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15th September 2021

The epidemiology and disease burden potential relating to private water supplies in Scotland

Epidemiology PWS

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. This is supplemented with preliminary work looking at the linkage of human gastrointestinal illness with private water supply microbiological failures and the scoping out of a quantitative microbiological risk assessment approach for PWS in Scotland. 

13th September 2021

Aerosol/droplet sampling of wastewater for SARS-CoV-2

Aerosol Report Front Cover

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.  Wastewater based epidemiology (WBE), in which the extent of infection in a community can be assessed by sampling and identifying viral RNA in wastewater, has been implemented in Scotland, rest of UK and elsewhere to help provide epidemiology data. This has been very successful in the main, however, the resolution of the system tends to be at wastewater treatment plant (WWTP) catchment level or major sewer lines leading to the WWTP.

In some cases it may be necessary to assess the level of infection close to the source so that data can be obtained at a building or building complex level. This project, led by Prof. Michael Gormley (Heriot Watt University) and sponsored by CREW, sought to investigate and prove the concept of detecting viral RNA in aerosols and droplets found in building sanitary plumbing systems (SPS). The hypothesis tested was that when a toilet (which contains faeces, urine, or vomit of a person infected with SARS-CoV-2) is flushed, the virus will be present in the aerosols and droplets generated within the system, and then be carried in the airstreams. Sampling the airstreams will capture the aerosols and droplets which can then the tested for the presence of viral RNA.

Findings: The research was carried out on a dedicated 2-storey SPS test rig with the capability to flush micro-organisms and detect their transport across two floors of a building.  The research demonstrated that viral RNA can be detected using bioaerosol sampling methods within a building’s sanitary plumbing system and so very near-source sampling is possible. The work also identified some practical implications for WBE in this setting, for example, sampling aerosols from SPS is influenced by environmental and water chemistry conditions, e.g. relative humidity and dissolved salts within the system.  It was also discovered that the most effective location to detect viral RNA is near the base of the vertical stack or from the horizontal collection drain at the bottom of the vertical stack, just before it connects with the main sewer using passive methods, thus greatly simplifying sampling. This proof of concept investigation has established effective very near-source sampling techniques in a laboratory setting and the next phase will be to test in live buildings which is already underway.

8th September 2021

Phosphorus recycling possibilities considering catchment and local agricultural system benefits: a review and regional Scottish case study

P Flows Report_Front Cover

This project was developed to downscale aspects of Scotland’s country-scale phosphorus (P) mass balance by looking at potential for regional recycling. The research firstly examined the background context of P sustainability in terms of recycled P sources, usage opportunities and constraints via a literature review. Secondly a case study, with a waterbody to regional basis, was developed to examine coupling that region’s P-rich resources from wastes with the local agricultural land for goals to both offset the raw imported resource of chemical phosphate fertiliser and limit P pollution of waters. Factors such as material availability, compositions, costs and transport were examined alongside the spatial distribution of agricultural land, crop usage constraints and basic environmental pollution risks.

Initial case study selection of a waterbody with P water quality failure led to examining a rural catchment bordering a city with extensive availability of current and potential recyclable P in excess of the catchment farmland. The inventories of available materials within municipal wastewater and commercial digestate sectors were complex to assemble. To effectively utilise the recycled P masses materials as fertiliser replacement not exceeding crop requirements it was necessary to go beyond the catchment bounds to a larger region of increased planning complexity (in terms of road transport distances, multiple planning boundaries). Simplifications were necessary in the assessment of swapping environmental risks between chemical and recycled P fertiliser forms, since practical tools and models are not yet available across diverse material compositions, soil and crop management combinations.

Phase I Climate Change Impact Assessment: Evaluating evidence-based changes in management strategy to steer adaptive responses for mitigating climate change impacts on water quality in Scottish standing waters

Scotland’s water environment is facing a climate crisis. This changing climate is already impacting on many standing waters across Scotland in the wake of the warmest decade (2011-2020) on record. There is an urgent need for collaborative environmental leadership to up the scale, pace and impact of fit for purpose climate mitigation strategies to safeguard the integrity, biodiversity, and sustainable use of Scottish standing waters now and in future.

The vision is that through this project Scotland will receive the evidence-base it needs to help steer the formation, prioritisation, and implementation of adaptive responses by key stakeholder organisations, for example through policy-based to nature-based solutions and coordinated management practices, to mitigate climate-driven risks and impacts these could have on the water quality of Scottish standing waters under different climate scenarios.

 

 

 

Project Scope

The overall aim of Phase I is to produce an evidence-base which addresses the urgent need to assess and understand climate change impacts on the water quality of Scottish standing waters[1]. This evidence-base will be used to inform and serve the collaborative development of mitigation strategies in Phase II for realising impact at multiple scales.

 

Research questions to be answered through this project:

  • Is there evidence of a causal link between climate change impacts and water quality issues in Scottish standing waters at national, regional, and local scales?
  • What are the main types of climate-driven water quality impacts identified in Scottish standing waters, under current and projected climate change scenarios?
  • Which areas, locations, and types of Scottish standing waters are currently most to least at risk in terms of water quality issues from climate change impacts at national, regional, and local scales?
  • Which areas, locations, and types of Scottish standing waters will likely experience exacerbated water quality risks under projected climate change scenarios?
  • What factors contribute to the risk of water quality issues from climate change impacts in Scottish standing waters at national, regional, and local scales?
  • What factors need to be considered for mitigating climate-driven risks to water quality in Scottish standing waters, under current and projected climate change scenarios?

[1] For the purpose of this project proposal Scottish standing waters will include lochs, reservoirs, and other locally important still waters. Using the criteria in Annex 1 of the SSSI site selection guidelines (2018) we would not expect this project scope to cover standing waters which are temporary or less than 1ha in area or 1m in depth (we recognise the value of ponds and pools however they are likely to be functionally and biologically distinctive with different data/evidence/tools available; canals are recognised as important but also excluded from this project scope as they are considered slow moving waters).

Project Objectives

Objective 1. Use Phase I to establish and deliver a preliminary evidence-base to evaluate the extent to which:

1.1 Climate change impacts are driving a current and future risk of water quality issues in Scottish standing waters with assessment undertaken at national, regional, and local scales.

1.2 Climate change impacts on water quality in Scottish standing waters are mediated through catchment management practices, in-lake processes, and other interacting factors (e.g. prevailing weather; hydrological extremes) in current and projected climate change scenarios.

 

Objective 2. Apply expert opinion, best available data, and combined outputs from Objective 1. to answer these 6 key strategic water research questions through this project:

2.1 Drivers and Impacts:

  • Is there evidence of a causal link between climate change impacts and water quality issues in Scottish standing waters at national, regional, and local scales?
  • What are the main types of climate-driven water quality impacts identified in Scottish standing waters, under current and projected climate change scenarios?

2.2 Risk:

  • Which areas, locations, and types of Scottish standing waters are currently most to least at risk in terms of water quality issues from climate change impacts at national, regional, and local scales?
  • Which areas, locations, and types of Scottish standing waters will likely experience exacerbated water quality risks under projected climate change scenarios?

2.3 Factors:

  • What factors contribute to the risk of water quality issues from climate change impacts in Scottish standing waters at national, regional, and local scales?
  • What factors need to be considered for mitigating climate-driven risks to water quality in Scottish standing waters, under current and projected climate change scenarios?
Contact Pauline Lang
27th August 2021

Dynamic Coast - Coastal Erosion in Scotland

CREW - Dynamic Coast

 

Coastal erosion is widely acknowledged to be a cross cutting issue affecting disparate interests (infrastructure, cultural and natural heritage, port facilities etc.) and
a coordinated approach to align effort across sectors is essential.

The Dynamic Coast was commissioned by CREW to provide the strategic evidence base on the extent of coastal erosion in Scotland. This will support the Scottish Government and the Scottish Public Sector decision-making and indicate areas of highest coastal erosion risk, where a more detailed evidence base may be required. The initial research published in 2017 by CREW, provided businesses and communities with readily interpretable evidence and modelling, based rates. This 2021 publication updates and supersedes the 2017 work, by including increased extents of eroding shoreline and the latest climate change projections on sea level rise, with an aim to help society become ‘sea level wise’ by planning now for our changing climate.   

There is international recognition that, for many countries, some of the first and most obvious effects of climate change will be through increased erosion and flood impacts on the coastline. Governments and organisations around the world are undertaking risk assessments to inform and shape new flexible adaptive approaches to better manage these growing risks. Many European partners and fellow UK administrations are searching for more sustainable approaches to address anticipated changes to our coastal assets. As relative sea level continues to rise, and storm impacts increase, many are questioning the assumption that existing artificial coastal defences should be raised and extended. The United Nations Intergovernmental Panel on Climate Change (IPCC) anticipates that the default management approach on the coast will become ‘avoidance and adaptation’ rather than the current ‘hold-the line’ via artificial defences. But where, when and how might  adaptation be implemented?

Given the lifespan of Scoland’s coastal infrastructure and other assets, together with the IPCC projections of anticipate climate change, the most appropriate route forward is by framing proposals within the precautionary principle, supported by a robust evidence-base of past changes and modelling of anticipated future changes, checked against appropriate coastal monitoring.  

For more information, please visit www.dynamiccoast.com and read the research summary and synopsis below.

30th July 2021

Slender Naiad (Najas Flexilis) Habitat - Site Prioritisation

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. To help stem the decline of the Slender Naiad and hopefully restore its populations, a research programme was set up and funded by CREW, and carried out by the UK Centre for Ecology & Hydrology in collaboration with the University of Stirling. In the first phase of this project, Gunn and Carvalho (2020), with the support of a number of aquatic plant experts, reviewed the available information on the habitat requirements of the Slender Naiad (https://www.crew.ac.uk/publication/slender-naiad-najas-flexilis-habitat-quality-assessment).

In the second phase of this project, the phase one findings were used to identify lochs in Scotland with suitable habitat for Slender Naiad. It could either be present at these sites yet unrecorded, or they would be lochs to be prioritised for its re-introduction. Suitable sites were first identified using water quality (alkalinity and nutrient) data. Applying a combination of thresholds for alkalinity and nutrient concentrations produced an initial list of 4092 potentially suitable lochs across Scotland. To refine this list, a novel method was developed to use existing data on other aquatic plants to identify habitat suitability. This process was carried out by evaluating a set of 80 “associated” aquatic plant species that have previously been recorded at known Slender Naiad sites. For each of these 80 species an “Indicator Value” score was calculated based on their occupancy and fidelity at sites with, and without, the Slender Naiad. Application of this methodology generated a shorter list of 867 potentially suitable lochs. Further prioritisation of sites on the mainland and sites within 60 km of an existing Slender Naiad sites produced a final short-list of 156 lochs as priority sites for further conservation action.

Of the top 20 ranked sites from the short-list of 156 lochs, the majority occur in Argyll, Dumfries, Galloway, and Stirlingshire, all close to known existing Slender Naiad sites. Additional criteria that could also be used to rank the priority list of sites for further investigations, such as connectivity to other lochs or absence of invasive non-native species in the area, were also highlighted.

It is quite possible that the Slender Naiad may already be present at some of these selected priority sites but may have been missed previously if the site was not surveyed sufficiently, or was previously surveyed too early in the summer season. It is recommended that field surveys be undertaken to first check whether the listed priority lochs hold undiscovered Slender Naiad populations and check the environmental quality (water quality and absence of invasive species). Because of the difficulties in surveying rare submerged aquatic plants, we also recommend sampling loch sediments to check if the seeds of Slender Naiad are present. If it is confirmed through site survey that the slender Naiad is not present, and that these lochs still meet the species’ environmental requirements, then these would be strong candidates for either the re-introduction of the Slender Naiad.

The impact of shadow flicker or pulsating shadow effect, caused by wind turbine blades, on Atlantic salmon (Salmo salar)

A review of the available literature relating to the impact of shadow flicker on freshwater fish, with a particular focus on Atlantic salmon in rivers. This may, depending on the evidence delivered, inform policy in relation to the placement of wind turbines in areas adjacent to rivers in the Scottish context.

Onshore windfarms have become a common sight within the Scottish countryside and may impact freshwater environments and the fish that they support in a number of ways. These include changes to water quality caused during construction and drainage, or damage to vulnerable freshwater habitats (such as gravels used by fish for spawning) during stream and river crossings. The issue of shadow flicker or pulsating shadow effects is a potential impact which has not been investigated with regard to the placement of onshore wind turbines but has been raised in respect to its potential impact in offshore installations. New turbines and the installation of larger turbines during the repowering of established sites, may have the potential to impact Atlantic salmon (Salmo salar). A species which is already undergoing significant declines throughout its natural range, and a feature within Special Areas of Conservation (SACs), may be adversely impacted by shadow flicker. This literature review will inform regulators and others as to whether this is an issue, whether it is not, or whether more targeted research is needed. It cuts across a range of policy areas, including renewable energy, climate change and conservation of features within designated sites and wider fisheries management.

 

Project Objectives

• Review the current literature on ‘shadow flicker’ on freshwater fish with a particular focus on Atlantic salmon; 

• Use examples from the literature to provide insights into the actual biological impact that these may have on Atlantic salmon in rivers; and 

• Suggest ways in which this issue, should it be shown to be significant, can be mitigated or used to inform wind turbine placement near rivers.

 

Research Questions to be answered through this project:

1.  What are the potential biological and ecological impacts/responses of shadow flicker on Atlantic salmon at an individual level at each life stage within a river system?

2.  Do Atlantic salmon habituate to repeated disturbance and may that increase susceptibility to other pressures, such as predation risk?

3. Can the impact of flicker be extrapolated to the whole Atlantic salmon population of an affected river?

4. Are there ways in which this issue can be successfully mitigated?

 

 

 

 

Contact Pauline Lang
8th June 2021

Developing a probabilistic risk model to estimate phosphorus, nitrogen and microbial pollution to water from septic tanks

Image of septic tank modelling report

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.  

Under the requirements of the Water Framework Directive, there is a need for SEPA to identify pressures contributing to water quality downgrades and to put in place appropriate and feasible measures to return waters to good status. SEPA currently use the SAGIS model to identify major pollutants including phosphorus (P) loads and concentrations at the waterbody scale. However, assumptions regarding parameterisation and uncertainty of SAGIS model outputs, particularly in rural areas, make it difficult to quantify the sources of P pollution from septic tanks. A new approach to modelling the contribution of STS P loading is therefore required to inform mitigation strategies, while accounting for uncertainties.

The aim of this project was to review the literature and develop a new probabilistic modelling approach, based on Bayesian Belief Networks (BBN), to improve understanding of soluble reactive phosphorus (SRP) losses to surface water from STS. This was initially undertaken for seven pilot catchments and then at a national scale. The model included a range of risk factors related to SRP losses from STS, resulting in simulated SRP losses that were comparable with previously available estimates. The project also considered what factors would need to be applied for modelling nitrogen (N) and microbial (FIOs) pollution risk from STS.

Key findings indicate that: (1) Poor performance of a large proportion of STS and hence the risk of SRP leaching to water bodies are related to the lack of proper soakaway system, poor soil quality, undersized STS, and lack of maintenance. Hence the literature review suggested multiple risk factors contributing to STS pollution risk to watercourses need to be considered when simulating SRP losses; (2) Model sensitivity analysis identified STS effluent concentration, STS density, and connectedness as the most important risk factors; (3) Upgrading of STS treatment to secondary or tertiary level, improving STS maintenance and/or disconnecting STS direct discharges to watercourses would be most effective in mitigating SRP losses at catchment scale; (4) The model could be adapted relatively easily to simulate microbial (faecal indicator organisms) and nitrogen losses from STS to surface water. A detailed catchment-based survey of STS condition would be beneficial to validate and improve BBN model parameterisation.

Taking a collaborative approach in the water sector: Lessons learned from the Metropolitan Glasgow Strategic Drainage Partnership (MGSDP)

The Metropolitan Glasgow Strategic Drainage Partnership (MGSDP) is a non-statutory, voluntary, partnership between public bodies involved in managing surface water, water quality, flood risk, investment planning and economic development in a regulatory, service provision, asset management and / or infrastructure provision capacity.

The aim of this project is to summarize, assess, and review the partnership since its start in 2002, and to provide recommendations based on lessons learned, geared towards three principal areas of interest:

(i) Recommendations for the MGSDP regarding any possible opportunities for improvements of the partnership;

(ii) Recommendations for practitioners and stakeholders, with a particular focus on how similar partnerships may benefit other cities and regions in Scotland;

(iii) Recommendations for key areas of policy and regulation within the Scottish Government (and its bodies) about the benefits of taking a collaborative partnership approach in the water sector.

 

The project was requested by the Flood Risk Management team at Scottish Government, and co-developed with Scottish Canals, Glasgow City Council, and CREW. The project was commissioned and funded by CREW, and is delivered by a multi-disciplinary team from the Universities of Abertay and Herriot Watt. The project steering group includes representatives from: Scottish Government, SEPA, Scottish Canals, Glasgow City Council, GCV Green Network, Dundee City Council, Aberdeen City Council, Scottish Water and ClimateXChange (CXC).

Project Objectives

The research questions for this project include:

How has the partnership developed since its start in 2002? What changes/impact have occurred since 2002? What obstacles exist? What recommendations can be given to the partnership? What can be learned for the management of flood risk and other aspects of water management in other areas of Scotland, in particular Scottish cities?

 

19th May 2021

Water Breakthrough Challenge

£40m Water Breakthrough Challenge now open for entries

The first Water Breakthrough Challenge is now open. The Challenge, delivered by Ofwat and Nesta Challenges supported by Arup, is calling for ambitious, innovative projects which can drive long-lasting benefits for customers, society and the environment. Water companies in England and Wales can apply for between £1 million and £10 million in funding to deliver initiatives they would otherwise be unable to invest in or explore, and are actively encouraged to enter in partnership with organisations within and outside the water sector. Entries close on 3 June. Selected entrants will be invited to submit further details from 28 June, with the winners to be announced in September 2021.

Please click on the Water Breakthrough Challenge communications word document below for more information, website link and contact details. We encourage you all to share this opportunity within your own organisations and networks. The comms pack includes a full press release, suggested social posts and media assets.

 

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