ASSESSING THE VULNERABILITY OF SHALLOW GROUNDWATER DOMESTIC WELLS IN NAURU

Nauru’s water resources are limited and under stress with an expected increase in prolonged dry periods due to climate variability. There are no fresh surface water sources and Nauru relies mostly on rainwater for its potable water needs. Desalinated water is currently supplying about 20% of the population water requirements but during period of prolonged drought, where rainwater is limited, the communities reliance on desalinated water can increase to more than 90%. At current maximum capacity, desalinated water is able to produce about a third of Nauruan water needs; moreover, this technology is consuming a significant amount of energy.
Groundwater is a limited natural freshwater source available on the island which is relied upon for domestic use and plays an important role in the water budget of the island with potential for increased development in the future.
In order to improve our knowledge on the actual reliance and use of the groundwater resource and to assist in its future development, a groundwater survey was undertaken in Nauru from March to April 2010, along with a sanitary survey of domestic wells. Shallow groundwater is particularly vulnerable to faecal contamination from surface activities and wastewater disposal. The sanitary surveys were used to identify major risks and threats to contamination and to inform the community on risk mitigation options.
337 wells were identified and an estimated 350 wells are located in the low-lying coastal plain area. 230 were in use and at least 40% of the population has access to groundwater at the time of the survey. An estimated 298 KL of groundwater is currently abstracted each day in Nauru and this usage is likely to increase in dry periods. This usage indicates that groundwater is currently
the second most important water resource in volumes abstracted in Nauru, with harvested rainwater being the most important. Groundwater in the main is being used for non potable purposes including washing clothes, showering/bathing, outdoor uses, flushing toilets, washing dishes, and to a lesser extent cooking, with a few households using it for drinking purposes.