WATER SUPPLIES ARE GRADED

Taupo Times, Volume 19, Issue 99, 23 December 1970, Page 12

WATER SUPPLIES ARE GRADED

Water supplies are then grouped into four categories: satisfactory ; satisfactory source, unsatisfactory distribution; unsatisfactory source, satisfactory distribution ; unsatisfactory. These gradings are designed to measure the extent of conformity to the World Health Organisation's International Standards for Drinking Water" adopted as a basic standard for New Zealand by the Board of Health in 1960. Despite recent improvements, the report concludes that "there is much to be done in providing improved water treatment, through the use of better sources of water and in giving more attention to contamination of water in the reticulation, before it can be claimed that the country 's water supplies are reasonably satisfactory.' The Department of Health proposes to develop its own environmental health laboratories, primarily for the testing of water, and the report suggests that wherever possible local authorities should provide their own facilities for the essential daily testing of water. Local authorities should. also study the need for training waterworks employees in the maintenance of the reticulation as well as in the operation of water treatment plants. There should be a nucleus of permanent outside staff with sufficient training in the public health aspects of water supplies to ensure that water supplies are not contaminated during work on the reticulation the report says. Eighty-five per cent of the population on public water supplies receives water from satisfactory sources — an increase of 12 per cent since 196$. This is stated in the "1970

Grading of Water Supplies in New Zealand' , published by the Board of Health. Eighty-two per cent of the population is now served by distribution systems with satisfactorily low health risks, compared with 50 per cent in 1965, says the report. Since 1965 authorities have made substantial improvements in the quality of water supplied to consumers. The report emphasises the difficulty in providing a water supply to smaller communities. Tables in the report show that 92 per cent of the completely unsatisfactory water supplies are for communities of less than 5000 people. "Municipalities and the

Government are each responsible for 25 per cent, and county councils for 46 per cent, of unsatisfactory supplies," the report says. Grading is based on a system of merit and demerit marks for the main features of the supply and distribution systems The "supply ' grading assesses health risks associated with the quality of water at its source and the degree to which these risks are reduced by water treatment processes and other relevant factors. Demerit marks are given for a number of factors in the distribution' system which affect the quality of the water and are thus a risk to health.