The Mekong River Delta in Vietnam is the largest agriculture and aqua-culture production region. As the furthest downstream region of the Mekong River bounded by both the East Sea (South China Sea) and the Gulf of Thailand, the Delta forms a large tropical wetland (Tuan and Wyseure 2007). The bulk of the land in the Delta is just 2 m above mean sea level (Wassman et al. 2004). Historically and practically, the people have settled along the river and canal banks. Human life, agricultural and aquaculture production as well as domestic water supply in the Delta depend greatly on the changing water regime of the Mekong River. There are only two seasons in the Mekong Delta: the rainy season and the dry season. Due to the effect of the tropical monsoon, flood flows in the rainy season are about 25-30 times greater than dry season flows which occur between March and April (Öjendal 2000). The Mekong Delta is known as the “rice bowl” of Vietnam. The Delta has a population of 20 million inhabitants living on 4 million hectares of land (Sanh et al. 1998, Be et al. 2007). The people living in the Delta depend completely on the water resources (mainly the surface waters of the Mekong River) for drinking and domestic purposes, crop irrigation, fish and shrimp farming, transportation of goods, and industrial production. As a general rule, any increase in industrial and agricultural activity upstream may affect water quality in downstream areas. Like many other regions in Vietnam, the Mekong Delta is confronted with severe water-related problems, of which pollution, drought, and flooding are increasingly becoming worse. Realizing that the health of the people is one of several factors ensuring the sustainable development of the country, the Vietnamese government and international development agencies have implemented many water supply and environmental sanitation programs.  According to GSO (2013), about 98.1% of inhabitants in urban areas and 87.9% in rural areas in Vietnam had access to hygienic water. In recent years, several drinking water plants and wells have been built; however, most of them are located in cities, small towns, and suburban areas. In distant rural areas, farmers still access water directly from rivers, canals, ponds, or shallow wells. In Tra Vinh Province of the Mekong Delta, there is a high level of dependence on groundwater resources for both domes-tic and agricultural purposes. There is an overexploitation of groundwater with use estimated at approximately 65,000 m³/day. This is leading to high competition amongst groundwater users for their daily activities including irrigation of crops, shrimp farming and processing, livestock production, and industrial development and services. The reduction in both quality and quantity of groundwater resources is a significant problem for sustaining people’s livelihoods in the coastal Mekong Delta.