A significant proportion of the population of Limbe, a coastal town in Cameroon, relies on ground water (gw) to satisfy their drinking water needs. The coastal aquifer is threatened by pollution from sea water intrusion and hence the aim of this study was to determine the suitability of the water. Physico-chemical analysis were carried out on samples collected from the study area and the Revelle Index was calculated and used to determine the extent of pollution from seawater intrusion. The water quality index (WQI) was calculated using values of the pH, bicarbonate, chloride, total dissolved solids and the electrical conductivity. The results showed that 23% of the groundwater in the study area is slightly polluted by seawater intrusion. Using the WQI, it was found that about 34.4% of the ground water resources in the study area is currently good for drinking while 65.6% is either poor, very poor or unsuitable for drinking. In order to reduce the intrusion of sea water into the aquifer, a halophyte plant like mangrove should be planted at the mouth of the main river in Limbe.
Key words: Coastal aquifer, pollution, salinity, water quality index, Revelle Index.