Mold after a flood or water leak in Oklahoma City

Oklahoma City floods fast. On May 6, 2015, Will Rogers airport recorded 7.10 inches of rain in 24 hours, and the National Weather Service issued the first flash flood emergency in the city's history (NOAA Climate.gov). That month ended with 19.48 inches, the wettest month on record for Oklahoma City. The three wettest Mays in the city's books are 2015, 2013 and 2019 (NWS Norman). A burst washing-machine hose produces the same mold clock on a smaller scale. Whatever brought the water in, the next two days decide how much of the house you have to tear out.

The 24 to 48 hour window

EPA's guidance is to dry water-damaged areas and items within 24 to 48 hours to prevent mold growth (EPA). Oklahoma State University Extension repeats the same window for storm and flood cleanup, and adds that porous materials like carpeting and drywall are especially vulnerable (OSU Extension). Past that point, assume that anything still soaked has started growing mold, even if you can't see it yet.

First steps, in order

1. Be safe first. Don't walk through standing water near outlets or appliances that may be live. If you run a generator, EPA's disaster guide says to keep it outside and away from the home because of carbon monoxide (EPA).
2. Photograph everything before you move it, including water lines on walls and furniture, then call your insurer. OSU Extension gives the same advice.
3. Get air moving. If the weather allows, OSU suggests opening windows and leaving room, closet, cabinet and drawer doors open. Fans and a dehumidifier help once the standing water is gone.
4. Pull what won't dry. Carpet, pad, drywall and insulation are porous. OSU Extension singles out carpeting and drywall as especially vulnerable, and EPA says porous materials that stay wet and grow mold may have to be thrown out (EPA).
5. Protect yourself. EPA's disaster guide calls for an N-95 respirator at minimum, plus goggles and gloves. CDC specifies goggles that seal around the eyes and gloves made of nitrile, vinyl or rubber (CDC).

Not all water is the same

Clean water from a supply line is one thing. Water that came off the street, out of a creek, or up through a floor drain is another. EPA says that when the damage came from sewage or other contaminated water, you should call in a professional experienced in that kind of cleanup (EPA). OSU Extension says the same about storm water mixed with sewage. That applies to water that crossed a yard and came under the door, too. Porous items it touched, like upholstered furniture, mattresses, carpet and drywall, are generally a loss.

When it becomes a remediation job

If mold is already visible across more than about 10 square feet, OSU Extension points to EPA's homeowner and renter guide to mold cleanup after disasters, and EPA's remediation guidance calls for containment at that size. The same applies if the water sat for days before anyone could get in, or if the HVAC system pulled damp air from the flooded area. At that point the job is mold remediation, not drying. EPA also says to finish the mold cleanup before moving back in.

After it's dry

Flood-damaged homes in this metro tend to get hit again, because the grading or drainage that let water in the first time is still there. EPA recommends making sure the ground slopes away from the foundation and keeping gutters clean and repaired (EPA). If you sell later, Oklahoma's seller disclosure form asks about past flood, storm run-off and sewer backup damage, and about mold treatment. See buying or selling a home.

Questions people ask

How fast does mold grow after a flood?

EPA says wet materials should be dried within 24 to 48 hours to prevent mold growth. After that, assume anything still soaked is growing mold, even if you can't see it yet.

Can I save drywall that got wet?

Sometimes, if it was clean water and the wall dries within EPA's 24 to 48 hour window. Drywall that soaked up contaminated floodwater, or stayed wet longer and grew mold, generally has to come out.

Who handles sewage or creek water in the house?

EPA says to bring in a professional with experience in contaminated-water cleanups. Inside Oklahoma City limits and Oklahoma County, the City-County Health Department also takes complaints about visible sewage inside a dwelling.