Blonde students living at the University of Newcastle are looking suspiciously at their showerheads, after noticing their golden locks turning a ghoulish shade of green.
Third-year civil engineering student Melissa Brueckner, 20, said she had been reading about remedies online after noticing the lighter hues in her hair gradually changing colour over the past month.
"One of the solutions was to put tomato sauce into it, but I'm not worried enough to do that!" she said.
Ms Brueckner travelled from New Jersey in the United States to spend the first semester of the year in Newcastle.
She said a friend had warned her after mid-semester break that other blonde students on campus had twigged that their tresses were transforming colour.
"A few weeks after I got back I started noticing mine going green too and it's continued to get worse, although it's plateaued a little bit now," Ms Brueckner said.
"Sometimes my friends say 'You're looking especially green today'.
"I don't swim in the pool here – so it's got to be the showers.
"But I don't think it's a health concern – plus I'm sure there's a really easy fix."
The Newcastle Herald spoke to a number of students at the Callaghan campus on Thursday.
None of the students who lived in older accommodation had experienced or noticed the problem in their neighbours.
But it is understood students who live in the four new, eight-storey towers have been discussing the problem and sharing the link for the university's online incident reporting system.
Ms Brueckner lives in West Residence, which has a green colour theme.
"I see it as a bit of tower pride," she said, laughing.
"I wanted to dye my hair blue, so I'll take green for free."
Hunter Water Corporation chief customer service officer Jeremy Bath said the theory that chlorine turned blonde hair green was an urban myth.
"What actually turns blonde hair green is oxidised copper, which councils often add to the water in local swimming pools," he said.
"If a student's hair has turned green, then I suggest the university look at their plumbing and specifically the quality of their copper pipes.
"Copper in the local water network is about 1/20th of the Australian Drinking Water Guidelines, so Hunter Water can absolutely rule out complementary hair colouring from our water network."
A University of Newcastle spokeswoman said the new student accommodation was completed in January and was constructed with all new materials.
"The University is currently exploring the potential cause," she said.
Newcastle Herald
