Groundwater Quality

Council monitors groundwater quality across the District at a number of locations. This page gives an overview of Tasman District Council's groundwater quality monitoring.

About Groundwater Quality

Overall, groundwater in the Tasman District is of excellent quality and able to be used for a range of purposes. There are some areas where groundwater quality is degraded.

Groundwater quality is a measure of the chemical characteristics of a particular groundwater, often called its chemical signature. This chemical signature is a reflection of the groundwater’s journey into and through the ground and includes natural processes as well as influences from human activities.

Natural processes

Natural processes that influence groundwater quality are dominated by the interaction of the groundwater and the rock that makes up the aquifer. The respective chemical compositions of the rock and how long the groundwater remains in contact with it are reflected in the groundwater quality.

Human impact

Humans influence groundwater quality in two main ways - contamination from land use and surface activities in the groundwater recharge areas. How much the groundwater is susceptible to surface influences will depend on the nature of the aquifer (including its depth) and its degree of confinement (where an impermeable layer, such as clay, caps the aquifer).

Human influences on groundwater quality can include excessive nutrients  (such as nitrate), bacteriological contamination (such as from wastewater effluents) and pesticide residues.

Further Information