Riverlands’ chlorination risks tainting wine industry

Wine Marlborough and the Marlborough District Council have told central Government that chlorinating Riverlands’ town water supply risks irreparably damaging the wine industry and regional economy.

Representatives from both organisations, agree that the unique local water supply issue has national and international repercussions for the region’s economy, due to chlorine activating the fungus that causes ‘cork taint’ – a musty sock smell and taste – in wine.

The Riverlands town supply links to 30 homes and 10 wineries at the Riverlands and Cloudy Bay Business Parks, which see more than half of the country’s wine flow through its tanks.

Wine Marlborough’s Marcus Pickens and Ruth Berry, Marlborough District Council’s operations and maintenance engineer Stephen Rooney say leaving the water supply unchlorinated is the only economically viable option for the wineries at Riverlands and Cloudy Bay Business Parks.

“Cork taint from the corks only impact the odd bottle, and the reaction from the New Zealand wine industry was to get rid of corks all together - this is on an industrial scale so one part per trillion of chlorine could ruin not only hundreds of thousands of litres of wine, but the entire reputation of New Zealand wine,” says Marcus.

“We know the fungus is present in circumstances, as wineries still do their best to eliminate it. But if we chlorinate the supply and the fungus is present, it only takes one part of chlorine per trillion to cause the fungus to activate and ‘cork’ the whole container.

Wine Marlborough Advocacy Manager Ruth Berry spoke at the Local Government (Water Services) Bill submissions in Wellington, while the Marlborough District Council and Wine Marlborough continue to work on a collective exemption with national water regulator Taumata Arowai.

The submission requested a 20-to-30-year exemption period for the site with five-yearly compliance checks, as opposed to the standard five-year exemption period.

“Chlorinating the water at Riverlands puts over 50% of New Zealand wine, including grapes from across the country, and the subsequent $1.2 billion dollars of exports at huge risk”, summarises Ruth.

“Usually, wineries would be able to access unchlorinated water from bores, but the area has no suitable groundwater over-allocated anyway, so we know the council understand the circumstances.

“Chlorine doses for residual disinfection is 200,000 to 600,000 ppt, and the threshold for TCA to cause cork taint is one ppt – it’s completely impractical to filter it all.

“Wine exports are growing, but the value of them is growing faster than so it means that our product is seen as high-quality – this directly risks the quality the industry has built.”

Mary says that wineries understand that the exemption’s costly requirements to manage the unchlorinated water supply will fall on their shoulders and not onto ratepayers, just like current food safety regulatory requirements.

When approached for comment, Kaikōura MP Stuart Smith, said “it’s a sensible position to seek the exemption as the wine industry knows chlorine is no good for wine and I think we should be able to accommodate that.”

And while exemptions have only been given to occurrences where chlorination is commercially unviable for installation reasons – such as DoC huts – Marcus says  they believe their case is just as commercially unviable for export reasons.

“It’s a situation with industrial water the new Bill hasn’t anticipated - we’ve looked into filtration options, but when we’re working with one part per trillion and a billion-dollar risk there’s absolutely no way we can actually guarantee the quality of about half of all New Zealand’s wine”.