Pond de-sludge project shows promise

16:00, Nov 25 2012

An innovative project using tiny bacteria and designed to save South Taranaki ratepayers big money is progressing well.

In what could be a New Zealand first, the South Taranaki District Council has begun adding a special species of bacteria to the Hawera effluent pond in an effort to de-sludge it.

Council operations and projects manager Viv Eyberg said that after the first round of testing he was cautiously optimistic.

"The latest sludge samples, taken a few weeks ago, were very encouraging and have prompted us to undertake a 3D survey of the pond so we can ascertain the whereabouts, and total volume of, the remaining sludge in the pond," he said.

"We believe that it (the project) has exceeded our expectations but still need to remain cautious until the 3D survey has been completed."

About 85,000 cubic metres of sludge needs to be removed, at a cost of about $4 million using conventional methods.

Advertisement

Under the trial project the bacteria produce exo-enzymes which break down the sludge making it soluble.

If successful, the total cost to ratepayers will be about $600,000.

"Other councils are also now testing the process, obviously encouraged by what they see happening here in South Taranaki," he said.

Mr Eyberg said the summer months would also give the tiny bacteria a nudge in the right direction.

"The bugs are sluggish in cooler water and frisky in warmer water - not much different from humans."

Exactly what micro-organisms are being used are a closely guarded secret of Parklink, which touts itself as "specialists in harvesting nature's most powerful biological forces".

However, Mr Eyberg said the particular microbial bacteria used were indigenous to New Zealand and have been approved by MAF since 1993.

Taranaki Daily News