Cal Water Guerneville customers north of the Russian River are being asked to use only boiled tap water or bottled water for drinking, preparing food and brushing teeth until further notice after a water main break interrupted water service Monday.

California Water Service (Cal Water) and the state Water Resources Control Board said customers should continue to either boil water or use bottled water until further notice,

Failure to follow this advisory could result in stomach or intestinal illness.

Any time water pressure drops below the threshold set by the state, as it does during a water main break, water quality samples are taken to ensure that water quality wasn’t affected.

Crews were making repairs to the water main and will then test to determine if the water is safe.

It wasn’t announced what caused the break in the line or exactly where the break was discovered.

Tap water is safe for showering, bathing and other household uses.

All tap water used for drinking, preparing food, and brushing teeth should be boiled rapidly for at least one minute before use, the agency said. Customers should also discard ice cubes made from tap water or their refrigerator’s water line. If you have pets and are unsure about providing water to them, the agency suggests consulting your veterinarian.

For more information on household water use during a boil water advisory, contact the Centers for Disease and Control and download a fact sheet.

The agency can be reached at 800-220-4299.

If you prefer to use bottled water during this advisory, save your receipts for reimbursement. They can be mailed to 14028 Armstrong Woods Road, Guerneville, CA 95446, to the attention of: Bottled water reimbursement.