Wastewater

Wastewater comes from many sources, such as:

• households — poos, wee, laundry water, rubbish, medicines and cleaning products
• industrial production — toxic chemicals, heavy metals, persistent organic pollutants and oils
• agriculture — irrigation run-off, animal waste, agricultural chemicals and medicines
• urban environments — stormwater, rubbish, vehicle pollution, public toilets and other debris.

Wastewater contains pathogens such as bacteria, viruses and protozoa (a group of single-cell organisms). These can cause disease if people come into contact with them. The most common symptoms caused by contact from wastewater are:

• stomach bugs
• throwing up (vomiting)
• runny poos (diarrhoea)
• skin, throat, ear and eye infections
• chest infections.

Wastewater can also contain chemical waste. If it enters our waterways and coastal areas people, animals and plants can be exposed.

Systems in New Zealand to keep people and wastewater separate are normally very effective. However, there are situations where people can come into contact with wastewater. This most often happens when wastewater overflows out of a sewer or wastewater pipe, usually because the pipes are blocked or overloaded during heavy rain.

In areas without piped sewage systems, some form of onsite wastewater disposal is used. Septic tanks are the best known variety and are common in rural parts of Aotearoa.

Wastewater overflows can contaminate streams, rivers, harbours, and the coast. This can make swimming and collecting food from these sources risky.

The role of public health

Public health:

• provides advice to and works with local councils and water services to reduce the number of wastewater overflows happening in our regions
• puts outs alerts to the public when there are significant risks from contact with recreational water areas contaminated by wastewater
• has a role in notifiable disease surveillance, which includes some diseases and illnesses caused by contact with wastewater.

If you see a wastewater overflow avoid it, keep tamariki and pets away and report it to your local council.

If overflow is on your property, the council may direct you to call a plumber or a drainlayer. You will need to pay for the work yourself.

Councils in Aotearoa — Local Government New Zealand (external link)

If you are planning a day in the water, check the quality to make sure it is safe.

Recreational water safety (external link)

Land Air Water Aotearoa (external link)

Safeswim (Auckland and Northland only) (external link)

If you have come into contact with wastewater:

• wash your hands or shower depending on the nature of contact
• wash the clothes you were wearing
• call your health provider, or Healthline on 0800 611 116, if you start to feel sick.