The Chai Nat Flood Situation in 2026: The Latest Figures

According to the Department of Disaster Prevention and Mitigation (DDPM) report of 2 October 2026, flooding in Chai Nat affected 7 districts: Mueang Chai Nat, Manorom, Wat Sing, Sapphaya, Hankha, Nong Mamong and Sankhaburi, covering 1,581 households, and the report noted that water levels were still rising. These numbers change every day, so please follow the latest announcements from the DDPM and provincial authorities.

At the national level, the DDPM reported on 2 October 2026 that floods were affecting 31 provinces plus Bangkok, with 1,245,581 households and 3,535,206 people affected. The main causes were heavy to very heavy rain over a sustained period, combined with runoff flowing down from the North. Chai Nat sits at the head of the lower central plains, with the Chao Phraya River running through it, so it lies directly in the path of that water.

Fifteen hundred households may sound small compared with some provinces, but for each family it means an entire home, a lifetime of belongings and the health of everyone under that roof. The worry is not only the damage you can see. It is what the water leaves behind that you cannot see: bacteria from sewage, viruses that cause diarrhoea, mold spores buried in timber, and a smell that simply will not go away.

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

Grandma Boonma's House in Wat Sing and the Smell That Would Not Leave

Picture a wooden house raised on stilts in Wat Sing district. Grandma Boonma, 72, lives there with her son, who farms rice, her daughter-in-law and a three-year-old granddaughter. The open space under the house used to hold a bamboo daybed, sacks of fertiliser, a water pump, hoes and spades, and some of the paddy rice the family keeps to eat through the year. As the water slowly rose, they managed to carry only part of it upstairs. The rest sat in murky, tea-coloured water for days.

When the water went down, the son spent three days shovelling mud from under the house, washing the timber posts with well water and hauling away moldy sacks of paddy. His wife poured bleach over the concrete floor and scrubbed. Everyone thought the job was done. But a week later, a smell like wet laundry left to ferment was still rising through the gaps in the upstairs floorboards. In Grandma Boonma's bedroom, beside the wall that had been under water, small black spots appeared along the edge of the wood. The little girl started sneezing every morning and Grandma developed a dry cough at night.

The son had waded through floodwater every day to check his fields, and he had a cut on his foot from floating debris. Nobody in the family realised that the calf pain and low fever he had for two days might be leptospirosis until the village health volunteer told him to go to hospital immediately. This is not one family's story. It is a picture that repeats in riverside villages across Chai Nat every time the water comes.

There are three lessons here. First, washing what you can see is not the same as disinfecting what you cannot. Second, a musty smell is a signal that moisture and microbes are still present. Third, any illness after a flood needs a doctor first, and the house needs to be restored in the right order.

Every Kind of Germ Chai Nat Floodwater Brings: Bacteria, Viruses, Mold and Odour

The water that pours into homes in Chai Nat is not clean rainwater. It has crossed rice fields, animal pens, septic tanks, cesspits, drains and rubbish piles on the way. Whatever was in its path comes into the house with it. The invisible threats fall into four main groups.

1. Bacteria: E. coli, Salmonella and Leptospira

E. coli lives in the intestines of people and animals. Finding it in water or on surfaces after a flood means there has been faecal contamination. Some strains cause severe diarrhoea and stomach cramps, and in young children or older adults they can lead to dehydration quickly. Salmonella and other sewage-related bacteria cause food poisoning if dishes, chopping boards or kitchen counters that touched floodwater are not cleaned properly.

Leptospira causes leptospirosis, known in Thai as "rat urine disease". The bacteria live in the urine of rats and some other animals. When floods cover fields and villages, the bacteria spread through the water and enter the body through cuts, scrapes or skin that has softened from long soaking. Farmers and anyone who has to wade through water in agricultural districts such as Wat Sing, Hankha, Nong Mamong and Sankhaburi face a higher risk. The warning signs to remember are sudden high fever, headache and marked pain in the calf muscles, sometimes with red eyes. If you have these symptoms after wading, see a doctor right away and tell them you were in floodwater, because the disease is treatable when medication starts early.

2. Viruses: Norovirus, Rotavirus and Hepatitis A

Norovirus is extremely contagious. A tiny amount can leave a whole household vomiting and with diarrhoea within a day or two. It survives on surfaces for a long time and resists quick, superficial cleaning. Rotavirus is a major cause of diarrhoea in young children, while hepatitis A spreads through food and water contaminated with faeces, causing fever, fatigue and yellowing of the skin and eyes. When people are crowded together in evacuation centres or relatives' homes, respiratory viruses such as influenza also spread more easily.

3. Mold: The Silent Threat in Wooden Houses and Concrete Walls

Mold can start growing within 24 to 48 hours after materials get wet, which is why the World Health Organization and the US CDC stress drying out as quickly as possible. Many homes in Chai Nat are built of wood, a material that soaks up water deeply and releases it slowly. Molds such as Aspergillus, Penicillium and Cladosporium grow inside the timber, between floorboards, under vinyl flooring, behind wardrobes and inside mattresses. Their spores float in the air and trigger symptoms in people with allergies, asthma or weak immunity: persistent coughing, blocked noses, itchy eyes and skin irritation.

4. Musty Damp and Sewage Odours

The familiar post-flood smell in Chai Nat homes comes from two sources. The first is the volatile compounds released by mold and bacteria as they break down organic matter. The second is gas from leftover mud and sewage, such as hydrogen sulphide with its rotten-egg smell. These odours are more than a nuisance. They tell you that decay and microbial growth are still going on inside the house, which is why covering them with perfume does not solve the problem.

Who in a Chai Nat Household Is Most at Risk

Everyone in a flooded home can be exposed, but some people need extra care.

• Older adults, who make up a large share of Chai Nat farming families. Immunity weakens with age, and many live with diabetes, high blood pressure or lung disease, so infections hit them harder.
• Young children, who crawl on floors, put things in their mouths and become dehydrated quickly with diarrhoea.
• Pregnant women, who should avoid cleaning heavily molded areas or using strong chemicals.
• People with chronic illness or weak immunity, such as kidney patients, people on chemotherapy and those with asthma.
• Farmers and anyone who must wade to work, who carry the highest risk of leptospirosis and wound infections. Wear rubber boots and gloves, and wash with clean water immediately after wading.

If anyone at home has a fever, calf pain, diarrhoea that will not stop, vomiting, difficulty breathing or a red, swollen wound, please go to your community hospital or the provincial hospital without waiting. Disinfecting your house is about prevention. It is not a treatment for illness.

What Chai Nat Families Face After the Water Goes Down

Health: Allergies, coughing, sneezing, rashes, diarrhoea and leptospirosis risk all come with a house that is not truly clean, especially bedrooms where everyone spends many hours a day.

Money: Farming families who have just lost a rice crop or pomelo harvest now face repair bills, replacement furniture and medical costs. If mold is left to eat into wooden structures for too long, the cost of tearing out and replacing timber can be many times higher than dealing with it early.

Time: Scrubbing over and over because the smell and mold keep returning eats into time that should go to restoring the fields or returning to work.

Business and reputation: Shops, restaurants, homestays and small businesses in Mueang Chai Nat or Sankhaburi that still smell musty lose customers. The feeling that "this place still isn't clean" damages trust faster than people expect.

Family and peace of mind: Worry about the children and sleepless nights over the smell mean moving home brings less relief than it should.

Why the Usual Fixes Are Not Enough for Chai Nat Homes

Bleach alone: Bleach kills germs on smooth surfaces, but it barely penetrates raw wood or bare concrete. Mold rooted deep in timber grows back, and using bleach in a closed room produces fumes that irritate the lungs. Never mix it with toilet cleaners or ammonia.

Fans alone: Fans help things dry, which is good and necessary, but they also blow mold spores all over the house and do nothing about germs in the air or in hidden corners.

Air fresheners and perfume sprays: These only mask the smell for a while. When they wear off, the old odour comes back, and some people are sensitive to fragrances, which makes allergies worse.

Painting over mold stains: New paint covers the black marks for a few weeks, but living mold underneath pushes the paint until it bubbles and peels, releasing the musty smell again.

What every one of these methods misses is the air and the places a cloth cannot reach. That is exactly where ozone gas does its work.

WHD Ozone Disinfection for Chai Nat: The Final Step That Cleans the Air Itself

World Health Disinfection (WHD) provides residential and building ozone disinfection. The team is based in Bang Khae, Bangkok 10160. Customers in Chai Nat can contact the team to plan a service by phone at 065-556-6294 or on LINE at @whd268. The team will ask about the size of the area and the condition of the house, and confirm travel and coverage case by case. WHD has no branch in Chai Nat and cannot promise same-day arrival.

How Ozone Works

Ozone (O3) is a form of oxygen made of three atoms and is a strong oxidiser. When ozone gas meets viruses, bacteria and mold, it breaks down their cell walls and outer structures, and it also breaks apart odour molecules. Afterwards, ozone reverts to ordinary oxygen (O2), so it leaves no chemical residue on surfaces or furniture. According to test results certified for the company by Thailand's Department of Medical Sciences and Intertek (UK), WHD's ozone treatment eliminates viruses, bacteria and mold by 99.99%. You can review the details on the certification page.

The big advantage for wooden houses in Chai Nat is that ozone is a gas. It moves into the gaps between floorboards, behind cupboards, under beds, into ceiling voids and into damp corners that cloths and brushes never reach.

The Ozone Treatment Process

1. Survey and planning: The team asks about or assesses the floor area, number of rooms, flood depth and the spots where smell or mold is strongest, then divides the house into zones.
2. Preparation: All people, pets and plants leave the area. Doors and windows are closed, and cupboards and drawers opened so the gas can reach inside.
3. Filling: The ozone generator runs until the gas fills the zone.
4. Contact time: The ozone is left to work on germs and odours for the set period.
5. Rest and ventilation: The machine is switched off and the ozone is allowed to revert to oxygen, then the space is aired before anyone goes back in.

A typical cycle takes about 30 minutes per zone, depending on the size and condition of the area.

Safety rule: Ozone treatment is carried out in a closed space that is empty of people, pets and plants, and you go back in only after the rest and ventilation period. Ozone is a step after mud removal, washing and drying. It does not replace cleaning, and it is not medical treatment.

10 Reasons Chai Nat Families Choose Ozone After a Flood

1. It reaches between boards and under the house. Stilt houses are full of gaps, and ozone gas gets into them far more thoroughly than wiping.
2. It covers every germ group. Bacteria, viruses and mold, at 99.99% according to the company's certified test results.
3. It breaks odours down at the source. Musty and sewage smells are broken apart rather than covered with perfume. Read more about our home ozone service.
4. No chemical residue. Ozone turns back into oxygen, which suits homes where toddlers crawl on wooden floors.
5. It is quick. About 30 minutes per zone, and the family can return after ventilation.
6. It protects older relatives. It reduces airborne mold spores in bedrooms, a common trigger for coughs and allergies.
7. It helps rice stores and storerooms. Spaces that held rice and farm tools and now smell musty can be treated. (Any rice, paddy or food touched by floodwater must be thrown away, not eaten.)
8. It works for businesses. Restaurants, grocery shops and dormitories in town can reopen with confidence. See our ozone service for buildings.
9. It has recognised testing behind it. Tested by the Department of Medical Sciences and Intertek, as certified for the company.
10. Better value on larger jobs. Ozone jobs of 15,000 baht or more come with a free medical-grade disinfectant spray for everyday use. Ask about the promotion.

Before and After Ozone: How a Chai Nat Home Changes

Note: results depend on cleaning and drying before treatment. Badly damaged materials, such as mattresses that were submerged or gypsum boards that have gone soft, should be removed and replaced.

Example case (an illustrative scenario explaining the process, not a verified review)

Somjai's Curry-and-Rice Shop in Town

Somjai runs a curry-and-rice shop in a two-storey wooden shophouse in Mueang Chai Nat. Knee-deep water sat inside for several days. When it went down, she and her staff shovelled out the mud, threw away every ingredient and condiment that had touched the water, washed the floors and walls with cleaning solution and left doors, windows and fans open for days. Yet some regulars still remarked that the shop "smells a bit musty", and upstairs, where she sleeps, the ceiling gave off a damp odour.

She contacted WHD on LINE. The team asked about room sizes and water depth, looked at photos of the problem spots and advised her to take down the soggy gypsum ceiling panels first and give the space a few more days to dry. They then scheduled ozone treatment in two zones: the shop front and kitchen, and the upper floor. Everyone stayed outside the building during treatment. After the rest and ventilation period, Somjai found the lingering smell had dropped to the point where she barely noticed it, and she reopened with a sign telling customers the shop had been cleaned and ozone-treated.

What made this work was not ozone alone but the correct order: discard contaminated items, wash, dry, and then treat.

Chai Nat Flood Recovery Checklist: Before and After Ozone

Before going back in

• Wait until the authorities say it is safe. Check the structure, timber posts and stairs for sagging or rot.
• Switch off power at the breaker. If sockets or wiring were under water, have an electrician check them first.
• Watch for snakes, centipedes and other dangerous animals hiding under the house and in piles of belongings.
• Wear rubber boots, rubber gloves, a mask and eye protection.

While cleaning

• Remove mud as soon as possible before it dries onto floors and posts.
• Throw away all food, rice, paddy, condiments and medicines that touched floodwater.
• Discard mattresses, pillows, soft toys and absorbent items that cannot be washed.
• Wash surfaces with clean water and detergent, then disinfect surfaces that touch food.
• Open doors and windows and use fans to dry the house, ideally within 24 to 48 hours.
• Remove gypsum ceilings, insulation or laminate flooring that has soaked up water.

On treatment day

• Make sure all people, pets and plants are out of the area.
• Open cupboards, drawers and internal doors so the gas spreads everywhere.
• Go back in only when the team confirms the rest and ventilation period is over.

After treatment

• Ventilate regularly and keep indoor humidity down.
• Watch spots that used to grow mold or smell. If the problem returns, moisture is still building up and you need to find the source.
• Wash hands often, drink clean water and keep up good hygiene for everyone at home.
• If anyone feels unwell, see a doctor promptly.

FAQ: Ozone Disinfection in Chai Nat

1. Does WHD have a branch in Chai Nat?

No. WHD's team is based in Bang Khae, Bangkok. Customers in Chai Nat can call 065-556-6294 or add LINE @whd268 to plan a service, and the team will confirm travel and coverage case by case.

2. Does the house need to be dry before ozone treatment?

Yes, it should be. Ozone comes after mud removal, washing and drying. If walls or floors are still soaking wet, mold still has moisture to keep growing. The team will help assess whether the space is ready before booking a date.

3. Can people stay inside during treatment?

No. All people, pets and plants must leave the area, and you go back in only after the rest and ventilation period.

4. How long does it take?

Typically about 30 minutes per zone. Homes with several rooms or floors are treated zone by zone, so the total time depends on the size of the property.

5. Does ozone treatment prevent leptospirosis?

Ozone reduces germs in the treated space, but leptospirosis is caught by wading in contaminated water or mud. Protect yourself with boots, cover wounds and wash straight away. Anyone with fever and calf pain after wading must see a doctor immediately.

6. Can old wooden houses be treated?

Yes. Ozone gas penetrates the gaps in timber well, but wood that has rotted or gone soft from the water should be repaired or replaced first so that the treatment works and the house stays structurally safe.

7. Is there a promotion?

Ozone jobs of 15,000 baht or more receive a free medical-grade disinfectant spray. Ask for details by phone or LINE.

Make Your Chai Nat Home Safe Again

Talk to the WHD team about planning post-flood ozone disinfection in Chai Nat, whether for a stilt house, a townhouse, a shop or a dormitory.

Get Ozone Advice for Chai Nat

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

Related Services and Reading

• Residential and building ozone disinfection
• Disinfection spraying service
• Certificates and test results
• Contact us

References

• Bangkokbiznews, flood situation report citing the DDPM: bangkokbiznews.com/news/news-update/1254629
• Thai PBS flood coverage: thaipbs.or.th/news/content/558960
• World Health Organization fact sheets: who.int/news-room/fact-sheets
• CDC flood cleanup guidance: cdc.gov/floods
• Department of Disease Control, Thailand: ddc.moph.go.th