The 2026 (B.E. 2569) Tha Sao, Sai Yok Flood: What Was Reported

According to The Bangkok Insight on 30 September 2026 (B.E. 2569), the armed forces sent personnel to survey damage around Moo 9, Tha Sao sub-district, near the Hat Ngio bridge in Sai Yok. Electrical appliances and equipment in the accommodation building of a training centre in the area were all damaged. Low-lying areas were still flooded, the Khwae Noi River level had begun to fall, and conditions were expected to return to normal within two to three days (source: The Bangkok Insight, 30 Sep 2026). Conditions change daily, so follow local announcements as well.

Nationally, the Department of Disaster Prevention and Mitigation reported, as of 06:00 on 7 October 2026 (B.E. 2569), flooding in 27 provinces plus Bangkok, 123 districts, 984 sub-districts, 1,154,875 households and more than 3.1 million people (source: Government Public Relations Department).

Sai Yok is a district of mountains and forest with the Khwae Noi River running through it. Village homes sit alongside resorts, raft houses and riverside guesthouses. When the river spills into low ground it carries fine silt and organic matter from upstream hills and forest. That silt is home to enormous numbers of soil bacteria, and it is what keeps the earthy smell alive inside a house after the water has gone.

A Typical Scenario: A Riverside Guesthouse Where the Smell Would Not Leave

Example case written to illustrate a common situation. It is not an interview with any business owner or resident.

Tom runs six small wooden bungalows on the Khwae Noi in Sai Yok, single-storey with low raised floors and en-suite bathrooms. In late September the river rose fast and flowed into the front row of bungalows, the lowest ones, covering floors, bathrooms and the space under the beds. Tom and his staff could not move all the mattresses, blankets and appliances out in time.

Two days later the water dropped. They shovelled out dark brown mud, hosed the floors and opened every window. Yet the first thing that hit them in each room was a damp, earthy smell mixed with mustiness, like a cellar or the smell of soil after rain but many times stronger. Curtains hanging above the waterline smelled of it. Mattresses lifted onto tables had soaked it up too.

Tom tried air freshener, scented candles and charcoal odour absorbers in every room. Each worked for a few hours; by the next morning the earthy smell was back, and guests booked for the long weekend were calling to ask whether the bungalows were ready.

After asking around, he learned that this kind of smell is not just a leftover odour. It is a sign that silt and moisture are still inside the building: under the floorboards, in joints, in bathroom grout and in materials that soaked up water. So he started again in the right order: lifting swollen floor panels, discarding flooded mattresses, washing silt from under the floor, drying with fans and dehumidifiers, and only then asking about ozone treatment, one bungalow at a time when no guests were staying.

What Are Actinomycetes and Streptomyces?

Actinomycetes are bacteria with an unusual habit: they grow as branching threads, much like fungi, and can form tiny spores, which is why people often mistake them for mold. The best-known genus is Streptomyces, found in soil almost everywhere on Earth, where it breaks down plant litter, leaves and other organic matter and helps keep soil fertile.

Streptomyces is also famous in medicine: many antibiotics used for decades were discovered from these bacteria, including streptomycin, which takes its name directly from the genus.

Geosmin: the compound behind the earthy smell

Streptomyces and some other actinomycetes release volatile compounds called geosmin and 2-methylisoborneol (2-MIB), which smell earthy and musty. The human nose is extremely sensitive to geosmin and can detect it at tiny concentrations. That is why the smell of soil after rain, river mud and the occasional earthy taste in tap water are so noticeable even when only traces are present.

When floodwater carries silt into a home and the home stays damp for days, these soil bacteria keep growing in the mud left in corners, under floors and inside wet materials, releasing odour compounds continuously. The earthy smell does not fade on its own while silt and moisture remain.

Is Streptomyces dangerous?

In general, Streptomyces is not a common cause of illness in healthy people. Infections are rare and usually linked to deep wounds with long contact with soil. What matters more is that an earthy, musty smell indoors signals moisture and leftover silt, the same conditions in which mold and other flood-borne microbes thrive. The World Health Organization's guidance on dampness and mould in buildings links indoor dampness and mold with respiratory symptoms such as coughing, worsening asthma and allergies, especially in children and people with chronic conditions.

Put simply, the earthy smell is not the enemy itself; it is a warning that the house is not yet truly clean and dry.

Why Sai Yok Homes Smell So Strongly After the 2026 Flood

River and forest water carries heavy silt. Water flowing down the Khwae Noi through hills and forest brings fine sediment and organic matter. When it recedes, a layer of mud is left on floors, under furniture and in every joint.

Wooden, low-raised floors dry slowly. Many riverside homes and bungalows have a shallow gap under the floor where silt collects but is hard to reach. Waterlogged timber takes a long time to dry, so odour rises through floor joints constantly.

Damaged power and appliances. Reports said appliances in some buildings were entirely damaged. Without fans, air conditioning or dehumidifiers, drying slows dramatically.

Humid valley air. Riverside land in a valley is naturally humid. Late-season showers, morning mist and limited sunshine mean wet materials dry more slowly than on open plains.

Low-lying areas still under water. Some low ground remained flooded, so nearby homes kept receiving moisture and odour from outside.

Fabrics and cushions absorb odour. Curtains, mattresses, pillows, fabric sofas and rugs soak up smell and moisture from the air of rooms closed for days, even if they never touched the water.

Where Earthy and Musty Odours Hide in a Flooded Home

• Under wooden floors and in floor joints, where silt hides out of sight but keeps smelling.
• Bathroom grout and floor drains clogged with mud, often smelling of earth and sewer together.
• The lower part of walls, especially gypsum or plywood that soaked up water, and behind built-in cabinets.
• Mattresses, pillows, fabric sofas and cushions.
• Curtains and rugs, which absorb airborne odour.
• Wardrobes, cupboards and drawers with no airflow.
• Air conditioners and ducts exposed to water or high humidity, which may hold mud dust.
• Under-house spaces, storerooms and carports, where mud is thickest and dries slowest.
• Fridges and electrical appliances that were submerged; beyond odour, they are a shock risk and must be checked by an electrician first.

If the smell shifts from earthy to mold-like, rotten-egg or sewage, there may be mold growth, wastewater or an affected septic tank, and those causes need separate attention.

Symptoms in Damp, Earthy-Smelling Homes and Who Is Most at Risk

This is general information, not a diagnosis. The earthy smell itself does not make people ill, but a home that is still damp with leftover silt usually also carries mold spores, mud dust and many microbes in the air, which can trigger the following in sensitive people:

• Blocked or runny nose and sneezing, like an allergy flare-up indoors.
• Dry cough or scratchy throat, especially at night or on waking.
• Wheezing or breathlessness in people with asthma.
• Itchy, red or watery eyes.
• Headaches and a stuffy, unrefreshed feeling in closed rooms.
• Itchy skin after contact with mud or damp fabrics.

Who should take extra care

• Babies and young children.
• Older adults.
• People with asthma, chronic lung disease or allergies.
• People with weakened immunity or serious illness.
• Pregnant women.
• Anyone handling mud for long periods; wear a mask, gloves and boots and cover wounds.

Difficulty breathing, chest tightness or symptoms that persist away from the house need a doctor. Anyone who waded through floodwater and develops a high fever, calf pain or red eyes must see a doctor promptly and mention the exposure, as this may be leptospirosis. Wounds that touched mud and become red, painful or pus-filled also need medical attention.

Why Open Windows, Perfume or Charcoal Do Not Remove the Earthy Smell

1. The source is still inside

While silt sits under floors, in drains and in joints, and while things stay damp, soil bacteria keep releasing odour. Treating only the air gives temporary relief.

2. Perfume and sprays only mask

Fragrance covers the earthy smell for a few hours, and sometimes the mix becomes an odd odour that feels worse.

3. Charcoal and baking soda have limits

They help in small, closed spaces such as cupboards and drawers but cannot keep up with a whole room that has a continuing source.

4. Open windows in a house that is still wet

Ventilation helps, but if materials are waterlogged and the outside air is humid, indoor moisture falls very slowly. Add exhaust fans and dehumidifiers once electricity is safe.

5. Painting or covering damp surfaces

Painting over or laying new flooring on damp surfaces traps moisture and odour inside and may lead to mold later.

6. Forgetting fabrics that hold odour

Even in a clean room, curtains, cushions and mattresses that absorbed the smell release it back into the air. Wash, sun-dry or replace them, and deal with the room air at the same time. This is where ozone after cleaning helps most.

Ozone After the 2026 Sai Yok Flood with WHD: How It Helps with Odour

Ozone (O3) is a strongly oxidising gas. According to the company, it breaks down the cell structures of viruses, bacteria and fungi and the molecules that cause odours, then reverts to oxygen (O2) with no chemical residue. The company states its service has been tested and certified by Thailand's Department of Medical Sciences and Intertek (UK) for eliminating viruses, bacteria and fungi at 99.99%, according to the company's certification.

Earthy, musty odour is one of the main reasons people search for ozone after a flood: the gas spreads through the whole room, reaching air, curtains, cushions, ceilings and corners a cloth cannot, so it reduces lingering odour rather than covering it. For Streptomyces specifically, we make no claim that ozone eliminates it. It belongs to the bacteria, one of the groups WHD's service targets according to the company, and you can ask the team for test data.

Be clear on one point: if silt remains under the floor or materials are still wet, the smell will return. Ozone does not penetrate deep into timber, gypsum or soaked mattresses, so silt removal, stripping damaged materials and drying always come first. Once the source is dealt with, ozone finishes the job in the air and on surfaces.

WHD's ozone process for homes and guesthouses

1. Survey and assessment. Send photos or video of rooms, under-floor spaces, bathrooms and the worst-smelling spots by LINE. The team estimates area, zones and preparation.
2. Clean and dry first. Remove mud, wash silt from under floors and drains, strip swollen floor panels or walls, discard unsaveable mattresses and rugs, wash curtains and dry the rooms.
3. Empty and seal the room. People, pets and plants out; doors and windows closed.
4. Ozone cycle, zone by zone. About 30 minutes per zone, depending on size and conditions; multi-bungalow sites can be planned one unit at a time.
5. Rest and ventilate. Let ozone break down, then ventilate as the technician advises before re-entry.
6. Re-entry and ongoing care. Check odour and humidity again. If the earthy smell returns, there is still a silt or moisture source to find.

Is Ozone Dangerous? Safety Rules

• Empty room: no people, pets or plants during treatment, because room-treatment ozone irritates the airways.
• Closed room: never open it mid-cycle.
• Ventilate before re-entry, as the technician advises.
• Remove silt and dry first. Ozone does not remove mud or replace stripping flooded materials.
• Flooded appliances must be checked by an electrician before use.
• Not medical treatment. Anyone with breathing or other symptoms should see a doctor.

10 Reasons Sai Yok Homes and Guesthouses Should Consider Ozone After the 2026 Flood

1. It reduces earthy, muddy and musty odours left after cleaning, with ozone odour removal.
2. It does not just mask smells; according to the company it breaks down odour molecules.
3. It reaches curtains, cushions and ceilings that absorb airborne odour.
4. It targets viruses, bacteria and fungi at 99.99% according to the company's certification.
5. No chemical residue and no harsh cleaner smell, because ozone reverts to oxygen.
6. It suits riverside resorts and guesthouses that need rooms ready quickly after the water drops.
7. About 30 minutes per zone, planned room by room or unit by unit.
8. New curtains and bedding will not absorb the old smell when ozone is done after cleaning and before refurnishing.
9. Preparation advice on what to strip, wash and dry. See post-flood ozone for homes.
10. Families and guests feel at ease when a door opens onto a room with no earthy, musty smell.

Checklist: Removing the Earthy Smell After the 2026 Tha Sao, Sai Yok Flood

Before entering

• Make sure power is off and the structure is safe; watch for rotten or sagging floorboards.
• Wear a mask, rubber gloves and boots; cover wounds.
• Watch for snakes and centipedes sheltering indoors after the water drops.

Before ozone

• Remove all mud and silt, including under floors, under furniture and in drains.
• Strip swollen gypsum, plywood or floor panels; discard unsaveable mattresses and rugs.
• Wash curtains, sheets and pillowcases; sun-dry fully.
• Wet-mop floors; do not dry-sweep mud dust.
• Ventilate, use exhaust fans and dehumidifiers once electricity is safe.
• Have flooded appliances and air conditioners checked before use.

Treatment day

• People, pets and plants out; doors and windows closed.
• Wait for rest and ventilation as advised.

After ozone

• Smell the room in the morning after it has been closed overnight; if the earthy smell returns, look for remaining silt or damp.
• Ventilate daily and run a dehumidifier in stuffy rooms.
• See a doctor if breathing symptoms do not improve.

FAQ: Earthy Smell and Ozone After the Sai Yok Flood

What causes the earthy smell after a flood?

Partly soil bacteria called actinomycetes, such as Streptomyces, which produce geosmin. When silt stays in a damp house, they keep releasing odour.

What is Streptomyces and is it dangerous?

A common soil bacterium that breaks down organic matter and is the source of many antibiotics. It is not a common cause of illness in healthy people, but the smell signals dampness where mold and other microbes grow.

How do I get rid of a musty smell after floodwater recedes?

Remove all silt, including under floors and in drains, strip swollen materials, wash curtains and cushions, dry the house, then use ozone in empty rooms for lingering odour.

How is an earthy smell different from a mold smell?

Earthy smells like wet soil after rain; mold smells heavy and stale, like old clothes in a cupboard. Both mean moisture. Visible mold must be removed and cleaned too.

Does ozone remove the earthy smell?

According to the company, ozone breaks down odour molecules and targets viruses, bacteria and fungi at 99.99% per its certification. We make no claim for Streptomyces specifically, and if silt or damp remains the smell returns, so clean and dry first.

Is ozone dangerous? Can I stay home?

Do not stay in the room. It must be empty and closed, then rested and ventilated before re-entry.

How much does ozone treatment cost?

It depends on area, zones and site conditions. The team quotes after assessment. Call 065-556-6294 or LINE @whd268.

Is there ozone service near me in Kanchanaburi or Sai Yok?

WHD is based in Bang Khae, Bangkok 10160, with no Kanchanaburi branch. Contact the team by phone or LINE to confirm travel and dates.

Can I keep a flooded mattress that smells of earth?

A thick mattress soaked in muddy water rarely dries inside and the smell usually returns, so discarding it is generally advised. Sheets and pillowcases can be hot-washed and sun-dried.

How long should the house dry before ozone?

It depends on materials and weather; wooden homes in valleys may take longer. There must be no standing water and materials must be truly dry. Start cleanup and drying as soon as possible, ideally within 24 to 48 hours.

Talk to WHD About Ozone Odour Removal After the 2026 Sai Yok Flood

Still smelling earth and must after cleaning? Send photos and the team will help find the source and plan cleaning, drying and safe ozone treatment.

See the Ozone Disinfection Service

Call 065-556-6294 · LINE @whd268

World Health Disinfection, Bang Khae, Bangkok 10160. Provincial enquiries by phone and LINE. Pricing by quotation.

Related Links and References

• Residential and building ozone disinfection
• Ozone cleaning service
• The Bangkok Insight, 30 Sep 2026: damage survey in Tha Sao, Sai Yok
• PRD: national flood summary, 7 Oct 2026
• WHO: Fact sheets
• CDC: Floods

Health information here is general and is not a medical diagnosis.