Backflow Prevention

What is backflow?

Backflow can occur from anyone’s water connection when the pressure in their private system exceeds the pressure in the public water supply (such as when the public system is shut down for maintenance, there’s a break in the main, or a major fire etc). This can create a syphon effect that could allow any contaminates present inside the private property to enter the public water supply.

Certain types of properties where this could occur are identified in the water supply regulations in the Health Act. These properties are legally required to have a backflow preventer fitted at the property boundary to protect the public water supply from contamination. These Health Act requirements haven’t been enforced for a number of years, however, recent events (in Havelock North in particular) have highlighted the need for this to be followed up and acted on.

What properties require Backflow Prevention Devices?

The Health Act specifies a range of different property types that are required to have backflow prevention devices installed, and classifies them as high, medium or low risk:

High risk:
  • Includes operations in urban/industrial areas – e.g. chemical plants, sites using, processing or manufacturing toxic materials, hospitals, rest homes, medical and dental centres, vets, funeral directors, truck washing, butchers shops, and commercial laundries.
  • Operations in rural areas – e.g. farms, and equine establishments.
  • Connections on the trunk mains connecting water sources to the towns in Matamata, Morrinsville and Te Aroha are regarded as a high risk due to the number of persons who could be potentially affected.
Medium risk:
  • Risks in rural/urban areas – e.g. lifestyle blocks under 2 ha where stock is grazed, hairdressers and car washing facilities.
Low risk:
  • Processes on the property have the potential to discolour water or change water taste or odour but do not endanger health.
  • Examples include: Hose taps for domestic irrigation systems and hose taps used for filling swimming pools and spa pools.

What is required?

Over the next 12 months, all properties that require backflow prevention devices (including those that currently don’t have one, or have one that isn’t compliant) will be required to install a device or air gap separation device at the property boundary. This will then need to be inspected and recertified annually.

The priority and deadlines for the installation of these is:

  1. Installations completed and/or certified by 31 December 2018: Meat works and food processing plants, butcher shops, chemical plants, dental, medical and veterinary clinics, properties connected to trunk mains, hospitals and retirement homes, mortuaries, sites using or manufacturing chemicals, saleyards, equine establishments and council pump stations and treatment plants.
  2. Installations completed and/or certified by 30 April 2019: Farms and lifestyle blocks greater than 2 ha where stock is grazed.
  3. Installations completed and/or certified by 31 August 2019: Lifestyle blocks less than 2 ha where stock is grazed and hairdressers.

We understand that this is short notice for a number of businesses and are open to discussion on the timeframes, or the option of paying off a device (e.g. over three years).

Installation of backflow prevention devices

You can have your device fitted by any plumber but it must be certified by a qualified and authorised plumber. There are three businesses in the district who can certify backflow prevention devices:

  • Comag Matamata – 07 888 8883
  • Ron Johnston Morrinsville - 07 8896469
  • JT Carter Plumbing Te Aroha - 0800 582 278

Once the certifying firm has certified the current backflow device or the installation of a new device, they will forward council a copy of the paperwork so we can update our records.

Recertification of your backflow prevention device will then be required annually (before the 12 month expiry since the last certification). We will send out reminder letters but it is your responsibility to ensure your backflow device is recertified by the due date.

Questions and more information

We held a Facebook Live Q&A session on the Matamata-Piako District Council Facebook page on Thursday, 6 September to explain backflow prevention, what the requirements are, and answer any questions, which you can view at any time.  

If you have any queries please feel free to contact Graham Robertson on 07 884 0060.