Questions and Answers


1. Why should I store water if I'm going to have to treat it?

Remember, if you stored water ahead of time, treatment of the water is an extra precaution. Keeping water in a drinkable condition depends upon many factors: was it stored properly - was it replaced after 6 months - etc.


In general, this is really a two-part question.

i. Why bother storing water if I have to treat it anyway?

ii. What would cause me to treat it?


i.     Why store? People can live a day or two wit6out water, but not much longer. After an earthquake or other emergency, the water pipes may be broken or otherwise unavailable through normal means. Lots of people will be buying water from stores, which will soon run out. Storing enough water for all the members of your family for three days is important so you have it on hand and are able to immediately care for your family.


ii.    Why treat pre-stored water? If water is stored improperly (in heat, lid not tight, outside air comes in contact with the water, etc.), or if the freshness/expiration date is exceeded, the water may become contaminated. As an extra precaution, you may wish to treat it, if you notice these conditions or if you are unsure of when you stored or purchased the water.


2. Should I treat the water that I have stored before I use it?

If you believe it was not stored properly, or you notice the water is cloudy or has an odd odor, you would be advised to treat stored water before using it.


3. Should I treat tap water or bottled water before I store it?

You do not need to pre-treat municipal tap water or bottled water before storage.


4. What is the difference between distilled water and other bottled water?

Distilled water has been turned into steam and then collected. This process results in water with fewer contaminants than water that has not been distilled. Distilled water is recommended for storage for those people who have immuno-compromised health conditions.


5. We use a well at my house. Can we store water from the well?

Yes, after you treat it.


6. We have a well. Do I still need to store water?

Yes. Your well system can be damaged or otherwise contaminated during an earthquake or other emergency. BEFORE storing well water, treat it by boiling.


7. How long does water last in storage?

Keeping water safe for drinking depends upon many factors, including how tight the water container lid is - the temperature of the area where the water is stored - the type of container used - what the original source of water way - the location of where the water is stored - how the water was originally treated - etc. Because there are many situations that can affect safe drinking water, your emergency water supply should be replaced every 6 months. Mark you calendar for the months of October and April to change your water - these are earthquake preparedness months in

California and when the daylight savings time changes. When you do replace your water, water utilities suggest that you recycle the water by watering your plants. When you store your water, write the date you stored the water right on the container with an indelible marker. This will remind you when you purchased or bottled the water. Sometimes water you buy at the store has an expiration or freshness date - check the date. As a note, you may be able to purchase specially designed air-tight pouches or packages of water. These packages typically have expiration dates on them, and can last as long as five years. Look under the listing of "Earthquake Supplies" in your local phone

company directory for vendors that may have these pouches. Frozen water can last indefinitely. If you have room in your freezer, you can freeze water. Freezing water can make your freezer work more efficiently, and you can but the frozen water in your refrigerator to keep your cold items fresh while the power is out. When you fill a clean, food-grade container with tap water to freeze, do not fill the container to the top, because water expands when frozen. Leave room in the top of the container for water to expand. Once your water thaws you can drink it, but do not refreeze it.

Replace frozen water that thaws.


8. Where do I store water?

Water quality is best when water is stored in clean food-grade containers with tightly fitting lids. The containers should be located in a dark, cool, accessible location within your home, secure from animals. Examples include clothes closets, linen closets, under decorative end tables, etc. Be sure you put your water in a place where you can regularly check the bottles for leaks. You can also freeze water. (See previous question for information.)


9. Where can I get large containers -25 to 50 gallons?

Look in our local phone company directory under "Earthquake Supplies."


10. Can I use a household container to store my water?

You can use any clean, food-grade, plastic, re-sealable container or drum. Be sure that it can seal tightly. Clean the container thoroughly before using. Do not use a container that held toxic materials.



1. Can I use water from my pool?

Pools and hot tubs are maintained for body contact, not drinking. Water from you pool can be used for cleaning dishes, clothes, and personal hygiene. It should not be used for food preparation or drinking because of heavy metals that accumulate in a pool and the high chlorine dosages used to keep it healthy for body contact.


2. Where else can I get water?

As a last resort, you can use water from your water heater and toilet tank. (Do not use the water from the toilet bowl.) Water from these sources should be strained through a cloth before use.


3. Can I really drink water from the water tank on the back of the toilet?

As long as there are no drop-in deodorizers or cleaners in your toilet tank, water from the tank may be drinkable. Use clean cups to bail water out and strain it through a cloth before use. (Do not use the water from the toilet bowl.)


4. We have a well. Can we use it after an emergency?

Wells can be damaged or contaminated during an earthquake or other emergencies. Always treat well water after an emergency.





1. What is a "boil order"?

A "boil order" is an emergency alert announcement from the health department that the water company cannot guarantee the quality of the tap water. The tap water should be boiled. If you cannot boil the water, you may treat it with bleach. (For directions, see the next question and answer.) This order will be announced over the radio and television and printed in the newspaper.


2. How do I treat water to make it drinkable?

Step 1:

Look at the water in the bottle, or pour it into a see-through, clean container. If you notice the water is not clear, strain the water through a clean handkerchief, paper towel, or cloth.

Step 2:

Treat the water by either boiling it or adding bleach if you cannot boil it.


Boiling Water

Boil the water for 5 minutes. Let it cool to room temperature before drinking.


Use of Bleach

If you do not have a way to boil the water, add bleach to each gallon of water. Use only bleach marketed for industrial purposes, as household bleach now has less of the disinfecting agent. It is no longer an acceptable product for treating water during emergencies. Measure the bleach. For each gallon add:

1/4 measuring teaspoon

or 1 milliter

or 16 drops.

If you use the drop method, keep a clean, unused medicine dropper available. If you do not have a dropper to measure with, you can soak part of a clean paper towel in bleach, lift up the paper towel, and allow 16 drops to fall into the gallon of water. Mix water and bleach solution thoroughly by stirring or shaking in a clean, food-grade container. Let stand for 30 minutes before using. You should notice a slight chlorine odor or taste. If not, repeat the dosage and let stand for an additional 15 minutes. If the water still does not have an odor or taste of chlorine after a second treatment, DO NOT drink the water.


During the summer Clorox announced its change in formula from the new to the improved product. The change included increasing the concentration of sodium hypochlorite (the disinfecting product) from 5.25 % to 6 % as well as adding additional items such as sodium hydroxide, which has not been in bleach before. The EPA has not announced its approval of the product for consumption, as it takes a very long process to gain that approval.

The following is a statement from Clorox:

Yes, it is true that Clorox is changing the concentration of its regular household laundry bleach from having a 5.25% concentration of Sodium Hypochlorite to 6%, and have added Sodium Hydroxide to the formula. They are doing this to reduce the size of the containers and in response to market research. They are introducing "Clorox Ultra" slowly across the country, starting in the West and Midwest. It will be on the East Coast by fall. They will completely eliminate offering the "old" Clorox bleach upon introduction of the "new" Clorox Ultra. However, Clorox stated that the new formula has been tested and is safe to use to treat water at home.


3. What is boiling?

Water is boiling when large bubbles from the bottom of the pan rise quickly to the top and break the surface of the water.


4. How can I make treated water taste better?

Pouring treated water from one container to another will add oxygen to the water and make it taste better.


5. Can I use my camping filter instead of boiling or adding bleach?

Boiling is recommended. There are many types of camping filters for different uses, and not all filters can eliminate all germs. If you have a camping filter that protects against Giardia, you may consider using it.


6. Why can't I use iodine or water purification tablets?

We do recognize that other treatments are available, but they are not recommended. Iodine and other chemicals in water purification tablets have been known to cause additional health problems for people with kidney or liver problems. And, as many as 8 out of every 100 people in the United States have a liver or kidney problem - without being aware of it. If you do use water purification tablets or liquid anyway, follow the manufacturer's directions.


7. Can I boil water on my camping stove? What about my barbecue?

You can boil water on your camping stove or outdoor gas grill if you have enough fuel. Never use charcoal briquettes inside the house because they can quickly poison the air in the house. Charcoal briquettes are good for cooking food, but typically do not generate enough sustained heat to boil water. Water spillage may also cause ash to get into your water.


Who developed these guidelines?

The material was developed in 1997 by a joint committee consisting of State Health, the Alameda and Contra Costa County Health Departments, East Bay Municipal Utility District, American Red Cross, and the Offices of Emergency Services from the City of Oakland and the State of California. The information was gathered from information provided by the U.S. Environmental Protection Agency and the Centers for Disease Control and Prevention (part of the U.S. Public Health Service) and are intended for general use. Information about the change in the Clorox Bleach formula was incorporated in 2001.




How to handle waste in the event of an earthquake.

The day after the earthquake a strong aftershock rocks the Quake Ready neighborhood, causing a sewer line break in the middle of the street. The houses around the break have untreated sewage seeping into their homes. Some people have lost sewer service in their homes and are lining toilets with plastic bags to use as port-o-potties. Over the radio the health Department directs several neighborhoods, Including quake readies, to cease using their well water because it may now be contaminated by sewage.


What should neighbors do to deal with sewage in their homes?


If sewage floods the lower portion of your house and cannot be drained away you should contact the sewer repair agency in your area or contact the emergency response unit responsible.

You can attempt to build a barrier to stop the flow using sand bags or other materials but remember to wear rubber boots or galoshes and rubber gloves when working with wastewater.

Remove your footwear and gloves in that order before re-entering the house.

Change your clothes and wash your hands and face before touching anything in the home. Do not rub your eyes, touch your face, eat, and drink fluids until you have washed up. Wastewater is a significant source of pathogenic bacteria and should be considered an infectious waste. If drinkable water is not available for washing use non drinkable water disinfected with a teaspoon of bleach per gallon. Otherwise simply avoid the affected area until repairs can be made. If the main sewer line is broken only qualified utility maintenance personnel should make repairs and you may have to be patient and deal with the inconvenience for a short time, as they will probably be overburdened with requests for service. If the wastewater pipeline from your house to the street is broken it is your responsibility to make repairs and you should contact a plumber.


What should neighbors do with bags of toilet waste? How are they handled and where should they be

stored? Who is responsible for their disposal?

Human fecal material can be stored temporarily in plastic bags out of doors in garbage cans. Place the cans in the shade if possible where there is good air circulation. Do what you can to minimize nuisance odors affecting your neighbors. Human waste can be buried in your backyard if you live in a private residence but you should provide at least 18 inches of cover soil to minimize odors. It is better to separate liquid waste from solid waste as much as possible. Unless drainage pipes are broken in the home it would be better to continue to urinate in the toilet even if it cannot be flushed than to attempt to cart it away. Non-drinkable water can be used if available to flush toilets if there is no water pressure. Have disposable alcohol wipes on hand if clean water is unavailable to clean your hands.

Typically the contracted trash hauler would be responsible for removing human waste if it is in plastic bags.


What are some of the Health Issues that can result from untreated waste and having contaminated water in the drinking water system?

Disease causing microorganisms are very prevalent in human waste and if consumed inadvertently with contaminated drinking water can lead to gastrointestinal-type illnesses. The symptoms of these illnesses are typically vomiting, diarrhea, nausea, cramps, loss of appetite, weakness and dehydration. The local Public Health or Water Department will issue alerts if problems exist. All medical problems should be brought to the attention of local authorities.


James Salerno, Water Quality Bureau

San Francisco Public Utilities Commission

1657 Rollins Rd. Burlingame, CA 94010 Email:


San Francisco Water Quality Hotline (877) 737-8297 or (650) 652-3127 days and (650) 872-5900 nights