Key points
The occurrence of harmful micro-organisms in groundwater is a primary concern for human health. Their presence can lead to rapid and major outbreaks of illness, sometimes with fatal consequences. This indicator shows the proportion of groundwater wells in the Waikato region in which Escherichia coli (E. coli) are detected.
- Micro-organisms are contaminating some of our groundwaters.
- Micro-organisms are more commonly found in wide diameter wells, which are more difficult to seal from surface influences or poorly completed wells.
- Shallow wells and wells near potential sources of micro-organisms such as septic tanks, offal holes and stockyards are more likely to be contaminated.
- Drinking water guidelines are exceeded when E-coli are found to be present.
- E-coli were detected in nine of the 82 wells sampled.
Source: Environment Waikato
What agencies are doing
- Environment Waikato provides environmental education about wastewater disposal and management, as well as appropriate well construction. Guidelines have been developed for farm dairy effluent and sludge application to pasture, to avoid polluting groundwater.
- Rules and policies in sections 3.5 and 3.8 of the Waikato Regional Plan address management of discharges which may lead to microbial contamination and safe well construction and location.
- Environment Waikato is also involved with Crown Research Institutes in research to determine appropriate management and setback distances from water supplies.
What you can do to help
- Seal around your well (for example, with a concrete pad around the casing) to prevent contaminants entering your well directly, and enclose the top of the well.
- Fence around your well or bore to keep animals away.
- Ensure that groundwater supplies are well spaced from possible microbial sources such as septic tanks and offal holes.
- Test your groundwater supply to check for microbial contamination and identify possible sources.
- Obtain guidelines for farm dairy effluent and sludge application to pasture.
More information
More detail on this indicator, including how and where this information is collected, is available here.
What we want to achieve
The community outcomes we are seeking to achieve by monitoring micro-organisms in groundwater are:
- The iconic landscapes and natural features of our environment define and sustain us. We respect and celebrate them as taonga.
- Our natural environment is protected and respected. Its ecological balance is restored, its air, soil and water quality is improved and its native biodiversity is enhanced.
- The traditional role of iwi and hapu as kaitiaki is acknowledged, respected and enabled.
- Our region’s waterways have consistently high water quality.
- We have reliable, efficient and well-planned infrastructure and services, including transport that is safe, interconnected, and easy to get to and use.