Pesticide Management for Better Water Quality (PEST-MAN)

EPA logo

State date: 01/01/20                    End date: 31/12/23

Funder: EPA

Principal Investigator: Prof Mark Healy (with Drs Alma Siggins and Liam Morrison (NUI G), Per-Erik Mellander  (Teagasc), and Paraic Ryan (UCC), and Breda Moore and Sandra Lacey (T.E. Laboratories, Carlow)

Budget: € 452,004


An increasing world population means that there will be inevitably an increased demand for food. To address this, international policy has been towards intensification of agriculture, which, in turn, is transposed in various national programmes of measures [e.g. DAFM (2010) in Ireland]. This has led to an increased intensity of farming practices in some countries (Eurostat, 2017). This is linked with the increased use of pesticides, as their use enhances efficiency per hectare of land farmed (Pretty and Bharucha, 2014). In Ireland, for example, 2,861 tonnes of pesticides were used in 2017 (DAFM,2017), of which herbicides and fungicides comprise the main types of pesticides used (DAFM, 2017). The urban environment also represents an important arena of pesticide use. Pesticides are employed by home owners and pest control professionals to protect property, prevent or destroy unwanted species including insects and weeds, and minimise disease threats.  Although they are an integral part of modern, industrialised farming practices and are commonly used in urban settings, pesticides may have an adverse effect on microbial communities in soils (Jacobsen and Hjelmsø, 2014), waterbodies (Munz et al., 2017), and on human health (Kim et al., 2017).  Pathways of pesticides in rural and urban environments are mainly via the soil as surface runoff and leached water, and are largely driven by the nature of the rainfall in the period after application (McGrath et al., 2008). For example, it has been established that the concentration of pesticides in surface soils, at the time of significant rainfall events, is correlated with the concentration observed in drains or rivers immediately afterwards (Nolan et al., 2008). Further, land management practices such as irrigation and application coinciding with rainfall events can increase a pesticide’s ability to leach (McManus et al., 2017).  

PEST-MAN (PESTicide MANagement for better water quality) will use a DPSIR (Drivers, Pressures, State, Impacts, Responses) framework to assess how drinking water and human health may be affected by pesticide use in Ireland. Driving forces may be social, economic, political, or environmental, that cause pressures on the environment. These pressures may change the state of the environment, which in turn impacts on the provision of ecosystem services, such as the provision of good quality water. Finally, socio-political systems can initiate responses that aim to minimize and mitigate negative impacts and enhance ecosystem services. These responses may take place via policies, environmental management, incentives and governance. Within the DPSIR framework, PEST-MAN will adopt a source-pathway-receptor approach to the study.

The overarching aim of this proposal is to use a multidisciplinary approach merging soil processes, molecular biology, engineering, and quantitative risk assessment methodologies to: (1) understand the drivers and pressures for the use of pesticides in the environment, (2) examine their fate and persistence, (3) evaluate any potential impact and risks to the environment and human health, (4) develop a low-cost, passive, in-situ method to remediate pesticides in the environment, and (5) disseminate knowledge and engage stakeholders and the general public in the project.    PEST-MAN will utilise data from six catchments monitored as part of the Agricultural Catchments Programme (ACP), two of which have already been intensively monitored for pesticides (Ballycanew and Castledockerell). It will use low-cost, passive remediation techniques using ‘waste’ and organic materials to remediate pesticides in catchments where pesticides have been measured in surface and groundwater, and will monitor their efficacy using novel passive samplers in the streams draining the impacted catchments. 

Water management for the sustainable use and protection of peatlands

EPA logo

Start date: 01/04/19      End date: 31/03/21

Funder: H2020 - Water Joint Programming Initiative

Principal Investigator: Prof Mark Healy and Dr Oisin Callery


Peatland are important in several regions as they contribute to many ecosystem services such as drinking water provision, biomass production and flood retention. When peatlands are drained, negative environmental impacts include reduced surface water quality, loss in biodiversity and green house gas emission. Peatland water management must consider ways to: i) reduce water-related environmental impacts, ii) produce crops and biomass, iii) limit subsidence and soil loss, iv) prevent fire during droughts, v) viable solutions for restoration and after use of degraded sites. Water management must consider different type of peatlands, different land use options, climate, and socio-economic settings. As peat subsides, acid sulphate soil may be exposed with time (from below peatlands). In coastal lowlands, acid surges and salt water intrusion add to the complexity of water management. To limit impacts on surface water and to reach environmental and sustainable development goals; water and land protection on peat soils should be better developed. The potential mitigation options depend on several issues such as land use, peatland type, hydrological setting, climate, geology and the socio-economic setting. Several recommendations for future peatland management have been discussed, suggested and/or required by authorities and NGOs. The options suggested often involve water management with effects on land use and therefore on local communities, land owners and biomass producers. The options outlined should be scientifically sound and tested in practice. Lack of effective, simple and robust water management options to achieve the policy goals result in stakeholders’ frustration, lack of compliance and poor environmental practice guided by an “opportunity driven strategy” rather than “conservation of ecosystem services” approach. This proposal aims to develop the scientific knowledgebase on   peatlands and water management for different types of peatlands found in peat rich areas of Northern Europe and Indonesia. The work is organized in 5 work packages (WPs) devoted to: i) Analysis of peatland use impacts on hydrology and water quality, ii) Solutions for efficient water management and water quality control, iii) Tools for integrated land and water management on peat soils, iv) Stakeholder involvement and communication to outline best management options, v) Project management and coordination. A database on peat soil hydrology, water management options and a toolbox on methods for water management will be developed with educational material for capacity building in different regions. This will allow stakeholders to make water management plans on local and catchment scale that meet multiple policy goals and allow a transition for smarter water and land management and suitable solutions to future decision-making.

The mitigation of soil and groundwater impacts using mixed waste media

Yellow flag (new)

Start date: 1/6/18          End Date: 31/5/21

Funder: Marie Skłodowska-Curie Innovative Training Network

Principal Investigator: Dr Mark Healy (NUI Galway), Mr Mark Bowkett (T.E. Laboratories Ltd.), Prof Owen Fenton (Teagasc)


INSPIRATION (managing soil and groundwater impacts from agriculture for sustainable intensification) is a multidisciplinary European Training Network composed of 26 partners in 9 European countries, which aims to develop low-technology management practices, monitoring approaches, modelling and decision-making tools, and innovative technology applications in the field of sustainable agriculture by a combination of fundamental and applied science ( The research focuses on understanding and predicting the environmental fate of nutrient and organic pollutants from agricultural practices and managing their impact on soil, water and climate systems to ensure sustainable production. It links lab- to catchment-scale studies of biogeochemical processes with field-scale evaluation of novel monitoring and management concepts, using state-of-the-art methods. The network will provide high-quality research training to young scientists, through 15 fully-funded Early-Stage Researcher (PhD level) fellowships. The network includes leading research groups, regulators, advisory bodies, water utilities, consulting firms, commercial R&D and multinationals. The project has an international advisory group and will undertake a comprehensive programme of knowledge transfer and outreach activities with other scientific networks and professional bodies in this field. 

This is an industry-based PhD and the project will focus on the mitigation of soil and groundwater impacts from agriculture using mixed waste media. The main objectives of the PhD will include the following:
1. Identification of locally sourced raw materials across partner countries used in isolation or in combination that have the capacity to mitigate mixed contaminants and are safe to recycle back on land. 
2. Evaluation of performance and biochar and other potential media in this application.
3. Development of methodology to measure NKP and other contaminants in the media. Passive sampling and microfluidic technologies will be considered.
4. Development of in-process monitoring to provide information for modelling on lab pilot plant.
5. Field deployment of measuring technology to monitor performance of media in a field application.


Phosphorus recovery for fertilizers from dairy processing waste

Yellow flag (new)

Start date: 01/10/18    End date: 09/09/21

Funder: Marie Skłodoswka Curie Innovative Training Network

Principal Investigator: Dr Mark Healy (NUI Galway), Prof Owen Fenton (Teagasc)


Phosphorous (P) is essential for life, but it is a finite resource. The industrialization of food production in order to feed a rapidly expanding population is giving rise to serious leakage of P through the global agricultural food system. This is particularly pertinent in the dairy industry, where losses of P are causing environmental damage and ultimately putting food safety at risk. About 2-3% of the incoming milk for dairy processing is lost during cleaning operations, via washing steps and through occasional milk spills.4 The production of dairy products such as cheese and yogurt gives rise to P-rich dairy processing waste (DPW), and as a whole, the dairy industry is the EU’s largest industrial food wastewater contributor and one of the main sources of P-rich industrial effluent.5,6 The recent abolition of EU milk quotas (2015) has resulted in a 2.8% annual growth in milk production with a corresponding increase in DPW.7 If the management of DPW does not improve, then leakage of nutrients will continue to intensify, leading to environmental problems such as the eutrophication of water bodies by P run-off from soil.

In 2014, rock phosphate was included in the list of EU critical raw materials due to its importance to the EU agrifood sector.8 Europe has no significant phosphate mines and the concentration of rock P in geopolitically sensitive regions was identified as a threat to European food security. The fertilizer industry is the largest user of P (1.1 million tonnes in 20159) therefore alternative sources to rock phosphate are urgently needed. The EU, through its Circular Economy Package (2016), has prioritized the recovery and safe reuse of plant bioavailable P from food and municipal waste streams, including DPW.10 This will add resilience in the event of disruption of supply to the EU while simultaneously mitigating the environmental consequences of P leakage.

To date, finding a solution to reusing P from DPW, other than direct land spreading of dairy wastewater sludge, has been hampered by a lack of available technology, suitably trained personnel and a market for the products. To stimulate innovation in technologies for producing substitutes for mined phosphate rock from P-rich wastes, the EU has proposed changes to the Fertilizers Regulations, which would permit CE labeling of waste-based fertilizers in order to ease their access to the single market11. This opens opportunities for the dairy processing industry to innovate by adapting technologies and new waste management strategies to minimize P leakage while benefiting from emerging market opportunities. To ensure the long-term economic and environmental sustainability of these non-mineral fertilizer products, they will need to provide plant crops with required nutrients and should not negatively impact on the environment or adversely affect the safety of food or animal feedstuff.

To achieve the goal of phosphorus recovery for new fertilizers from DPW, we must conduct robust scientific investigations, develop and test new technologies, train a new generation of researchers, re-configure current DPW processes, and share information and findings with industry, policymakers, standards bodies, and regulators. Our proposed multi-disciplinary, intersectoral research programme will directly address this need.

REFLOW will provide a unique opportunity for researchers to obtain the knowledge and skills needed to develop and deploy new technologies for socially and environmentally responsible innovative management of DPW, and to stimulate new markets for recycled P. This ETN will provide advanced training to a new generation of high-achieving early-stage researchers through a structured PhD programme, focused on three overall research goals.

1. To develop and demonstrate processes for the recovery and reuse of phosphorous (P) products from DPW;

2. To establish their fertilizer value and optimum application rates through laboratory protocols and field trials;

3. To address the environmental, social, food safety and economical challenges, ultimately finding marketdriven solutions for the new processes and fertilizer products.


Objectives: To model the fate and transport of P in novel fertilizers from DPW, added to soil and its impact on P soil cycling processes. Undertake batch, column and field plot experiments using soils from a long term P trial: Monitor the fate and transport of 33P radiolabelled DPW fertilizers added to soils (scintillation counter) in incubation and column experiments using intact soil cores from baseline soils that have never received P and soils that have undergone build-up and depletion cycles. Measure leaching losses from column experiments; At plot scale, P fractions and available P trends over a full grass growth year will be established on baseline plots and plots receiving fertilizers from DPW to establish changes in available P concentrations at varying application at rates, measured in conjunction with grass growth mesurements; Results from the incubation, column and plot scale experiments will be synthesised to model chemical and biological interactions between P derived from dairy waste and native soil P.

Expected results: A time-series database of available P concentrations and grass growth on soil under baseline conditions, and soils receiving DPW fertilizers. A database of changes in soil P fractions following the addition and assimilation of dairy waste to soils that have never received P and soils that have undergone build up and depletion cycles. Leaching P losses from baseline soils that have been amended with dairy waste; A model of soil P cycling and physico-chemical processes following DPW fertilizer additions; Guidelines on management of DPW fertilizers in terms of timing and rates of application on grassland soils, to maximise plant uptake and minimise nutrient losses to water.


Treatment of selenium-rich wastewater in constructed wetlands


Start date: 01/04/19    End date: 31/03/22

Funder: Science Foundation Ireland

Principal Investigator: Prof Piet Lens, Dr Mark Healy,  and Dr Collette Mulkeen


Selenium (Se) is an important element that was recognized as an essential nutrient for humans and animals by the World Health Organization in 1970.  Se concentrations above 400 μg Se per day can lead to toxic effects such as hair and nail loss, disruption of the nervous and digestive systems in humans.  In soil, Se occurs in various forms including selenides, elemental Se, selenite, selenate and organic Se compounds.  In aquatic systems, Se is mainly found in its inorganic forms as selenide, selenite, selenate and insoluble elemental Se (Vesper et al., 2008). The oxidized forms of Se: selenite and selenate are toxic to living systems due to their high bioavailability and bioaccumulation capacity. Se in natural waters is a minor component with a typical range of concentration of <0.1 up to 100 μg L-1, while in ground waters, Se concentration tends to be greater due to large contact times between rocks and water (F. Fordyce, 2007). In drinking water, a provisional limit of Se of no more than 40 μg L-1 has been fixed by World Health Organization (WHO, 2017).

An interest in treatment of wastewater using technologies based in natural systems started in the 50’s (Vymazal, 2008) and has grown in the recent years, in particular for constructed wetlands (CWs) systems (Pavlineri et al., 2017). The advantage of CFWs is the minimal requirement of mechanical elements, therefore, they are considered low cost and maintenance technology, and frequently well appropriate for treatment of smaller wastewater flows (Huang et al , 2012). CFWs have been used to remove Se from oil refinery wastewater (Hansen et al., 1998) and agricultural drainage water (Lin and Terry, 2003).

Important aspects from treating Se-laden wastewaters in CWs are to manage and dispose properly the Se-enriched plants obtained after harvesting. As disposal methods, Carvalho and Martin (2001) suggested three approaches: 1) Se-enriched plants can be used as feed for animals with low Se diet, 2) addition of Se-enriched plants as organic fertilizer to biofortify staple crops and 3) in the case of the Se-enriched plant material has unsafe levels of elements considered toxic for animal feeding , i.e. arsenic or mercury, biomass can used a biofuel to generate energy. The first two approaches mentioned above will improve the nutritional value of animal products and crops with Se whereas the third one will reduce the consumption fossil fuels on energy production.

The aim of the research is to investigate the Se removal potential of Constructed Floating Wetlands (CFWs) using two aquatic floating plants and provide design recommendations for improved Se removal rates. In addition to this, the Se-enriched biomass harvested from CFWs will be tested as a potential slow-release Se fertilizer in pot experiments.

The specific objectives are:

1. Evaluation of the potential of Se removal of two aquatic floating plant from water.

2. Optimization of the removal of Se from the water by varying treatment parameters in CFWs using the aquatic floating plant with higher potential of Se removal.

3. Evaluation of the effect of nutrients in the Se removal efficiency of CFWs optimized using run-off water from an agricultural site in Ireland.

4. Assessment of the potential of Se-enriched aquatic floating plant harvested from CFWs as Se-fertilizer.



Macro-algal blooms in transitional and coastal waters

EPA logo

Start date: 01/02/19       End date: 31/01/21

Funder: EPA

Principal investigator: Dr Liam Morrison (NUI Galway), Dr Mark Healy (CoI)


This project will combine Earth Observation technologies, in situ monitoring of water quality and seaweed tides, and laboratory experiments in order to: i) identify the most important pressures affecting these estuaries; ii) generate useful information about the ecological status and water quality to inform policy; and iii) develop solutions to reach a good ecological status and improve ecosystem services. All these aims will be accomplished through the development of five work packages: WP1 will assess water quality in water catchments; WP2 will monitor the development of green tides using satellite images; WP3 will provide information to predict the effectivity of management actions in a global change context (i.e. climate change; eutrophication; and emergent pollutants) based on laboratory experiments; WP4 will develop ex-situ cultivation protocols for different seagrasses to restore seagrass meadows or use seagrasses as biomonitors; WP5 will create a net of volunteers to improve the monitoring of green tides in those estuaries (i.e. water quality, bloom extent and internal C:N in seaweed tissue). Additionally, a sixth WP will be focused on the communication of the results and in the development of a protocol for good practices to reduce nutrient losses in agriculture.

Use of soil water characteristic curve to determine solute travel times in sensitive catchments

Start date: 1/9/15           End date: 31/8/18

Funder: NUI Galway

Principal Investigator: Dr Bryan McCabe and Dr Mark Healy (NUI Galway), and Dr Owen Fenton (Teagasc)

Budget (€): c. €60,000


The soil water characteristic curve (SWCC) describes the volumetric water content of a soil at a given matric potential. The SWCC allows elucidation of solute transport timescales. Contexts in which the SWCC may be successfully used include the determination of ‘lag time’ between good agricultural practices and the determination of travel times of contaminated plumes arising from industrial practices. The proposed research work aims to use the centrifugal method to determine solute transport in different soil types and in different contexts.


Measurement and abatement of ammonia emissions from agriculture

Teagasc logo

Start date: 1/5/16           End date: 31/9/20

Funder: Teagasc

Principal Investigators: Prof Mark Healy (NUI Galway), Prof Gary Lanigan and Dr William Burchill (Teagasc), and Dr Barbara Amon (ATB, Germany)

Budget (€): 88,000


Nitrogen contained in slurry is an important source of N on Irish farms. However, a large proportion of this N can be lost from slurry via ammonia (NH3) gas emissions. These emissions are also detrimental to the environment. Agriculture contributes 98 % of the total NH3 emissions in Ireland. The cattle sector is by far the largest source of these emissions, comprising 72% of total emissions, with these emissions arising principally during animal housing and slurry storage (48%). This is important given that Irish livestock numbers are expected to grow post quote while EU national NH3 emissions targets are set to be more stringent up to 2030. Slurry storage emissions is one potential area were NH3 emissions can be reduced on Irish farms. However, little is known about the extent of slurry storage emissions in Ireland and the effectiveness of strategies to reduce NH3 emissions under Irish conditions. 

The objectives of this MSc will be to assess the effect of a number of potential strategies to reduce emissions from slurry storage. The effect of these strategies will be quantified using twelve concrete slurry storage tanks (volume of 1 m3) at a purpose built slurry storage facility.  A dynamic chamber approach will be used to estimate NH3 loss with gaseous emissions measured at the chamber inlets and outlets using a photoacoustic gas analyser and/or acid trapping. This will allow the simultaneous measurement of NH3, methane, nitrous oxide and carbon dioxide, and will allow assessment of NH3 loss and any positive or negative feedback these strategies have on greenhouse gas emissions.


Kavanagh, I., Burchill, W., Healy, M.G., Fenton, O., Krol, D., Lanigan, G.J. 2019. Mitigation of ammonia and greenhouse gas emissions from stored cattle slurry using acidifiers and chemcial amendments. Journal of Cleaner Production 237: 117822.  Kavanagh et al. J. Cleaner Prod.

Assessment of materials used in land drainage systems

Teagasc logo

Start date: 1/9/18           End date: 31/8/22

Funder: Teagasc

Principal Investigators: Dr Patrick Tuohy and Dr Owen Fenton (Teagasc), Dr Mark Healy (NUI Galway)

Budget (€): 88,000


The installation of land drainage systems is widespread in poorly drained regions of the country. The performance and working life of these drainage systems is dependent on the quality and suitability of the materials used in the field drains, and on keeping such drains well maintained. The range of materials available in terms of pipes and pipe envelopes does not easily fit into any standard classification, and many different combinations of both are in use. Stone aggregates, used as drain envelope, often have a geographical bias due to local geology and preference. The deposition of iron ochre in drainage pipes is also a major problem in iron-rich soils. Therefore, there is a huge variation in the performance and life-span of drainage systems.

This research aims to assess the performance, capacity and life-span of a range of drainage materials (pipe and envelope) in a range of soil types to establish best practice in material specification and design. There will be scope to assess the performance of some alternative envelope materials to offset the cost associated with stone aggregate and to investigate the nutrient attenuation capacity of stone media. Another element of the study will examine methods of reducing and the remediation of iron ochre deposition in drainage systems. The appraisal of drainage system material performance will inform farmers, contractors and other stakeholders involved in land drainage works of best practice in system design. A reduction in and the remediation of iron ochre deposition in drainage systems will improve drainage system performance and increase life-span. Such measures will ultimately improve the return on capital invested in land drainage works. If a cheaper alternative to stone aggregate is found to be appropriate, this has the potential to substantially reduce the cost of land drainage, thereby increasing the economic viability of land drainage works.

Optimizing dairy farmyard infrastructure for the management and treatment of soiled water

Teagasc logo

Start date: 01/10/18           End date: 31/09/22

Funder: Teagasc

Principal Investigator: Prof Mark Healy and Dr Alma Siggins (NUI Galway), Dr Pat Tuohy , Dr Daire O' Huallachain and Prof Owen Fenton (Teagasc)

Budget (€): 88,000


The removal of milk quota restrictions, coupled with Food Wise 2025 targets, has heralded an increase in dairy herd sizes. This expansion in dairy production has resulted in increased volumes of dairy soiled water (DSW). DSW is an effluent from the milking parlour, collecting yards, roadways and other hard-standing areas, and consists of a dilute mixture of cow faeces, urine, milk, detergents and sediment. Approximately 10,000 litres of DSW is produced per cow per year on Irish dairy farms. DSW is potentially a major source of pollution; therefore measures are required for its management, storage, treatment and disposal. Options for the treatment of DSW to reduce nutrient load and lessen the environmental impact have not been employed to any significant extent. These include solid separation, nutrient attenuating amendments, filtration systems and Integrated constructed wetlands (ICW). There is little guidance regarding the optimal design, construction, operation and maintenance of suitable DSW treatment systems. This project will address gaps in knowledge on the status of DSW, review current practices and attitudes towards its management and control, assess the capacity, effectiveness and economic advantages of DSW treatment systems and outline a strategy to optimize their usefulness.


Journal papers:

Mohamed, A.Y.A., Siggins, A., Healy, M.G., O hUallachain, D., Fenton, O., Tuohy, P. 2020. Appraisal and ranking of poly-aluminium chloride, ferric chloride and alum for the treatment of dairy soiled water. Journal of Environmental Management 267: 110567.