Porter Ranch / Granada Hills Boil Water Notice: What You Need to Know
Porter Ranch Granada Hills Boil Water: The communities of Porter Ranch and Granada Hills in Los Angeles recently experienced a Boil Water Notice issued by the the Los Angeles Department of Water & Power (LADWP). This advisory affects many residents in zip codes 91344 and 91326, and offers guidance on how to keep yourself safe until water quality is confirmed.
Below, we break down what happened, what risks are involved, how to safely use water, and how to know when it’s cleared.
What Triggered the Boil Water Advisory?
The boil water notice stemmed from a mechanical failure during repair work on a pump station that feeds a 10-million gallon water tank serving the area.
While crews attempted routine repairs, a valve controlling water flow broke and failed to reopen, which in turn reduced system pressure and cut off normal disinfection protocols.
Since water pressure dropped, there was a risk that contaminants — including bacteria, viruses, or parasites — could infiltrate pipes. In line with standard public health precautions, LADWP and state regulatory agencies issued the advisory to require boiling for consumption.
The affected area is roughly bounded by north of Rinaldi Street or I-118 Freeway (whichever is further north) and west of Balboa Boulevard.
LADWP estimated that resolution might take up to a week but cautioned extra time could be required due to the complexity of restoring system pressure and validating water quality.
What Are the Health Risks?
When a boil water notice is in effect, the primary danger is microbial contamination. While not all such advisories mean that contamination is proven, they are precautionary, because loss of pressure can allow disease-causing organisms to enter the system.
Possible symptoms of waterborne illness include:
- Nausea, vomiting, diarrhea
- Abdominal cramps
- Headaches, low-grade fever
These are particularly risky for infants, elderly people, pregnant women, and those with compromised immune systems.
Even if you feel fine, consuming untreated water during such an advisory is not recommended, since contamination may not always produce immediate symptoms.
Safe Practices During the Boil Water Advisory
Boiling Protocol
- Bring tap water to a full rolling boil for at least 1 minute (i.e. bubbling vigorously), then allow it to cool before use.
- Use boiled water (cooled) for drinking, cooking, making ice, washing produce, and for preparing baby formula or beverages.
- Even if your home has a filter, you must still boil — most household filters do not remove viruses and bacteria.
Alternate Disinfection (if boiling isn’t feasible)
If boiling is not possible:
Use unscented household bleach:
- For clear water: 8 drops (¼ tsp) bleach per gallon
- For cloudy water: filter through clean cloth, then use 16 drops (½ tsp) per gallon
- Mix thoroughly, let stand for 30 minutes before use
- A slight chlorine smell indicates disinfection has occurred
Use water disinfection tablets, following manufacturer instructions precisely.
Other Household Uses
Dishwashing:
If hand washing, use boiled/cooled water, or after washing scrub with detergent, then rinse with a dilute bleach solution (1 teaspoon unscented bleach per gallon of warm water). Let utensils air dry thoroughly.
Dishwashers may be used only if they reach at least 150 °F (65.6 °C) and include a full drying cycle. Many home models don’t reliably reach that; if uncertain, rinse in bleach solution.
Bathing / Washing:
- It is generally safe to wash and bathe, as long as you avoid swallowing water.
- For people with open sores, wounds, or compromised immunity, it’s safer to use boiled/cooled water or bottled water.
Brushing Teeth:
Do not use tap water directly — use boiled/cooled or bottled water instead.
Auto, toilets, lawns:
- Flushing toilets is safe (unless a “do not use” order is additionally posted).
- Use of water for landscaping or washing cars is generally fine.
How the Situation Changed & When It Was Lifted
After several days of ongoing testing, the water system serving Granada Hills / Porter Ranch was deemed safe again.
On August 12, 2025, LADWP officially lifted the Boil Water Notice.
The announcement advised residents to flush their pipes by running all faucets for about five minutes to clear any residual water that may have sat in lines.
Affected customers were also given a $20 bill credit to offset the flushing process
While the advisory was active, water service had been restored for many of the affected customers (for uses like showers, toilets, landscaping), but drinking water use was restricted until full testing passed.
Key Takeaways for Residents & Future Preparedness
- Stay informed: Monitor LADWP announcements and maps to know whether your address is in the affected zone.
- Use safe water practices: Whenever a boil advisory is in place, adhere strictly to boiling or disinfecting protocols.
- Don’t rely solely on filters: Many household filters don’t remove microbes; boiling is the safer bet in a boil-water event.
- Plan ahead: Keep bottled water stock, and have a system for safely storing boiled water for later use.
- Pipe flushing after lifting: Even after the notice is lifted, flush your home pipes to clear any stagnant water.
- Health vigilance: If you experience symptoms like diarrhea, nausea, or cramping, seek medical advice promptly, especially for vulnerable individuals.
- Community sharing: Some households may not receive direct notices — share the information with neighbors, schools, community centers, or rental residents.
