The flood in Pathum Thani this year is not a two-day event. According to the Department of Disaster Prevention and Mitigation (DDPM) report of 2 October 2026, seven districts of Pathum Thani province were still affected: Thanyaburi, Mueang Pathum Thani, Sam Khok, Khlong Luang, Lam Luk Ka, Nong Suea and Lat Lum Kaeo, covering 182,290 households, and water levels were still rising. These figures change daily, so please follow the latest announcements from DDPM and the provincial authorities.

Nationally, DDPM reported on the same day that flooding affected 31 provinces plus Bangkok, with 1,245,581 households and 3,535,206 people affected. The main causes were sustained heavy to very heavy rain combined with runoff from the north. Pathum Thani sits between the Chao Phraya River and the dense Rangsit canal network, so it receives water both from the river and from countless side canals.

This guide covers every kind of germ flood water brings (bacteria, viruses, mold and sewage odor), the right recovery order, and where ozone fits: as the finishing step after cleaning and drying, never a replacement.

A typical scenario (an illustrative example, not a review from any specific customer)

A Lam Luk Ka townhouse: the water is gone, but the ground floor smells like a drain

Nok works in an office in Bangkok and bought a two-storey townhouse in a housing estate in Lam Luk Ka district several years ago because the commute was manageable and the price was right. The estate sits close to a side canal linked to the Rangsit system. In late September, heavy rain fell for several nights in a row. The canal crept into the estate's roads and then into the house, through the front door and up through the drain at the back.

Water on the ground floor stood at mid-shin for almost a week. Nok, her husband, their six-year-old son and her diabetic mother moved upstairs, but the cabinet under the stairs and her mother's spare mattress were soaked. Everyone waded out to work and shops through grey water that some days smelled like a septic tank.

Once it receded, the family shoveled out mud, hosed the floor, wiped the walls with bleach and left the doors and windows open. On the surface, the house looked almost normal. But three days later a musty, drain-like smell still hung in the living room, especially when the air conditioner was switched on. Small black spots appeared along the bottom of the gypsum wall under the stairs. Their son developed a runny nose and a night-time cough, and Nok's mother complained that a graze on her ankle, which had touched the water, was not healing.

This picture is common across Pathum Thani estates. The house looks clean, yet moisture and microbes hide where the eye cannot see. The mother's wound needs a doctor quickly, since diabetics are more prone to infection; the house needs a complete recovery, not just a washed floor.

Why Pathum Thani flood water carries so many germs into homes

Pathum Thani's geography makes every flood complicated. On the western side, Sam Khok and Mueang Pathum Thani districts face the Chao Phraya River, where many riverside homes are raised wooden houses or half-timber, half-concrete buildings. On the eastern side, Thanyaburi, Khlong Luang, Lam Luk Ka and Nong Suea are criss-crossed by the Rangsit canal and its side canals. Over recent decades, much of this former rice land has turned into housing estates, townhouses, dormitories, markets and factories.

When heavy rain and northern runoff arrive together, the water in the canals and river is no longer clean rainwater. It has flowed across roads, through drains, septic tanks and household sewage tanks, rubbish piles, fresh markets, animal pens, fertilized rice fields, and factory and warehouse yards. In dense areas such as Rangsit and Khlong Luang, flooded septic tanks overflow or back up, so standing water often contains fecal contamination.

Duration matters too. DDPM reported that water levels in Pathum Thani were still rising in early October. When water stays in a house for days, porous materials such as gypsum board, plywood, laminate flooring, mattresses, fabric sofas and carpets soak up dirty water deeply. They remain a reservoir of moisture and food for microbes for weeks, even after the surface feels dry.

Finally, estate townhouses are often sealed for air conditioning, with windows only front and back, so dampness and odor linger.

Every kind of germ that comes with the Pathum Thani flood

1. Bacteria from sewage and mud

The most common bacteria in flood water come from human and animal intestines. E. coli is used as an indicator of fecal contamination, and it travels with many other organisms that cause diarrhea and food poisoning. These bacteria settle on floors, the lower parts of walls, kitchen utensils, chopping boards, food cupboards and children's toys that were submerged. When hands touch them and then the mouth without washing, the result can be diarrhea, stomach cramps, nausea, vomiting and fever.

A disease to take seriously in a province that mixes rice fields with dense communities is leptospirosis. Leptospira bacteria live in the urine of rats and some other animals, mix into standing water and mud, and enter the body through cuts, scratches or skin that has been soaked for a long time. Typical symptoms are a sudden high fever, headache, marked muscle pain especially in the calves, and red eyes. Anyone who has waded through flood water and develops these symptoms within a few days to two weeks should see a doctor immediately and mention the flood exposure. Leptospirosis is treatable when antibiotics start early.

Soil and water bacteria can also infect wounds. Any wound that becomes swollen, red, hot or pus-filled must be checked by a doctor.

2. Viruses spread by water and surfaces

Viruses linked to contaminated water, such as norovirus and rotavirus, cause sudden vomiting and diarrhea and spread easily through hands, surfaces and food, especially in dormitories and shelters. Hepatitis A can also be linked to contaminated water and food. Cleaning high-touch surfaces matters as much as shoveling out mud.

3. Mold growing in a house that is still damp

Public health guidance from agencies such as the CDC notes that mold can begin growing on wet materials within 24 to 48 hours. Pathum Thani homes that held water for days are therefore at very high risk. Common post-flood molds include Aspergillus, Penicillium and certain black molds that favor cellulose materials such as the paper face of gypsum board and plywood. Mold releases tiny spores into the air that can cause a blocked nose, sneezing, itchy eyes, coughing, throat irritation and asthma or allergy flare-ups. People with weakened immunity can face more serious fungal infections.

In Pathum Thani townhouses and estate homes, mold likes to hide behind the lower part of gypsum walls, under click-lock laminate or vinyl floors, inside built-in cabinets made of particleboard, under staircases, along wooden door frames, inside mattresses, fabric sofas and curtains, and inside air conditioners that pull damp room air through their coils.

4. Musty and sewage odors that refuse to leave

Post-flood smells have several sources. A rotten-egg or drain smell comes from sulfur compounds formed when organic matter in sewage and mud decays without oxygen. An earthy, old-storeroom smell comes from volatile compounds released by growing mold and bacteria. A sour smell usually comes from fabrics and cushions that never dried properly. These odors are more than a nuisance; they signal that moisture or microbes are still present somewhere in the house.

Who is most at risk

Take extra care with the elderly, young children who crawl and put things in their mouths, pregnant women, people with chronic illnesses such as diabetes, kidney or heart disease, people with allergies or asthma, and anyone with weakened immunity. They should return home only after cleaning and drying are complete, should not scrub mold themselves, and should see a doctor promptly if they feel unwell. Ozone treats the home environment; it is not a medical treatment.

Different Pathum Thani homes, different risk points

Townhouses and estate homes in Thanyaburi, Khlong Luang and Lam Luk Ka: the weak points are gypsum partition walls and ceilings, laminate floors, built-in cabinets and closed rooms. Water often backs up from drains and septic tanks, so ground-floor bathrooms and kitchens smell especially strong. Have the septic system and drains checked and working before ozone treatment, or the smell will simply return from its source.

Dormitories and apartments around Rangsit and Khlong Luang: many small rooms sit side by side on shared plumbing. Flooded ground-floor rooms usually lose mattresses, wardrobes and curtains. If mold and odor are not fully dealt with, the next tenants develop allergies and leave quickly, which hits the owner's income directly.

Raised wooden houses along the Chao Phraya in Sam Khok and Mueang: these homes are used to water, but enclosed ground-floor spaces converted into rooms, floorboards and posts soaked for long periods, and old belongings stored below are ideal for mold. Wood dries much more slowly than concrete, so wait until it is truly dry before painting or sealing.

Farmhouses in Nong Suea and Lat Lum Kaeo: water crossing fields and animal pens brings animal waste and farm chemicals; clean flooded rice stores and sheds separately, with gloves and boots.

Shops, offices and warehouses: with many people coming and going, smell and cleanliness directly affect customers, staff and reputation.

The real cost Pathum Thani families carry after the water recedes

Health and time: after a flood, household members often fall sick one by one: a child's lingering cough, adult diarrhea, an infected wound. Many residents commute to Bangkok or industrial estates, so days off for hospital visits and scrubbing hurt income.

Money and reputation: repairs, furniture and mattresses add up, and painting over a damp wall means paying twice when mold breaks through. For dormitory, shop and restaurant owners, musty smells are noticed instantly and a few bad reviews linger.

Family wellbeing: a house that still smells unclean causes stress and poor sleep. Restoring it properly is also restoring daily life.

Why the usual post-flood fixes are not enough

Bleach alone: bleach can disinfect smooth, hard surfaces, but it penetrates poorly into porous materials like gypsum and wood, so deeply rooted mold survives. Mixing bleach with ammonia or certain toilet cleaners can release dangerous gases. Always follow the label and ventilate.

Fans alone: they dry the surface, not the inside of a wet wall, and can spread spores. Pair them with dehumidifiers.

Air fresheners: fragrance masks odor briefly; the musty smell returns.

Painting over mold: the most common mistake in estate homes. If the wall is still damp, paint blisters and stains return within months.

Using the air conditioner uncleaned: its coil and drain tray become a mold reservoir. Have a technician clean it first.

All of these reach only what you can see and touch, while germs and odors spread through air, gaps and porous materials. That is where ozone helps, after cleaning and drying.

How WHD ozone disinfection works for Pathum Thani homes

Ozone (O3) is a three-atom form of oxygen with strong oxidizing power. Released at a controlled concentration into a closed room, it spreads throughout the space, including corners, the underside of furniture and gaps that cloths and sprays cannot reach. Ozone breaks down the cell structures of bacteria and mold and the outer layers of viruses, and reacts with odor-causing molecules. It then reverts to oxygen (O2), leaving no chemical residue on surfaces.

According to test results certified for the company by Thailand's Department of Medical Sciences and Intertek (UK), the World Health Disinfection (WHD) ozone system eliminates viruses, bacteria and mold by up to 99.99% under test conditions. The team plans each job according to floor area, number of rooms and the level of flood damage.

The process step by step

1. Assessment: a call or LINE chat about house size, number of floors, how high the water rose, where the smells and mold are, plus photos for planning.
2. Readiness check: confirm that mud has been removed, surfaces washed, badly damaged materials discarded and the house reasonably dry.
3. Room preparation: people, pets and plants leave the area completely. Cabinets, drawers and internal doors are opened so ozone can circulate; external doors and windows are closed.
4. Ozone release and contact time: typically about 30 minutes per zone, depending on room size and condition. Larger homes are treated zone by zone.
5. Rest and ventilation: ozone is allowed to revert to oxygen, then the space is ventilated before anyone re-enters.
6. Handover and aftercare advice: guidance on humidity control and the spots to watch over the following weeks.

Safety, stated clearly: ozone treatment is carried out only in an empty, closed space with no people, pets or plants inside. Nobody enters during treatment, and re-entry happens only after the rest and ventilation period the team specifies.

Service area: WHD is based in Bang Khae, Bangkok 10160, and does not have a branch in Pathum Thani. The team can plan service visits across the province, including Thanyaburi, Mueang Pathum Thani, Sam Khok, Khlong Luang, Lam Luk Ka, Nong Suea and Lat Lum Kaeo, with coverage, scheduling and travel confirmed by phone at 065-556-6294 or LINE @whd268. While water is high and some roads are impassable, schedules depend on real road conditions, so same-day arrival cannot be promised.

For ozone jobs of 15,000 baht or more, customers receive a free medical-grade disinfectant spray under the company promotion, useful for wiping high-touch surfaces after moving back in.

10 reasons Pathum Thani residents finish flood recovery with ozone

1. It reaches where hands cannot. As a gas, ozone gets behind cabinets, under stairs, into ceiling voids and under beds, all common in townhouses.
2. It tackles odor at the source. Rather than masking smells like a spray, it reacts with the molecules behind musty and sewage odors.
3. It covers several germ groups at once. Bacteria, viruses and mold, through a residential ozone disinfection service tested to 99.99% according to company-certified results.
4. No chemical residue. Ozone returns to oxygen, which suits homes with small children and elderly relatives once the ventilation period is over.
5. It helps reduce airborne mold spores. Important for allergy and asthma sufferers.
6. It is quick. About 30 minutes per zone, with no need to move out for days.
7. It suits dormitory and rental owners around Rangsit and Khlong Luang who need rooms back on the market quickly and odor-free.
8. It protects your repair investment. Done after drying, it lowers the chance of mold returning under new paint or behind repaired walls.
9. Experience across building types: homes, condos, hotels, offices, factories, schools and hospitals. See the ozone service page.
10. It gives the family back its confidence. A home clean in both the visible and invisible sense lets life return to normal. Talk to the WHD team.

Before and after: what Pathum Thani homeowners typically see

Note: results vary with the extent of damage, the quality of initial cleaning and humidity control afterwards. Heavily damaged or deeply moldy materials still need to be removed and replaced.

Example case (a hypothetical scenario to explain the process, not a real customer review)

A Khlong Luang dormitory owner and 12 ground-floor rooms to return to tenants

Ek owns a three-storey dormitory in Khlong Luang district, let mostly to students and factory workers. All 12 ground-floor rooms sat in about a hand-span of water for several days. When it receded, Ek removed swollen mattresses and particleboard wardrobes, hosed the floors and ran dehumidifiers for days.

The problem was that the ground-floor corridor still smelled, and returning tenants said their rooms were too musty to move back into. Ek contacted WHD on LINE and sent photos and a floor plan. The team advised cleaning every air conditioner first, confirming the shared drain no longer backed up, and cutting out the lower gypsum walls in two rooms that were still damp. Only then was an ozone date set, treating groups of rooms zone by zone, with upstairs tenants informed in advance and access to the ground floor closed during treatment.

After treatment and ventilation, the rooms felt fresh and the corridor odor dropped markedly. Ek fitted new mattresses and raised wardrobes. Ozone worked best as the final step of a complete recovery, not a shortcut.

Pathum Thani flood recovery checklist: before and after ozone

Before going back in

• Check DDPM and Pathum Thani provincial announcements that water in your area has truly receded.
• Switch off power at the main. If sockets or the breaker board were submerged, have an electrician inspect them first.
• Wear rubber boots, rubber gloves and a mask. Watch for snakes and centipedes sheltering indoors.

During cleanup

• Remove all mud and debris, wash floors and walls with clean water and detergent, then disinfect surfaces following product labels.
• Discard flooded food, medicines and cosmetics, plus mattresses and fabric sofas soaked in dirty water.
• Cut out damp or moldy lower gypsum walls and lift swollen laminate so the structure behind can dry.
• Ventilate and run dehumidifiers until the house is truly dry, not just dry on the surface.
• Check septic tanks and drains so sewage does not back up.
• Have air conditioners professionally cleaned before use.

On ozone day

• Move all people, pets and plants out of the area.
• Open cabinets, drawers and internal doors; close external doors and windows.
• Re-enter only when the team confirms the rest and ventilation period is complete.

After ozone

• Ventilate regularly and keep controlling indoor humidity.
• Check former mold spots weekly. If stains return, moisture is still building up and the source must be found.
• Wait until walls are fully dry before repainting.
• If anyone develops fever, calf pain, diarrhea, a persistent cough or an inflamed wound, see a doctor right away.

FAQ: ozone disinfection after the Pathum Thani flood

The water has not fully receded. Can I book now?

Yes, you can contact the team and plan ahead, but the actual treatment must take place after the water has gone and the house has been de-mudded, washed and dried. Treating a home with standing water or mud on the floor will not be fully effective.

Does WHD have a branch in Pathum Thani?

No. WHD is based in Bang Khae, Bangkok. The team can plan service in Pathum Thani, with coverage, timing and travel confirmed by phone at 065-556-6294 or LINE @whd268.

Can we stay inside during treatment?

No. Ozone treatment must be done in an empty, closed space without people, pets or plants, and re-entry is allowed only after the rest and ventilation period. In a two-storey townhouse the team may treat one floor at a time, but the zone being treated is always empty.

If we use ozone, can we skip cleaning?

No. Ozone comes after mud removal, washing and drying. It cannot replace cleaning, and leftover mud and dirt reduce its effectiveness.

How long does it take?

Typically about 30 minutes per zone, not counting preparation and the ventilation period. Total time depends on house size and the number of rooms.

Does ozone prevent leptospirosis?

Ozone reduces germs in the air and on surfaces inside the home, but it does not treat or prevent disease in the body. The key protections are avoiding wading, wearing boots, washing right after contact with flood water, and seeing a doctor promptly for fever or calf pain.

Is your Pathum Thani home still musty or showing mold after the flood?

Talk to WHD about planning post-flood ozone disinfection for homes, townhouses, dormitories and shops in every district of Pathum Thani.

See the Residential Ozone Disinfection Service

Call 065-556-6294  |  LINE @whd268  |  worldhealthdisinfection@gmail.com

Promotion: ozone jobs of 15,000 baht or more include a free medical-grade disinfectant spray.

Related pages

• Residential and Building Ozone Disinfection
• Disinfection Service
• Test certificates
• Contact us

References

• Bangkokbiznews: DDPM flood situation report
• Thai PBS: flood situation
• CDC: Floods (cleanup and mold guidance)
• WHO fact sheets