... and runoff, the tides and the depth of bars in the sea in front of the estuaries. Otherwise, in early rainy season, nearly 1,6 million hectares of the delta are infected by the acidity water ... wastewater. • Ground water is the main source for the lower parts of the delta such as coastal areas and poor water-distribution places. In rural water supply, the opinion the groundwater is the ... sources, i.e. rain water, surface water and ground water. Depending on the location and the periods of the year as well as the difference living conditions, the people should choice their own-ways...