Impacts of Blending Drinking Water from Desalination into Existing Distribution Systems

A new desalination plant in eastern England will pump chemically different water into old cast-iron pipes, and researchers want to know whether that blend will corrode the network or breed bacteria. The project addresses a practical blind spot. Water companies increasingly turn to desalination as droughts strain traditional supplies, but desalinated water has a different chemical profile—lower in hardness, alkalinity, and disinfectant residual—than the river or reservoir water it will mix with. No one has systematically tested how those differences affect the iron pipes, biofilm, and scale that line decades-old distribution systems. Working with Anglian Water, the team will run lab and pilot-scale experiments using actual pipe sections from the network. They will vary the final water chemistry—adjusting corrosion inhibitors, hardness ions, and disinfectant doses—and measure corrosion rates, disinfectant decay, biofilm growth, and the release of metals like iron and manganese. If the research succeeds, water companies will have evidence-based blending protocols before commissioning new desalination plants. That could prevent unexpected pipe failures, discoloured water, or microbial regrowth—problems that quietly disrupt supply and erode public trust. The work is applied, not fundamental: its value lies in a specific, actionable answer for a looming infrastructure challenge.