Materials like polyvinyl chloride (PVC), polypropylene (PP), ultra high molecular weight polyethylene (UHMW-PE) are used for the construction of drinking water supply systems. It was found that regardless of the type of material the distribution network is built of, microorganisms formed biofilms on every available surface. The pipes material plays a key role in terms of biofilm formation. Important factors are the surface roughness, adhesives, plasticizers, stabilizers, which can be a source of nutrients for bacteria. The metabolic activity of microorganisms on polymer materials, induces migration of compounds from the material into water. The aim of this study was to present the differences in the structure and the metabolic profile of biofilm formed on the technical materials.