In 2015, a review of Scotland’s Water Sector was published by CREW in support of the Scottish Government’s Hydro Nation Strategy. This work reported on the scope and the scale of Scotland’s Water Sector, and how different parts of the sector link together using visual tools in the form of Scotland’s Water Map.

Onsite wastewater treatment systems (OWTS), the majority of which are septic tanks, are a contributing factor to phosphorus and faecal microbial loads. OWTS contribute to waterbodies failing to meet Water Framework Directive (WFD) objectives and as such, measures to improve the quality of OWTS discharges are required. Literature has been reviewed for a range of measures designed to reduce phosphorus and pathogen concentrations in effluent from OWTS. A feasibility assessment focussed on their application, effectiveness, efficiency, cost and ease of adaptation.

This project set out to explore the possibility of producing a set of four risk maps that could be used to determine the risk of diffuse pollution occurring within Scottish agricultural catchments. The key soil-based factors likely to affect water quality were deemed to be:

This report covers control measures for 13 high or moderate impact, and one ‘alarm’ species on the UKTAG list that were not covered by the Aldridge report for Natural England. It draws information from published and unpublished literature, listed best  practices, technical reports, unpublished reports, project websites and expert knowledge. For each species, a report was written to present essential background information about the ecology and biology of the species. This is followed by a list of  invasion pathways and known techniques to limit further spread.