Waste kept out of Oroua River
Feilding’s treated wastewater is being discharged to land for the first time in the town’s history, to keep most of it out of the O¯ roua River.
Effluent from the town’s wastewater treatment plant will mostly be used on land after a $35 million irrigation system was turned on for the first time last week.
The Manawatu¯ District Council faced stiff criticism about 10 years ago, when its wastewater plant was found to be offloading high levels of nitrogen and phosphorus to the O¯ roua River during summer when flow levels were low.
Infrastructure general manager Hamish Waugh said the two chemicals were widely known to create black algae in rivers, and the finding prompted officials to upgrade its plant in Feilding and search for alternative ways to dispose of the town’s waste.
‘‘The more we take out of the river during the low-flow zones, the better it is for the environment,’’ Waugh said.
Although the council was still unable to irrigate to wet land during winter, Waugh said river flows were much higher and diluted waste, leaving minimal damage on a river’s ecosystem.
The plant on Kawakawa Rd has operated since 1967, but parts of it dated back to 1905.
Investment in the plant meant it now had two storage ponds, with a capacity of 50 million litres, to spray waste on to 180 hectares of surrounding farmland through five centre-pivot irrigators.
Grass is grown for baleage and harvested about six times each summer. It is then sold, with profits going back into the council’s wallet and, with luck, would decrease the cost of rates, Waugh said.
The council had met opposition from neighbouring landowners, who believed their homes, washing and drinking water was in danger of being sprayed, Waugh said.
But the council had planted trees along its boundary fences, dug runoff ditches and built stopbanks.