Patients at the maternity unit at Taranaki Base Hospital are being forced to drink bottled water because of issues with ageing pipes.
Te Whatu Ora Taranaki operations acting group director Katy Sheffield said test results in June indicated a higher than usual iron content reading in the affected area.
"As a precautionary measure while we work to replace the remaining pipes, regular testing of iron levels and provision of bottled drinking water will continue," Sheffield said.
The latest water test results showed no adverse results.
"We are still working at pace to fix the issues with some pipes affecting the colour of tap water in the postnatal and labour wards. Clear running tap water is now available in our neonatal ward, Sheffield said.
Ongoing replacement of pipework would in collaboration with hospital unit leaders, to minimise the impact to maternity services users.
"Our Infection Prevention Control team has advised that the tap water in these areas is still suitable for handwashing, and as per usual hand hygiene protocols, hand sanitiser is encouraged."
Sheffield said the issue was likely to have been caused by pipework in the maternity block's 1950s building.
A new maternity ward was currently being built on the hospital grounds as part of the Project Maunga Taranaki Base Hospital redevelopment project and was due to open next year.