1. Community sources include commercial buildings, office buildings, hotels and hospitals that discharge waste water bacteria substance mass. Most of which are organic compounds and vegetable cleaning detergent.
2. industrial plants, such as sugar and fish sauce factory. Detergent factory factory factory coloring and tanning factories producing carbonated water. Discharges into water from these factories often have a high rate of waste water easily.
3. the source for farmers. Various sources of current farmers commonly used cleaners and defeat more enemies. Cause the residues by plant and by soil and will be flushed with rain water flow according to the various sources of water by decomposition of water source will occur slowly accumulated in the water become more harmful to the environment and humans.
4. water source, which may occur when spoilage is in lack of oxygen. Most of the diversity is caused by sediment long then die at the same time.