The situation at Tha Nam Nonthaburi and Wat Bang Khwang in 2026 (B.E. 2569)

According to Thai PBS, at 06.55 on 7 October 2026 (B.E. 2569) the Chao Phraya River at Tha Nam Nonthaburi had risen to the watch level of 1.80 to 2.30 metres and a yellow flag was raised. The municipality ran four water pumps around the clock, placed sandbags around the pier, and there was standing water in some spots. The areas named were the Tha Nam Nonthaburi pier district and the Wat Bang Khwang community, an old riverside neighbourhood whose people have lived alongside the river for generations.

When the water starts to fall, the pumps stop and the sandbags are lifted, residents discover that the real work has only begun. The ground beneath raised houses is coated with a thin layer of silt, the narrow alleys between homes smell musty, and the pier pavilion, wooden walkways and steps down to the boats stay damp for days. This is exactly where large-area disinfection matters most.

Life outside the flood wall: why every flood means starting again

Many communities along the Chao Phraya sit outside the flood wall or riverbank protection. When the river reaches the watch level, water enters these areas before anywhere else, and it leaves later, because it can only drain once the river itself falls.

Several features of these communities make disinfection harder than in an ordinary neighbourhood.

• Wooden houses raised on posts, with beams and plank floors that soak up moisture and countless corners that hands cannot reach.
• Narrow alleys and walkways where cars and trucks cannot enter, and where equipment that needs long hoses or mains power is awkward to use.
• Piers, floating landings, pavilions and steps down to the water, all public spaces that many people pass through every day.
• Many older residents, and some households with bedridden patients or small children, who are the most vulnerable to infection.
• Electricity that may be cut off, or not yet safe, in some spots after the water recedes, so electric tools cannot be used at first.

The germs that arrive with floodwater, and why washing alone is not enough

Floodwater brings more than mud. Water that has flowed through drains, toilets, septic tanks, animal pens and rubbish heaps carries several groups of germs into homes and shared spaces.

Bacteria

• E. coli, a marker of faecal contamination that can cause diarrhoea.
• Salmonella, which spreads through food and utensils touched by dirty water and causes stomach pain, diarrhoea and fever.
• Leptospira, the cause of leptospirosis, which comes from the urine of rats and other animals and enters the body through cuts or skin that has been soaked for a long time.

Viruses

• Norovirus and rotavirus, which cause vomiting and diarrhoea and spread easily through hands and surfaces, especially among small children.
• Respiratory viruses such as RSV and influenza, which spread more easily when people have to crowd together in pavilions or temporary shelters during a flood.

Moulds

Moulds grow fast on wood, fabric, mattresses and damp walls, especially in raised wooden houses that dry slowly. A musty smell is the first warning. Mould can make breathing problems worse for people with allergies or asthma and for older adults. Agencies such as the CDC advise cleaning and drying out as soon as possible after a flood to reduce the chance of mould.

Washing with water and detergent removes mud and grime well, but it does not remove all the germs left on surfaces. The correct order is: shovel out the mud, wash and clean, then apply a properly registered disinfectant according to its label. Across a whole community, an engine-powered mistblower is the tool that makes this last step realistic in the limited time available.

The burdens riverside communities carry after the water goes down

The area is larger than manpower can cover

One alley may hold dozens of houses, each with an under-house space, kitchen, bathroom and front yard, not counting shared walkways, the pier pavilion and the temple grounds. With a small hand-pump sprayer, the operator has to stop to pump and refill constantly, and one alley can take several days.

Most of the workers are older people

Many younger residents have to go straight back to work once the water falls, so the people left to clean are often elderly. Asking older residents to carry a tank and pump by hand all day is not acceptable.

Time to reopen shops and the pier

Riverside shops, food stalls and boat landings need to reopen fast. Every closed day is lost income, and customers will only return when the place feels clean and safe.

Community health

The weeks after a flood are when people are most likely to fall ill with stomach infections, skin problems, leptospirosis and mould-related allergies. Anyone who develops a high fever, calf pain or severe diarrhoea after wading through floodwater must see a doctor straight away. Environmental disinfection reduces risk but never replaces medical treatment.

Why buckets, mops, hand-pump sprayers and small sprayers fall short

The equipment a community already has is not wrong, but each item has limits when the job is the whole neighbourhood.

• Buckets and mops work on flat indoor floors but cannot reach between posts, beams, the underside of plank floors or the lower parts of walls. They use a lot of solution and a lot of energy.
• Hand-pump or compression sprayers have small tanks, need constant pumping, lose pressure quickly, produce large droplets and only reach a short distance, so the operator must walk close to every surface.
• Small battery sprayers are handy indoors, but the battery runs down fast, and while the power is off or unsafe, charging becomes a real problem.

What a riverside community really needs is a machine with enough airflow to carry disinfectant droplets a long way, that runs without mains power, that can be carried down narrow alleys, and that lets just a few trained operators cover the whole community.

What is the SOLO PORT 423, and which specifications matter

The [SOLO PORT 423](https://www.worldhealthdisinfection.com/en/product/15428-17449/solo-port-423) is an engine-powered backpack mistblower made by SOLO Kleinmotoren GmbH in Germany. Its engine drives a fan whose air stream breaks the liquid into fine droplets and carries them to the target area. World Health Disinfection (WHD) sells this model in Thailand.

Key specifications according to the manufacturer, SOLO

• Single-cylinder two-stroke engine, displacement 72.3 cm³
• Engine output 3.0 kW (4.1 HP)
• Spray-liquid tank 12 litres
• Maximum airflow 1,400 m³/h
• Horizontal reach about 12 metres
• Dry weight 11.0 kg
• Sound pressure at the operator 97 dB(A), sound power 110 dB(A)
• Vibration up to 6.3 m/s²

Further details according to WHD's product information

• Fuel tank 1.4 litres; dimensions 68 x 45 x 34 cm
• Electronic ignition, BING float carburettor, key MAHLE parts and a Nikasil-coated cylinder
• Long nozzle with a wide-angle diffuser, a rotatable spray tube, and a UV-resistant translucent tank with a wide filler opening
• One-hand control lever for throttle, dosing and stop, a padded harness and four-point anti-vibration mounts
• WHD describes the output as ULV with droplets under 30 microns, which saves chemical. The droplet size you actually get depends on the nozzle and settings.

How the SOLO PORT 423 helps a community cover large areas

The strength of an engine-powered mistblower is its air stream. A maximum airflow of 1,400 m³/h, according to SOLO, carries droplets into gaps that hands cannot reach, and a horizontal reach of about 12 metres lets the operator stand at the mouth of an alley or the edge of an under-house space and send the mist inside, without crawling into every cramped, damp corner.

Under raised wooden houses

The space beneath a raised house is where water stands longest and dries slowest. After the mud is removed and the area washed, the operator can spray from outside along the posts and beams, turning the rotatable spray tube upward to reach the underside of the floorboards.

Alleys and shared walkways

A 12-litre tank lets the operator spray continuously over a much longer distance than a small sprayer. Walk along the alley at a steady pace and use the wide-angle diffuser so the mist coats the walls on both sides.

Piers, landings, pavilions and steps to the water

These public spaces have handrails, benches and waiting areas that many people touch. Spray only when the area is closed and empty, and avoid putting disinfectant directly into the river by spraying towards surfaces in a direction away from the water.

Because it runs on a two-stroke petrol engine, the SOLO PORT 423 works without waiting for electricity, which matters a great deal in the first days after the water falls, when some households are not yet ready to switch the power back on.

Remember that the machine only delivers the chemical. The disinfecting effect depends on the product you use. Choose a properly registered disinfectant and follow its label, for example Chemgene HLD4H, which WHD sells, mixed and applied according to its label and Safety Data Sheet (SDS).

10 reasons a riverside community should own a SOLO PORT 423

1. The water returns every year, so the machine pays back over time. A community outside the flood wall will use it nearly every flood season, not just once.
2. No waiting in a queue. Spraying can start as soon as the water falls, following the community's own plan.
3. No mains power needed. The petrol engine runs even while the electricity is still off.
4. Strong airflow reaches under houses and between posts. Maximum airflow of 1,400 m³/h, according to SOLO.
5. About 12 metres of reach. Operators do not have to step into every damp, enclosed spot.
6. A 12-litre tank. Longer continuous spraying and fewer stops to refill.
7. Fits down narrow alleys. A backpack unit needs no trolley and no long hoses.
8. Takes the load off older residents. A few trained operators handle the job instead of every household spraying on its own.
9. Useful all year. Beyond floods, it can apply disinfectant in shared areas or be used for insect control according to the chemical's label. See more on the [SOLO PORT 423 product page](https://www.worldhealthdisinfection.com/en/product/15428-17449/solo-port-423).
10. Made in Germany, sold in Thailand. Ask [WHD](https://www.worldhealthdisinfection.com/en/product/15428-17449/solo-port-423) directly about operation, spare parts and a quotation.

Before and after the community has its own sprayer

Step by step: disinfecting a riverside community after the flood

Preparation

1. Check safety before entering. Make sure the electricity is off or safe, no cables are under water, and houses and wooden walkways are not rotten or unstable.
2. Draw a simple community map. Divide it into zones such as Alley 1, Alley 2, the pier, the pavilion, the temple grounds and the shops, and decide the order, starting with the places people use most.
3. Tell households in advance. Announce the day and time, and ask residents to move people, pets, food, utensils and children's items out of the area.

Cleaning

1. Remove mud and rubbish. Shovel silt from under houses, walkways and drains, and separate hazardous waste from ordinary rubbish.
2. Wash with clean water and detergent. Scrub stained surfaces, wash posts, handrails and wooden floors. Disinfection works best on clean surfaces.
3. Let the air through. Use sunlight and wind to dry the area faster, and discard items that stayed soaked and cannot be dried, such as mouldy mattresses or carpets.

Disinfection

1. Prepare the disinfectant according to the label. Mix a properly registered disinfectant at the ratio shown on the label and use a funnel to fill the tank without spilling.
2. Put on protective equipment. Ear muffs or plugs, chemical-resistant gloves, goggles or a face shield, the respirator the label requires, long sleeves and boots.
3. Work with the wind. Walk so that the wind carries the mist away from you. Never spray into the wind or towards people or animals.
4. Work from top to bottom and from inside to outside. Start under the house and on the inner walls, then back out to the walkway, so the mist coats surfaces evenly without soaking them.
5. Protect the river. Do not spray disinfectant directly into the river. On the pier, spray towards the bank.

After spraying

1. Keep the area closed for the time stated on the label. Keep people and pets out until the label's re-entry time has passed.
2. Clean the machine. Rinse the tank and nozzle according to the manufacturer's manual, and store leftover chemical in its original labelled container.
3. Keep a record. Note which zone was sprayed, on which day, with which product and how much.

Safety when using the SOLO PORT 423

An engine-powered mistblower is a powerful machine and must be used carefully every time.

• Protect your hearing. Sound pressure at the operator is 97 dB(A), according to SOLO, so always wear ear muffs or plugs.
• Limit continuous operating time. The machine vibrates, so rotate operators and take regular breaks. One person should not spray all day.
• Chemical protection. Gloves, goggles or a face shield, a respirator, long-sleeved clothing and boots, as required by the chemical's label and SDS.
• Refuel safely. Switch the engine off and let it cool before refuelling, away from flames, and never smoke while refuelling.
• Weight when full. The machine weighs 11 kg empty and roughly 23 kg or more with a full 12-litre tank. Adjust the harness to fit snugly and watch out for slippery planks and pier steps.
• Keep people and animals out of the spray zone. Close the alley temporarily, put up signs and have someone watch the entrance.
• Follow re-entry times on the chemical label, especially for homes with small children, older adults or patients.
• Train operators. Make sure every operator reads the manual and practises before spraying for real.

Who should own the machine, and what if you are not ready to buy

In a riverside community, the owner can take several forms. A municipality can buy it as official equipment and lend it to flood-prone communities. A community committee can buy it from a community fund. A temple can own one to care for its grounds and the neighbourhood around it. Or riverside businesses can pool their money. What matters is a named person responsible for the machine, a trained spray team and a storage place that does not flood.

Agencies purchasing it as official equipment can request a SOLO PORT 423 quotation from WHD by phone or LINE. Pricing depends on quantity and terms, so no figures are given in this article.

If a community is not ready to buy and would prefer a professional team to do the work, it can choose WHD's disinfection service as a separate option.

Frequently asked questions about the SOLO PORT 423 for riverside communities

How much does the SOLO PORT 423 cost?

WHD does not show a price online because it depends on quantity and purchasing terms. Ask for a price and quotation on 065-556-6294 or LINE @whd268.

What is the difference between a backpack mistblower and a thermal fogger?

A thermal fogger uses heat to turn the liquid into smoke. The SOLO PORT 423 uses an air stream to break the liquid into a mist without heating it, which suits applying disinfectant onto surfaces after a flood.

How far can the SOLO PORT 423 spray?

About 12 metres horizontally, according to SOLO. Actual reach depends on wind, nozzle and settings.

How big is the tank and how heavy is the machine?

The tank holds 12 litres and the machine weighs 11.0 kg dry, according to SOLO. With a full tank it weighs roughly 23 kg or more.

Should I wash first or disinfect first after a flood?

Always remove mud and wash first, then apply disinfectant, because mud and grime stop the disinfectant from reaching the germs.

Which disinfectant can I use in the SOLO PORT 423?

Use a properly registered disinfectant whose label covers this type of application, such as Chemgene HLD4H, and always mix and apply it according to the label and SDS.

Can I use it when there is no electricity after the flood?

Yes. It has a two-stroke petrol engine, so there is nothing to plug in or charge.

When can people go back inside after spraying?

Follow the re-entry time on the chemical label, and ventilate before children, older adults and pets return.

If we do not want to buy a machine, is there a spraying service?

Yes. Communities and organisations can hire WHD's disinfection service as a separate option.

Is your community ready to own a SOLO PORT 423?

Request a quotation and ask about specifications, operation and suitable disinfectants for post-flood work. The WHD team is ready to advise.

View SOLO PORT 423 and request a quote

Call 065-556-6294 | LINE @whd268

Further reading and references

• SOLO PORT 423 backpack mistblower against dengue for municipalities and SAOs (Thai)
• Spraying against emerging diseases with the SOLO PORT 423 for provincial public health offices (Thai)
• Chemgene HLD4H disinfectant
• WHD disinfection service
• Local news source: Thai PBS, 7 October 2026 (B.E. 2569); national data: PRD, DDPM figures of 7 October 2026 (B.E. 2569)
• Post-flood health advice: CDC and Department of Disease Control