What You Need to Know About Disinfecting Water, In Case of an Emergency 

For the first time ever, the National Weather Service has issued a tropical storm watch for San Diego County. That’s because Hurricane Hilary is headed our way. 

There haven’t been any notices about the county’s drinking water supply, but in the event of a hurricane, flood or water pipe breakage, county officials might recommend using only bottled water, boiled water or disinfected water until water service goes back to normal. 

If that happens, here’s what to do, according to the Environmental Protection Agency. 

First, some background: Hurricane Hilary, which is now a Category 4 hurricane, is expected to bring high winds and heavy rains that could cause dangerous flash flooding in parts of the county. 

Coastal cities could get 2 to 3 inches of rain from Saturday through Monday, inland valleys could receive 2 to 4 inches and the mountains and deserts could get 5 to 7 inches, the Union-Tribune reported Friday. 

Winds blowing 35 mph to 45 mph, with gusts reaching up to 65 mph, could impact Escondido, El Cajon, Poway and Lakeside the most.  

How do hurricanes affect drinking water? Hurricanes can cause flooding, and floodwater typically contains lots of toxins and contaminants from soil, sewage and chemicals. And if water treatment plants are impacted by the storm, they may not operate at full capacity and water lines could be compromised. 

There’s also the possibility of heavy rains and floods uprooting trees and other debris, causing water line pipes to break or crack. Those toxins and contaminants could then get into a city or region’s water supply. 

Disinfecting water: If San Diego County’s drinking water gets contaminated this weekend, residents will hear about it from county officials and local authorities. 

They may issue a boil water notice, which means residents should boil their water before drinking it. Here are steps provided by the EPA: 

• If water is cloudy, let it settle and filter it through a clean cloth or coffee filter. 
• Bring water to a rolling boil for at least one minute. 
• Let water cool naturally and store it in clean containers with covers.     

If you can’t boil water, the EPA says you can also use regular, unscented chlorine bleach products to disinfect water. But the agency recommends following these specific guidelines carefully and precisely.  

Residents can also use bottled water or water that’s been properly prepared and stored as an emergency water supply. 

More information on storing water supplies can be found here.