Estimating the spatial distribution of artificial groundwater recharge using multiple tracers

Area of Science:

• Hydrogeology
• Environmental Chemistry
• Water Resource Management

Background:

• Groundwater management relies on understanding water types and spatial distribution.
• Managed aquifer recharge (MAR) using surface water creates hydraulic barriers against contamination.
• Assessing tracer efficacy in MAR systems is crucial for reliable water resource management.

Purpose of the Study:

• To estimate spatial artificial infiltration in a Swiss drinking water production area.
• To classify water types using hydrochemistry, stable isotopes, and organic micropollutants.
• To compare the effectiveness of different tracers in assessing infiltration and water types.

Main Methods:

• Stage-discharge relationships were used to estimate spatial artificial infiltration.
• Water types were classified using hydrochemistry, stable isotopes, and organic micropollutant data.
• Systematic comparison of tracer information on distribution and mixing ratios was performed.

Main Results:

• All tracers indicated very similar spatial distributions of artificial infiltration, despite mixing ratio uncertainties.
• The eastern part of the infiltration system exhibited the highest infiltration rates.
• The western part of the infiltration system showed the lowest infiltration rates.

Conclusions:

• Stable isotopes, micropollutants, and hydrochemistry are valuable for groundwater assessment in MAR systems.
• Consistent spatial infiltration patterns were observed across different tracers.
• Optimizing infiltration balance could enhance groundwater mound distribution and prevent contamination inflow.