Law soils development plans

By WAYNE THOMPSON

Oratia, once the fruit basket of Auckland on the fertile Waitakere foothills, is becoming a patchwork of lifestyle blocks.

But a new rule on soil levels of copper - left there from the orchards' fungicides - means some of the lush topsoil must be scraped off and carted away.

Duje Nola, 75, plans to subdivide the West Coast Rd orchard settled by his father in 1932.

He wants to sell sections of the 4.1ha property for a retirement income, yet leave enough land for his family to keep their roots in Oratia.

A selling feature of the orchard, he says, is its thick carpet of turf. This adds to the beauty of the setting and stops the soil slipping into the gully streams.

But a new planning rule means that lush green mantle could be ripped up by scraper and buried under a layer of clay.

The rule is in response to a study of contamination of horticultural soils last year by the Auckland Regional Council and Auckland District Health Board.

High concentrations of copper were found.

Although the Ministry of Health is unaware of any cases of copper poisoning from horticultural land, it took the precaution of setting a standard measure for safe concentrations.

The Waitakere City Council adopted the measure and now requires tests for copper on each site before allowing a change in land use to subdivision for lifestyle blocks or residential.

In order to sell sections, Mr Nola and fellow orchardists will have to reduce copper levels - mainly by undertaking earthworks.

The copper in the soil came from a fungicide sprayed to protect fruit trees.

Copper sulphate fungicide, also known as bluestone or bordeaux mixture, was used in orchards, vineyards, glasshouses and home gardens throughout the country.

In Oratia, orchardists dispute that their land holds harmful quantities of copper.

They challenge the official measure for how much copper is a health hazard, saying it is harsher than in other countries.

Mr Nola said he spent $2000 on testing soil in his orchard.

The tests showed some places were "just over" the limit of 80 parts per million.

Mr Nola said removing soil would destroy the natural landscape, and the cost of the work would make the sections too expensive.

"This rule makes no sense and cuts across human rights," he said.

"I've been using copper spray for 60 years and I haven't been poisoned off. Some orchardists have lived to 102."

Oratia has about 135 properties, but the ratepayers' association does not know how many of these have a copper problem.

Mr Nola said he was unlucky with his timing, because many other owners of horticultural land in Waitakere had already subdivided and sold for housing and offices.

The regional council and district health board back 80ppm as an indicator of the need for further site investigations.

The chairwoman of the Waitakere City Council environment committee, Penny Hulse, said the council had no choice but to accept this national trigger level for soil tests.

"Legally we have to take a precautionary approach. But we understand that Oratia people feel they are facing a barrage of controls.

"We have tried to ensure we are being sensible," Mrs Hulse said, "and we are keen to talk things through with Oratia people about making the soil test regime as user friendly as possible."

Almost 40 per cent of Waitakere's housing growth will be on countryside at present outside the city's urban limits.

Mrs Hulse said the impact of the copper limits on section development costs was of concern.

Ministry of Health senior adviser Jim Waters said the 80 ppm level for copper was based on the national guideline for timber treatment chemicals found in housing land. Copper was in timber treatment chemicals.

An Auckland Regional Council environmental protection officer, Eddie Grogan, said the council was conducting trials of remedies for different site situations.

This information could save developers the expense of removing the topsoil, he said.

In some cases, soils could be blended to reduce concentrations.

nzherald.co.nz/environment