Drinking water company Dunea Duin en Water produces drinking water from the Meuse River, which contains a variety of organic micropollutants (OMPs) from upstream activity. OMPs found in Dunea’s source are plant protection products, pharmaceuticals, hormones and endocrine disruptors and X-ray contrast media. Continues development of measuring equipment has resulted in lower detection limits for most substances and measuring programs are expended yearly. Consequently, more substances are found in the Meuse River and other surface water bodies. Dunea is currently performing research to extend the multiple barrier treatment with advanced oxidation processes (AOP) via UV and hydrogen peroxide. Mostly medium pressure (MP) mercury vapour ultraviolet lamps are used that emit a broad spectrum of light, coinciding with the absorbance spectrum of many substances, which results in a high photolytic capacity. Low pressure (LP) mercury vapour lamps emit ultraviolet light at just one single wavelength (254 nm). Consequently, the direct photolysis of target substances is less effective and the yield of hydroxyl radicals is lower compared to MP lamps. However, LP lamps have advantages over MP lamps such as significantly lower energy consumption and fewer by-products such as Assimilable Organic Carbon (AOC) and nitrite are formed. The objective of this research is formulated as follows: Performance comparison of low pressure versus medium pressure mercury vapour lamps in advanced oxidation via UV/H2O2, by means of experimental research with a pilot-scale set-up.