Marlborough groundwater is generally of very high quality, and can normally be used without treatment. However, groundwater in some areas contain substances that can affect human health or aesthetics.
Aesthetics mean non life-threatening problems such as staining whiteware or causing unacceptable tastes or odours.
These substances can occur either as a result of naturally occurring processes, such as the weathering of rocks, or due to man-made inputs such as fertilisers or pesticides.
Most contaminants found in Marlborough's groundwater, with the exception of nutrients, are from natural sources.