A “GREAT plume of black stuff” seeping into the Swan River caused an East Fremantle resident to confront a council contractor this week.

David Bell had been walking his dog, Mignon, near the Left Bank pub when he spotted the material polluting the otherwise crystal-clear river.

He traced the mess back to a Horizon West worker cleaning out the ponds at nearby Bincentennial Falls.

“It was a beautiful day and I was watching the swans in the river: the water was crystal clear,” Mr Bell says.

“Then I saw this great plume of black stuff seeping into the water towards them. It was jet black and looked disgusting.”

Upon being confronted the worker phoned his boss and the pump was switched off.

East Fremantle acting CEO Gary Clark maintains the seepage had been “clear water”, not “sludge”, and it had entered the river via an overflow drain.

“The contractor initially pumped out the top 300mm of clear water in the pond to make the pump accessible to be assessed for removal,” he says.

“The overflow drain by design diverts pond overflow, and stormwater, under Riverside Road into the river.

“Once the clean water is removed the remaining water and ‘sludge’ is then cleaned out by a pump truck.”

Mr Clark says the actions of the contractor are being assessed to ensure they meet the council’s procedures.

He says the ponds are cleaned out every two to three years: on this occasion the pump required removal for servicing.

by STEPHEN POLLOCK