Fixes in the works for wastewater
All but one of Manawatu¯ ’s wastewater treatment plants are failing compliance tests, but the man in charge of them says plans are afoot to both fix the problems and save ratepayer money.
The compliance issues have become public knowledge, after Horizons Regional Council started publishing data about the plants.
Of the eight plants run by Manawatu¯ District Council, only Himatangi was complying.
Most of the other plants had problems with discharge volume and high nutrient readings in waterways.
The Feilding plant, which has gone through various upgrades in recent years, was not complying because it was discharging too much soluble inorganic nitrogen.
Manawatu¯ District Council general manager of infrastructure Hamish Waugh said officials were working on a solution.
The plan involved piping waste from smaller places, like Halcombe and Cheltenham, into the Feilding plant.
Doing so would save the council money, as it would not have to upgrade the small plants or reapply for as many resource consents, Waugh said.
‘‘We’re trying to leverage off the investment the ratepayers have already made.’’
The pipes would cost about $8 million, with the money to be budgeted in next year’s Long-term Plan.
The council had a consent to discharge wastewater from the Feilding Plant on to land and had bought ‘‘millions of dollars’’ of farm land to make that possible, he said.
Irrigation systems were being set up and would be tested over the summer to check how it affected ground water.
‘‘The short-term impact is that we are not meeting our nitrogen targets,’’ Waugh said.
However, testing upstream and downstream from the Feilding plant’s outlet into the Oroua River showed little to no harm.
Although the Feilding plant was breaching its nitrogen targets, Waugh said it was not by much.
The consent allowed 30 grams of soluble inorganic nitrogen per cubic metre, but the Feilding plant’s average was in the low 30s.
At a recent Horizons meeting, strategy and regulation manager Dr Nic Peet said 17 of the 46 plants in the region were judged to significantly not comply with their consents. But of those 17, only two – Halcombe and Sanson – were affecting rivers through E coli discharge.
Although the report was only a ‘‘snapshot in time’’, Peet said the number of non-compliant plants raised concerns.
‘‘We need to keep a close eye on it for the next few months to ensure it doesn’t get worse. Only then will it come clear if it’s a blip or something more long term.’’