Up close, after it has travelled more than 300km, the Waikato River is so muddy that you cannot see your feet if you are standing just knee-deep beside its banks.

New Zealand is perfectly positioned to road-test the next generation of ultra sustainable "green cars", which could play a crucial role in our future, a visiting US innovator says.

In London they're making some big changes to the roads, adding two-way segregated cycle tracks along around 25 Km of bike routes.

About 225 million tonnes of plastic are produced globally each year. New Zealand imported nearly 210,00 tonnes of nurdles last year and 61 per cent of plastics made in New Zealand are used for packaging.

Hu Li's heart sank when she realised that she could gauge how close she was to home by the colour of the air.

Lime will be spread over Wanganui's wastewater treatment ponds from today to try and stifle the foul odour coming from the plant and drifting across most of the city.

International wastewater experts Cardno BTO are in Wanganui to look at ways of reducing the smell from the city's water plant.

People feel uncomfortable seeing discarded plastic bags out of place, such as in the landscape, writes Al Gillespie. Plastic bags are virtually without substance.

International wastewater experts will be in Wanganui today to begin looking into whether the city's wastewater treatment plant can be saved.

The foul-smelling black sludge clogging up the river mouth at a Northland beach is not human or animal effluent, but it's still not a good idea to swim in the area, officials say.

A beachgoer is disgusted with the state of one of Auckland's top beaches, after it was left with so much rubbish on the sand it resembled "a dump".

People are being warned to protect themselves and their dogs against toxic algae in Masterton's Waipoua River after levels increased.

Discharging untreated wastewater into the sea is "not an option" for the Wanganui District Council, says Mayor Annette Main.

Thirteen days before the world's top male triathletes dived into the chilly, salty Waitemata Harbour for the grand final of their championship series, the water was sampled for signs of bacterial contamination.

Auckland Council scientists are developing a computer model that will predict, for beach swimmers, the amount of sewage pollution on any given day.

John Key has dismissed criticism of New Zealand's "100% Pure" brand, by comparing it to a McDonalds marketing campaign.

Editorial: Russel Norman is absolutely right to say that scientists must be free to perform their academic duty to report environmental degradation.