Treatment and Disposal of
Effluent from a 450 Ton Per Day
Kraft Pulp and Paper Mill into
Classified Inland Waters
J. L. VICKERMAN, Chief Civil Engineer
New Zealand Forest Products Limited
Tokoroa, New Zealand
INTRODUCTION
This paper describes the methods of disposing of effluent from the Kinleith
Pulp and Paper Mill of New Zealand Forest Products Limited, prior to discharge
into the Waikato River, a classified inland waterway.
The mill produces sulphate pulp from locally grown radiata pine and is at
present working up to a production level of 500 tons/day. The pulping is integrated with a five stage 100 tons/day bleaching plant and four Kraft paper
machines of 335 tons/day combined output. Located near the geographic centre
of the North Island of New Zealand, adjacent to Company owned forest resources,
the industry was initiated with the commissioning of a 110 tons/day pulp mill in
1953 and a single paper machine in 1954.
It was the first chemical pulp mill to operate in the country and sanction was
given by the pollution control authorities to commence production without any
effluent treatment installation, but with some restriction upon the discharge.
Waste flow was discharged into the head of a stream system where a progressive
dilution of 5:1 took place down an 8 mile course to the Waikato River. The
stream course lies within the company's forest area, on a gradient that falls 630 ft
before entering into a lake formed by a hydro electric impoundment on the river.
With the passing of the years mill production has increased and diversified
while pollution control regulations havebecome more firmly established on a National scale.
Within the past year the Waikato River has become a classified waterway and
the requriements which now apply in respect to pollution of Maraetai Lake are
Class D of the "New Zealand Water Pollution Regulations, 1963" and are as follows:
(a) The temperature of the waters shall not be raised above 75 F, or (if the
temperature of the waters exceeds 70 F in their natural condition) shall
not be raised by more than five F above the natural temperature of the
waters.
(b) The acidity or alkalinity of the waters as measured by the pH shall be
kept  within the range of 6. 0 to 8.5.
(c) The waters shall not be tainted so as to make them unpalatable, nor contain toxic substances to the extent that they are unsafe for consumption
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