by Andrea Albertin | Aug 27, 2021
Prepare an emergency drinking water supply for your household before a storm hits. Image: Tyler Jones, UF/IFAS.
Storm season is upon us. During a natural disaster, normal drinking water supplies can quickly become contaminated. To be prepared, collect and store a safe drinking water supply for your household before a storm arrives.
How much water should be stored?
- Store enough clean water for everyone in the household to use 1 to 1.5 gallons per day for drinking and personal hygiene (small amounts for things like brushing teeth). Increase this amount if there are children, sick people, and/or nursing mothers in the home. If you have pets, store a quart to a gallon per pet per day, depending on its size.
- Store a minimum 3-day supply of drinking water. If you have the space for it, consider storing up to a two-week supply.
- For example, a four-person household requiring 1.5 gallons per person per day for 3 days would need to store 18 gallons: 4 people × 1.5 gallons per person × 3 days = 18 gallons. Don’t forget to include additional water for pets!
What containers can be used to store drinking water?
Store drinking water in thoroughly washed food-grade safe containers, which include food-grade plastic, glass containers, and enamel-lined metal containers, all with tight-fitting lids. These materials will not transfer harmful chemicals into the water or food they contain.
More specific examples include containers previously used to store beverages, like 2-liter soft drink bottles, juice bottles or containers made specifically to hold drinking water. Avoid plastic milk jugs if possible because they are difficult to clean. If you are going to purchase a container to store water, make sure it is labeled food-grade or food-safe.
As an extra safety measure, sanitize containers with a solution of 1 teaspoon of non-scented household bleach per quart of water (4 teaspoons per gallon of water). Use bleach that contains 5%–9% sodium hypochlorite. Add the solution to the container, close tightly and shake well, making sure that the bleach solution touches all the internal surfaces. Let the container sit for 30 seconds and pour the solution out. You can let the container air dry before use or rinse it thoroughly with clean water.
Best practices when storing drinking water
- Store water away from direct sunlight, in a cool dark place if possible. Heat and light can slowly damage plastic containers and can eventually lead to leaks.
- Make sure caps or lids are tightly secured.
- Store smaller containers in a freezer. You can use them to help keep food cool in the refrigerator if the power goes out during a storm.
- Keep water containers away from toxic substances (such as gasoline, kerosene, or pesticides). Vapors from these substances can penetrate plastic.
- When possible, use water from opened containers in one or two days if they can’t be refrigerated.
- Although properly stored public-supply water should have an indefinite shelf life, replace every 6-12 months for best taste.
More information on preparing an emergency drinking water supply can be found on the CDC website and in the EDIS Publication ‘Preparing and Storing an Emergency Safe Drinking Water Supply‘
by Andrea Albertin | Jan 31, 2020
Contact you local county health department office for information on how to test your well water. Image: F. Alvarado Arce
Residents that rely on private wells for home consumption are responsible for ensuring the safety of their own drinking water. The Florida Department of Health (FDOH) recommends private well users test their water once a year for bacteria and nitrate.
Unlike private wells, public water supply systems in Florida are tested regularly to ensure that they are meeting safe drinking water standards.
Where can you have your well water tested?
Your best source of information on how to have your water tested is your local county health department. Most health departments test drinking water and they will let you know exactly what samples need to taken and ho w to submit a sample. You can also submit samples to a certified private lab near you.
Contact information for county health departments can be located at: http://www.floridahealth.gov/programs-and-services/county-health-departments/find-a-county-health-department/index.html
Contact information for private certified laboratories are found at https://fldeploc.dep.state.fl.us/aams/loc_search.asp
Why is it important to test for bacteria?
Labs commonly test for both total coliform bacteria and fecal coliforms (or E. coli specifically). This usually costs about $25 to $30, but can vary depending on where you have your sample analyzed.
- Coliform bacteria are a large, diverse group of bacteria and most species are harmless. But, a positive test for total coliforms shows that bacteria are getting into your well water. They are used as indicators – if coliform bacteria are present, other pathogens that cause diseases may also be getting into your well water. It is easier and cheaper to test for total coliforms than to test for a suite of bacteria and other organisms that can cause health problems.
- Fecal coliform bacteria are a subgroup of coliform bacteria found in human and other warm-blooded animal feces, in food and in the environment. E. coli are one group of fecal coliform bacteria. Most strains of E. coli are harmless, but some strains can cause diarrhea, urinary tract infections, and respiratory illnesses among others.
To ensure safe drinking water, FDOH strongly recommends disinfecting your well if the water tests positive for (1) only total coliform bacteria, or (2) both total coliform and fecal coliform bacteria (or E. coli). Disinfection is usually done through shock chlorination. You can either hire a well operator in your area to disinfect your well or you can do it yourself. Information for how to shock chlorinate your well can be found at http://www.floridahealth.gov/environmental-health/private-well-testing/_documents/well-water-facts-disinfection.pdf
Why is it important to test for nitrate concentration?
High levels of nitrate in drinking water can be dangerous to infants, and can cause “blue baby syndrome” or methemoglobinemia. This is where nitrate interferes with the blood’s capacity to carry oxygen. The Maximum Contaminant Level (MCL) allowed for nitrate in drinking water is 10 milligrams nitrate per liter of water (mg/L). It is particularly important to test for nitrate if you have a young infant in the home that is drinking well water or when well water is used to make formula to feed the infant.
If test results come back above 10 mg/L nitrate, use water from a tested source (bottled water or water from a public supply) until the problem is addressed. Nitrates in well water can come from fertilizers applied on land surfaces, animal waste and/or human sewage, such as from a septic tank. Have your well inspected by a professional to identify why elevated nitrate levels are in your well water. You can also consider installing a water treatment system, such as reverse osmosis or distillation units to treat the contaminated water. Before having a system installed, contact your local health department for more information.
In addition to once a year, you should also have your well water tested when:
- The color, taste or odor of your well water changes or if you suspect that someone became sick after drinking well water.
- A new well is drilled or if you have had maintenance done on your existing well
- A flood occurred and your well and/or septic tank were affected
Remember: Bacteria and nitrate are not the only parameters that well water is tested for. Call your local health department to discuss your what they recommend you should get the water tested for, because it can vary depending on where you live.
FDOH maintains an excellent website with many resources for private well users at http://www.floridahealth.gov/environmental-health/private-well-testing/index.html, which includes information on potential contaminants and how to maintain your well to ensure the quality of your well water.
by Andrea Albertin | Jun 8, 2018
Flooding along the South Prong of the Black Creek River in Clay County on September 13, 2017. Photo credit: Tim Donovan, Florida Fish and Wildlife Conservation Commission (FWC).
As hurricane season is upon us again, I wanted to share the results of work that UF/IFAS Extension staff did with collaborators from Virginia Tech and Texas A&M University to help private well owners impacted by Hurricanes Irma and Harvey last year. This work highlights just how important it is to be prepared for this year’s hurricane season and to make sure that if flooding does occur, those that depend on private wells for household use take the proper precautions to ensure the safety of their drinking water.
About 2.5 million Floridians (approximately 12% of the population) rely on private wells for home consumption. While public water systems are regulated by the U.S. Environmental Protection Agency to ensure safe drinking water, private wells are not regulated. Private well users are responsible for ensuring the safety of their own water.
Hurricanes Irma and Harvey
In response to widespread damage and flooding caused by Hurricane Harvey in Texas and Irma in Florida in August and September 2017, Virginia Polytechnic Institute and State University (VT) received a Rapid Research Response Grant from the National Science Foundation to offer free well water testing to homeowners impacted by flooding.
They partnered with Texas A&M AgriLife Extension’s Well Owner Network (run by Diane Boellstorff and Drew Gholson) and us, at UF/IFAS Extension to provide this service. The effort at VT was led by members of Marc Edward’s lab in the Civil Engineering Department: Kelsey Pieper, Kristine Mapili, William Rhoads, and Greg House.
VT made 1,200 sampling kits available in Texas and 500 in Florida, and offered free analysis for total coliform bacteria and E. coli as well as other parameters, including nitrate, lead, arsenic, iron, chloride, sodium, manganese, copper, fluoride, sulfate, and hardness (calcium and magnesium). Homeowners were also asked to complete a needs assessment questionnaire regarding their well system characteristics, knowledge of proper maintenance and testing, perceptions of the safety of their water and how to best engage them in future outreach and education efforts.
Response in the aftermath of Irma
Although the sampling kits were available, a major challenge in the wake of Irma was getting the word out as counties were just beginning to assess damage and many areas were without power. We coordinated the sampling effort out of Quincy, Florida, where I am based, and spread the word to extension agents in the rest of the state primarily through a group texting app, by telephone and by word of mouth. Extension agents in 6 affected counties (Lee, Pasco, Sarasota, Marion, Clay and Putnam) responded with a need for sample kits, and they in turn advertised sampling to their residents through press releases.
Residents picked up sampling kits and returned water samples and surveys on specified days and the samples were shipped overnight and analyzed at VT, in Blacksburg, VA. Anyone from nearby counties was welcome to submit samples as well. This effort complemented free well water sampling offered by multiple county health departments throughout the state.
In all, 179 water samples from Florida were analyzed at VT and results of the bacterial analysis are shown in the table below. Of 154 valid samples, 58 (38%) tested positive for total coliform bacteria, and 3 (2%) tested positive for E. coli. Results of the inorganic parameters and the needs assessment questionnaire are still being analyzed.
Table 1. Bacterial analysis of private wells in Florida after Hurricane Irma.
| County |
Number of samples (n) |
Positive for total coliform (n) |
Positive total coliform (%) |
Positive for E. coli (n) |
Positive for E. coli (%) |
| Citrus |
1 |
0 |
0% |
0 |
0% |
| Clay |
13 |
5 |
38% |
0 |
0% |
| Hernando |
2 |
1 |
50% |
0 |
0% |
| Hillsborough |
1 |
1 |
100% |
0 |
0% |
| Marion |
19 |
5 |
26% |
1 |
5% |
| Monroe |
1 |
0 |
0% |
0 |
0% |
| Pasco |
40 |
19 |
48% |
1 |
3% |
| Putnam |
61 |
19 |
31% |
0 |
0% |
| Sarasota |
16 |
8 |
50% |
1 |
6% |
| Overall |
154 |
58 |
38% |
3 |
2% |
Of 630 samples analyzed in Texas over the course of 7 weeks post-Hurricane Harvey, 293 samples (47% of wells) tested positive for total coliform bacteria and 75 samples (2%) tested positive for E. coli.
What to do if pathogens are found
Following Florida Department of Health (FDOH) guidelines, we recommended well disinfection to residents whose samples tested positive for total coliform bacteria, or both total coliform and E. coli. This is generally done through shock chlorination by either hiring a well operator or by doing it yourself. The FDOH website provides information on potential contaminants, how to shock chlorinate a well and how to maintain your well to ensure the quality of your well water (http://www.floridahealth.gov/environmental-health/private-well-testing/index.html).
UF/IFAS extension agents that led the sampling efforts in their respective counties were: Roy Beckford – Lee County; Brad Burbaugh – Clay County; Whitney Elmore – Pasco County; Sharon Treen – Putnam and Flagler Counties; Abbey Tyrna – Sarasota County and Yilin Zhuang – Marion County.
We at IFAS Extension are working on using results from this sampling effort and the needs assessment questionnaire filled out by residents to develop the UF/IFAS Florida Well Owner Network. Our goal is to provide residents with educational materials and classes to address gaps in knowledge regarding well maintenance, the importance of testing and recommended treatments when pathogens and other contaminants are present.
Remember: Get your well water tested if flooding occurs
It’s important to remember that if any flooding occurs on your property that affects your well and/or septic system, you should have your well water tested in a certified laboratory for pathogens (total coliform bacteria and E. coli) and any other parameters your local health department may recommend.
Most county health departments accept samples for water testing. You can also submit samples to a certified commercial lab near you. Contact your county health department for information about what to have your water tested for and how to take and submit the sample.
Contact information for county health departments can be found online at: http://www.floridahealth.gov/programs-and-services/county-health-departments/find-a-county-health-department/index.html
You can search for laboratories near you certified by FDOH here: https://fldeploc.dep.state.fl.us/aams/loc_search.asp This includes county health department labs as well as commercial labs, university labs and others.
You should also have your well water tested at any time when:
- The color, taste or odor of your well water changes or if you suspect that someone became sick after drinking your well water
- A new well is drilled or if you have had maintenance done on your existing well
Testing well water once a year is good practice to ensure the safety of your household’s drinking water.
