SCIENCE EXPLAINED: Why our water tastes ‘earthy’
DESPITE what can only be described as an ‘earthy’ taste, Tweed shire’s water is safe to drink according to the council.
Tweed Shire Council says it treats our raw water supply to remove naturally occurring taste and odour compounds, called Geosmin and Methylisoborneol (MIB).
Across the past five days, Tweed Laboratory Centre tests have shown these taste and odour compounds have increased fivefold in the Bray Park Weir pool, where the bulk of the region’s reticulated supply is drawn.
A council spokesman said the change was most likely a result of ongoing blue-green algal blooms in the Tweed River, including the weir pool.
Human noses and tastebuds can detect Geosmin and MIB at low concentrations.
Water and wastewater operations manager Brie Jowett said in hot dry weather, the situation with algae can change within hours.
“(This) requires us to constantly tweak our water treatment processes to remove the taste and odour compounds produced by the algae,” she said.
“While we have again made adjustments to our processes, the water currently in the reticulation network will have to work its way through the system before things improve.
“The water is perfectly safe to drink despite the musty taste and odour.”
The first blue-green algal bloom of the season was recorded in Clarrie Hall Dam in late August and there have been ongoing blooms since then in both the dam and the Tweed River.
The alerts have moved between green and amber along with changes in the weather.
In early November after some rain, flows in the Tweed River improved reducing algae levels and the water treatment processes were dialled down as the blooms dissipated.
“But in the past five days the taste and odour compounds caused by algae in the raw water have increased more than fivefold and we now have to dial up our treatment processes,” Ms Jowett said.
Ms Jowett urged Tweed residents to be patient as the water worked its way through the system and urged caution before investing in any costly water filtration unit.