Biofilms and microbially influenced cuprosolvency in domestic copper plumbing systems

Aims: To survey biofilm accumulation within domestic copper plumbing pipes in South Australian drinking water distribution systems and examine its rol e in copper solvation (cuprosolvency). Methods and Results: Cold water copper pipes were sampled from two differen t plumbing systems receiving filtered and unfiltered potable water respecti vely. Biomass was quantified by total organic carbon measurements and viabl e cell counts and microbial activity by respirometry. Biofilm accumulation was related to water chemistry within the systems, particularly nutrients, alkalinity and conductivity, as well as water turbulence. Laboratory coupon experiments were used to determine the effect of extracted biofilm on copp er solvation. Biofilms were shown to be capable of both increasing and decr easing aqueous copper concentrations in comparison to sterile controls. Conclusions: The results suggest that water quality may influence the accum ulation of biofilms in copper plumbing systems, as well as potential cupros olvency activity. Significance and Impact of the Study: The presence of biofilms in copper pl umbing systems and their ability to influence aqueous copper concentrations has implications for both public health and the management of distribution systems.