[COURTESY MAXWELL WATER SUPPLY CORPORATION] ▲ A boil water notice has been issued for areas of San Marcos until further notice. [Alyssa Vidales/American-Statesman] ▲

Residents in areas of San Marcos are advised to boil their water before use after a water line break, city officials said.

Maxwell Water Supply Corporation issued a boil water notice Saturday night, asking customers to boil their water before washing their hands and face, brushing their teeth or drinking it.

To ensure all harmful bacteria is destroyed, the company said, water should be brought to a rolling boil and then boiled for at least two minutes.

Persons most at risk of illness include children, seniors and people with weakened immune systems, the water company said.

The company said public water system officials will notify customers when it's no longer necessary for them to boil their water.

Areas affected include:

- Saddlebrook (Sun Communities)

- North Point Subdivision

- Harris Hill Road

- Blanco River Walk

- Post Road

This story is developing; check back for updates.