Bridport black water no cause for concern

A black, non-toxic substance being discharged into the Trent Water Estuary.

March 20, 2024

By Rachel Williams

A black substance being discharged into the Trent Water Estuary via a stormwater outlet, often discolouring the entrance to the river mouth, was non-toxic and no cause for alarm, according to TasWater officials.

The water authority confirmed that it was Powdered Activated Carbon (PAC) which is commonly used to remove odour and taste issues from drinking water.

Fran Smith, Head of Water and Environment Services at TasWater, said the organisation was reviewing the need for PAC use at the Henry St Plant, where it was entering the stormwater drainage.

Ms Smith said TasWater would be looking at methods to manage and minimise the discharge.

The substance is used at Bridport for most of the year but its visual impact was being felt more in the dry conditions, she said.

“Due to higher demand in summer, the plant operates and backwashes more frequently, using more carbon,” Ms Smith said. 

“We aim to minimise any discharge and impact on the environment.  We are working to minimise the amount of carbon used and alternative ways to capture the carbon.

“Carbon is used in home water filtration systems and some drink bottles and is safe and non-toxic.  There is no cause for any environmental alarm.”

Dorset Council Environmental Health Officer Robert Masterman said Council had received a number of enquiries about the discharge from concerned residents and had spoken to TasWater.

Dorset Coastal Working Group Convener Louise Brooker said it had stained rocks and she would raise the issue at the group’s next meeting because it was not a good look for the thriving tourist town.

“People have noticed it and it is great that they have raised the issue because they are more environmentally conscious and caring for Trent Water.  The health of the estuary is starting to blossom and become a more attractive place for birdlife and fish so it is really important that it is looked after,” she said.

Ms Smith said TasWater was spending $1.5 billion on water and sewer network and treatment plants over the next five years.

A 22km pipeline project to pump water from Scottsdale to Bridport is still being investigated and is a Council priority project to help address Bridport’s water needs.