A Rotorua timber mill is defending the standard of the effluent it puts into a stream used by the penny divers at Te Arawa.
Walton Lee says the Puarenga stream, which runs near Whakarewarewa Village in Rotorua, is polluted and he's calling for more stringent rules for companies discharging into it.
Tests over the years have shown poor results for water quality and Mr Lee says companies like the Red Stag Timber Mill could be doing much better.
But Tim Charleson, the mill's environmental manager, says the company carries out regular chemical tests on its effluent and it's meeting the conditions of its resource consents.
Health agencies advise children not to swim in the stream, but the penny divers continue to use it.