Groundwater report labelled as propaganda

Groundwater quality has "no significant relationship" with land use, a Ministry for the Environment report says.

The report, produced for the ministry by Crown research institute GNS Science, has prompted Green Party claims of "propaganda".

Environment Minister Nick Smith said turning around water quality was one of the Government biggest environmental challenges. "It's going to require an ongoing slog over many years and decades to reverse some of the pollution of our water systems," he said.

The report said nitrate and E. coli levels breached health standards at 5 per cent and 23 per cent, respectively, of 973 monitoring sites, including 279 in Canterbury.

Quality was rapidly changing at a third of the sites, with "patterns that suggest human influence". But the report said there was "no systematic or significant relationships" between groundwater quality and land use or land cover.

Green Party co-leader Russel Norman said the claim was absurd and "propaganda".

He said the uncertainty in the report suited the Government's political agenda "to downplay the environmental impacts of agricultural intensification".

Early last year, the ministry pulled a controversial chapter from its state of the environment report that pointed to industrial dairying as the largest cause of environmental decline.

Norman suggested the latest report followed political pressure, but Smith said he was disappointed such accusations were being made of officials at independent Crown research institutes.

However, he was "a little surprised" at the conclusion because the popular notion was that land-use intensification led to water-quality problems.

Smith said he would defer to the specialists who prepared the report rather than favour popular opinion.

Ministry adviser Mike Thompson, who reviewed the report, said it was not the report's intention to dismiss the link between groundwater and more intensive land use.

The ministry has also released league tables that rank the water quality of New Zealand's major rivers on 2007 data.

Two Canterbury monitoring sites, the Waitaki at Kurow and the Hurunui at Mandamus, rank in the top five for best nutrient quality out of 77 sites on 35 rivers.

For recreational use, Tasman's Motueka was the top-ranked river, while the Hakataramea was sixth and Waitaki at Kurow 10th.

- © Fairfax NZ News