WATERBORNE WASTES, DISPOSAL OF
For every million gallons of water used in the home and by industry, nearly a million gallons of contaminated water have to be disposed of into inland or tidal waters. In the early days of the settlement of New Zealand, pollution of natural waters did not present a great problem. The population was small and as there were few waterborne-sewage disposal systems, the bulk of the human wastes did not reach inland or tidal waters. As time went on the population increased considerably, urban communities grew into large towns, farming became more intensive, and secondary industries developed. This led to the introduction of waterborne-sewage disposal systems with outfalls into streams, rivers, harbours, or ocean waters, and to outfalls from industries discharging large quantities of liquid wastes, particularly those associated with primary industry, such as freezing works, dairy factories, woollen mills, and such like. The consequence was that more and more of the country's natural waters were polluted in varying degrees, and it became more difficult, for example, to locate uncontaminated sources for urban and industrial water supplies.
With the growth of the population, development has spread into areas which were formerly remote places. Whereas years ago discharges of polluting wastes from the more remote towns and rural industries did not cause offence to many, the increased use of the motor vehicle and improved roading has meant that areas which were once regarded as out of reach are now popular recreational areas where the quality of the water is of considerable concern to the public.