Water is consumed as such or used as ingredient or production aid in the food production chain. Providing safe (drinking) water to the food industry is thus crucial. Invasion of pathogens in drinking water, and cyanotoxin production by blue-green algae in surface waters pose emerging risks to public health and economy. This project aims at ensuring biostable conditions in drinking water to avoid microbial regrowth and presence of cyanotoxins in the water supply for the food industry, and to prevent invasion of waterborne pathogens in the production process without the use of biocides. In a first part, we will define “invasion” and “biostability”. In a second part, we aim to achieve true water biostability. To develop biostable drinking water, the innovative approach of this project aims at creating an environment which is oligotrophic in all available nutrients, but eutrophic in energy. Therefore, H2 and O2 will be added as energy sources to stimulate growth of hydrogen oxidizing bacteria (HOB). This is expected to result in a twofold advantage: nutrient depletion by HOB and “strengthening” of the indigenous community by HOB seeding. We will evaluate both modes of action separately. Also, we will examine the potential of HOB to increase the water biosafety by removing cyanotoxins from surface water supplies for the food industry. In a last stage, we aim to achieve biostable and safe water by HOB seeding in lab- and full-scale GAC reactors.