Issues
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.
Focus areas for Marlborough District Council surveys include Rarangi, Riverlands and the Wairau Valley.
Higher levels of arsenic, manganese, iron, chloride, and boron have been measured in some wells.
Pesticides have not been found in high concentrations in Marlborough groundwaters with the exception of isolated cases involving well head contamination.
Likewise, microbe contamination doesn’t appear to be a significant issue, even in relatively densely settled rural residential type settlements.
Potabilty is the word used to describe the whether water is suitable for human consumption and meets the New Zealand Ministry of Health Drinking Water Standards 2005.
Marlborough District Council has produced fact sheets for information on these subjects: