The water system of the community is always yellow or green.

There may be several reasons why the water system in the community is always yellow or green:

1. pipeline aging: the water supply pipeline in the residential area may have been seriously aging, especially in the area where galvanized pipes are used. In the case of water flow or water pressure change, impurities, rust and dirt on the pipe wall may be washed down, resulting in yellow or green water.

2. Pipeline fouling: If the water supply pipeline in the residential area has been used for more than ten years or decades, the water may turn yellow or green due to internal fouling. In this case, the problem of yellow water or green water can be solved as long as the pipeline is cleaned and the attachments on the pipe wall are removed.

3. Corrosion of pipes and fittings in users' internal pipes or residential pipe networks: If pipes and fittings in users' internal pipes or residential pipe networks are corroded, the water may be yellow or green.

4. Secondary pollution of secondary water supply facilities: If the secondary water supply facilities in the community are polluted, the water may turn yellow or green.

5. Grid-connected operation of pipeline emergency repair construction: In the process of pipeline emergency repair construction or grid-connected operation, some impurities or dirt may be introduced, resulting in yellow or green water.

6. The polluted source water exceeds the conventional purification capacity of the waterworks: If the polluted source water exceeds the conventional purification capacity of the waterworks, it may cause the water to turn yellow or green.

To solve the problem of yellow water or green water system in residential area, we can try to clean the pipeline or replace it. Before implementing any solution, it is recommended to consult professionals or property management companies to ensure correct and effective operation.