Napier health officials are investigating a raw sewage spill on Awatoto Road.
On Tuesday afternoon, Fire and Emergency set up cordons in the Awatoto area near the golf course and told people to stay away. People evacuated in the afternoon were allowed back in their houses in the evening, but cordons remained.
Three fire trucks, two tankers and a Hazmat Command Unit were at the site.
Just after 5.30pm on Tuesday, police said State Highway 51 at Awatoto near Clive Bridge, which was closed after a leak at the wastewater treatment plant, had re-opened.
Medical Officer of Health Bridget Wilson told Checkpoint it was an unfolding situation and health protection officers were still assessing the situation.
Anyone who might have been exposed could become sick and they should seek medical treatment immediately.
"Contact with sewage is always an issue from the perspective of infection," Wilson said.
"People who come into contact with raw sewage are at risk of, the main risk is around gastroenteritis, so tummy bugs, vomiting, diarrhea, but also it can lead to skin infections if you've got open wounds that have been in contact."
Cordons went up at Napier's Awatoto Road on 21 February, after a sewage spill in the area. Photo: RNZ / Nick Monro
"It's mainly spread when the gastro bugs get into people's mouth" - Medical Officer of Health Bridget Wilson
The message for people doing clean-ups was to assume the silt is likely to have been contaminated by sewage.
"It's really important that when people are undertaking clean up that they take some really practical steps to reduce their risk of becoming unwell," Wilson said.
"[Wear] masks, gloves, if possible an N95 mask, especially as silt starts to dry and we see dust in the air. But other really practical things thick sole boots, because we're starting to see people coming in with foot injuries, having stood on things in silt, nails et cetera ... long-sleeved trousers and tops where possible."
There was no indication yet of any increase of gastro bug hospitalisations in the area, but GPs have told officials they were seeing gastro cases come through, Wilson said.
Cordons went up at Napier's Awatoto Road on 21 February, after a sewage spill in the area. Photo: RNZ / Nick Monro
Most of the time people can manage gastroenteritis at home by themselves.
"It's mainly spread when the gastro bugs get into people's mouth. So it's really important to wash your hands, wear gloves when you're cleaning up, but after you've finished cleaning up, it's really important to wash your hands and shower off if you can," Wilson said.
"Obviously it can also just be spread person to person, when you might be looking after someone who is unwell. If you've got someone who is unwell at home, really, really important to wash your hands thoroughly and often. And actually ventilate your house, if someone is vomiting in the house, open up the windows [to] ... reduce the risk of spreading it amongst the household."