Brown water that came through some taps in Springvale on Thursday is not harmful, Whanganui District Council says. 

Whanganui District Council senior water engineer David Rudolph said the discolouration of the water could be caused by bio film — bacteria or micro-organisms that form a slimy substance — inside the pipes. 

“The bio film inside the pipe builds up because once you’ve got pressure inside the pipes, and that can cause discolouration, and you’ve got different material in the ground such as steel. 

“It’s not harmful, but we recommend that we flush it through, because any discolouration causes an issue.” 

There was a planned shut-off for a reinstatement of a main repair in Springvale on November 16. 

“We had a few complaints from before the shut-off and just around 12.35pm, but talking to our admin team we had no further complaints after the water was restored. 

“Once we reinstate we tell people to run their tap for 10 minutes if they notice dirty water.” 

Rudolph said the council was always concerned about reports of dirty water but there was a process to ensure they were informed. 

Notices were delivered to properties to warn them of the shut-off and an alert was also put out through the free mobile app Antteno.