Why Does Water Turn Black in Fire Hydrant Pipelines Overnight? Seeking Insights

I observed black-colored water from the fire hydrant pipelines, especially at some points but not all points. What is the exact reason why the water becomes black in color? The initial filling water was good. However, when checking the water the next day, it had turned black.

Thank you.
Regards.

Dear Mr. Shrikant,

Reasons for Black-Colored Water in Fire Hydrant Pipelines

There are two reasons for this issue:
1. If the water is stagnant
2. Due to the oxidation of MS, water turns black in color.

Do not worry. You should conduct weekly trials of the hydrant points to resolve this problem.

Thanks,
Abhay

As rightly said by Mr. Abhay, corrosion can be one of the reasons for this. Also, make sure there are no other impurities present nearby which may enter the hydrant line due to leakage, such as crude oil, slugs, or any solution that could be making the water black.

Regards,
Hansa Vyas