A notice for residents to boil their tap water before using is immediately in effect until Sunday for those living near the Cupertino-Saratoga border, according to San Jose Water.

The advisory was prompted by a sudden loss of water pressure caused by nearby construction activity, the company said in a statement. Residents are advised to use bottled water, or boil tap water for at least one minute before using it for drinking, cooking or brushing their teeth.

The full list of affected streets are listed on the company’s website.

Boil water alerts are issued when there is a decrease in pressure of one of the main water pipes. The incident can be caused by events like breaks, power outages, or maintenance activities.

Drops in water pressure can sometimes allow pollutants to seep into the water supply. Boiling water can kill any potential harmful organisms that might have made their way into the drinking water, the company states.

This is a developing story. Check back for updates.