The Resource Management Act requires councils to monitor the state of the environment within their region.
The aim of monitoring Marlborough's groundwater resources are:
- Identify spatial and temporal trends in aquifer behaviour
- Provide benchmarks for consent compliance
- Maintain real time information to Council and community
- Provide data for reviewing effectiveness of the district plan
Council maintains 28 wells as part of Council's groundwater quantity network. Recorders are positioned in the wells and automatically keep record of:
- Aquifer level (at 15 minute intervals)
- Water temperature (some sites only)
- Electrical conductivity (at some wells near the coast)
There are also a number of sites sampled for specific projects that do not form part of the permanent network. An example of this is the monitoring work carried out at various spring-fed streams to identify the relationship between groundwater and surface water flows.
Samples are taken from a number of wells across the region as part of various local and national groundwater quality programmes which are summarised in the table below.
|Programme||Sampling frequency||Number of sites||Parameters|
State of the environment
Range of chemical and physical parameters
Selected sites are also sampled annually for microbes, isotopes, and pesticides
|Coastal sentinel||Summer||6||Sodium and chloride|
|National pesticides||4-yearly||20||58 herbicides/fungicides/insecticides|
The samples taken are analysed at external laboratories. The results of these samples help us to determine:
- The origin or evolution of groundwater
- Characteristics in aquifer behaviour
- Land use impacts
- Health risks of drinking groundwater
A number of other groundwater quality parameters or tools such as isotopes are used or measured as part of other specific projects.