Aquifer Storage and Recovery as a tool for self-sufficient fresh water supply
Aquifer Storage and Recovery (ASR) of fresh (often surface or rain) water is a well-known method to overcome seasonal or periodical water scarcity problems in areas with periodical water excess in contra-phase with peak demands. When the only suitable target aquifer is brackish or saline, ASR becomes more difficult to apply due to (i) upward bubble drift by density driven flow, (ii) earlier negative effects of lateral bubble migration (less mixing allowed for Cl than for constituents that sorb), and (iii) potentially more severe water quality problems by water-aquifer interactions, due to clay mobilization, enhanced cation and anion exchange, and enhanced redox and dissolution reactions. As a result, the recovery efficiency (RE) of the ASR system can become insufficient.
The main research questions are:
- How can ASR systems be improved so as to maintain or enhance favorable soil-water interactions (like denitrification and biodegradation of pollutants) while minimizing the negative interactions with the local environment (such as arsenic mobilization)?
- What are the risks of well clogging during ASR operation and what can be done to prevent this clogging?
- How can ASR fresh water lenses be monitored and prevented from drifting away due to lateral groundwater flow and/or buoyancy?
- How can the ASR performance within a region be estimated a priori using ASR performance estimation methods, basic hydrogeological data and GIS?
Link with TUD-PhD student Koen Zuurbier (PhD defence fixed on May 10, 2016)
Funding by Knowledge for Climate
Long-term physical effects of Aquifer thermal energy storage systems
Aquifer thermal energy storage (ATES) is one of the important measures needed in the global energy transition. The number of ATES systems in The Netherlands is expontentially growing, and therefore potentially interfering ‘in cresendo’ with other (conjunctive) subsurface use such as water supply. The research aims at comprehensive understanding of the chemical, hydrological and thermal impacts of ATES systems. The main questions to solve are: (i) what are the long-term energy balances of ATES?, (ii) what are the long-term effects on the subsurface thermal regime?, and (iii) how does this compare to disturbances caused by climate change, land-surface change (notably urban development), and groundwater supply well fields?
Link with TUD-PhD student Philip Visser.
Funding by Centre of excellence for sustainable water technology (TTIW) Wetsus
Collaboration with dr. Henk Kooi (Deltares)
WaterTagging: DNA-microparticles for tracing and modelling water flows and travel times in natural systems
Societal demand for water safety is continuously increasing, being it resilience against flood/droughts, clean water for ecosystems, recreation or safe drinking water. Robust methods to measure temporal and spatial patterns of water and contaminant pathways are still lacking. This project aims to develop and apply (1) innovative, robust, and environmental-friendly silica-protected iron oxide micro-particles tagged with artificial DNA to trace contaminant movement and travel times of water in natural systems and (2) an innovative coupled model approach to capture dynamics in hydrological pathways and their effects on water quality. The distinctive property of DNA-tagging is the infinite number of unique tracers that can be produced and their detectability at extremely low concentrations. Such tracers give the water sector a unique tool for in-situ mapping of transport of contaminants and pathogenic microorganisms in water systems and (alternative) drinking water production sites (groundwater, river bank filtration). Multi-tracer techniques will open the door to highly innovative approaches to modelling water quality processes, based on travel times that explicitly take into account temporal and spatial flowpath heterogeneity. Together, DNA-tracers and travel time-based modelling will improve protection of water resources and drinking water production sites and help safely closing water and substance cycles and use of alternative water sources.
The research task of TUD aims at quantifying particle and contamination transport flow paths in porous media and travel times in groundwater protection areas.
Link with TUD/UU-PhD student (to be recruted; UU = Univ. Utrecht)
Collaboration with IHE-UNESCO, ETH, Deltares, BioLegio, HydroRock, KWR, UU.
The Influence of gravel pit lakes on the hydrology and hydrochemistry of the surrounding aquifer
The Netherlands alone have 500 sand pits. The presence of quarry lakes may have both negative and positive influences : they may form a hazard for swimmers when the banks are unstable or if the water is contaminated, they may be a disturbance of the original landscape. On the other hand, quarry lakes provide opportunities for society as they may become natural or recreational areas or places where to store fresh water, energy or sludge. In order to make sure that the gravel pit lakes are used well, more knowledge about the hydrology and hydrochemistry of the quarry lakes and surrounding aquifers is needed. The main research questions were:
- What are the hydrological and hydrogeochemical processes in and around selected qravel pit lakes (gravel and sand pits filled with groundwater), in both the Netherlands and Italy?
- How does a multitude of quarry lakes affect a fluvial system, aquifer or catchment?
- How will climate change affect quarry lake systems?
Link with TUD-PhD student Pauline Mollema (PhD successfully defenced on 12 Febr. 2016)
Funding: The Italian study was partly funded by the City of Ravenna and ENI. WML supported the work in the Dutch gravel pits
Dynamics of plant ecology and base chemistry in fen and fen meadows in the Netherlands
Cation and nutrient status in wetlands is regulated by interactions of chemical soil properties and solute transport by groundwater flow or flooding. These interactions are strongly influenced by redox changes due to rewetting, solute transport caused by changes in groundwater and surface water supply, and by removal of the top soil and subsequent soil succession. This project focuses on the effects of restoration measures on topsoil chemistry and mid- and long-term prospects (> 5 year) for restoration of basiphilous vegetation. Most attention will be paid to regulation of the base chemistry and its effects on vegetation. Nutrient chemistry and toxicants for plants are also included in this study because restoration measures influence vegetation development by changes in nutrient dynamics and concentrations of toxicants. More specifically this thesis focuses on:
- the effects of interaction of basic cation fluxes by seepage and soil organic matter accumulation on restoration of basiphilous vegetation
- the effects of cation and phosphorous chemistry on fen vegetation, after rewetting of groundwater fed, degraded, rich fens.
- sustainability of base rich conditions and basiphilous vegetation in dune slacks fed by dune groundwater and by artificial infiltration of surface water
- effects of artificial flooding with base rich surface water on base and nutrient chemistry and vegetation in an acidified and desiccated alder car
Link with TUD/UA-PhD student Camiel Aggenbach (UA = Univ. Antwerpen)
Funding: Joint Research Program of Dutch Waterworks (BTO-KWR).
Analysis and management of the Damour coastal, dolomitic limestone aquifer, South Beirut, Lebanon
Karstified coastal (dolomitic) limestone aquifers are very vulnerable to pollution and salt water intrusion. The Damour aquifer system south of Beirut is no exeption to this rule. The hydrogeology and inorganic hydro- and geochemistry are investigated in order to reveal the crucial water quality problems and their causes, and to manage current and future groundwater scarcity and quality problems. The main research questions are:
- To what extent does saltwater intrusion affect the groundwater quality in the Damour coastal aquifer compared to other anthropogenic factors, and do limestones react differently from dolomitic limestone?
- What are the main hydrogeochemical processes responsible for the current groundwater conditions and their influence on the future scenarios of the system?
- What is the baseline (natural) groundwater composition in the limestone and dolomitic limestone units?
- What are the possible aquifer restoration schemes and practical solutions to rehabilitate the studied aquifer or similar coastal aquifers?
Link with TUD/AUB-PhD student Wisam Khadra
Funding: Partial funding by International Navigation Trading and Contracting Co. (INTC), Lebanon.
Clogging of pumping wells
Many wells for water supply show cumbersome aging problems, resulting in elevated costs due to the monitoring of well performance, increased energy consumption or capacity losses in case of well clogging, well rehabilitation and well replacement. Although research during the past decades revealed many of the causes of well clogging and methods to prevent and treat clogged wells, well clogging still is a pandemic well problem and many questions remain to be answered.
In this study, the focus is on:
- the identification of short-cirquit flow around wells using microbiological profiling of groundwater
- risk prediction of chemical well clogging based on water quality, various site conditions and well construction
- predicting the effectiveness of regeneration techniques for mechanically clogged wells
- very special or rare cases of well clogging such as due to Al(OH)3 and silica gel applications.
Link with TUD-PhD student Martin van der Schans
Funding: Joint Research Program of Dutch Waterworks (BTO-KWR), TKI.