The work will help protect Hartlepool’s bathing water quality and ensure it meets tougher EU bathing water directive standards, as well as reducing the risk of sewer flooding to nearby homes.
The two sites, located near Tees Road, serve up to 155,000 people from Hartlepool, Seaton Carew, Billingham and surrounding areas.
Seaton Carew Headworks provides a preliminary treatment of sewage which screens and removes grit from wastewater, before it is transferred to Seaton Carew Sewage Treatment Works for an additional three stages of treatment.
The treated flows are then pumped back to the headworks and returned safely to the environment.
During the project, machinery used to treat the wastewater will be replaced and upgraded and new, innovative treatment systems will be installed.
The work is due to get underway on Monday 10 August and is expected to last until the end of June 2016. It will be carried out by contractors Interserve Construction.
Northumbrian Water project manager Dean Thompson said: “Protecting and enhancing the environment is at the heart of our business and the project in Seaton Carew will help us to sustain this.
“By refurbishing various processes and assets, we can also improve the reliability of the works, ensuring they are fit for future generations and reducing the likelihood of flooding to nearby homes.”
The project forms part of Northumbrian Water’s £150 million programme in AMP6 to upgrade and maintain its 412 sewage treatment works.
A version of this story first appeared on WWTonline.