Wet wipes blocking a drain Photo:
Unblocking wastewater pumps jammed with wet wipes has cost Tasman District ratepayers more than $80,000 in the past five years.
Since last July, there have been 49 callouts to pump station blockages across the district - costing ratepayers more than $15,000 in this financial year alone.
Tasman District Council community infrastructure group manager Richard Kirby said if that trend continued its annual bill for clearing wet wipes from pump stations was likely to be over $30,000.
Kirby said, not only were the blockages costly, these could sometimes damage the pump beyond repair, or result in raw sewage being discharged into the environment.
"It's actually a significant issue for us. It happens very, very frequently and we don't want wet wipes, flushed down the toilet because they do block up their pumps, and causing our staff to get have to go out and clear them at all hours of day and night and there's an extra cost in clearing these wipes from the pumps."
Most pump stations in the district used macerating pumps, that were unable to cut through wet wipes, which jam the impeller and force the pump to stop working.
Each blockage takes several hours to clear and the pumps must be craned out, pulled apart, cleared, reassembled and reinstalled.
Pump stations in Riwaka, Brightwater and Māpua have been the most affected - with nine blockages at Brightwater's main pump station costing more than $3500 dollars to fix.
Residents in the affected areas had been reminded not to flush wipes - but Kirby said despite this, they were still being flushed down the loo.
"One of the difficulties with a sewerage system is you don't know where the wet wipes come from so you just have to put a blanket message out. You can't go to individuals because you don't know who's done it."
Alongside wet wipes, clothing has periodically caused an issue in the seaside village of Māpua, where tops, underpants and even a pair of jeans have blocked the [https://www.rnz.co.nz/news/national/451727/undies-clothing-flushed-down-mapua-toilets-clogging-sewerage-pumps
pump station on multiple occassions since 2015].
"I'm not sure how you get jeans down the toilet but that happened and it created quite a bit of damage for the pump," Kirby said.
"At the end of the day, it's the cost factor to ratepayers - the more we have to clean pumps out, the more we have to increase our rates to cover it, so I suppose everybody's paying for misdemeanors by individuals."
Clothing aside, Kirby said at least 90 percent of the pump station blockages were caused by wet wipes.
He said wipes should never be flushed down the toilet, even if the manufacturer claimed they were flushable. Only the three Ps - pee, poo and paper - should be flushed down the toilet.
The issue was a nationwide one and Kirby said the Tasman District Council would consider a petition to have wet wipes replaced with a more frangible material or have them removed from the market completely.
