SALT, magnesium, calcium and potassium are at elevated levels in the region's drinking water supplies and residents with high blood pressure should consult their doctor, according to Fitzroy River Water.
In an emailed letter to Yeppoon's Gary and Glenda Toon, FRW admits that dissolved mineral content in the Fitzroy Barrage storage has increased significantly in the past three to four months. And unless there is heavy rain soon, it is likely to get steadily worse.
The current sodium concentration in the region's water is three times stronger than the level at which people susceptible to high sodium intake should seek medical advice.
Jason Plumb, FRW's manager of treatment and supply says there's nothing the organisation can do and the problem will only be resolved when summer rains flush the lower parts of the river system.
Mr and Mrs Toon, who live in Taranganba, wrote to the council to complain that a white residue remained on their car and house windows after they had been washed with tap water.
"I didn't expect a response so quickly or in such detail. It's very disturbing to be told that it could be four or five months before salinity levels drop," said Mr Toon.
"I suffer from mildly elevated blood pressure and this worries me. If the council and FRW have put this medical advice in writing to me I think they should go public and issue official advice to everyone."
Mr Plumb's letter says that the mineral content in the drinking water supplied from the Glenmore Water Treatment Plant is making the water saltier and harder than normal.
"Although the increased saltiness and hardness of the water can have a negative effect on the taste, the water continues to meet Australian Drinking Water Guidelines and is safe to drink," says the letter.
But in a sentence that will raise concerns throughout the region, Mr Plumb says: "Members of the public that are sensitive to increases in their daily sodium intake should consult their family doctor or other health professional should they have any concerns."
Thousands of people supplied by FRW are on medication for high blood pressure, a condition which can lead to an increased risk of heart attacks and strokes.
The letter goes on to say that people may notice a fine dry residue on cutlery or other surfaces and an increase in the amount of residue inside kettles or on the surface of heating elements.
Mr Plumb says that where possible, FRW will supply as much of the Capricorn Coast as possible with water from Waterpark Creek, but high demand means there is no alternative to supplementing the coast supply with water piped from Glenmore.
Mr Toon said he suspected mines were responsible for the elevated salt levels and wondered if the authorities were being as honest as they could be about the reasons for the problem.
"I'm 54 and lived in the region all my life and I've never seen this problem before. Something is changing and that's what's worrying me," he said.
FRW is not able to remove salt during the treatment process after drawing water from the Barrage storage. Two weeks ago, in response to questions from The Morning Bulletin, FRW denied there was any Ecoli in the water and said it was not aware of any gastro issues related to the water.
Gardeners across the region have complained that sensitive plants have died or shown signs of disease and some experts have pointed the finger at the salty water.
A council spokesman said yesterday that the current sodium concentration at Glenmore was 58mg/litre and that people who were susceptible to high sodium intake should take medical advice when the concentration became greater than 20mg/litre.
There is no health guideline in the Australian standards for sodium.
"It is expected that the saltier water will continue to slowly flow downstream to Rockhampton unless there is a significant rainfall in the coming weeks," a statement issued said yesterday.
"FRW has requested that the Department of Resource Management consider more regular updates to the public in relation to the Fitzroy catchment and salinity as part of its role as the water supply regulator."
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