To ensure the safety and quality of drinking water, water quality monitoring is carried out. Water quality indicators are key indicators for evaluating the quality of drinking water, and should be comprehensively and normatively monitored, mainly including the following items:

1. COD (Chemical Oxygen Demand)
The COD test can reflect the total amount of organic pollutants in water. The COD detection result should be controlled within 100mg/L.

2. BOD (Biochemical Oxygen Demand)
BOD is an indicator reflecting the ability of microbial decomposition and consumption of organic matter in water, and the BOD detection result should be controlled within 30mg/L.

3. PH value
The pH value is an indicator of the acidity and alkalinity of water, which can further reflect the stability of the water. The detection result of pH value should be between 6.5 and 8.5.

4. Transparency
The main factors that determine transparency are suspended substances, iron and manganese plasma in water, and the transparency test results of water should be greater than 0.5 meters

5. Ammonia nitrogen
Ammonia nitrogen refers to the ammonia gas, ammonium ions, and free amino groups in water. The ammonia nitrogen content should be controlled within 1.5mg/L.

6. Total phosphorus and total nitrogen
The total phosphorus and total nitrogen content are key indicators for evaluating the nutritional status of water bodies.
The total phosphorus content should be controlled within 0.2mg/L.
The total nitrogen content should be controlled within 1.0mg/L.

7. Heavy metals
The content of heavy metals is an indicator for measuring the degree of water pollution. The lead and mercury content should be controlled within 0.01mg/L; The content of chromium and cadmium should be controlled within 0.05mg/L; The content of tin and magnesium should be controlled within 0.02mg/L.