Cyanide worry over water

Press, 8 December 1988, Page 33

Cyanide worry over water

PA Wellington Lower Hutt’s water supply is in danger of contamination from cyanide waste believed to be in the old Wingate and Silverstream tips, says the Lower Hutt water resources manager, Keith Davis.

A report by Mr Davis on Wellington region landfill pollution was included in the pollution and hazardous substances management report issued by the Government recently.

Mr Davis said the Railways Corporation did not keep records of where it dumped large quantities of cyanide waste produced during the 1950 s and 19605, but workers

report it was dumped in Wingate.

When Wingate closed in 1972 or 1973, the corporation probably began dumping cyanide at Silverstream. All landfills had some elements of cyanide but Wingate and Silverstream were a particular concern because they were upstream of the infiltration zone to Lower Hutt’s artesian water supply system. “We’ve got no idea of quantities. All we can do is place on record that there is a concern that in the past chemicals have been dumped in areas we don’t know,” he said.

All landfills were tested regularly to monitor pol-

lution levels. “We would have picked up cyanide when we were testing at Wingate, but we never have. Our tests have not revealed anything getting out, but we haven’t done any tests in the landfill itself because it is buried and all grown over.

“Someone would have to go out there and dig holes and drill." The pollution risk was difficult to assess and depended on many factors. “It depends on the situation — whether there has been interaction with other chemicals and whether the stuff is intact,” he said.

“If the drums open up

and the chemical is intact it will get out into the waterways.” Mr Davis said legislation was needed to ensure that hazardous chemicals and wastes were properly disposed of.

“Had there been adequate legislation at the time, uncontrolled discharge waste such as cyanide at Wingate would not have occurred,” he said.

Mr Davis is a chemist and a member of the Inter-Agency Co-ordinat-ing Committee which produced the report. The old Wingate tip is now a terraced section along a built-up area of the Eastern Hutt Road.