Under the Waters Pollution Act of 1953, the Pollution Advisory Council was established with the responsibility of preventing and abating water pollution throughout New Zealand. In 1963 regulations were made under this Act to permit the Council to classify inland and coastal waters according to their established or potential uses. These classifications and water uses are defined as follows:

Water quality standards have been laid down to protect these different uses in the receiving waters. Following the classification of any waters, all outfalls discharging polluting wastes into them must be registered and covered by a permit setting out the conditions under which discharge may be made. The permit also indicates the standard of treatment of the waste discharge which the Council considers necessary to maintain the prescribed standard in the receiving waters. It then becomes an offence to allow the discharge of a waste which is likely to cause the quality of the receiving water to vary outside this standard.

How best to deal with several million gallons a day of contaminated wastes is a huge and costly problem. A survey conducted in 1962–63 by the Ministry of Works indicated that about 85 per cent of the total population of the cities and boroughs (1,639,000) was served by a public waterborne system of sewage disposal. The proportion of this urban population provided with a generally satisfactory form of public-sewage disposal system was just less than 60 per cent, while a further 15 per cent was served by an unsatisfactory system.