SALINA- SALine INntrusion in coastal Aquifers: Hydrodynamic Assessment and Prediction of Dynamic Response.

The world's population likes living by the sea. Currently approximately 53% of us live on the 10% of the earth's surface that is within 200km of the coast; this is forecast to rise to 75% by 2050. This increased concentration of people in restricted areas will place greater stress on natural resources including water supplies. These resources must be used in a judicious manner if we are to live within our means. Meeting the needs for providing potable water to 75% of humanity from such a limited resource forms a major global challenge facing society in the 21st Century.

Groundwater has been recognised for some time for its capacity to provide good quality water, particularity in places where other water sources have either poor quality, requiring expensive (and environmentally unfriendly) treatment technologies, or are unavailable. However, it needs to be used cautiously. Over-pumping of coastal aquifers can lead to seawater contaminating groundwater supplies, thereby destroying otherwise valuable resources. Contamination by even 1% salt water can be enough to render freshwater unfit for use. This issue is of concern in the UK, where saline intrusion (SI) can affect the quality of water used for human consumption, as well as for industrial purposes (process water and irrigation). Further afield, this matter is of pressing concern across Europe, particularly in Mediterranean countries, as well as in other water-stressed arid and semi-arid regions of the planet where use of desalinisation technologies may not be viable over the long term.

The UK Water Research and Innovation Partnership has highlighted weaknesses in the UK water industry that could prevent it from maintaining its position against increasing external competition. In order to develop a 10% Global market share, worth $8.8 billion, the UK needs to invest in water research to maintain its competitive edge. The partnership has identified opportunities for developing innovative water technologies in 21 areas, where it believes that the UK can compete on the world stage. Developing these technologies requires a firm scientific underpinning. This proposal addresses developing expertise in the area of SI using accurate monitoring, prediction and control systems. Findings will underpin protocols that will increase the effectiveness of sustainable water infrastructure management through demand management tools.

The proposal's multidisciplinary research team from Queen's University Belfast and Imperial College London brings together expertise in the areas of experimental hydrodynamics, process engineering, numerical simulation, computational fluid dynamics, field hydro-geology and geophysics; this is further strengthened through active involvement of the British Geological Survey. The integration of experimentation with testing and monitoring in real world environments, along with improved numerical simulation that will lead to the development of an early warning system for salt water breakthrough to provide a sustainable managed approach for water abstraction in coastal areas.

Understanding the movement of seawater and freshwater within coastal aquifers, and the interactions that take place under naturally complex ground conditions, provides the key to unlocking suitable approaches for designing and maintaining effective water management systems needed to meet the ever growing demand for high quality freshwater in coastal areas. Our vision is to create a novel system capable of providing early warning of salt water intrusion within groundwater wells. This advance notification, of up to 8 days, will allow actions to be taken in advance of contamination occurring. A dynamic model, which will further help with the understanding of the transient processes that govern SI movement under real world conditions, will provide a novel practical management suite of tools for water suppliers and environmental regulators.

Research into saline intrusion (SI) has been largely discipline specific. This approach, although leading to considerable advances, has often limited its wider impact. Multidisciplinary / cross university collaboration, implemented at a range of scales, lies at the core of SALINA. The diversity of expertise enables the proposed research's scope and objectives to go beyond the confines of discipline-specific investigation to develop a holistic approach to tracking SI. The QUB and ICL team's research methodology has been developed with the aim of making research outcomes accessible to scientists and engineers, in both academic and industrial settings, and fostering further collaboration across disciplines and with stakeholders from a range of backgrounds. The UK Water Research and Innovation Partnership (UKWRIP) have identified a number of weaknesses in the UK water industry that prevents it from maintaining its position in the face of increasing competition, despite considerable potential. In order to develop a 10% share in the water sector global market, worth $8.8 billion, the UK needs to define areas of expertise. In regard to opportunities for innovative water technologies UKWRIP identifies 21 areas where it believes the UK can compete competitively. This proposal addresses the fields of accurate monitoring, prediction and control systems and protocols that increase the effectiveness of sustainable water infrastructure management.

SALINA will provide advanced and world leading understanding of the processes that govern saltwater intrusions in coastal aquifers. It will develop and demonstrate the technology required to warn of imminent SI breakthrough, while facilitating asset owners to make sustainable management decisions to:

Provide the fundamental undertaking of the interactions that are required for SP to be used as an early warning system for intrusion,

Establish a fundamental understanding of the interactions and influence of the key drivers within an intrusion,

Provide detailed data, from both field and laboratory, that can be used to assist the validation of site specific simulations, and

Apply improved assessment techniques to assist with remediation studies.

Major beneficiaries will be asset owners (local authorities and regional water companies), regulators, engineering consultants and other researchers working within the water sector. While the research is of immediate impact within the UK, the principles and understanding will be world leading and applicable elsewhere including countries bounding the Mediterranean Sea and more generally in arid and semi-arid coastal regions across the planet.

The outputs and outcomes from the research will allow beneficiaries to:

Make a step change in the understanding of the interactions that control the transient nature, and the extent of, salt water intrusion within heterogeneous ground, beyond the present state-of-the-art which concentrates on
homogeneous conditions. This knowledge will be of fundamental value to regulators, utilities and consultants in developing more robust asset management systems that allow for the implementation of strategies to ensure
sustainable supplies of potable water from coastal aquifers.

Fulfil the requirement of asset management by providing notification of the imminent arrival of salt water at abstraction locations allowing them to develop area specific protocols to avoid SI.

It will integrate findings of highly controlled laboratory investigations with responses observed under real world conditions allowing the development fully transient 3D models (4D) of SI in naturally heterogeneous coastal
aquifers while providing methodologies for asset management across any given site.

Develop high quality / high impact methodologies that can be implemented in a variety of future research programmes beyond the duration of the research programme.