Emerging water futures

Climate change poses a substantial threat to Scotland’s air, water, soils, geology and all living things – our natural capital. There is therefore an urgent need to research the impacts of climate change on Scotland’s assets such as plants, animals, fungi, insects, microbes (biodiversity) and our diverse range of habitats like forests, moorlands, wetlands, farmland, to understand how they may respond and be able to provide essential ecosystem services (the benefits we get from nature), such as water and climate regulation and ability to supply food.

This project which started in April 2022 and runs until March 2027 aims to support development of a proactive approach to water management under future environmental change. The project will:

  • Develop methods and use climatic projections, to understand a) the vulnerabilities of Scotland’s water resources to drought and b) future risks to water quality from nutrients and ECs (pharmaceuticals, microplastics, antimicrobial resistance genes)
  • Establish a baseline of ECs across Scotland to inform future response
  • Develop and apply trans-disciplinary approaches to evaluate options to monitor, mitigate and adapt to future threats to water scarcity and quality

In the context of future environmental change, the are recognised challenges around managing water resources, including drought and risks from emerging contaminants, as recognised at policy level in the RBMP 2021-27 and the recast Drinking Water Directive (rDWD) (increased focus on ECs and requirement for novel coliphage test for drinking water); SEPA National Water Scarcity Plan and Water Resources Management Plan.

The key drivers of this research are the needs of policy makers and managers to:

  • Have tools to predict where and when drought may occur in Scotland.
  • Understand where vulnerabilities to drought lie in our environment, economy and society.
  • Understand future changes in water quality in Scottish catchments; what drivers of change are and how this impacts ecosystem services and water users.
  • Improve and monitor rural drinking water quality and increase awareness of potential health risks from their water supplies.

The project will integrate model-based assessment of future risks to water quality and quantity under a range of scenarios, with new empirical water quality data and socio-economic risk assessment for drinking water supplies in four related work packages.

This WP aims to advance national scale understanding of future droughts and vulnerabilities of Scotland’s freshwater resources related to three dependent sectors/receptors (e.g. agricultural abstraction, wetland habitats, and migratory salmonids).

The drought of 2018 raised the profile of droughts in Scotland, with broad coverage of impacts, e.g. on whisky production. Future occurrence and magnitude of droughts are predicted to increase, with periods previously only occurring once every 40 years happening once every 20 years by 2050 , based on the Standardised Precipitation-Evapotranspiration Index (SPEI) for 2021-2040 found. Recent work by NatureScot increases in extreme droughts (SPEI ? -2) across Scotland with highest likelihood in eastern Scotland including Grampian and Caithness. However, these spatial patterns do not always map on surface water.

We will build an integrated trans-disciplinary drought vulnerability decision support framework, integrating approaches and data from all workpackages and build on recent UK level research on drought and water scarcity.

Emerging contaminants such as pharmaceuticals and personal care products and microplastics have been detected in surface and ground waters, sewage effluent and at trace concentrations in drinking waters. There are data gaps in baseline information on pharmaceuticals in the water environment in Scotland in 18 local authority areas (367 catchments) and a bias towards effluents and river sediment. Also, antimicrobial resistance is a biological emerging contaminant characterised as ‘the silent pandemic [that] could have consequences far more deadly than COVID”, reflected in the UK 5-year Action Plan for AMR 2019-2024 and the SOHNAP group’s “One-Health” approach, with clear emphasis on the role of the environment in transmission of antimicrobial resistance.

Emerging contaminants have potential to cause both ecotoxicological effects and impacts on human health, therefore their prevalence is of particular concern with respect to drinking water sources. Some emerging contaminants are known drivers of antimicrobial resistance – e.g. antibiotics (selectors), pharmaceuticals and personal care products and inorganic pollutants such as heavy metals (co-selectors). Microplastics threaten biodiversity, ecosystem services and potentially human health, yet minimal data pertain to their detection in Scottish freshwaters.

This project will fill data gaps and complement Chemical Investigation Programme data by identifying and mapping key emerging contaminants in freshwaters through three field campaigns.

While the impacts of future change on water quality in Scotland represent a major knowledge gap, water quality modelling frequently suffers from lack of available data at a high-enough spatial and temporal resolution as well as high uncertainty. We will develop novel monitoring and modelling approaches that are urgently needed to address these challenges.

Monitoring approaches:

Monthly data typically available from national regulatory water quality monitoring is at risk of under-estimating true pollutant concentrations and loads, making it difficult to inform cost-effective targeting of pollution mitigation measures. Wide deployment of high-temporal resolution monitoring instruments continues to be hindered by high cost and there is an urgent need for innovative techniques for cheaper, reliable high resolution field assessment to understand pollutant sources, pathways and responses to mitigation measures. Here, we will develop and test novel near-real time monitoring approaches using in-situ sensors to aid understanding of current and future water quality in terms of nutrients and emerging contaminants and inform adaptive management in Scotland.

Modelling approaches:

Modelling facilitates an understanding of both current drivers and future risks to the water environment. However, the application of models to antimicrobial resistance is rare and hindered by lack of data, limited mechanistic understanding and a failure to consider the role of environmental factors (in addition to anthropogenic activities) on transmission. The temporal and spatial dynamics of antimicrobial resistance genes in catchment systems is likely to be important in influencing risk levels across seasons and scales but is not well represented in models to date. Further, while new emerging contaminants appear every year, for many we do not have sufficient monitoring data or knowledge to characterise their behaviour in the environment. Here, we propose to simulate the fate and risks of emerging contaminants using a Bayesian Belief Network (BBN) that facilitates integration of diverse data sources (literature, expert opinion, spatio-temporal data) within a causal framework and is particularly suitable in situations with scarce data or incomplete knowledge and building a holistic trans-disciplinary system-based approach to quantitative risk assessment.

The BBN will be integrated with environmental change scenarios generated in WP1 to assess future water quality risks from emerging contaminants. Diffuse nitrogen pollution from agriculture continues to pose a major threat to surface and groundwater quality in Scotland. Nitrate Vulnerable Zones, designated under the EC Nitrates Directive are reviewed every four years using data from SEPA’s monitoring network and national scale modelling of nitrate leaching to groundwater using the NIRAMS model. Here we will i) update the national scale nitrogen model NIRAMS with current climatic and land use variables, ii) explore the integration of groundwater resources modelling aspects in NIRAMS with the drought vulnerability modelling framework developed in WP1 and iii) generate simulations to refine a Gaussian process emulator that will be applied to produce probabilistic simulations of groundwater nitrate concentrations under future climate and land use change scenarios.

This WP combines qualitative social sciences methods with risk mapping, feasibility assessments, and somatic coliphage test development to build an interdisciplinary understanding of the risks, impacts, and responses that arise from growing uncertainty and variability in drinking water supplies/quality. We will provide recommendations to support rural supply planning, assess the risks to drinking water through the development of novel tests and engage rural communities to enhance the resilience of these supplies.

Rural drinking water is one area of supply that is significantly impacted by the emerging threats to Scotland’s water resources and services that are posed by pollution and contamination, low levels of user awareness, and climate change impacts. Users and managers of these supplies must contend with the increased regularity of low flow conditions and drought, health and social impacts of poor drinking water quality, as well as the need to respond to changing policy and regulatory environments. Although these impacts play out across multiple scales, rural households and businesses dependent on private water supplies, experience these challenges in very material ways, and often find themselves tasked with developing coping strategies and innovating in the face of growing uncertainty. As such, rural private water supplies are an appropriate case study for examining: the socio-economic factors that amplify/mitigate vulnerability to water shortages and water quality issues, attitudes and perceptions of risk associated with water supplies, and the feasibility of self-monitoring to support a wider self-supply management model.

At the same time, changes to the recast Drinking Water Directive created new obligations for regulatory monitoring of somatic coliphages in source waters and through the treatment train. Existing culture-based methods are labour intensive, with a need for more rapid tests, especially. a molecular-based method. Of interest are development of RT-qPCR quantification of viral genome biomarkers and metagenomic and metatranscriptomic sequencing of whole viral genomes.

This project is funded by the Scottish Government RESAS Strategic Research Programme (SRP) 2022-27.

It is project ‘JHI-D2-1’ within the Natural resources Theme and the Water topic.