Around 3.3% of Scotland’s population (182,516 people) are served by private water supplies (PWS) together with transient visitors such as tourists. This project sought to develop an understanding of the epidemiology and disease burden contribution of PWS in Scotland on the public health of the populations (indigenous and transient) exposed to the PWS. The project report comprises a risk profile to provide current knowledge about the risks of gastrointestinal pathogens associated with private water supplies in Scotland.

Since the onset of the COVID-19 pandemic in early 2020 - caused by the spread of the SARS-CoV-2 virus - scientists, engineers and epidemiologists have grappled with obtaining information about the extent of the prevalence of infected people in the community in different settings. Understanding community prevalence is an essential component of the fight against the virus, and plays a major role in informing public health officials and help Governments plan for the inevitable waves of infection.

The Slender Naiad (Najas flexilis) is a rare submerged, rooted aquatic plant, typically found in clear-water, lowland lakes. Within the UK sites it is now currently found only in Scotland, with its strongholds historically in Argyll, the Hebrides and Perthshire. Its mainland sites are under increasing threat, primarily from nutrient pollution and competition from invasive non-native species.

Septic tank systems (STS) are private sewage treatment facilities which typically serve the population not connected to main sewer networks. There is substantial uncertainty about the impact of septic tanks on water quality, primarily because of a lack of information about the location, number and condition, and inadequate monitoring of the effects of septic tank discharges to surface water and groundwater.  

Wastewater-based epidemiology (WBE) has received increasing attention over the past year across the world. In the UK, local, regional and national wastewater monitoring programmes were established in 2020 to detect severe acute respiratory syndrome coronavirus (SARS-CoVID-2) patterns in human sewage to monitor outbreaks. The establishment of these monitoring programmes has seen considerable investment into establishing the infrastructure, methodology and resources needed to sample, analyse, and interpret data from WBE.

A systematic review of evidence on lags in water quality response to diffuse pollution control measures implemented in Scotland is reported. The review focused on key pollutants in catchments smaller than 300 km² in temperate regions. Findings were evaluated based on catchment typologies (e.g. catchment size, precipitation, land use, pollutant residence time, and soil /waterbody type) and data/analyses (e.g. monitoring design and record length). There was no evidence supporting fixed timeframes for a water quality response to measures or catchment typology -based lags.

This study investigated the current state of knowledge reported in the literature on the sources of natural phenolic compounds; factors that trigger their release into the environment; their risks to water sources and potential mitigation measures to reduce these risks. A potential risk assessment methodology, which assesses the terrestrial sources of phenolic compounds and the potential risk to ground and surface waters was presented. 

The main findings and recommendations from this study are: 

Sampling wastewater from a community can be a relatively straightforward way to determine if specific agents are being excreted by that population. As SARSCoV-2, the causative agent of COVID19, can be present in the faeces of infected people, then it may be possible to determine if a community has infected individuals by monitoring the wastewater or other sewage samples for the presence of the virus.

Factoring ecological significance of sources into phosphorus source apportionment: Phase 2