Wipes and rocks wreaking havoc on Tasman's wastewater

The cost of clearing blockages from Tasman’s wastewater system has almost doubled.

By Max Frethey of Local Democracy Reporting

From January 1 to November 30 last year, Tasman District Council spent $33,344 on clearing blockages compared to $61,042 for this year.

The dramatic cost escalation is despite the number of blockages increasing by a smaller percentage, from 76 to 97.

Three quarters of the blockages were caused by wet wipes, clothing, or raggage – the term for a coagulated combination of flushed items that could include wipes, fabric, and other unidentifiable materials.

In 2024, clearing those blockages accounted for almost 80% of the total cost, but this year it has fallen to just under half the total, at $30,000.

The steep cost increase comes as just five blockages accounted for more than a quarter of the district’s final bill, primarily driven by rocks that appeared to be being washed into the network during storms.

Once blocked, wastewater pump stations must be craned out, pulled apart, cleared, reassembled, and then reinstalled.

Wastewater blockages are a perennial problem in Tasman, where an overflow last year caused by wet wipes, oil, and grease resulted in a boil water notice being applied to dozens of Motueka homes, prompting councillors to consider a wet wipe “rebellion”.

“We are carrying out detailed analyses of all blockages and are building a full database so a clear picture of the problem can be established,” a council spokesperson said.

“We will use this data and these insights to develop a management plan; however, this will take time to establish trends and patterns.”

Riwaka’s Jenkins pump station, which had the greatest number of blockages in 2023 and 2024 despite only serving 50 properties, has dropped off Tasman’s list of most problematic stations.

“We never got to the bottom of the problem at Jenkins, but this year, there were only three blockages, so potentially the problem person has moved or seen the error of their ways,” the spokesperson added.

The pump station with the most blockages in 2025 was the Warren Place station, which serves a “very small” industrial area in Māpua, with 12 blockages.

Another Māpua pump station, the Aranui-Higgs station, came in second with 10 blockages.

That pump station has been a historic problem for Tasman District Council, specifically with blockages caused by clothing.

In third, same as 2024 and 2025, with nine blockages, was Motueka’s Puketutu Grove station, which, like the Aranui-Higgs pump, serves a large residential catchment.

Of this year’s 97 blockages, 19 occurred in low-pressure pump systems that only serve individual properties, unlike a pump station, which typically serves many properties.

There are more than 1200 council-owned low-pressure pump systems in Tasman.

Routine maintenance is not undertaken on those systems, but contractors do attend when issues arise.

Generally, the council funds the cost of the first call out to a low-pressure pump system blockage, but the cost of fixing future issues falls on the affected household.

Residents are encouraged not to tip oil or grease down the sink, and to only flush the ‘three Ps’ – paper, pee, and poo – down the toilet.

However, new, voluntary wet wipe standards have been introduced across Australia and New Zealand to determine whether products were suitable to be flushed.

A few, but not all, of the commercially-available wet wipes now met the flushability standards and were distinguished by a special flushable logo.

To be flushable, wipes cannot block pumps or affect their power draw, must break apart into small pieces as they move through the wastewater network, sink instead of float as they enter treatment plants, biodegrade, and be plastic-free.

Additionally, the council says that drug packets, money, dildos and other sex toys, Lego figures, and toy cars were “pretty common” finds in the local wastewater network.

“From all the stuff we find, I do find Lego figures and toy cars most intriguing,” says a representative of Downer, which is contracted to maintain and operate Tasman’s three waters network.

“Are there kids out there who use a toilet seat as an IndyCar race circuit, or Lego water world? I don’t know.”

False teeth, teddy bears, “expired” pet fish, and construction materials have also been found in the region’s wastewater in prior years, while other finds elsewhere in the country included a gun, car batteries, and a double mattress.

Local Democracy Reporting is local body journalism co-funded by RNZ and NZ On Air