Local authorities are required by the Health Act to maintain healthy conditions within their districts, and they carry out these functions with the general advice and oversight of the Medical Officer of Health.
They are empowered to make health bylaws, and are required to appoint a sufficient number of health inspectors to investigate cases of infectious disease, and to report on them to the Medical Officer of Health. They are required also to carry out inspections for the detection and removal of nuisances and conditions injurious to health, and to inspect food shops, food premises, and eating houses to ensure that they comply with regulations under the Health Act and with the local bylaws.
Healthy conditions in dwellings and places of work and entertainment are a responsibility of the local authorities who must provide and maintain safe water supplies as well as adequate sanitary services for the removal and disposal of refuse. They must also exercise control over offensive trades.
Challenge for Health: A History of Public Health in New Zealand, Maclean, F. S. (1964).