ESR on recent drinking water survey results
ESR scientists say the recent drinking water survey results reinforce the importance of treating water to make it safer to drink, and having robust monitoring systems.
ESR drinking water scientist Dr Chris Nokes says some of the registered water suppliers covered in the recent Ministry of Health report failed to meet standards because their sampling programmes did not meet monitoring requirements.
The report prepared for the Ministry of Health by ESR, surveys networked drinking-water supplies that serve populations of more than 100 people and covers the period July 2016 to 30 June 2017.
Dr Nokes says to meet standards, water supplies have to meet two key components; one covering the quality of the water and another related to the sampling requirements. Some water supplies failed because too few samples were taken. However, he says there are some water supplies that are at an unacceptable risk of being unsafe, and that may be due to under-resourced systems.
Drinking water contaminated by bacteria from humans or animals poses the greatest risk of disease. The detection of an indicator organism in the water such as E.coli shows that water has been in contact with faecal matter, indicating the possibility of pathogens, which a water supplier needs to respond to.
Drinking-water supplies that meet the bacteriological requirements of the standards are also likely to be safe from most viruses.
Dr Nokes says there is evidence to show that ensuring drinking-water is free of disease-causing organisms is an important measure in protecting public health.
He says bacteria can cause illness soon after a person has consumed contaminated water and the consequences of infection can be severe.