Napier City Council will be carrying out a water mains cleaning programme between May 1 and the end of August.
Letters will be circulated to the residents of the affected streets to notify them of when the work will be conducted in their neighbourhood. Suburbs affected are Taradale, Greenmeadows, Tamatea, Pirimai, Onekawa and Marewa, and the work will take place on weekdays after 9am between Tuesdays and Fridays.
To carry out the work, a foam swab, called a "pig", is forced through the main, scouring it clean as water pressure propels it along before it exits the main.
Water mains cleaning is part of a routine programme of work carried out by the council every winter, when water demand is typically low, says Jon Kingsford, director infrastructure services.
This is on top of the water improvement programme which the council is undertaking at the moment.