Outfall Safari


River Crane – ZSL

In 2022 Forth Rivers Trust is going to be carrying out the Outfall Safari citizen science project on the River Almond and the River Leven in the Forth catchment.

Outfall Safari was originally created for the River Crane, a tributary of the Thames in West London, which has suffered from some major pollution issues in recent years. It was created by Crane Valley Partnership, the Environment Agency, Thames Water, the Zoological Society of London and the Friends of River Crane Environment. It was first run in 2016 on the River Crane and has since taken place on many other rivers in Greater London and beyond.

River Crane – ZSL

Outfall Safari is a citizen science method used to locate and assess the impact of polluting outfalls in our rivers and report them if necessary. Polluted outfalls can be a result of the surface water drainage system which carries rainfall runoff into rivers. Water from rainfall flows down drains into a system of pipes, which discharges the water into rivers at certain points known as surface water outfalls. However, outfalls can be a source of pollution to the river when wastewater makes it into the surface water system due to misconnections in the system. When washing facilities or household appliances are incorrectly plumbed in, it can lead to their wastewater entering the surface water drainage system and discharging into rivers. Evidence of this pollution can be seen around a polluting outfall, such as grey fungus, water discolouration, or rag waste in the river or caught on the banks.  

Evidence of pollution at an outfall – ZSL

When polluted surface water outfalls discharge wastewater into the river, it can contribute to elevated phosphate and ammonia levels and a reduction of dissolved oxygen in the water, which has a detrimental effect on the biodiversity of the natural habitat.

Outfall Safari aims to locate these polluting outfalls in our rivers with the help of volunteers carrying out surveys along the length of the river over a two-month period. The location of outfalls found is recorded, and the outfall is assessed to rank its impact. If the ranking system marks an outfall as seriously polluting it is reported immediately to SEPA.

Overall, Outfall Safari will give a broader picture of the scale of the pollution issues in the river, with the hopes that it will encourage greater investment to tackle the problem. Forth Rivers Trust will be carrying out Outfall Safari on the River Leven in Fife, and a stretch of the River Almond in West Lothian, with local training sessions taking place before the survey period starts. If you are interested in taking part, follow the links below to find out more and sign up.

River Almond at Almondell