Environment Waikato is taking a precautionary approach to chemicals which have contaminated the Waikato River following last night’s chemical fire in Hamilton.
All downstream water users and Watercare Services have been advised to shut down their intakes until the “slug” of contamination has passed.
The articulated truck, with both trailers laden with chemicals and paint, burst into flames about 8pm last night on Cobham Drive. Eight fire engines from Hamilton and surrounding towns attended the fire.
Environment Waikato placed barriers to limit chemicals flowing into drains which flow into the Waikato River and used sucker trucks to mop up the wash.
The chemicals on the truck included dairy cleaning agents, pesticides, biocides and a large quantity of paint.
Environment Waikato believes that only a small quantity of the chemicals flowed into the river from the original fire which took time to be contained but has advised that the chemicals had had some immediate effect on local streams and about two dozen fish and eels were killed. Staff took samples during the night and are continuing to sample today and observe the river at various places, water scientist Bill Vant said.
It was likely that fish living in the river itself were able to detect and avoid the slug as no more dead fish had been seen so far.
The slug and contaminants that followed had left a pink dye in the river, which was not harmful itself, as it was a biodegradable tracer paint. Because of the time taken for water to travel down the river, the slug was likely to reach the sea by tomorrow evening.
The contaminants were likely to be well diluted by the swiftly flowing river but people should also avoid swimming or using the water north of the city for the next 24 hours, he said.