Wastewater education

What to and what not to flush

Over the last two years there has been an increase in community awareness and subsequent response to the number of wastewater overflows that have been occurring within the Waikato district.

A number of these overflows have occurred in Raglan and have resulted in the harbour being closed to both swimming and seafood collection.

But wastewater overflows aren’t limited to Raglan. Overflows happen across the district and in August 2016, Council received a report outlining initial responses to the level of overflows from the wastewater network and supported a continual improvement programme (CIP) approach to managing the overflow issues.

A review was carried out between September and November 2016 to determine what else could be done over the medium and long term to provide a sustainable improvement, recommendations from that review included

  • employing more specialist water and wastewater staff,
  • the purchase of standby generators,  
  • improved wastewater operational knowledge and control across the district,
  • a proactive network jetting and condition assessment programme,
  • and a district wide public education programme.

Council has a goal of reducing overflows as much as practicably possible but acknowledges that it is not possible to completely rule them out and need the community’s help.

Wastewater overflows are caused by:

  • Blockages caused by foreign objectives within the network or at pumping stations either in wet or dry weather
  • Inadequate capacity within the network, relative to the flow being transported – this is normally an issue in wet weather
  • Failure of key equipment (e.g. pumping stations) or power at key installations (e.g. pumping stations)

The effects or consequences of wastewater overflows are that:

  • They result in the pollution of waterway (streams, rivers and harbour)
  • Give rise to public health issues, if next to people or where they swim,
  • They cause a loss of utility for sanitary services for customers

Whilst the Council interventions will unboubtably lead to positive results, the community’s support and action will improve these results and for that reason the districts communities are being asked to do that bit through a public education programme.

As part of this public education work, material will be distributed to all public toilets in the district and all households will receive information letting them know what should and shouldn’t be put down the loo and kitchen sink. Council will have a presence at public events such as market days where we will share the message. Accommodation providers, real estate agents and plumbers will have access to information to circulate to their customers.

The wastewater education programme will then look to be embedded in schools around the district.

What we know so far

We know that people are putting non-flushable items such as rags, wet wipes, nappies and undies down the loo and fats, oil and grease down the kitchen sink. This in turn blocks the wastewater system and is the main cause of wastewater overflows (81 per cent in 2014-16) in our district. The remainder of overflows are due to network issues.

So we’re undertaking, among other things, a district-wide public education programme to alert the district to this problem.

Blocking materials

We find all sorts of blocking materials in our wastewater network. Some examples include:

  • Baby wipes
  • Band aids
  • Cigarette butts
  • Cleaning wipes
  • Clothes
  • Condoms
  • Cotton buds
  • Cotton wool
  • Dental floss
  • Face masks
  • Facial wipes
  • Bottom wipes
  • Fat, oil, grease
  • Food
  • Fruit labels
  • Goldfish
  • Hair
  • Kitty litter
  • Nappies
  • Nappy liners
  • Rags
  • Sanitary pads
  • Socks
  • Tampon applicators
  • Tampons
  • Tissues
  • Toilet roll tubes
  • Wet wipes

News, useful resources, information and tips


Wastewater network cleaning under way in Ngaruawahia and starts soon in Huntly

15 May 2017

Waikato District Council is continuing its work to improve the wastewater network in the district.

Following on from the cleaning and inspecting of underground wastewater pipes in areas in Raglan, contractors have moved on to areas of Ngaruawahia and Huntly this month.

Cleaning the pipes will remove blockages caused by objects like nappies, pieces of cloth and wet-wipes.

These blockages can lead to wastewater spills, which is something Council is trying to avoid.

Once clean, the pipes can be inspected via Closed Circuit Television (CCTV) cameras. The inspection provides valuable information about the condition of the pipes which helps Council plan what maintenance is needed.

General Manager Service Delivery, Tim Harty says this work forms an important part of a district-wide assessment into the condition of Council’s underground pipes. 

“It is part of Council’s ongoing commitment to improving wastewater infrastructure so that we can minimise any wastewater overflows or leaks,” he says.

The contractors, InterGroup Ltd, are currently working in Ngaruawahia and are due to start the cleaning and CCTV inspection in Huntly around 19 May. Work will continue until the end of June 2017.

Residents in the affected areas will receive letters before work starts in their neighbourhood.

Those letters advise residents to keep toilet lids closed when not in use while contractors are working in their areas. It also recommends adding a weighted object to the top of the toilet lid while cleaning is being carried out in the rare event that it causes a surge in flow in the wastewater pipes.

If there are manholes or access chambers on private property, the owner will be contacted and arrangements will be made.

Council thanks the Huntly and Ngaruawahia communities for their support of this important work.

For more information please contact:
John Brown
Communications Advisor
Waikato District Council
07 824 8633
communications@waidc.govt.nz