Well owners are being encouraged to test their drinking water regularly, because many contaminants can not be seen, smelt or tasted.

In a statement, Environment Canterbury water and land science manager Dr Elaine Moriarty said regular testing was one of the simplest ways to protect household health.

“Private wells can become contaminated with harmful bacteria and viruses, such as E. coli, as well as nitrate, heavy metals and other chemicals,” Dr Moriarty said.

“Some contaminants occur naturally, while others come from human activities. Because many can’t be seen, smelt or tasted, testing is the only way to know for sure if your well water is safe to drink.

“Floodwater can contain sewage, animal waste, agricultural runoff and disease-causing microorganisms that can enter wells or groundwater supplies. 

“That fast-flowing water can wash contaminants into groundwater supplies, especially if the wellhead casing is not securely sealed, which is why it’s important to check your wellhead regularly.”

The wellhead should be elevated, at least half a metre above the ground, surrounded by a concrete apron, and securely sealed.

 Testing a private drinking water supply was straightforward, so it was just a matter of getting into a regular habit of testing, she said.

Well owners could order a testing kit from an accredited laboratory, collect a sample following the instructions provided and return it to the lab for analysis.

The “don’t guess — test!” campaign aimed to show testing was important and easy to do, by providing practical information about what to test for, when to test and how to do it.

For those who owned a private drinking water supply, it was their responsible to ensure the water was safe to drink.

Depending on how many people used the drinking water supply, it might  be necessary to register it with the Water Services Authority — Taumata Arowai.

Environment Canterbury recommended testing private well water:

  • Every three months for E. coli.
  • Every year for nitrate.
  • Every three years for heavy metals and organic chemicals.
  • Additional testing was recommended after heavy rain events or flooding.

For more information visit Ecan’s private drinking water supplies webpage ecan.govt.nz/wellwater or visit Taumata Arowai for accredited laboratories, public guidance on drinking water safety, or to register a drinking water supply: taumataarowai.govt.nz — Allied Media