Improved Drinking Water Quality after Adding Advanced Oxidation for Organic Micropollutant Removal to Pretreatment of River Water Undergoing Dune Infiltration Near the Hague, Netherlands

The presence of organic micropollutants (OMP) in surface water and water recovered from Managed Aquifer Recharge and Recovery (MARR) systems creates serious concerns. OMP pose potential health effects and difficulties to remove, due to diverging physicochemical properties and low concentrations. The addition of an advanced oxidation process (AOP) to existing pretreatment of surface water for MARR was expected to improve OMP removal. Drinking water utility Dunea for The Hague and surroundings (The Netherlands) investigated the effects of AOP on water quality in a part of its dune catchment area. The results were compared to a period without AOP pretreatment before dune infiltration. Water quality analyses showed that both periods were comparable, except that biological activity in the infiltration ponds was higher in the period without AOP. The introduction of AOP increased the overall removal of OMP and resulted in improved drinking water quality. Other potential effects of AOP, such as increased levels of degradable organic matter, AOP byproducts, transformation products, toxicological or microbiological effects were not observed or were cancelled out during subsequent MARR. These results show that addition of AOP to MARR is a suitable approach for increasing OMP removal, without negative effects on drinking water quality