New Challenges For Water Quality Management

  • Simon Upton

"The Government has funded a five year programme to tell us more about the health, environmental and agricultural risks related to water quality," the Honourable Simon Upton, Minister for the Environment, said today.

The results of the first year of the Freshwater Microbiological Research Programme were today announced by the Minister for the Environment, Mr Upton, the Associate Minister of Health, Hon Tuariki John Delamere and the Minister for Food, Fibre, Biosecurity and Border Control, Hon John Luxton.

"After just one year, preliminary results show that the things we have traditionally measured as indicators of contamination don't tell us enough about the health risks," Mr Upton said.

"While over the last twenty years great strides have been made in improving the appearance and water quality of some New Zealand rivers, through the treatment of sewage, industrial and dairy shed discharges, new information has raised new challenges."

A pilot study for this major water research programme has found the expected pathogens such as giardia and cryptospiridium. The Ministry for the Environment is co-ordinating the research, which is a joint venture with the Ministries of Health and Agriculture and Forestry and is supported by regional councils.

Mr Upton said that because new techniques of testing for disease-causing organisms were being used in the research, it was not clear whether these particular water quality problems had existed for some time, were increasing or decreasing. However, New Zealand does have relatively high rates of illnesses which can be spread through water.

The studies to date show a high presence of well known pathogens such as, Giardia, Cryptosporidium, Salmonella and Campylobacter in the lower Waikato. Levels of pathogens recorded on the upper Ruamahunga and the lower Waimakariri Rivers were of a lesser concern.

These disease carrying bugs can cause stomach upsets (gastroenteritis), diarrhoea, abdominal pain, vomiting and weight loss. Nausea, flatulence, fever and malaise may also occur. They are recognised internationally as threats to public safety.

"The Government is interested in pinpointing the sources of these pathogens so that we can address ways to improve further our water quality," said Mr Upton.

Sources of contamination include sewage discharges, farm runoff, possums and birds. Runoff from pasture appears to be a significant problem in the Waikato."

Health Waikato maintains ongoing public health surveillance in the district.

The Ministry of Health warn that the bacterial counts in the Waikato River indicate that the water is unsafe to swim in. Environment Waikato has posted notices warning against swimming. Treated public drinking-water supplies at Cambridge, Hamilton, Ngaruawahia and Huntly are tested regularly and are found to be safe to drink.

Mr Upton said that the lack of knowledge in the microbiological area has caused real problems for water managers in the past. It's difficult to manage what you don't know about. The programme's findings will allow more informed management actions, such as closing swimming sites in rivers or improving treatment.