Extraordinarily high levels of manganese in town water after rain causing a problem in Tweed Shire

EchoNetDaily, 31 February 2020: 

Following recent rains the water supplied to the Tweed Shire catchment has been appearing dirty as a result of the high mineral content that has washed into the river following the long dry spell. 

On Wednesday evening Tweed Shire Council stopped pumping water through the reticulation network in a bid to isolate the issue of dirty water to Murwillumbah. 

However, this has been unsuccessful and the dirty water has spread to other areas of the shire. 

Residents are advised that while the water is unsightly, it is fit for drinking. 

However, it should not be used to wash clothes, particularly light-coloured clothes, as it may stain them. 

Difficult treatment process 

‘The levels of manganese in the weir pool are extraordinarily high,’ manager water and wastewater Anthony Burnham said. 

‘These elevated levels of mineral are a result of the recent intense rain washing a lot of organic matter into the waterways, which has then drawn on the dissolved oxygen levels as it decays. 

‘The dissolved oxygen level in the weir pool is now very low, exacerbating the minerals issue as the manganese and iron is dissolved and not in its usual particle form, making it harder to remove.’ 

Council is now drawing water from the top layers of the weir pool, where the water quality is better. 

Removing iron and manganese from the water during the treatment process if finicky and requires constant fine-tuning of the treatment process.

‘Our water treatment process was unable to achieve that fine balance yesterday and the discoloured water is now more widespread throughout the reticulated water network,’ Mr Burnham said.....