Ngā whatunga wai haumaru Safe Networks

Safe Networks is a joint initiative between our Healthy Waters department and Watercare. It is funded through the Water Quality Targeted Rate.

It aims to reduce public health risks at Safeswim sites and other prioritised areas. Safe Networks team members investigate by taking water samples, analysing the level and type contamination and also by looking for the source of the problem.

We then work to stop the contamination spreading and reduce the risk to the public.

Faecal contamination (human and animal waste) in our waterways can be caused by:

• cross connections between the stormwater and wastewater networks
• damaged public and private drainage.

When faecal contaminants are found to come from human sources, drainage investigations are made to find how and where wastewater is getting into the stormwater network or stream.

Where contamination is found to come from natural or non-human sources (for example, birds, dogs or cows) we contact staff in other Healthy Waters programmes to look at options for animal management and control.

Poor water quality can pose a risk to public health, particularly in recreational areas shown in Safeswim.

There is a high risk of poor water quality at our beaches and streams, particularly:

• after heavy rain
• in areas serviced by ageing pipe infrastructure
• in areas with ageing onsite wastewater systems (private septic tanks)
• following rainfall after long spells of dry weather.

There are different ways of looking into water quality issues. The method we choose will depend on how bad the contamination is and the size and complexity of the water area.

The Safe Networks team weighs up these factors and selects the most appropriate investigation type to track the contamination.

The four main investigation methods are:

• Outlet screening: We collect water samples from stormwater outlets or streams discharging directly into Safeswim sites.
• Network screening: We collect water samples from locations upstream of a Safeswim site in the stormwater network (manholes) or upper stream regions.
• Public asset investigation: We assess the condition of public stormwater and wastewater systems using CCTV cameras,  smoke testing Injecting non-toxic smoke into a sewer or stormwater and watching to see where the smoke escapes. and dye testing Dye used to confirm a connection between a stormwater and wasterwater system. .
• Private drainage inspections: We check commercial and residential drainpipes to ensure they are connected correctly and in good condition. We contact residents before an inspection is done on their property.

For commercial and residential inspections on private property, we check:

• roof downpipes are plumbed to the public stormwater network
• gully traps A deep seal trap which is provided on the external face of a wall for disconnecting the waste water flowing from the kitchen, bath, washbasin and floors from the main drainage system. gully traps are raised off the ground to prevent surface and flood water entering the wastewater network
• wastewater pipes are connected to the public wastewater network.

Investigations can take up to six months or more. We need to gather enough results under different weather conditions (wet and dry) to understand the causes of the contamination.

When we find public assets with issues, we pass on urgent or easy-to-fix problems to the relevant Healthy Waters or Watercare operational teams.

When issues are more complex or may be resolved as part of a larger task, our results are referred to teams responsible for long-term improvement projects and asset renewal programmes.

To check where our water quality investigation team is working, visit the Safe Networks viewer website for desktop or Safe Networks viewer website for mobile / tablet.

To get involved in improving your local waterway, see Programmes promoting water quality.

To learn how you can reduce wastewater overflows and protect local waterways, visit the Watercare website.