Authors:
Koen Zuurbier | KWR Watercycle Research Institute | Netherlands
PhD Gualbert H.P. Oude Essink | Deltares / Utrecht University | Netherlands
Dr. Niels Hartog | KWR Watercycle Research Institute | Netherlands
Main topic: Demonstration of successful local, small-scale managed aquifer recharge (MAR) techniques worldwide to improve local freshwater supply and discussion of their potential elsewhere.
Session goals:
1.Provide an overview of recent field-tested concepts and current developments for small-scale MAR-techniques in coastal areas.
2. Discuss the feasibility and challenges for solving freshwater management challenges in. developing small-scale MAR-techniques as affected by site-specific conditions (e.g. hydrogeological settings, maintenance and legislation).
Description:
Local, small-scale managed aquifer recharge (MAR) may provide site-tailored freshwater management solutions in coastal areas that are increasingly under pressure through both population growth and climate change. These solutions may provide flexible solutions world-wide for varying conditions, such as more extreme water events (drought and pluvial flooding). The local MAR-solutions demonstrate robust solutions for freshwater management by exploiting temporal natural freshwater sources (rainwater, surface water, drainage water, waste water) for abstraction upon storage in times of demand for irrigation, industrial, and drinking water purposes. Through the analysis of various field cases it can be demonstrated how to deal with different geological settings, application in brackish/saline groundwater, water quality changes and pre-treatment preceding injection.
Names of presenters and titles of presentations.
Session moderator: Dr. Niels Hartog (KWR Watercycle Research Institute / Utrecht University)
Part 1 Small-scale dedicated MAR field-pilots
0:05 1. An introduction to the rise of MAR for local freshwater management in the Netherlands.
Carl Paauwe, Waterbuffer foundation
0:15 2. The use of sophisticated well configuration to enable freshwater aquifer storage and recovery (ASR) in coastal aquifers
Koen Zuurbier, KWR Watercycle Research Institute
0:15 3. Potential for removal of pathogens during aquifer storage and recovery (ASR) in an agricultural setting for self-sufficiency of freshwater
Jouke Velstra, Acacia Water
0:15 4. Large scale application of small scale managed aquifer recharge (MAR) systems in the saline coastal delta of Bangladesh
Boris van Breukelen, VU University Amsterdam
Part 2 Suitability of local, small-scale MAR in coastal areas
0:15 5. On promising techniques for local fresh groundwater supply in the Southwestern Delta, The Netherlands: GO-FRESH.
Gualbert Oude Essink, Deltares and Utrecht University
0:15 6. MAR as a solution for freshwater management on a small Danish island (Falster)
Klaus Hinsby, GEUS
0:15 Discussion
0:05 Wrap-up; which are the important research questions, directions for the future, challenges and how can we address them?
1.
Introduction on the recent rise of small-scale MAR for freshwater supply.
2.
Innovative ASR-concepts were recently developed and successfully field-tested: ASR-Coastal system equipped with multiple partially penetrating wells (MPPWs) for deep injection and shallow recovery in brackish aquifer, and a Freshmakersystem with superimposed horizontal directional drilled wells to enlarge shallow freshwater lenses. This research has led to the development and field validation of innovative and sophisticated, but yet cost-effective aquifer ASR solutions for freshwater management.
3.
Two pilot sites have been set up to provide farmers with a complete solution for self-sufficiency of fresh-water in a saline environment. In addition to self-sufficiency in water from ASR, reducing the risk on pathogenic bacteria with this complete solution seems promising. In a single well system the pathogenic bacteria removal is expected to be dependent on residence time. A multi-well system is set up to enhance bacteria removal by extending the soil passage from infiltration well to abstraction well.
4.
100 small-scale pilot MAR systems were built in the 3 South western districts of Bangladesh, Khulna, Sathkira and Bagerhat in the period 2009-2014. These MAR systems placed in brackish aquifers are filled in the monsoon with pond or rooftop water. The current systems show that the systems are working quite well, but that there is room for improvement, especially related to operation & maintenance, water quality, governance, and business development. This presentation will summarize the main findings of the MAR pilots and present the plans for further scientific research to these systems.
5.
Here, we will elaborate on Climate Proof Fresh Groundwater Supply for the Southwestern Delta, a low-lying saline environment in The Netherlands. We will demonstrate that local fresh water storage and supply actually works from a technical point of view through showcases: 1. infiltration via drainage, storage and recovery of freshwater in a sandy creek ridge, and 2. optimizing the freshwater volume in shallow rainwater lenses by different types of deep drains. In addition, we will show that upscaling the showcases to other areas, both technical and socio-economical, is feasible.
6.
The Marielyst area is facing saltwater intrusion problems both from the sea and fossil marine waters in the deeper part of the exploited chalk aquifer. In an ongoing study, initial assessments are made on the potentials of small-scale MAR to control saltwater intrusion and to reduce risks of flooding from drainage canals, and eutrophication of transitional and coastal waters around the Island.