Objective: Description of the knowledge to use water in daily life of the people of Cat Ba island, Hai Phong 2015. Subjects and Methods Study: Description cut of 3 households Tran Chau, Xuan Dam, Hien Hao commune was chosen as the subject of investigation. Results: The subjects answered correctly on such high standards: There are no pollutants in the sky-water (72.9 percent)
Gutter system from dirt (79.7 percent)
Good rain water filter media before entering the tank and with a lid (89.8 percent)
Scoop place where there is no risk of contamination (58.4 percent)
Frequently change the water periodically wash (80.1 percent). The subjects were interviewed answered correctly express the specific understanding and accuracy for each key standard rate of more than, less than 50 percent, such as a round toilet wells 10 m (60.0 percent)
Lower the toilet wells (50.0 percent)
Other pollution sources within the well by 10 m (48.6 percent)
There is no standing water puddles on the concrete within 2m (44.3 percent)
There wells guarantee (52.8 percent).