ABSTRACT
A method is presented to predict and quantify the hydrogeochemical impact and sustainability of artificial recharge (AR) systems. Eight hydrogeochemical impacts are defined: the resulting pollution level in recharge(d) water (input and aquifer) and in soil (sludge and aquifer), the sludge accumulation rate and 3 leaching rates (leading to decalcification, oxidation and loss of sorption capacity, of the aquifer). Each impact is quantified by an index, which relates the actual state of the recharge system (either AR or river bank or natural) to the state in a similar, but clean natural background area. Combination of these 8 indices yields the hydrogeochemical sustainability index for which also a radar plot is presented.
The required data input consists of (a) quality of recharge water; (b) native hydrogeochemistry of target aquifer; (c) natural backgrounds; and (d) hydrological characteristics of the recharge system. The method is integrated in the expert model Easy-Leacher 4.6 (explained elsewhere in this volume), but can also be applied independently and in other background areas than the Netherlands.
