New research from biogeochemists, hydrologists, and environmental engineers from the University of Pittsburgh has uncovered previously overlooked impacts of a widely used water treatment practice. The practice, targeted at preventing lead pipe corrosion through the addition of orthophosphate, alters urban stream chemistry through phosphate leaking according to the study.
Published in the journal PLOS Water, the study found that the alteration of stream chemistry can lead to acceleration of eutrophication, the process in which excess nutrients can lead to excessively large algal blooms and plant growth.
Working with local water authorities the team studied five different streams to assess changes in pre- and post-implementation of orthophosphate corrosion control practices. Ultimately, the researchers discovered a statistically significant increase in phosphorus and other metal concentrations in stream water following the implementation of the corrosion control practices.
We were surprised by how clearly the effects of drinking water treatment appeared in stream chemistry. This finding suggests that our underground infrastructure isn't as sealed off from the environment as we often assume," said Dr. Anusha Balangoda, Assistant Teaching Professor in Geology and Environmental Science in the School of Arts & Sciences. "Our study is the first to examine urban stream chemistry and the influence of drinking-water additives."
"We absolutely need to protect people from lead in drinking water," added Dr. Emily Elliott, co-founder and chair of the Pittsburgh Water Collaboratory and professor in Geology and Environmental Science. "But we also need to understand how these treatments affect our rivers and ecosystems."
Phosphate corrosion inhibitors are used in drinking water systems throughout North America, the United Kingdom, and other parts of Europe. The team notes that the potential ecological consequences of these practices remain "largely unexplored, particularly in the U.S."