How Water Quality is Monitored

Colour photograph of water monitoring equipment.A variety of meters and sampling techniques are used to monitor physico-chemical characteristics of water. These include some of the following:

Field Meters (Hand Held)
  • Conductivity
  • Dissolved Oxygen (hand held probe employing membrane diffusion along with silver/gold anode for oxygen detection)
  • pH
  • Turbidity
  • Temperature.
Data Loggers (Multi-probed)
These units are independent and fully submersible data loggers which can be deployed in the field for a specified period of time (days to weeks). These units measure diurnal fluctuations for parameters such as dissolved oxygen, temperature, pH, conductivity and turbidity.

In situ Data Loggers
These units are usually permanently deployed at Stream Gauging Stations and provide long term continuous data (seasonal). Some of the parameters measured by these units are dissolved oxygen, conductivity, temperature, turbidity and river level.

Pump Samplers
These units collect water samples only. Often used during flood events in order to measure turbidity, total suspended solids, total nitrogen and total phosphorus (all parameters bar turbidity are analysed in a laboratory). These units are usually deployed near Stream Gauging Stations so that in conjunction with flow, nutrient and suspended solid sampling, loading of rivers can be determined.

Water Samples
Additional water samples can be taken and later analysed by a NATA Laboratory to determine just some of the following:
  • Nutrients ( ie, total phosphorus, dissolved reactive phosphorus, total nitrogen, ammonia, nitrite, nitrate)
  • Total Suspended Solids (Turbidity)
  • General Ionic Composition: these usually reflect the underlying geology of the area sampled. These include Cations (ie calcium, magnesium, sodium, and potassium) and Anions (ie iron, fluoride, chloride, and sulphate)
  • Heavy Metals (ie copper, zinc, silica, manganese, lead, aluminium etc)
  • Microbiological (ie faecal coliform organisms, enterococci organisms).