Floodwater Exposure for Any Trade

Why this matters

After a storm every trade ends up in somebody's flooded basement: the plumber for the water heater, the HVAC tech for the furnace, the electrician for the panel, the appliance tech for the washer, the cleaner for what is left. Most of them are not water restoration crews and have not been trained to think of the water itself as the hazard. It can be energized. It carries sewage, fuel and farm runoff. It hides the floor drain cover that came off and the nail in the board under it. And it can make a tech sick for weeks with an infection whose name nobody in the shop has heard. This card is the working knowledge every trade needs before stepping into it; the restoration side lives on the WaterRestoration shelf.

Before anyone steps in: power, gas and exhaust

The protective action comes first: nobody enters standing water in a building until the power to that space is confirmed off. Water conducts, and a submerged outlet, extension cord, sump pump or appliance can energize the whole pool. The person who discovers this by stepping in does not get a second try.

• If you can reach the panel without standing in water, and the panel itself was never wet, a qualified person turns off the main breaker standing on dry ground, wearing dry boots, and the space is treated as live until that is done.
• If the panel is in the flooded space, below the high-water mark, or reachable only through water, nobody from the shop touches it. The utility disconnects at the meter, or a licensed electrician does. A panel that has been underwater is not reset; it is replaced or evaluated by an electrician.
• "The whole street lost power" is not a disconnect. Grid power can be restored without warning, and a neighbor's or homeowner's portable generator wired without a transfer switch can backfeed the house wiring.
• Gas. Floodwater shifts appliances and can break gas connections. If you smell gas, everyone leaves the building immediately, touches no switches and uses no phone inside, and calls the gas utility from outside. A water heater or furnace that sat in floodwater is not relit until its controls and burner are replaced or evaluated; the gas valve and control are not designed to survive submersion.
• Exhaust. Never run a gasoline pump, pressure washer or generator inside the house, in a basement, or in an attached garage with the door open. Carbon monoxide from small engines kills more people after floods than many people realize, and it does so in exactly the space your crew is working. Engines stay outdoors and away from openings, and a personal CO monitor on the crew is cheap insurance.

What is actually in the water

Floodwater that came from outside, rose from the ground, or backed up through a floor drain should be treated as grossly contaminated. Restoration standards call this Category 3 water: it is presumed to carry sewage and other harmful agents, whatever it looks like. Clear water is not clean water. A finished basement that flooded from a burst supply line starts out cleaner, but water that sits for a day or two and picks up what is on the floor degrades toward the same category. See related: Water Damage Category 1/2/3 Distinction.

What is commonly in it: raw sewage from overloaded systems, animal waste from yards and farms, gasoline, oil and heating fuel, pesticides and pool chemicals from garages and sheds, and debris with sharp edges. The illnesses come through three routes: swallowing (hands to mouth, splashes), skin breaks (cuts, scrapes, punctures), and the eyes. The sewage-specific hygiene routine is owned by The Sewage Contact Hygiene SOP, and the same routine applies here.

 FLOODED BASEMENT, SIDE VIEW (hazards by height)

 main floor ---------------------------------------
   panel [=] <- above the line? still verify dry
   outlet o  <- wall outlet near high-water mark
 high-water mark ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
   furnace  water heater   cord --+    o outlet
   [burner] [gas control]         |    (submerged)
 ~~~~~~~~~~~~ standing water ~~~~~|~~~~~~~~~~~~~~~
   floor drain (cover lifted)   sump pump (live?)
 slab ---------------------------------------------

The diagram shows why "the panel looks dry" is not the whole question: outlets and cords below the high-water mark, a sump pump on its own circuit and a submerged appliance can energize the water from points that are not the panel. And the floor drain whose cover lifted is an open hole you cannot see.

Wounds and tetanus

Cover every cut before going in, with a waterproof dressing, and wear waterproof gloves over it. A cut you get in floodwater is cleaned with soap and clean water as soon as possible, covered, and watched.

Tetanus is a bacterial infection from soil and debris entering a wound, and it is the reason flood workers get asked about boosters. CDC's guidance is that adults get a tetanus booster every 10 years, and that for a dirty or puncture wound, a booster is needed if the last one was more than 5 years ago. That is a doctor's or pharmacist's call on the day of the wound, so every tech should know roughly when their last tetanus shot was. CDC does not call for everyone in a flood area to be vaccinated; the point is to be current before you need it.

Vibrio is a bacterium that lives in warm, brackish coastal water, and floodwater from storm surge can carry it. It can infect a wound fast. A wound from coastal floodwater that turns red, swollen and painful, especially spreading redness within a day or two, needs medical care that day, and urgently for anyone with liver disease or a weakened immune system.

Leptospirosis

Leptospirosis is a bacterial infection spread through the urine of infected animals, mainly rats and other rodents, livestock and dogs. Floods spread it because they mix that urine into the water and soil. It enters through cuts and through the eyes, nose and mouth, including by swallowing splashed water.

The timing is what makes it dangerous to a shop: CDC gives an incubation period of about 2 days to 4 weeks. A tech who worked a flooded basement and comes down with fever, headache, muscle aches (often in the calves), red eyes, chills or vomiting a week or two later has a reason to tell the doctor about the flood. Most cases are mild, but some progress to kidney and liver failure, and it is treated with antibiotics, which work best early. The tech who says "I just have the flu" and does not mention the basement is the case that goes badly. See related: The Tech Got Sick Two Weeks After the Attic Job.

What to wear and how to work

• Waterproof boots that come above the water, with puncture-resistant soles where debris is likely. Wading in sneakers is how feet get cut and stay wet for hours.
• Waterproof gloves, with cut-resistant gloves underneath or over them when handling debris.
• Eye protection against splash. Floodwater in the eyes is a real exposure route.
• No eating, drinking, smoking or touching the face until hands are washed with soap and clean water. Hand sanitizer does not remove grime and is a backup, not the wash.
• Work clothes go in a bag, not into the cab, and get washed separately.
• Mold comes later. After a day or two of wet materials, mold growth begins, and disturbing it is an inhalation exposure. See related: Mold Exposure for Trades Who Are Not Remediators.

The law layer for the employer is federal: under OSHA's PPE standard, 29 CFR 1910.132, an employer whose workers face hazards like contaminated water and debris must assess the hazard and provide the protective equipment it calls for, at the employer's cost for most items. States running their own OSHA plans adopt at least that floor.

A worked example

A plumbing shop gets a call the morning after a storm. A homeowner has about 8 inches of standing water in an unfinished basement that holds the gas water heater, the furnace and the washer; the water came in through the foundation and up the floor drain. The panel is on the basement wall, its bottom edge about 4 feet above the floor.

The tech stops at the top of the stairs. He asks the homeowner whether anything is plugged in down there; the answer is the freezer and the sump pump. He cannot tell whether the panel has been wet, but it is well above the water, and the stairs land on the floor in the water, so he cannot reach it from dry ground either. Because reaching the panel means standing in the water, he does not go down. He asks the homeowner to call the electric utility for a meter disconnect, and the office calls a licensed electrician the shop works with.

Two hours later the utility has pulled the meter. Only now does the tech go down: rubber boots over his jeans, waterproof gloves over a waterproof dressing on a knuckle cut from yesterday, safety glasses. He notes the water heater's gas control and burner were submerged, closes the gas shutoff to the water heater and furnace, and tags both "flood damaged, do not relight." He does not run his gasoline pump in the basement; the pump stays outside, with the hose run in through a window, and he wears a CO monitor anyway. The ticket notes the water level, the submerged equipment, the time of entry and the PPE worn.

Change one fact and the answer changes. If the panel had been on the main floor, reachable from a dry hallway, and the homeowner had confirmed nothing had flooded up there, the tech could have had the main breaker turned off from dry ground and gone down the same morning. If the water had been 3 feet deep and over the panel, the electrician would also be evaluating the panel for replacement before anything was restored. In neither case does the shop relight the submerged water heater.

Twelve days later the tech gets a fever and aching legs. Because the basement visit is on the ticket with the date and the water source, he tells urgent care he waded floodwater with a cut hand. They test and treat him for possible leptospirosis rather than sending him home with flu advice.

References

• CDC, Flood safety: electrical hazards, carbon monoxide, wound care and tetanus guidance
• CDC, Leptospirosis: incubation, symptoms and flood exposure
• OSHA, Personal Protective Equipment, 29 CFR 1910.132; OSHA flood cleanup fact sheets
• IICRC S500, water damage categories; see related: Water Damage Category 1/2/3 Distinction
• See related: The Sewage Contact Hygiene SOP