Enhancing drinking water quality: Impact of biofilm in Danish PE pipe systems

Polyethylene (PE) pipes are often the chosen material when commissioning new drinking water pipes in the Danish non-chlorinated drinking water distribution system. Previous studies have identified numerous compounds leaching from PE pipes to drinking water. Here, the effect on enrichment cultures of young (8 weeks, FRE) and old (6 years, BUS, TBR) PE pipe biofilms was studied with a) 9
selected compounds known to migrate from PE pipes and b) a natural “PE-cocktail” obtained from crushed PE pipe. The 9 pure compounds had a limited effect on biofilm growth from BUS and TBR, while the activity of FRE biofilm was stimulated. The PE-cocktail stimulated activity of biofilms, and increased biofilm formation in BUS and FRE enrichments. These results highlight potential beneficial effect of biofilms on the distributed drinking water quality. Establishing and maintaining a diverse biofilm community in new PE pipes may benefit the water quality and the consumers.