Murky waters: NZ scores an own goal

• Published date: 29 May 2023
• Publication title: Bush Telegraph

In June 2022 the headline read Zero Pollution: Large number of Europe’s bathing waters meet highest quality standards

The text reported that in 2021 almost 85 per cent of Europe’s bathing water sites met the European Union’s most stringent “excellent” water quality standards.

The minimum water quality standards were met at 95.2 per cent of sites and only 1.5 per cent of all sites in the EU were considered poor quality — generally the result of short-term pollution.

The headline and the data are in marked contrast to the recent headlines in New Zealand following the release of the Ministry for the Environment and StatsNZ report Our Freshwater 2023.

Freshwater crisis ... Sobering snapshot of decline ... and NZ’s lakes and rivers in “appalling” state ... all paint a very negative picture.

These headlines then get picked up overseas, and New Zealand scores an own goal.

The EU reassures society and welcomes tourists — “zero pollution” is the soundbite.

New Zealand alarms residents and puts doubt in the minds of people planning to visit.

The UK Times stated that “New Zealand’s reputation as an environmental oasis has been damaged by official findings that show the national ‘religion’ of dairy farming has left almost half of the country’s rivers too polluted to swim in”.

The articles have muddled the various components of water quality, but the main swimmability criterion is bacterial contamination.

The UK has 67 million people in a slightly smaller area than occupied by New Zealand’s 5 million people and has 12.5 million dogs, 9.6 million cattle and calves, and countless birds, rabbits etc. Yet it, like the EU, is able to state that “the standard of bathing water quality in England is very high with over 93 per cent of bathing waters rated the highest standards of Good and Excellent”.

The EU and UK monitor bathing sites at intervals of less than a month during the bathing season — from May 15 to the end of September in England.

The EU bathing water directive states that for reporting purposes, samples taken during short-term pollution can be disregarded and replaced with a sample taken within a week.

In contrast, New Zealand’s reporting on swimmability in Our Freshwater 2023, is based on a model for the whole year.

Further, the predicted average infection risk is the “overall average infection to swimmers based on a random exposure on a random day, ignoring any possibility of not swimming during high flows or when a surveillance advisory is in place; actual...