Recharge systems for protecting and enhancing groundwate

116
TOPIC 1
Recharge systems / Injection well issues, aquifer storage and recovery
investigated. This includes investigation of the difference in geochemical composition and bacteria content in sediment
samples from an irrigated area, a non-irrigated area (reference area), and an infiltration basin, and the risk of
break through of pathogenic indicator organisms in an abstraction well. These investigations performed within the
EU-project ARTDEMO constitute the background for establishing a management strategy including an early-warning
system for an AR plant.
METHODS
The investigations include continuous monitoring (1994–2005) of the quality of the input water, soil water
and abstracted AR water. Additionally, sediment samples from 0–30 m below surface (m.b.s.) were collected in
October 2004 from an irrigated and a non-irrigated area using the solid flight auger drilling method. In March 2004,
sediment samples were collected from an infiltration basin at depths of 0.01 (filterskin), 0.07 and 0.35 m.b.s.
Geochemical analyses performed on the soil material included pH (NEN 6411), EC (NEN 6412), non-silicate
bound calcium (ICP-MS analysis on HNO 3 extract), calcite (Ca-extraction using HCl), organic carbon and total N
(pyrolysis of decalcified sample and subsequent gas detection by LEKO analyser) and grain size distribution
(