Contracting company admits dumping contaminated fill

Downer Alliance manager Dan Gerrard.

Contracting firm Downer has admitted it made a mistake when a quantity of fill contaminated with sewage was dumped a short distance from the Ohau River last week.

The company, which works in an alliance with Horowhenua District Council and has a manager based in the council offices, confirmed the fill had been wrongly taken to the site by one of its truck drivers.

Alliance manager and Downer spokesperson Dan Gerrard said the company was allowed by HDC to dump clean fill at the site, and just a "minimal" amount of contaminated material had been taken there.

Horowhenua District Council Group Manager Infrastructure Services Gallo Saidy.

"It sounds bad, but in terms of the actual risk - since the [water treatment] plant has been upgraded, the risk is minimal," he said.

He said there would have had to be a large amount of rain to wash contamination into the groundwater for there to be an issue, and that animals in and around the river posed more of a contamination risk.

"We've got really good processes in place in terms of communication, but clearly the driver misunderstood an instruction," he said.

Mr Gerrard said that once the company learned of the error, managers were instructed to organise diggers and loaders to clear it out and tidy the site.

"We admit that we made a mistake and we're going through an investigation process to make sure it doesn't happen again."

A member of the public, who wished to remain anonymous, alerted authorities to the contamination when he came across it while tramping.

He felt the situation had been downplayed, and that in subsequent communication with HDC they had tried to "pacify the severity of it".

"When I saw it I was shocked and disgusted," he said.

"Downer as a company should know better and they do know better, so I fail to understand how that kind of event takes place because it doesn't take a genius to figure out you don't put human waste in the vicinity of the water treatment plant, and most importantly on the water gallery intakes for the drinking supply of the town."

The man said there was more material dumped than Downer or the council was admitting, with both saying only a couple of truck-loads were dumped, and that not all of the material had been removed.

HDC maintains there is no threat to the town's water supply, and Gallo Saidy, the council's Group Manager Infrastructure Services said the area that was contaminated is "far away from the river where we take water".

He said it was 30m to 50m away.

"Even if there were 100 trucks, the chance of contaminating the water supply is very slim," he said.

He said the situation was " a storm in a teacup" and was nothing from an engineering perspective.

"Good on the gentleman that has highlighted it," he said.

"We've corrected it and it's not going to happen again."

He said there would not be any disciplinary action resulting, and as it was a mistake, not a deliberate act, a fine would not be imposed.

Mr Saidy said he trusted the contractor to have removed all the material, and that council and alliance managers had all learned from the situation.

They could put more robust processes in place to ensure mistakes such as this were not made again.

He said extra water testing would not be carried out as it was unnecessary, and regular testing was carried out as part of the plant's normal operations anyway.

MidCentral District Health Board's public health protection unit had been informed of the removal of the material, which Mr Saidy said was the end of it for them.