Author(s): Jayatha Dias-Wanigasekera; Gregory Shahane De Costa; Beatrice Dias-Wanigasekera
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Keywords: Groundwater Quality; Nitrate Contamination; Land Use
Abstract: Over 20 years of groundwater monitoring carried out by the Wellington Regional Council has identified a persistent area of NO 3 -N contaminations in the Coastal and Hautere Groundwater Zones in Kapiti Coast, Wellington, New Zealand. Time series data analysis has identified a decreasing trend in concentrations over time for the majority of sites monitored in the region as well as some a seasonal influence on nitrate levels of certain bores. Sites displaying consistently higher concentrations in NO 3 -N could be affected by point source contamination with a possibility that contamination plumes are also being transported to sites further down-gradient with time. Further analysis of climate data and land use data is needed in order to determine contaminant sources and areas vulnerable to nitrate accumulation. Transport modeling of NO 3 -N through the aquifer system will also be required in order to ascertain effects down gradient to contaminated sites.
Year: 2010