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

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, either combined sewers or separate wastewater and rainwater sewers, which then discharge the water into rivers at certain points. However, outfalls can be a source of pollution to the river when wastewater is wrongly discharged from these sewer systems.  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. 

When polluted 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 is 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.



River Almond

We are surveying from Polkemmet Country Park by Whitburn to Almondell Country Park by Mid Calder. We hope in the future to be able to run the project again, focussing on the upper and lower reaches of the Almond, and also some of the major tributaries.

We have recruited many volunteers from local groups such as River Almond Action Group, The Friends of Almondell, and SRUC, as well as both experienced volunteers from the RiverLife project and new volunteers from the local communities.

Currently, our volunteers on the River Almond have completed surveying, and we will now be analysing the data and compiling a final report for end of May 2022.

River Leven

Volunteer recruitment sessions took place in towns around the Leven, as well as an online training session. They will be surveying the full length of the Leven, from the loch to the mouth.

The volunteers are currently out surveying until the end of May, and then we will start to analyse the results.


  • To record and map the dry weather condition of all outfalls in our rivers
  • To assess and rank the impact of the outfalls and report those that are polluting to the regulator
  • To build evidence on the scale of the polluting outfall problem and drive an increase in investment to resolve it
  • To engage communities with their local rivers and inspire change


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.


We want to say a big thank you our funders, to everyone who has contributed to the crowdfunding campaign, and to all our volunteers who are out on the rivers! To find out more information, or to register your interest in future Outfall Safaris, get in touch with h.streater@forthriverstrust.org