Contact Us

For information about the Sullied Sediments project, contact:

Project Lead
Professor Jeanette Rotchell
University of Hull 
(+44)1482 465333 

Project Coordinator
Annabel Hanson
East & North Yorkshire Waterways Partnership
(+44)1482 391678

A map of where volunteers have been measuring phosphate levels

RiverDip Volunteer Sampling Map

The Sullied Sediments team has been implementing our citizen science programme, RiverDip, over the past two years. We have far exceeded our target of recruiting 80 volunteers to take phosphate measurements from their local waterways. This was made possible in part due to the launch of our RiverDip training website and training video in September 2020, which enabled us to reach 70 prospective volunteers based in Belgium, the Netherlands, the UK, Germany and Tunisia. To visit this site, please go to: https:/ The results from our volunteers' sampling tests have been uploaded onto a map, which can be accessed here:

Below are a few pointers for understanding how the map works:

Each pin represents a single record uploaded via the RiverDip app. The pins are colour coded to reflect the level of phosphate found at that location. We use five colours for five different levels: none, low, medium, high and ‘failed for one reason or another’.

As you will see, many of the records indicate low levels of phosphate or levels below what we can measure (shown as none on the map). We do see some areas where medium or high levels of phosphate are detected too. More often than not, these higher levels occur when sediment has been disturbed and the phosphate has been re-released into the water column, giving us a temporary area of high phosphate concentration.

On the map you will also see a number of ‘failed devices’: these are tests that have not yielded any useful results. This can occur for various reasons, for example water may not have been able enter the PAD, a shadow across the image could distort the image analysis or the image could be obstructed by debris in the sample. In developing anything new we always find problems but we can learn from these as we develop the sampling further. That’s all part of research!

RiverDip is currently on hold over the winter months. However, as a legacy of the Sullied Sediments project, we are now exploring how the programme can be continued in the spring. If you would like to become a RiverDip volunteer, please register your interest via the website or contact our Project Coordinator, Annabel Hanson, at