The winning contractors will be responsible for delivering essential frontline sewer services from responding to emergency calls to rehabilitating existing sewers.
Work will be carried out across four lots.
Maintenance and manholes workstreams will be the responsibility of Lanes Group, while Cappagh Browne will deliver on sewer rehabilitation projects, and McAllister Bros on sewer sealing.
The contracts will start in April 2025, spanning all five years of the spending period known as AMP8, with the potential for extensions.
Southern Water’s Head of Wastewater Networks, Alex Saunders, said: “We are delighted to have secured partnerships with industry leading suppliers who are experts in their respective technical disciplines.
“These agreements prepare Southern Water to meet the service levels expected by our customers and will help us to deliver on our environmental improvement ambitions for years to come.”