Many people think that if your water looks clean and tastes clean then it must be safe to drink. This is one of the measures of clean water but the bugs in water that can make you sick are so small they are invisible to the naked eye. There are national standards that define what makes water actually safe. The characteristics of water that can determine the safety of it are:
- Chemical e.g. level of heavy metals, arsenic or nitrates
- Microbial e.g. the bugs that make us sick like bacteria or protozoa
- Physical e.g. turbidity = dissolved matter in the water that changes the colour and makes treating the water hard
Your drinking water can become unsafe to drink in many different ways. There could be a farm upstream with animals pooing in the water or a dead animal in it that you don’t know about. Safe drinking water is really important for good public health as it protects people from a number of diseases and other contaminants. Public Health South works to achieve this by having an Internationally (IANZ) accredited Drinking Water Team who monitor and assess the quality of water supplies throughout the district.
Cyanobacteria is becoming more and more of a problem in our lakes and rivers. It is commonly known as ‘blue/green algae’ but is closely related to bacteria. They grow in colonies and can become a nuisance to water supplies by clogging up filters, giving water a bad taste and in some cases, release toxins into the water. People can be exposed to cyanobacteria by drinking affected water, or by swimming in water with algal blooms. This can cause various health issues and if the blooms become toxic then this can cause serious health problems. The more blue/green algae there is and the longer you are in water that has it, the more severe your possible symptoms are likely to be. If high levels are detected then health warnings will be issued however, it is best to be cautious.
On a day to day basis the DWA’s:
- Assist small water supplies via a Drinking Water Assistance Programme and providing advice/guidance
- Assess water suppliers compliance with the Health Act 1956, Part 2A and the Drinking-water Standards for New Zealand 2005 (Revised 2008)
- Assessing water suppliers Water Safety Plans
- Being aware of cyanobacterial blooms and issuing health warnings.
If you would like any further information please contact your nearest Drinking Water Assessor.