How multiple partially penetrating wells improve the freshwater recovery of coastal aquifer storage and recovery (ASR) systems: A field and modeling study

“Aquifer storage and recovery (ASR) of freshwater in brackish or saline aquifers can be an efficient technique
to bridge freshwater shortages in coastal areas. However, buoyancy effects may cause salinization
at the bottom of the ASR well during recovery, making a part of the freshwater irrecoverable. This study
shows how such freshwater losses can be reduced applying deep injection and shallow recovery by independently
operated multiple partially penetrating wells (MPPW) in a single borehole. A small-scale ASR
system with such an MPPW was installed in January 2012 and its operation was extensively monitored
until October 2012. A SEAWAT model was built and calibrated on the field measurements of this first ASR
cycle. The model was used to compare the MPPW with a conventional fully and partially penetrating
well. The freshwater recovery of those wells was 15% and 30% of the injected water, respectively, which
is significantly less than the 40% recovered by the MPPW. In subsequent cycles, no more than 60% could
be recovered by the MPPW, as mixing in the lower half of the aquifer remained a source of freshwater
losses. However, this recovery is significantly higher than the recovery of the conventional well types.
This study therefore shows that for less ideal ASR conditions, a viable system can still be realized using
MPPW.”

Copyright © 2013 Elsevier B.V. All rights reserved.

(Citaat: Zuurbier, K.G., Zaadnoordijk. W.J., Stuyfzand, P.J. – How multiple partially penetrating wells improve the freshwater recovery of coastal aquifer storage and recovery (ASR) systems: A field and modeling study – Journal of Hydrology 509(2014), p.430-441)