Last updated: 6 Oct 2026 | 4 Views |
At the end of September 2026, riverside families in Manorom, Wat Sing and Hankha districts of Chai Nat province had to change almost everything about daily life. The Chao Phraya River rose over its banks and flooded homes, in some places to between one and one and a half metres, and the water was still rising by about 20 centimetres a day. Many households swapped their cars for boats. This kind of flood is very different from a flash flood that comes and goes. Water stands for days or weeks, homes soak for a long time, moisture penetrates deep, and once it drains, germs, mold and musty odours linger for a long while. This article explains what long-standing flood water leaves inside a home, why washing alone is often not enough, and where ozone disinfection in Chai Nat fits in the recovery order.
A typical scenario (an illustrative example, not an interview with any resident)
Grandpa Lueak and Grandma Bun have lived most of their lives in a raised wooden house beside the Chao Phraya. The space under the house was where they sat in the afternoons, with a bamboo platform, water jars and farming tools lined up. In wet years the water would spread under the house for a few days and then go. This year it rose every day, a little at a time, until the space underneath was completely under water and it began lapping at the upper floorboards.
Their son, who works in town, paddled a boat in every morning with food and water; his old pickup was parked on higher road some distance away. The couple lived upstairs for almost three weeks. The toilet could not be used. The water under the house turned murky green and began to smell, and water hyacinth and rubbish caught against the posts. Grandma developed an itchy rash on her legs; Grandpa coughed every night.
When the water dropped enough to walk, Grandpa went down to look. Thick mud coated everything. The posts carried a tide line higher than his head, the bamboo platform had rotted, the jars were full of muddy water, and the upper floorboards that the water had reached were spotted black and soft to the touch. A musty smell rose through the whole house. Their son hosed everything down for two days, but the smell stayed.
Scenes like this are familiar to many families in Chai Nat's Chao Phraya communities. Long-standing water saturates wood, walls and belongings; the moisture then evaporates out over weeks, which is exactly when germs and mold grow best.
According to Matichon (30 September 2026):
For national context, Daily News reported DDPM data as of 06:00 on 5 October 2026: flooding affected 26 provinces plus Bangkok, 1,270,151 households and 3,519,416 people. Thai PBS reported that ONWR warned of heavy rain and flash floods from 5 to 7 October in the north and parts of the south, including upstream areas of rivers that feed the Chao Phraya.
Note: all figures are as of the dates in each report and change daily. Please follow the latest announcements from Chai Nat province, district offices and local agencies.
The Chao Phraya flows through Chai Nat from the north into the central plains. Riverside communities include traditional raised wooden houses, half-timber homes, single-storey concrete houses and market shophouses, and many families live from rice farming, orchards, livestock and trade. When the river overflows and keeps rising day by day, homes soak continuously, with effects quite different from a quick flood:
While boats replace cars, moving belongings, getting rid of rubbish and bringing in cleaning equipment are all harder. Many homes must wait until the water has fully gone before cleaning properly, which stretches the damp period even further.
E. coli from human and animal faeces causes diarrhoea and cramps; Salmonella contaminates food and utensils and causes food poisoning; and Leptospira, the cause of leptospirosis, is found in standing flood water contaminated with rat and animal urine. It enters through cuts or skin soaked for a long time, so people who wade every day to paddle, carry goods or tend animals face higher risk.
Warning: high fever, headache, muscle pain (especially in the calves), red eyes or severe fatigue after wading needs a doctor promptly; say you were exposed to flood water. Itchy or broken skin on the feet from long soaking should be kept dry and checked by a doctor or health worker.
With the ground floor unusable, many families crowd upstairs or move to shelters and relatives' homes. Norovirus and rotavirus, which cause diarrhoea and vomiting, spread easily via hands, food and utensils, while RSV and influenza spread more readily in humid air and crowded rooms.
WHO and CDC advise cleaning and drying as quickly as possible, generally within 24 to 48 hours after the water recedes. In homes that soaked for days, as in Chai Nat, mold often starts before the water has even gone, especially on surfaces above the waterline that stay constantly humid: walls above the tide mark, wardrobes, mattresses and curtains. Spores cause a blocked nose, coughing, sneezing, itchy eyes and rashes, and can trigger asthma and allergies.
Water that stands for a long time smells rotten from decomposing organic matter. When it drains, that smell does not leave with it; it settles into wood, walls and mud, mixing with mustiness from mold and sewage smells from septic tanks, and can linger for weeks.
Long floods leave water behind in places people forget: jars under the house, old tyres, flower pots, boats pulled up on the bank, and hollows in the yard. These pockets of still water can breed mosquitoes within days, adding another health concern on top of bacteria, viruses and mold. Emptying, scrubbing and covering containers is a simple step that belongs in every clean-up. It also helps the house dry faster, because every bucket of standing water near the walls keeps the surrounding air humid. Ozone treatment is done inside closed rooms and is not a mosquito control method, so outdoor water sources still need to be dealt with by hand, and local health officers can advise on community-level measures.
Young children, older adults, pregnant women and people with chronic conditions need extra care, and many riverside households include older family members.
Health. After living with standing water, many people have rashes, sore feet, coughs, a blocked nose or diarrhoea. Some of this may be linked to germs left in the house; if it does not improve, see a doctor at a hospital or subdistrict health centre.
Belongings and livelihoods. Farm tools, paddy, fertiliser, animal feed and appliances that sat under water for a long time are often badly damaged. Farming families carry losses at home and in the fields at the same time.
Time and labour. Cleaning thick mud and saturated materials takes a long time, and homes with only older residents must wait for relatives or volunteers to help with heavy work.
Peace of mind. Weeks of living surrounded by water, depending on a boat and watching the level climb every day build up stress. When the water is gone but the smell remains, the feeling that it is not over stays too.
Removing mud, washing and drying remain the core of recovery. Germs hidden in the air and corners, and deeply embedded odours, need an added step that reaches everywhere.
The Residential and Building Ozone Disinfection service from World Health Disinfection (WHD) uses ozone gas (O3), a strongly oxidising form of oxygen. Released into a sealed room, it spreads through the air, corners and material surfaces, breaking down the cell structures of viruses, bacteria and mold and breaking apart odour molecules, then reverts to oxygen (O2) with no chemical residue.
According to test results certified for the company by Thailand's Department of Medical Sciences and Intertek (UK), WHD's ozone system eliminates viruses, bacteria and mold by 99.99%. See the certification page.
Important: ozone does not replace mud removal, drying or medical care. It is an added step after washing and drying, done in an empty room with no people, pets or plants. Re-enter only after the rest and ventilation period set by the technician.
WHD's office is in Bang Khae, Bangkok 10160, with no branch in Chai Nat. Service is arranged by phone on 065-556-6294 or LINE @whd268. Distance, date, time and scope are confirmed first, and same-day arrival cannot be promised.
While the report described water still rising by about 20 centimetres a day, safety comes before disinfection. Ozone is only worthwhile once the water has fully gone and the house has been washed and dried.
Results vary with damage, humidity and preparation; rotted or deeply moldy wood may need replacing first.
(An illustrative example to explain the process, not a review from an identifiable customer.)
Nid is a farmer who lives in a half-timber house with her mother, who is in her eighties, next to a small wooden rice barn. As the Chao Phraya overflowed, the water slowly rose until it flooded the ground floor. Nid moved her mother to a relative's house on higher ground and paddled back every day to check on the house.
When the water had gone, Nid and neighbours shovelled mud out of the house and barn, threw away wet paddy, a mattress and swollen particle-board cabinets, washed floors and ran fans with doors and windows open for nearly two weeks. A stagnant, musty smell remained, and she did not want to bring her mother, who has a lung condition, back to it.
She phoned WHD and sent photos on LINE. The team suggested checking whether the wood still felt damp and, if so, waiting a little longer, then booked an agreed date. The technician treated her mother's bedroom, the living room, kitchen and barn zone by zone, resting and ventilating each before handover. Afterwards the smell dropped clearly, her mother came home, and Nid keeps the windows open and watches for damp corners, while her mother continues her regular doctor's appointments.
Q: Does WHD have a branch in Chai Nat?
A: No. WHD is based in Bang Khae, Bangkok. Service in Chai Nat is arranged by phone on 065-556-6294 or LINE @whd268, with travel and timing confirmed first.
Q: Is the 581-household figure for Manorom alone?
A: No. According to Matichon, it is the total for all of Chai Nat province across 5 districts and 22 subdistricts, not broken down by district.
Q: The water has not fully gone. Can I ozone upstairs first?
A: Not recommended. Wait until the water has gone and the house is dry, as moisture from below keeps rising upstairs.
Q: Can an older family member stay inside during treatment?
A: No. Everyone, including pets and plants, leaves the treated area and returns at the time the technician gives.
Q: Does ozone treat leptospirosis or sore feet?
A: No. It disinfects spaces and air; see a doctor for any symptoms.
Q: Can a rice barn or tool shed be treated?
A: Yes, if it can be closed. The team will assess and plan zones.
If your Chao Phraya riverside home in Chai Nat has been washed and dried but still smells musty, or you are worried about germs, the WHD team is ready to plan with you.
See the Ozone Service and Book
Phone 065-556-6294 | LINE @whd268 | worldhealthdisinfection@gmail.com
Note: details are as of the dates in the news and DDPM reports and change daily.
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