulations that control the treatment of waste water in Scotland has not been updated since 1998, before devolution.
A revised Urban Waste Water Treatment Directive was formally adopted by the European Parliament on 10 April 2024. The Scottish Government will need to review the legislation relating to waste water management if it wishes to meet its commitment to keep pace with developments in European environmental policy and legislation.
Mark Roberts, CEO of ESS said: “Despite high levels of public concern, there is a lack of transparent information about the operation and impact of storm overflows in Scotland. We have outlined steps that the Scottish Government, SEPA and Scottish Water should take to improve data and monitoring on storm overflows in Scotland.
“We are also calling on the Scottish Government to publish up-to-date, clear and specific guidance about the exceptional circumstances when it is permissible for storm overflows to spill. Our analysis has found that while some storm overflows appear not to spill at all, others spill more frequently and for longer periods than can be considered exceptional. This situation must be addressed.
“ESS expects the Scottish Government, Scottish Water and SEPA to respond to the recommendations laid out in the report within six months.”
