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Thousands of residents in Granada Hills and Porter Ranch are being strongly advised to boil their tap water before using, or to use bottled water.
The notice comes after the Los Angeles Department of Water and Power says a faulty valve knocked out the water supply to the area at 7 a.m. Wednesday.
Here’s what we know about the situation.
LADWP warns thousands in San Fernando Valley to boil tap water before using
Where is the outage?
The water issue affects 9,200 customers in Granada Hills and Porter Ranch, according to the utility. The outage area is bounded by these streets:
- Rinaldi Street to the south
- Balboa Boulevard to the east
- De Soto Avenue to the west
- The foothills to the north
A map of affected areas.
(
Courtesy Los Angeles Department of Water and Power
)
What happened?
On Tuesday, crews were making repairs at a pump station that connects to a 10 million gallon water tank.
A valve 24 feet underground that controls the flow of water to the tank broke and didn’t open. That cut off the flow going into the area’s pipes.
LADWP put out a plea for customers to conserve water Tuesday night, but the tank was drained by the morning.
It’s led to safety concerns because contaminants can be introduced when pipes lose water pressure. The utility is now “strongly advising” residents to boil water while testing is underway. LADWP will contact customers when the water is safe to drink.
How do you boil water?
Water should be boiled for at least one minute. The rule of thumb is to let it cool for about 30 minutes before using, according to the CDC.
That includes water used for brushing teeth and making ice cubes.
If you can’t boil it, you can also use unscented liquid bleach, according to LADWP. Here are the directions:
- For clear water, use 8 drops (1/8 teaspoon) of bleach for one gallon of water. For cloudy water, filter through a clean cloth and use 16 drops (1/4 teaspoon) of bleach for one gallon of water.
- Mix well and allow it to stand for 30 minutes before using.
- The water may taste or smell like chlorine — this means disinfection has occurred.
What’s being done to help?
Crews have been working on emergency repairs, but a temporary fix is expected soon. Mayor Karen Bass said at a news conference Wednesday they’re working with a specialized contractor to get water back into the tank.
“ We are hoping to restore water service with an emergency repair much quicker than the permanent fix will take,” she said.
Janisse Quiñones, the LADWP head and chief engineer, said the water is coming from the Metropolitan Water District. Pumping should start around 7 p.m. Wednesday night.
“ If they are successful, we may be able to restore water service in the next 24 to 48 hours to the whole area,” she said.
Permanent repairs may extend to the weekend.
But the weather will be very hot over the next few days, with the San Fernando Valley sticking around the mid-90s. Officials are urging residents to stay hydrated.
Three LADWP drinking water pickup sites will be open until further notice from 7 a.m. to 7 p.m. These locations also have portable showers, hand washing stations, mobile laundry units and portable toilets. Here’s a map:
Bass’ office says cooling centers with restrooms can also be used. For recreation and parks facilities, see here. For local library locations, see here.
The L.A. Fire Department has also deployed water tankers, engines and other resources to the area as a precautionary measure in case of fires, according to her office.
Updated August 6, 2025 at 5:11 PM PDT
This story was updated to include new information about the outage and the boil water notice.