In October 2012, a hurricane of unprecedented scope hit the East Coast. New Jersey was especially hard-hit with a catastrophic storm surge; at one point, 80 percent of Atlantic City was underwater — as were the swimming pools in that area, too. 

Much of the Gulf Coast from Florida to Texas is susceptible to frequent hurricanes and tropical storms. These storms cause seawater to head inland, resulting in massive flooding and water damage to coastal communities. And again, many swimming pools in these communities will be inundated with flood water, which can contain anything from saltwater, salt, sand, algae and phosphates to more serious things like sewage — which can possibly be contaminated by E. coli, giardia and cryptosporidium. 

Ideally, pools that have been contaminated with floodwater should be drained and refilled with fresh water. In cases where this isn’t possible or the damage is not as critical, water can be cleaned with chemicals, flocculation and filtration.

After any type of flood situation, pool equipment should first be inspected and verified to be in good working order. Of most importance: electrical devices. Be sure to test them and replace or repair as needed. In addition, the filter should be inspected before any attempt to clean dirty water in pools. The following is a suggestion for dealing with flooded pools. 

1. First, remove as much physical debris as possible.

2. Make sure all skimmer and pump baskets are free of debris with good circulation and filtration.

3. Superchlorinate the pool to at least 20 ppm. 

4. Maintain pH between 7.2 to 7.4.

5. Once chlorine has been added, follow immediately with a two-stage clarifier. As the filter system operates, add the proper amount of the first stage formula.

6. After 6 hours (or one turnover rate of the filter), add the second stage of the two-part clarifier and continue running the pool filter. 

The pool should clear completely within 24 hours after the second stage of clarifier is added. Backwash or clean the filter after 24 hours. If the existing system is damaged, this system can work with a portable filter system as well. 

Once the water is clear test for phosphates and treat with a phosphate remover if needed. Once phosphate levels have been lowered down to 200 ppb, add a good broad-spectrum algaecide, which will be effective against all types of algae. This type of cleanup method should ensure the pool water is clean and ready for regular maintentance, which should occur between 1 and 3ppm after treatment. 

For more information about treating hurricane-damaged pools, click here

Terry Arko is AQUA Contributor of AQUA Magazine.
Excellent suggestions. I have found after my 14 Hurricane clean ups that they are either a wind or water event. I would highly suggest if flooding occurs to treat for crypto as waste from animals and floating septic tanks can travel. If coastal do not be surprised to see a sodium level in pool and SWG's working properly. The same spray that turns many trees and plants brown contains salt from the ocean water and also is present in the pool water. I recommend my customers before a hurricane to add 3X a normal "shock" treatment (they understand that easier than trying to raise to XXppm) and add an algaecide (non-foaming). This way they can use the pool water for commode flushing after the storm when power is off and hopefully delay any algae blooms as we usually find it hot and steamy after the fact. Also, both Lowry and Arko are two of my most trusted sources for all things pool water chemistry related, so I meekly submit my 2 cents.
Great suggestions Wendy. There is nothing like experience to teach us something. Thank you for sharing your experiences.I am always looking for information to learn and pass along. Now I have more information on preparing for a hurricane.
I guess that will work if you happen to have a two-stage clarifier at home or if you can find a pool store open after a hurricane. But really, any clarifier should work. The secret to polymer and even natural clarifiers is to dilute them with as much water as possible before adding to the pool water. Most calrifiers have dosages of 1 oz per 1,000 gallons up to about 1 oz per 6,000 gallon of water. So you measure out a few oz and dilute it in a 5-gallon bucket of pool water and then add it to the water while walking around the pool. Even better is to use an eductor which is the type of sprayer that you attach to a garden hose and as the water goes through the sprayer, it sucks up the chemical. Many gardeners use these to spray insecticide or fertilizer on their plants. One company even puts an eductor sprayer on their bottles of clarifier. Lots of dilution makes the clarifier work fast. After clarifying the water which may take one or two treatments and multiple backwashes, its time to superchlorinate. I recommend a dose of chlorine that is equal to 40% of the CYA (cyanuric acid) level in the water. This ensures destruction and oxidation. If you are concerned that there may be crypto or giardia (there is no reason to think that there is just because there was a hurricane), you may decide to take remedial action with a two-stage clarifier, ozone, UV or AOP.