Fire and water: predicting and mitigating water pollution risk from wildfire ash

Lead Research Organisation: Swansea University
Department Name: College of Science

Abstract

Every year vegetation fires (wildfires and management burns) affect ~4% of the global vegetated land surface. This includes forests, grasslands or peatlands, which provide 60% of the water supply for the world's largest 100 cities and for 70% of for the UK's population. In England 114 km2 of uplands are affected by management burns alone and the UK Fire and Rescue Services attend to over 70,000 vegetation fires per year. Vegetation fires can have serious impacts on water quality, which, combined with the current and projected future further decline in fresh water availability and increase in fire risk in many regions around the world, has given rise to increased attention to water contamination risks from fire. The primary threat is ash left behind by fire, which can be transported very easily into water bodies by water erosion. Ash is typically rich in contaminants and its transfer into water supply catchments has led to numerous drinking-water restrictions and substantial treatments costs in recent years (e.g. for Belfast, Canberra, Denver, Fort McMurray, Sydney). In the UK, losses to the water industry from vegetation fires are estimated at £16 Mill. per year.

Models are widely used by scientists and land managers to predict soil erosion or flood risks after disturbance events such as harvesting or wildfire, however, no models currently exist that allow predicting of ash transport and associated water contamination risk following fire. This gap in knowledge and resource seriously compromises the ability of land managers to anticipate water contamination risks from fire and to implement effective mitigation treatments to reduce fire risk, prevent erosion after fire and, adjust water treatment capabilities.

This timely project brings together an interdisciplinary team of international experts from the UK, USA and Australia with the aim to address this critical knowledge and tools gap. Building on recent advances and proof-of-concept work in this field, we are now able to (i) obtain critical fundamental knowledge on wildfire ash transport processes and its contamination potential and, using this knowledge, to (b) develop the first end-user probabilistic model that allows predicting ash delivery and associated water contamination risk to the hydrological network.

The model will be validated for key fire-prone and fire-managed land cover types that have suffered critical ash-induced water pollution events in the past (including UK uplands, US conifer forest and Australian eucalyptus forest) using the first field dataset on ash transport parameters by water erosion and an extensive dataset on potential contamination by ash obtained through this project for these key regions.

To maximize the impact of the project, the web-based model will developed in collaboration with, and be made available to, users from land and catchment management sectors to support effective protection of aquatic ecosystems and drinking water supply from contamination by ash.

Planned Impact

The ability to predict the risk of water contamination is essential in supporting environmental protection, to prevent or mitigate pollution events and to reduce risks of drinking water restrictions and water treatments costs. Given that ash from wildfire can pose a serious threat to water quality and that fire-affected regions provide 60% of the water supply for the world's largest 100 cities and to 70% for the UK's population, the tool developed here will have a major impact on the risk management of water supply catchments. Existing tools to predict the risk of soil erosion, landslides and flooding following disturbance events such as ERMiT are already widely used in the land management sector. The project will therefore fill an obvious and important gap.

It combines fundamental and applied research, and will maximise its impact by involving end-users from the outset and by including effective pathways for delivering outcomes to the wider academic and management end-user community.

Scientific and Academic beneficiaries: The outcomes will include the first comprehensive datasets on ash transport parameters and contaminant concentrations for key land cover types and will be freely available via the Environmental Information Data Centre. Both datasets will provide critical information to researchers in hydrology, hydrogeology, and water quality to enable predictions of ash induced contamination risks. Whilst not a focus of this project, the data obtained will also be relevant to air- and groundwater quality researchers. We will disseminate the scientific results and links to the datasets via international conferences and gold open access publications in high-impact journals.

Industry and Policy Makers: The model will provide a critical tool quantifying potential ash delivery and contamination risk to managers in the design of effective mitigation plans to prevent fire-induced water and air contamination, one of the present risks identified by DEFRA in its UK Climate Change Risk Assessment (UK-CCRA) 2017. This model will also enable to generate simulations for current and anticipated future climate and land management scenarios that are valuable in informing policies regarding land management and in promoting more effective fuel control measures using management burns as suggested in the UK-CCRA 2017.

To maximize these impacts, we will include two-way information exchange from the very outset with our national and international partners and their collaborators from the catchment management sector (Welsh Water, Brecon Beacons National Park, Melbourne Water and the US Forest Service). An open-access on-line version of the model will be designed specifically for end-users. To fully achieve the transfer of knowledge to end-users we will carry out two face-to face workshops and webinars to provide training to managers from our PPs and other potential users.

Public engagement: The education and involvement of the wider society is critical to achieve the goal of reducing fire-induced risks. To that end, we will incorporate a simplified version of the model into the web-interactive activity "Fire and Water" for primary and secondary school children to showcase the importance of fire for the functioning of ecosystems, the usefulness of fire and thinning operations to control fuel loads and prevent extreme fire events, and the potential impacts of wildfires or prescribed burns in poorly managed forests or heathlands on water quality. This activity will be included in the ongoing educational programme of our PP Welsh Water and showcased regionally at the National Waterfront Museum and the National Museum Cardiff programmes, the science communication project Oriel Science, and the Swansea Science Festival to showcase the societal benefits of research and to inspire, and receive feedback from, the general public. As in our previous work, we will also take advantage of wider dissemination opportunities via the media.

Publications

10 25 50
 
Description - High contaminant contents in wildfire ash from Saddleworth and Brecon Beacon catchment areas

- Supported United Utilities, the UK's largest water supplier in mitigating contamination risk after the unprecedented 2018 Saddleworth Moor wildfires that burned large areas of United Utilities' drinking water supply catchments. This work included assessing the potential impacts of future fires in catchments at risk of intense burning if a fire should occur.

- Supported Australia's largest water supplier in mitigating contamination risk after the unprecedented 2020 wildfires that burned much of Australia's largest drinking water catchment. This included identification of erosion hotspots for mitigation treatments.

- The model developed in this project also supported water contamination risk assessments after the extreme wildfires in Oregon in summer 2020.
Exploitation Route Water contamination risk assessment and underpinning of mitigation measures in burned catchments in the UK, Australia and USA
Sectors Agriculture, Food and Drink,Environment

 
Description Following the 2018 Saddleworth Moor wildfire, one of the UK's largest wildfires in recorded history, we carried out a water contamination risk analysis. The fire burned deep into peatland and the ash was high in metal contaminants through a long legacy of emissions from its surrounding heavy industry. Based on this and our recent conceptual work, which included also an evaluation of fire effects on upland water resources in the we were able to directly advise on the likely most effective measures for protecting the reservoir from ash contamination risk. During an on-site meeting on July 11, led by Doerr with the United Utilities' Water Processes Technical Specialists and representatives from Moors of the Future, we advised to block drainage lines with straw and to cover the most severely slopes adjacent to the reservoir with permeable material. This advice was followed, and the procedures carried out by the UK's largest water supply company for the first substantive (and to date successful) mitigation measure for on-site water contamination risk mitigation following fire in the UK.
First Year Of Impact 2018
Sector Agriculture, Food and Drink,Environment
Impact Types Societal,Economic,Policy & public services

 
Description Our conceptual decision support model underpinning this grant has been adopted in its entirety in the National good practice operational guidelines for the Australian Water Industry
Geographic Reach Australia 
Policy Influence Type Influenced training of practitioners or researchers
Impact Following the catastrophic 'Black summer' 2019/2020 Australian wildfires, the Water Services Association of Australia (WSAA), who represent 20,000,000 urban water customers, adopted our decision-support framework for water contamination risk assessment and mitigation following wildfires in its entirety in their national industry guidelines providing a "structured approach to identifying mitigating strategies and undertaking risk assessments.
URL https://www.wsaa.asn.au/publication/national-good-practice-operational-guidelines-bushfire-managemen...
 
Description Presentation to OECD to influence policy
Geographic Reach Multiple continents/international 
Policy Influence Type Participation in a advisory committee
URL https://www.oecd.org/environment/cc/firstmeetingoftheoecdtaskforceonclimatechangeadaptation.htm
 
Description Collaboration with Uk and overseas water supply companies 
Organisation United Utilities Group PLC
Country United Kingdom 
Sector Private 
PI Contribution 1. Following the extensive Saddleworth Moor wildfires of June 2018, we began collaborative work with United Utilities sampling and monitoring the heavily burned Swineshaw catchment to assess water contamination risk following these fires. The helped us to advance our predictive contamination risk model and we provided them with a risk assessment for future fire in their not yet burned catchments. 2. The unprecedented Australian wildfire season of 2019/20 burned most of Sydney's main (and Australia's largest) water-supply catchment (270,085 ha). Based on the made in this project, we were able to provide Water New South Wales with (i) model outputs quantifying ash loads across their subcatchments (total load >2.5 Mill. T), (ii) expected contaminant concentrations in ash, and (iii) a risk analysis of ash and contaminant movement triggered by rainstorms of specific probabilities using our WEPP-PeP model. These outputs directly guided mitigation measures such as installation of fabric curtains across the lake to capture sediment and upgrading of water treatment capabilities [I,II]. Subsequent extreme rainfall (>250 mm on 10/02/2020) eroded all ash from the hillslopes. This modelled worse-case scenario resulted in large sediment plumes in the reservoir yet the mitigation measures enabled WNSW to continue supplying clean drinking water to Sydney.
Collaborator Contribution 1. We arranged a meeting on site with United Utilities, Moor for the Future and the land owner to advise on emergency hillslope and channel treatments to mitigate water contamination risk. The recommendations were followed and hillslope and channels treated with erosion prevention measures. United Utilities subsequently provided us with input on how to make our predictive contamination risk model even more beneficial to the end user. 2. Water New South Wales provided us with water quality data and discharge data that allowed us to calibrate the model as well as suggestions for model improvements in terms of its capabilities and outputs.
Impact The recommendations were followed and hillslope and channels treated with erosion prevention measures.
Start Year 2018
 
Description Collaboration with Uk and overseas water supply companies 
Organisation Water New South Wales
Country Australia 
Sector Private 
PI Contribution 1. Following the extensive Saddleworth Moor wildfires of June 2018, we began collaborative work with United Utilities sampling and monitoring the heavily burned Swineshaw catchment to assess water contamination risk following these fires. The helped us to advance our predictive contamination risk model and we provided them with a risk assessment for future fire in their not yet burned catchments. 2. The unprecedented Australian wildfire season of 2019/20 burned most of Sydney's main (and Australia's largest) water-supply catchment (270,085 ha). Based on the made in this project, we were able to provide Water New South Wales with (i) model outputs quantifying ash loads across their subcatchments (total load >2.5 Mill. T), (ii) expected contaminant concentrations in ash, and (iii) a risk analysis of ash and contaminant movement triggered by rainstorms of specific probabilities using our WEPP-PeP model. These outputs directly guided mitigation measures such as installation of fabric curtains across the lake to capture sediment and upgrading of water treatment capabilities [I,II]. Subsequent extreme rainfall (>250 mm on 10/02/2020) eroded all ash from the hillslopes. This modelled worse-case scenario resulted in large sediment plumes in the reservoir yet the mitigation measures enabled WNSW to continue supplying clean drinking water to Sydney.
Collaborator Contribution 1. We arranged a meeting on site with United Utilities, Moor for the Future and the land owner to advise on emergency hillslope and channel treatments to mitigate water contamination risk. The recommendations were followed and hillslope and channels treated with erosion prevention measures. United Utilities subsequently provided us with input on how to make our predictive contamination risk model even more beneficial to the end user. 2. Water New South Wales provided us with water quality data and discharge data that allowed us to calibrate the model as well as suggestions for model improvements in terms of its capabilities and outputs.
Impact The recommendations were followed and hillslope and channels treated with erosion prevention measures.
Start Year 2018
 
Title WEBcloud-WATAR end user modelling tool 
Description The WEPPcloud-WATAR tool (Water Erosion Prediction Project cloud model - Wildfire Ash Transport And Risk estimation tool) aims at quantifying fire-induced risks to water quality. This end-user model has been under development funded through this grant since 2018. It predicts the probability of both ash and soil, and the potential pollutants in them, to be delivered from burned hillslopes into stream channels and waterbodies. WEPPcloud-WATAR is powered by the well-established Water Erosion Prediction Project, WEPP model (Laflen et al. 1997), enhanced with the incorporation of channel hydrology and sediment routing routines (Wang et al. 2010; Wang et al. 2014). Its main advantage over other widely-used erosion models is that it has the capabilities to simulate transport not only of soil, but also of ash and pollutants contained in both, from the hillslopes. These enhanced capabilities provide much more comprehensive probabilistic and spatially distributed predictions of water contamination risk to water assets than other models. The model also automates the acquisition and processing of input data (climate, elevation, soil, and land management information, as well as ash composition) from available datasets, which substantially simplifies its application and reduces the time needed to produce simulations. WEPPcloud-WATAR has specific online interfaces for Australia (WEPPcloud-WATAR-AU), the USA (WEPPcloud-WATAR-US), and Europe (WEPPcloud-WATAR-EU)(https://wepp.cloud). 
Type Of Technology Webtool/Application 
Year Produced 2020 
Impact Used to inform major water suppliers (United Utilities-UK; WaterNSW-Australia) about erosion and water contamination risk following major wildfire events. 
URL https://wepp.cloud
 
Description Article in international press 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Article in "Die Welt" on Australian bushfires and their impacts (Die Welt is in German, but has a wide global distribution)
Year(s) Of Engagement Activity 2020
URL https://www.welt.de/wissenschaft/plus205013954/Feuer-in-Australien-So-viel-Klimawandel-steckt-in-den...
 
Description BBC radio interview 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact BBC Paul Hudson Weather show, 18 Nov. 2018
Year(s) Of Engagement Activity 2018
URL https://www.bbc.co.uk/programmes/p06qcc48
 
Description BBC1 world news live TV interview 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact BBC1 worlds news live TV interview (12 Nov. 2018) following the catastrophic wildfires of Nov. 2018 that destroyed the town of Paradise in California.
Parts of these were also are on various BBC radio stations.
Year(s) Of Engagement Activity 2018
 
Description Commissioned article for BBC world news 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Commissioned BBC world news piece "Why wildfires are breaking out in the 'wrong' countries",
https://www.bbc.co.uk/news/world-44941999;
>500,000 reads
Year(s) Of Engagement Activity 2018
URL https://www.bbc.co.uk/news/world-44941999
 
Description Conference Presentation: The Fire Continuum Conference, Missoula, USA, May 2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact Conference Presentation: Assessing water contamination risk following vegetation fire: challenges, opportunities and a framework for progress. The Fire Continuum Conference, Missoula, USA, May 2018
Year(s) Of Engagement Activity 2018
 
Description Conference presentation 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact European Geosciences Union Conference 2020

Santin, C., Jones, M. W., Neris, J., and Doerr, S. H.: After the fire: biogeochemical effects of charcoal and ash on fire-affected landscapes, EGU General Assembly 2020, Online, 4-8 May 2020, EGU2020-9433, https://doi.org/10.5194/egusphere-egu2020-9433, 2020
Year(s) Of Engagement Activity 2020
URL https://meetingorganizer.copernicus.org/EGU2020/EGU2020-9433.html
 
Description Conference presentation: 8th Int. Conf. Forest Fire Research 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact Conference presentation: Fire impacts on water quality: current challenges and opportunities for progress. 8th Int. Conf. Forest Fire Research, Coimbra, Nov. 2018
Year(s) Of Engagement Activity 2018
 
Description Euronews live - 2nd TV interview 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Euronews live - 2nd TV interview (19 Nov. 2018) following the catastrophic wildfires of Nov. 2018 that destroyed the town of Paradise in California and US president Trump's controversial comments on how to avoid such disasters.
Year(s) Of Engagement Activity 2018
 
Description Euronews live interview 1 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Euronews live TV interview (13 Nov. 2018) following the catastrophic wildfires of Nov. 2018 that destroyed the town of Paradise in California
Year(s) Of Engagement Activity 2018
 
Description Global media coverage 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Interview within an article on global problems arising from water contamination following wildfires. Published in the New York Times and numerous media outlets in print and digital around the world (4 Feb: 2020) "As forests burn around the world, drinking water is at risk"
Year(s) Of Engagement Activity 2020
URL https://apnews.com/972de4685a81c40bce76880a626cfa18
 
Description International Conference Presentation 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact AGU Fall meeting San Francisco: Presentation: "Incorporating water contamination risk from wildfire ash into the decision-making process: a new online tool for researchers and end-users" in conference session: H31H - Wildfire Effects on Water Resources, Landscapes, and Ecosystems
Year(s) Of Engagement Activity 2019
URL https://agu.confex.com/agu/fm19/meetingapp.cgi/Paper/611668
 
Description Invited presentation to OECD working group on global wildfire risk and potential impacts including on water quality 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact Presentation on wildfire and climate change at OECD task force meeting for climate change adaption to 80 OECD delegates from 38 countries. The working group intends to bring wildfire adaptation into general policy within the OECD
Year(s) Of Engagement Activity 2020
URL https://www.slideshare.net/OECD_ENV/task-force-on-climate-change-adaptation-stefan-doerr
 
Description Presentation and Q&A session for year 11 pupils at Berhamsted School 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Presentation and Q&A session for year 11 pupils at Berhamsted School in June 2020 (https://www.berkhamsted.com). This involved a general introduction about wildfire and specifics including how to mitigate fire impacts on water resources including the activities in this project.
Year(s) Of Engagement Activity 2020
 
Description Presentation at European Geosciences Union General Assembly 2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other audiences
Results and Impact Conference presentation:
An ecotoxicological assessment of wildfire ash produced in contrasting ecosystems. European Geosciences Union General Assembly, Vienna, 8-13 April 2018. (EGU2018-17183)
Year(s) Of Engagement Activity 2018
 
Description Presentation on the project outputs at a EC COST Action working group meeting, 1 March 2021 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Presentation on the project outputs at a EC COST Action working group meeting, 1 March 2021. Working group 3, COST Action FireLinks (https://firelinks.eu):
S.H. Doerr: "Predicting and mitigating fire impacts on soil and water quality following the Australian 2019/2020 wildfires: insights from Sydney's largest water supply catchment."
Year(s) Of Engagement Activity 2021
URL https://firelinks.eu/event/online-2021-wg3-meeting/
 
Description Science Week 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Policymakers/politicians
Results and Impact Display and interactive exhibit about water contamination risk of wildfires at the Welsh Government Office in Cardiff as part of the National Science week, 11 March 2018.
Direct engagement, quiz and discussion with Welsh Government officials, the press and the public.
Year(s) Of Engagement Activity 2019