Water treatment system makes global splash
A revolutionary water treatment control system developed in Wairarapa is rapidly spreading across the world.
Martinborough-based engineering company h2ope Ltd developed the Com::pass system for the Wellington Regional Council.
A pilot system was installed at the council's Wainuiomata water treatment station in 2007 and the full scale system at Te Marua in 2009.
Regional council water supply group manager Chris Laidlow said the savings in chemicals amounted to about 1000 tonnes, or $250,000 a year. Water quality had also improved and sludge was reduced.
"Our original intention was to improve water quality and treatment plant reliability, though it has had the added benefit of lower running costs," he said.
Council social and cultural wellbeing committee chairman Nigel Wilson said the system was provided to the regional council at no cost to ratepayers.
"The only thing we had to do was provide them [h2ope] with facility that they could test," he said.
"The corollary effect was that if you take 1000kg of chemicals out of the water, that is going to improve your water."
The council also gets a 5 per cent commission on all sales of the unit, he said.
h2ope Ltd managing director Jason Colton said systems were in use at 28 sites.
In New Zealand the process was used at plants in Dunedin, New Plymouth, Tauranga, Palmerston North, Matamata and Hamilton.
Elsewhere they were used in Australia and Britain, and the company was pushing into Europe and the United States.
The system won the Chemical Bio and Food Award at the New Zealand Engineering Excellence Awards last year.
Dr Colton said the treatment dealt with dissolved organic matter in water taken from rivers.
"It is like tannins from matter that falls from the bush after rainfall.
"It is produced by biodegradation of dead organic matter."
Dr Colton said chlorinating the water would produce tri-halo methane and halo acetic acid, which are both regulated in drinking water.
"You add nasties to the water if you add chlorine."
Instead a coagulant was added to form solids from the organic matter, aggregating it into blocks which could be removed.
The com::pass software finely controlled the addition of the coagulant chemicals.
"The critical factor in dealing with these materials is responding to changes," he said.
"They go from very low levels to very high very, very quickly.
The system monitored trends and operated predictively to anticipate required chemical dosing levels, he said.