1. Chromaticity: When the chromaticity of drinking water is greater than 15 degrees, most people can detect it, and when it is greater than 30 degrees, people feel disgusted. The standard stipulates that the color of drinking water should not exceed 15 degrees.

2. Turbidity: It is an expression of the optical properties of water samples. It is used to express the degree of clarity and turbidity of water. It is one of the most important indicators to measure the good degree of water quality. An important basis for evaluating the state of water treatment technology. The reduction of turbidity means that the content of organic matter, bacteria, viruses and other microorganisms in the water body is reduced, which can not only improve the disinfection and sterilization effect, but also help reduce the generation of halogenated organic matter.

3. Odor and taste: The main cause of water odor is the presence of organic matter, which may be caused by increased biological activity or industrial pollution. A change in the normal odor of the public water supply may be a signal of altered raw water quality or inadequate water treatment.

4. Substances visible to the naked eye: mainly refers to particles or other suspended substances that exist in water and can be observed with the naked eye.

5. Residual chlorine: Residual chlorine refers to the amount of chlorine remaining in the water after the water has been chlorinated and disinfected for a certain period of time. The continuous bactericidal ability in water can prevent the self-pollution of water supply pipelines and ensure the quality of water supply.

6. Chemical oxygen demand: refers to the amount of oxygen required by chemical oxidants to oxidize organic pollutants in water. The higher the chemical oxygen demand, the more organic pollutants in the water. Organic pollutants in water mainly come from the discharge of domestic sewage or industrial wastewater, and the rotting and decomposition of animals and plants into water bodies.

7. The total number of bacteria: the bacteria contained in the water come from air, soil, sewage, garbage and animal and plant corpses. There are various types of bacteria in the water, including pathogenic bacteria. my country's standard for drinking water is that the total number of bacteria in 1ml of water should not exceed 100.

8. Total coliform bacteria: It is an indicator bacterium of fecal pollution, and the detection of it can indicate whether there is fecal pollution in the water and the degree of pollution. In the process of water purification, after disinfection treatment, if the total coliform index can meet the requirements of drinking water standards, it means that other pathogenic bacteria are basically killed. The standard is no more than 3/L in the test.

9. Heat-resistant coliform bacteria: It is more appropriate than coliform bacteria to reflect the degree of food contamination by human and animal feces, and it is also an indicator of fecal pollution in water bodies.