Engineers will replace old water pipes at Moughland Lane, Oxford Road and adjacent roads as part of phase one.
United Utilities' project engineer Keith Saltmarsh said: "This phase will last for approximately 20 weeks and 500 customers in this area of Runcorn will benefit directly from it."
"These cast-iron pipes have been in the ground most of the last century," said Saltmarsh explaining the project's importance.
"Corrosion can cause bursts and leaks and natural deposits can build up in the pipes, which can cause low pressure and discoloured water," he added.
United Utilities engineers will be using the latest pipe-laying techniques called slip-lining to keep disruption to a minimum for local people.
"Slip-lining is the equivalent of keyhole surgery for water mains. We only need to dig small access holes instead of open trenches and then the new plastic pipes can be fed through the old ones," Saltmarsh explained."
The work is part of United Utilities' £2.9bn water quality and environmental improvement programme between 2005-2010.