Anyone in Nonthaburi who lives beside the Chao Phraya River or a canal knows that floods here rarely come and go just once. According to the Department of Disaster Prevention and Mitigation (DDPM) report of 2 October 2026, three districts of Nonthaburi province were affected: Mueang Nonthaburi, Bang Kruai and Pak Kret, and water levels were rising. That report did not give a household figure for Nonthaburi. Areas and numbers can change daily, so follow the latest DDPM and provincial announcements closely.

Nationally, DDPM reported on the same day that 31 provinces plus Bangkok were flooded, affecting 1,245,581 households or 3,535,206 people, after heavy to very heavy rain combined with runoff from the north. Nonthaburi sits on the last stretch of the Chao Phraya before Bangkok, so it receives northern water directly.

This guide explains what the Nonthaburi flood leaves inside a home (bacteria, viruses, mold, and the stubborn smell of canal mud and sewage), why riverside houses recover more slowly than others, the right recovery order, and how ozone disinfection finishes the job after washing and drying.

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

An old orchard house in Bang Kruai where the water comes and goes

Auntie Daeng is 68 and lives in a two-storey wooden house built in her family's old orchard in Bang Kruai district. Behind the house runs a small canal that joins the Chao Phraya. Only a few of the raised beds that once grew durian and mango remain; the rest is now lawn and parking for her children's cars. Every year at the end of the rainy season the canal rises, and lifting things onto high shelves has become routine.

This year the water came faster and stayed longer. It flooded the ground floor, which had been extended into a kitchen and living room. When the river ran high, water reached her ankles; when it eased, the water drained out, leaving a thin film of mud, only to return the next day. This went on for almost two weeks. The lower walls got wet, dried, and got wet again. Wooden flooring laid over the concrete slab buckled into waves, and green growth appeared on the legs of an old teak food cabinet.

Her ten-year-old grandson, who has asthma, usually stays every weekend. When her daughter brought him over after the water began to recede, he started coughing and wheezing within an hour and had to use his inhaler and go back to his mother's condo in Mueang Nonthaburi. Auntie Daeng says the house smells at night like canal-bottom mud mixed with wet laundry, no matter how long the fan runs, and her legs have started to itch where they kept touching the water.

Stories like this are common in Nonthaburi's orchard houses and riverside homes. The problem is not just visible dirt but moisture built up through repeated wetting, exactly what mold and bacteria love. Itchy rashes should be checked by a doctor or health worker, and a child with asthma should wait until the house is dry and fully restored before staying overnight.

How the Nonthaburi flood differs: a high river, repeated wetting and dense communities

The Chao Phraya flows through all three affected districts, Mueang Nonthaburi, Bang Kruai and Pak Kret, with many branch canals on both banks. Riverside water levels rise and fall with northern runoff and with tidal influence pushing up the river. Homes outside flood walls or along canals often see water enter and leave several times rather than flooding once and draining away.

Repeated wetting is a major obstacle to recovery. Each time the water drops, walls and floors start drying on the surface, but before they dry through, the water returns. Each round leaves a thin layer of mud that feeds microbes. Materials stay damp for weeks, far beyond the 24 to 48 hours within which agencies such as the CDC advise cleaning and drying to limit mold.

Nonthaburi is also densely populated, with housing estates, condominiums, apartments, shophouses, markets and old riverside communities packed together. Floodwater passes through drains, sewage sumps, household septic tanks and market areas, so fecal contamination is likely. In Bang Kruai and the orchard parts of Mueang district, water also carries silt from old raised beds and canal bottoms. This organic-rich mud rots quickly and causes the distinctive smell many families call canal-bottom odor.

Every kind of germ the Nonthaburi flood brings

Bacteria: from sewage, canal mud and rat urine

Urban flood water is often contaminated with intestinal bacteria such as E. coli and organisms that cause diarrhea, food poisoning and dysentery. They settle on kitchen floors, counters, utensils, the outside of fridges and anything that was submerged. Symptoms include diarrhea, cramps, nausea, vomiting and fever. Elderly people and small children dehydrate quickly; frequent watery stools, marked weakness, a dry mouth or reduced urine mean a hospital visit right away.

Leptospirosis deserves special attention in Nonthaburi, where canal banks, markets and community rubbish attract rats. Leptospira bacteria from rat urine mix into water and mud and enter through cuts, scratches or skin softened by long soaking. Key signs are sudden high fever, headache, severe muscle pain especially in the calves and red eyes; some people develop jaundice or reduced urine. Anyone who waded in flood water and develops these symptoms must see a doctor immediately and mention the exposure.

Skin soaked repeatedly is also prone to athlete's foot, itchy rashes and bacterial wound infections, particularly for people who wade to work every day. Wash feet with clean water and soap after wading, dry them well, and have any swollen, red or pus-filled wound checked.

Viruses: fast spread in multi-generation homes

Viruses spread through contaminated water, food and surfaces, such as norovirus and rotavirus, cause sudden vomiting and diarrhea and pass easily within extended families living under one roof, common in Nonthaburi's orchard and riverside communities. Hepatitis A is also linked to unsafe water and food. Hand-washing and daily disinfection of door handles, stair rails, remote controls and dining tables are essential after the water drops.

Mold: the real enemy of a house that keeps getting wet

Repeatedly wetted homes like those along the Chao Phraya and in Bang Kruai's orchards are ideal for mold. Common post-flood species include Aspergillus, Penicillium, Cladosporium and some black molds, growing on wood, damp plaster, fabric, leather, paper and ceilings. Airborne spores trigger allergies, sneezing, congestion, itchy eyes, coughing and asthma attacks, as happened to Auntie Daeng's grandson. People with weak immunity, lung disease or undergoing chemotherapy should avoid moldy homes.

In old wooden Nonthaburi houses, mold hides under timber flooring laid over concrete, where wooden posts meet the floor, behind old teak cabinets pushed against walls, under mattresses on the floor, inside clothing chests and in ceilings with recurring rain leaks. In condos and estate homes in Pak Kret and Mueang, it hides in drywall partitions, built-in cabinets, storerooms and air conditioners.

Odor: canal mud, drains and mustiness

Nonthaburi homes usually smell of a mix: canal-bottom mud from organic matter rotting without oxygen, a rotten-egg smell from sulfur compounds in sewage, an old-storeroom mustiness from compounds released by mold, and a sour note from fabrics that never dried. These smells mean moisture or microbes are still present, so covering them with fragrance does not solve anything.

Who needs extra care

Elderly people living alone by the water, young children, pregnant women, people with chronic illness, allergies or asthma, and anyone with weak immunity should let others do heavy cleaning, return only after the house is dry and restored, and see a doctor promptly if unwell. Ozone treats the home environment; it is not a medical treatment.

Three kinds of Nonthaburi homes, three recovery approaches

Riverside and orchard houses in Bang Kruai and Mueang: often wooden or half-timber homes with converted ground floors. The key is to wait until the water truly stops coming in before the main recovery; working while the river still rises and falls wastes effort. Wood dries slowly, so lift flooring laid over concrete and move old furniture away from walls to let air circulate.

Riverside communities and island areas in Pak Kret: many homes are wooden houses in rows, some doubling as shops or craft workshops. Recovery must cover both living and working space, and flooded goods or raw materials must be strictly sorted and discarded.

Estates, condos and shophouses in Mueang and Pak Kret: ground-floor rooms, storerooms, parking areas and plant rooms flood first. Drywall and built-in cabinets absorb water easily, and drains can back up sewage odor. Condo owners should coordinate with building management on plumbing and common areas before planning their own unit.

Damage that goes beyond the repair bill

Health: allergies, coughs, diarrhea, rashes and infected wounds often appear after the water drops, and they will not clear while the household keeps living with damp and mold.

Rising costs: flooring, cabinets, mattresses, curtains and appliances, plus labor, paint and air-conditioner cleaning. Recovery in the wrong order means mold returns and the work is repeated.

Time and work: many Nonthaburi residents work in Bangkok and must take leave to move belongings, clean and take parents to the doctor.

Home businesses: noodle shops, cafes, grocery stores and craft workshops in riverside homes depend on customer trust. One whiff of mustiness can turn into negative word of mouth.

Attachment to an old home: many riverside houses have sheltered several generations. Watching a family home decay from damp weighs heavily on elderly residents, so proper recovery supports wellbeing as well as health.

Why the smell stays after washing: common mistakes in riverside homes

Starting major recovery while water still comes and goes: well meant but wasted. During this phase, lift valuables, clear rubbish and rinse off mud; save the big job for when water has truly stopped entering.

Using bleach on everything: bleach works on hard, non-porous surfaces but does not penetrate damp wood and plaster, so deep mold survives. Never mix it with ammonia or other cleaners, and always ventilate.

Running fans on very humid days: fans help only when outside air is drier than inside. In a wet riverside season, fans alone will not dry materials to the core. Use dehumidifiers in rooms that can be closed.

Oiling or varnishing damp wood: sealing wood before it dries traps moisture inside, causing rot and mold from within.

Incense or air freshener: fragrance masks odor briefly, the source remains, and smoke in a closed room is bad for asthma.

These methods reach only visible, reachable surfaces, while germs and odors spread through air, wood joints and porous materials. Ozone fills that gap, once water has stopped entering and the house is cleaned and dried.

WHD ozone disinfection for Nonthaburi homes

Ozone (O3) is a strongly oxidizing gas. Released at a controlled concentration in a sealed room, it spreads everywhere, into wood joints, under furniture and into spots wiping cannot reach. It breaks down the cell structures of bacteria, mold and viruses and reacts with odor molecules, then reverts to oxygen (O2) with no chemical residue on surfaces. That suits old wooden homes and heirlooms that should not meet harsh chemicals.

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 99.99% under test conditions.

Service steps

1. Consultation and photos: share your location, house type, flood height and photos of smelly or moldy spots via LINE.
2. Readiness check: water no longer entering, mud and damaged items removed, surfaces washed, house reasonably dry.
3. Preparation: all people, pets and plants leave the area. Cabinets, drawers and internal doors open; external doors and windows closed.
4. Ozone treatment: typically about 30 minutes per zone; two-storey or multi-room homes are treated in zones.
5. Rest and ventilation: ozone reverts to oxygen, then the space is ventilated before anyone returns.
6. Aftercare advice: humidity control, spots to watch, and when it is safe to paint or seal wood.

Safety rule: ozone treatment takes place only in an empty, closed space with no people, pets or plants inside. No one enters during treatment, and re-entry is allowed only after the rest and ventilation period the team specifies.

Travel and coverage: WHD is based in Bang Khae, Bangkok 10160, and has no branch in Nonthaburi. The team can plan visits to Mueang Nonthaburi, Bang Kruai, Pak Kret and other districts, with area, timing and travel confirmed by phone at 065-556-6294 or LINE @whd268. For riverside communities or places reached by boat, equipment transport must be discussed in advance, and same-day arrival cannot be guaranteed.

Ozone jobs of 15,000 baht or more include a free medical-grade disinfectant spray under the company promotion.

10 reasons Nonthaburi riverside homes finish recovery with ozone

1. Made for wooden houses full of gaps. As a gas, ozone reaches timber joints, under-floor voids and behind heavy old cabinets.
2. Tackles canal-mud and musty odors at the source instead of masking them.
3. No chemical film on wood or heirlooms. Ozone returns to oxygen.
4. Fewer airborne mold spores, making the home more ready for asthmatic children and elders after ventilation.
5. Broad coverage: bacteria, viruses and mold through a residential ozone disinfection service tested to 99.99% per company-certified results.
6. About 30 minutes per zone, so elderly residents do not need to move out for days.
7. Good for home-based shops, giving customers back a clean, odor-free space.
8. Protects your repairs. Done after drying, it lowers the chance of mold under new flooring or paint.
9. Works for houses, condos and larger buildings. See the ozone service page.
10. Guidance from the start, so your recovery happens in the right order. Talk to WHD.

Before and after: a Nonthaburi riverside home restored in order

Note: results depend on damage, initial cleaning and humidity control afterwards. Rotten or deeply moldy wood and materials still need replacing.

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

A Pak Kret shophouse noodle stall near the pier reopens with confidence

Ton and his wife run a boat-noodle shop in a two-storey shophouse near a pier in Pak Kret district, with the shop and kitchen downstairs and their home upstairs. When the Chao Phraya ran high, about a hand-span of water flowed in and out for days and the shop closed for almost two weeks. Chest freezers, a wooden counter, tables and sacks of dry ingredients got wet.

Once water stopped entering, Ton discarded all flooded ingredients and goods, scrubbed the tiled floor and walls, sanitized utensils, had an electrician check the wiring and freezers, and removed the swollen wooden counter. But on the trial reopening day, regulars said the shop still smelled musty. Worried about customer trust, Ton contacted WHD on LINE.

The team advised checking the kitchen drain and grease trap for backflow, running dehumidifiers for a few more days, and removing all ingredients, food and utensils before treatment day. Ozone was scheduled on a closing day, with the whole family out during treatment and the ventilation period. Afterwards the smell dropped clearly. Ton installed a stainless-steel counter and reopened with a daily surface-disinfection routine. For food businesses, ozone is always an extra step after cleaning and discarding ingredients according to food hygiene rules.

Nonthaburi flood recovery checklist

While water still comes and goes

• Follow DDPM, Nonthaburi province and Chao Phraya water-level updates daily.
• Lift valuables and documents; cut power to flooded areas.
• Avoid wading; if you must, wear boots and wash right after contact.

Once water stops entering

• Have an electrician check the system before switching on.
• Remove mud, wash with clean water and detergent, then disinfect surfaces per label.
• Discard flooded food, medicine, mattresses and soaked fabrics.
• Lift buckled flooring, move furniture off walls, run dehumidifiers.
• Check drains, grease traps and septic tanks for backflow.
• Clean air conditioners before use.

On ozone day and after

• Everyone, pets and plants out; return only when the team confirms ventilation is complete.
• Open cabinets, close external openings, remove food and ingredients.
• Ventilate daily, control humidity and check former mold spots weekly.
• See a doctor promptly for fever, calf pain, diarrhea, persistent cough, rash or an inflamed wound.

FAQ: ozone after the Nonthaburi flood

The river is still rising and falling. When should we treat?

Wait until water stops entering and the house is de-mudded, washed and dried. Treating earlier means new moisture and mud bring the problem back. You can contact the team to plan in the meantime.

Does WHD have a branch in Nonthaburi?

No. WHD is based in Bang Khae, Bangkok, and plans visits to Nonthaburi, confirmed by phone at 065-556-6294 or LINE @whd268.

Can an elderly parent stay home during treatment?

No. Everyone, pets and plants must leave the treated area and return only after the rest and ventilation period. Arrange a short stay elsewhere for treatment day.

Can ozone replace washing the house?

No. Ozone follows mud removal and drying. It does not replace cleaning or removing damaged materials.

Will ozone harm antique wooden furniture?

The team assesses the space and advises what to store or move beforehand. Tell them in advance about valuable or delicate items.

Does ozone treat allergies or asthma?

No. It manages germs and odors in the environment; anyone with symptoms needs medical care.

Is your Nonthaburi home still smelling of mud or mold after the flood?

Talk to WHD about post-flood ozone disinfection for riverside homes, orchard houses, shophouses, condos and shops in Mueang Nonthaburi, Bang Kruai and Pak Kret.

See the Residential Ozone Disinfection Service

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

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

Related pages

• Residential and Building Ozone Disinfection
• Ozone and chemical residue reduction
• Test certificates
• Contact us

References

• Bangkokbiznews: DDPM flood situation report
• Thai PBS: flood situation
• CDC: Floods
• WHO fact sheets