How to recover from flooding

UK Health

Security
Agency

Published 27 October 2023

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Flooding recovery

The Flood and Water Management Act 2010 places a statutory duty on the Environment Agency to develop a National Flood and Coastal Erosion Risk Management (FCERM) Strategy for England. This strategy describes what needs to be done by all risk management authorities (RMAs) who are involved in flood and coastal erosion risk management for the benefit of people and places. This strategy requires all responsible bodies to plan, prepare and respond to future flood events, ensuring appropriate recovery activities are executed in a timely manner. These activities are for local and national government agencies, as well as for individuals, communities, industry and charity organisations.

The 'recovery phase' following a flood event includes cleaning and drying of homes and properties to ensure and check for any health risks as a result of the flood. This section explains the different aspects of flood recovery and the recommended ways to clean up, to minimise potential risks to public health, covering advice for frontline responders and important messages that they can provide to residents affected by flooding.

Cleaning up after a flood

Residents should be advised to check their insurance by contacting their insurance company and following their advice – for those unsure of their insurance status, the National Flood Forum on 01299 403055, or the Association of British Insurers can both be contacted for support.

They should speak to the local flood action group or flood warden – if there has been a serious flood in the area, the local authority may have chosen a place like the town hall as a 'flood hub' from which to organise recovery efforts. There may also be a nearby flood warden or flood action group. For more information, contact the National Flood Forum for help in finding local support.

People affected by flooding can contact their local authority for questions about recovering from a flood, such as disposing of used sandbags or damaged furniture. If they are unable to help with collecting large flood-damaged items, they will be able to advise on where and how to discard these items or when they may be collected.

Residents should wear protective clothing while cleaning up after a flood – floodwater can contain sewage, harmful pollutants or contaminants to humans and animals. When cleaning up a home affected by floodwater, the use of rubber boots, protective overalls or waterproof apron, and waterproof gloves are important to avoid exposure to floodwater.

Scrubbing, hosing or pressure-washing may cause a lot of splashing, so it's recommended to wear a standard face mask, such as those sold by DIY stores.

Eye protection such as goggles offer added protection and can be reused after thorough washing.

Hands should be washed thoroughly with soap and warm water after each clean-up session.

Clothes used for cleaning should be washed on a separate cycle from other clothes.

Electrical equipment checks

Residents should be advised to:

switch off the electricity supply if it is safe to do so and a flood alert has been issued in the local area
avoid turning on devices that use gas or electricity as there is a possibility they may have got wet – a registered electrician should be called to assess the condition and damage to electrical wiring, equipment and appliances that have been affected by the flood
contact their insurance company and landlord if applicable for advice and to get approval to carry out any repairs – residents should take photos of the damage and keep records where possible

Drying out process

Dehumidifiers

Once floodwater has receded, dehumidifiers can be used to collect moisture from the air and can aid in drying out a property. Water is collected in the dehumidifier and can be disposed of down regular water drains and sinks.

Safety precautions: this method should not be used to remove floodwater from the home. Electrical equipment should not be plugged in until it has been dried thoroughly and inspected by a qualified electrician. Where possible, face masks and eye protection should be worn when emptying the water collection tank.

Natural weathering

Natural weathering (and drying out) means to leave wet items out to dry naturally. This is a recommended way to reduce contamination levels, under dry weather conditions. This option may be the most appropriate approach for open areas such as gardens and parks, as sunlight and natural UV radiation are effective at killing micro-organisms.

Cleaning measures

HEPA vacuum

High efficiency particulate arresting (HEPA) vacuum cleaners contain a very fine filter (HEPA filter), which makes it useful when vacuuming as it filters out biological contaminants effectively. Please note that this can only be used on dry material.

Safety precautions: it's advisable to wear face masks as vacuums may produce dust particles. Electrical equipment should not be plugged in until it has been dried thoroughly and inspected by a qualified electrician.

Wet vacuum

Wet vacuum cleaners are designed to collect residual water from both hard floor surfaces and some soft furnishings such as carpets. Water is collected in the vacuum and can be disposed of down foul water drains and sinks.

Safety precautions: a normal vacuum should not be used when cleaning a wet surface. Where possible, face masks and eye protection such as goggles should be worn as vacuums can produce water droplets. Electrical equipment should not be plugged in until it has been dried thoroughly and inspected by a qualified electrician.

Normal vacuuming should not be used as a method to remove floodwater from the home.

Liquid detergents for cleaning

Floodwater can contain a mixture of harmful contaminants such as sewage, pathogens and pollutants, therefore, it is important to use effective cleaning solutions that will kill any of the above and avoid any harm to health.

Reactive liquids such as household bleach and detergents can be used effectively to remove and kill micro-organisms that may be present following floodwater contamination of surfaces in buildings (such as homes, schools or offices).

Household cleaning products and domestic detergents are widely available and can be found in most supermarkets and hardware stores. Diluted bleach can be used to mop hard floors or can be sprayed onto surfaces and then wiped off. Bleach should be left on surfaces for the contact time stated on the manufacturer's instructions to ensure disinfection is effective. Bleach residues should be wiped off surfaces.

Safety precautions: appropriate personal protective equipment (gloves, disposable plastic apron such as those available from DIY stores) should be worn when using these products and care should be taken to ensure that manufacturer's instructions are followed correctly. Cleaning activities should be carried out in ventilated spaces (for example with open windows) and bleach should not be mixed with other cleaning products as this could result in the release of harmful fumes.

Pressure hosing

Pressure hosing involves the use of high-powered water spray to remove surface contamination. Where possible wastewater should be collected for disposal or directed down water drains. Pressure hoses should be connected to a clean water supply.

Safety precautions: pressure hosing should only be carried out in outdoor environments, and appropriate personal protective equipment (gloves, disposable plastic apron, face mask and rubber boots) should be worn throughout.

Steam cleaning and hot washing

Steam cleaning and hot washing are 2 effective ways to clean upholstered objects (such as carpets, couches and sofas) around the house as a way to sterilise and deodorise damaged items. Steam cleaning uses machines that use steam and detergent solutions onto upholstered surfaces, carpets, tapestries and so on, which is then vacuumed before the fabric becomes saturated in the solution.

Steam cleaning physically extracts contaminants from materials and surfaces. The steam is applied by hand-held wands or automated systems, and the contaminated wastewater is collected for disposal and should be directed down water drains and sinks. Steam cleaners that use hot water are not suitable for silk, viscose or cotton velvet fabrics. Steam cleaning should be used on dry items.

Hot washing involves the washing of fabrics at temperatures above 60°C in a washing machine. This is not suitable for delicate items of clothing or for certain fibres, so washing instructions should be checked before using this method.

Safety precautions: safety face masks should be worn where possible as steam cleaning may produce water droplets. Electrical equipment should not be plugged in until it has been dried thoroughly and inspected by a qualified electrician. Clothing should not be hand washed at high temperatures; it should be done as per manufacturer's instructions, and appropriate protection should be used to prevent burns from hot water.

Specialist cleaning

Gentle or specialist cleaning can remove contamination from smaller objects (for example dry cleaning of a wedding dress or gentle cleaning of jewellery). This can be done after relevant items have dried out properly. Specialist cleaners should be advised that the item has been exposed to floodwater and possible harmful contaminants such as sewage.

Safety precautions: appropriate personal protective equipment (gloves, disposable plastic apron) should be worn throughout specialist cleaning processes.

Removal of contaminated material and debris

It is important to assess whether items that have come into contact of floodwater can be appropriately cleaned for reuse. If they are beyond repair or disinfection, they should be removed from the property and placed in appropriate disposal bins (such as council collection bins and skips). This is because these items can be harmful to health if not effectively cleaned or repaired and in some cases attract pests. 

Objects or furnishings that need to be checked for contamination, and considered for disposal:

small materials removed from the building (such as books, papers, pictures, wall hangings)
small equipment and office items (such as staplers, telephones, hand tools)
large durable materials removed from the building (such as furniture, computers, copiers, fax machines, printers)
building and decorating materials, such as carpeting, draperies, window blinds,   window air conditioners, ceiling panels, wallboard, and panelling
refuse, food, and other unwanted materials present at the site at the time of     contamination

Similarly, garden debris, grass and vegetation removal involves removing residual contamination by cutting the grass or collecting leaves in gardens, allotments, and other recreational areas.

Safety precautions: care should be taken when lifting heavy objects. Electrical equipment (such as leaf blowers) should not be plugged in until it has been dried thoroughly and inspected by a qualified electrician. Appropriate personal protective equipment should be worn when handling contaminated material for disposal. Contaminated items should be double bagged for disposal where possible, and bags containing contaminated food should not be left out in open areas as they will attract pests.

Cleaning surfaces

Recovery and decontamination of residential areas (such as homes, gardens, schools and playing fields) will be required once the floodwaters have receded. There are a range of different surface types that may need to be cleaned after a flood. The best approach to cleaning will depend on the surface or type of material involved (such as wall or carpet). For example, natural weathering (and drying out) may be the most appropriate approach for recreational areas as sunlight and natural UV radiation are effective at killing micro-organisms.

The following table details the different types of surfaces and the best and safest way to clean them.

Types of surfaces and how they can be cleaned in a safe manner

Surface types	Examples	How they can be cleaned
External building surfaces	Walls, roofs, windows, garages and paved areas	External building surfaces are usually quite robust, so active cleaning (household detergents or bleach) or pressure hosing are efficient and effective methods for cleaning.
Internal hard building surfaces	Walls, ceilings, hard floors	Internal hard building surfaces are also quite robust, so active cleaning (household detergents or bleach) are efficient and effective methods for cleaning.
Soft furnishings	Carpets, curtains, sofas, bedding	Soft furnishings are porous and absorbent and can be extensively damaged by floodwater. People will need to decide whether to throw them away or clean them (steam cleaning or a hot 60°C machine wash), and should remember to ask their insurer before discarding items if they cannot be cleaned (such as mattresses and carpets).
Personal (precious objects)	Photos, jewellery, books, CDs and so on	Personal (precious objects) can be gently cleaned once they have dried out.
Vehicles	Cars, motorcycles, bicycles	The outside of vehicles is quite robust, so active cleaning (household detergents or bleach) and pressure hosing are efficient and effective methods for cleaning. However, the inside of vehicles should be considered in the same way as soft furnishings.
Recreational areas	Parks and open spaces, gardens, allotments and playing fields	The cleaning of potentially contaminated soil and vegetation will depend on what it is used for. Removing obvious signs of contamination should be prioritised once the floodwater has receded. Natural weathering (and drying out) may be the most appropriate approach for recreational areas as sunlight and natural UV radiation are effective at killing micro-organisms.

Mould

Flooding and heavy rainfall may also affect indoor environmental quality, including increased exposure of households to mould. Changes in the absolute moisture content of the outdoor air may mean that increased ventilation may be required to remove moisture from the indoor environment. Heavy rainfall events increase the risk of rainwater ingress into buildings. The key to controlling mould is to control the moisture levels in the environment. After flooding, residents should be advised that:

mould can grow on damp walls – if this does not stop as their home dries, they should contact a specialist
heating, dehumidifiers and good ventilation can help dry out their home
small areas of mould can be removed easily with proprietary mould removal solutions available in hardware stores – if the mould persists or is extensive it may be advisable to contact a specialist cleaner who has experience in the field of fungal remediation and follow current guidance

Most people will not encounter any health problems from short-term exposure to mould and fungal spores. It is important to note, however, that there is medical evidence linking prolonged exposure to high levels of mould with exacerbation of asthma and eye and nose irritation in some individuals. If there is extensive fungal growth within a property and residents believe that their health might be affected, they should be advised to consult their GP.

Managing the physical health impacts of flooding

Flooding has extensive and significant impacts on health. Aside from direct effects due to – for example – death and injury, floodwater can contain a range of items that can be hazardous to health, such as:

human and livestock waste
sewage
household, medical and industrial hazardous waste (chemical, biological, and radiological)
physical objects (for example wood, vehicle debris, rubbish)
wild or stray animals (for example rodents, birds)
petrol or oil spillages

Many of these can increase the risk of spread of infection, although disease outbreaks linked to flooding remain rare in England. Hand washing is the most important way to get rid of harmful bugs. Using warm, clean water and soap, rinsing and drying hands after going to the toilet, before eating or preparing food, after being in contact with floodwater, sewage or with items that have been in the water is the most effective way of preventing infection. Cold water can be used if warm is not available. If there is no clean water, then disposable soapy, wet wipes or sanitising gel can be used to carefully clean all parts of the hands and dry them.

This section outlines approaches to management of food, water and chemical hazards arising following flooding, with the aim of minimising risks to public health. Advice spans recommendations for frontline responders and advice that should be provided to residents to manage potential hazards to their health and those of others.  

Food and food safety

Microbes and waterborne infectious diseases can be transmitted in floodwater and contaminate food, food storage and preparation areas. Flooding can disrupt power supply that can spoil perishable foods stored in fridges and freezers as a result of flooding. The kitchen or cooking space may have also been in contact with floodwater and will require a thorough cleaning before this space can be used for any food preparation.

General advice on food safety

The Food Standards Agency advises not to eat any food that has been touched or covered by floodwater or sewage. Residents should be advised that they should not:

salvage food that has come into contact with floodwater including tins as they may be damaged or contaminated and pose significant issues to health
eat any produce grown on an allotment or garden that has been flooded unless it has been cooked

Produce that might be 'ready to eat' such as lettuce or strawberries that were in the allotment or garden when it flooded should be thrown away. It is safe to eat produce that is to be cooked, even if it has been contaminated by floodwater, because cooking will kill any harmful germs that might be present. It is also safe to eat produce that is growing above the water and not contaminated with floodwater, such as fruit on trees.

Considering refrigeration, residents should be advised that:

if power has been cut off and their fridge has not been working for up to 4 hours but the door has remained closed, the food inside will be safe – if their fridge has not been working for more than 4 hours, it is advisable to throw away the food inside
if their freezer has not been working for more than 4 hours, they should throw away the food inside – they should throw away any ice cream that has gone soft; however, meat and fish that are still below 8°C can be refrozen or cooked and eaten

Residents should ask for advice from the environmental health service at their local authority if they have a catering business and have been affected by flooding.

Preparing food safely after a flood

Residents should be advised that they should always wash their hands with clean water (preferably warm water, but if that is not available, then cold water can be used) and soap and dry them, before eating or preparing food. This is especially important after going to the toilet and after being in contact with floodwater (including sewage or other items that have been in floodwater).

If there is no clean water, they should use disposable wet wipes or sanitiser gel to carefully clean all parts of their hands and dry them.

If there is a possibility that gas or electrical appliances have got wet, they should only be turned on once they have been checked by a qualified gas engineer or electrician.

Residents should clean and disinfect all work surfaces and all items to be used before food preparation such as plates, pans, cutlery and plastic or ceramic chopping boards, but wooden chopping boards and wooden spoons should be discarded if contaminated by floodwater. If they have a working dishwasher and mains water supply, this is a more efficient way to clean and sanitise smaller items.

They should also thoroughly clean the inside of their fridge and food cupboards if they have been touched by floodwater using a hot detergent solution or any other disinfectant.

Preparing baby formula

If residents think there are issues with the tap water supply in their property (for example an odour or discoloration of water) then they should not use this water to prepare baby formula. Residents should instead be advised to ensure they use bottled water that has been boiled and cooled for at least 30 minutes in a clean, covered container, and then follow the instructions on making the feed. They can also use ready-made formula milk as an alternative.

If they do not have gas or electricity to boil water, they can use unboiled bottled water but must then give the feed to the baby immediately. They should not, under any circumstance, give unboiled tap or tank water as these sources might be contaminated.

If giving a baby bottled water, residents should be advised to check the label for sodium or 'Na' and that it is not higher than 200mg per litre as a high concentration can be poisonous to babies.

Discarding flood contaminated food

Residents should be advised to:

put flood-damaged food and kitchen items in black plastic refuse sacks, double bagged if possible, seal them and put them out when the next refuse collection is due
remember to check with insurers before disposal because food may be insured; damaged food – including tins – should not be salvaged as they may be damaged or contaminated
ask for advice from the environmental health service at their local authority if they have a catering business and have been affected by flooding

Water supplies and water safety

Mains water supply and distribution network might not always be affected by flooding; however, it is important to check before using mains water. Private water supplies such as a well or spring can become affected.

General advice on water safety

Water companies have a duty to take all necessary steps to protect public health. For example, should water treatment works become flooded, alternative supplies will be made available, such as bottled water or water bowser, but in the meantime, consumers may be advised to boil water before drinking or temporarily stop using water for domestic purposes.

Residents should be advised not to use tap water if they think there are issues with the supply, such as an odour or discolouration of the water. Water that may be contaminated should not be used for any of the following:

to wash dishes
to wash food or during food preparation
to wash hands
to make ice
in baby formula

Water from the hot tap is not suitable for drinking, whether in flood circumstances or not.

Mains testing

Residents who notice a change in water quality, such as water discolouration, change in taste or smell should be advised to contact their local water company. While waiting for an answer, and if water is urgently required, they should boil all water intended for drinking or use bottled water.

The quality of tap water is the responsibility of the local water company, supervised by the Drinking Water Inspectorate.

If there is evidence that the tap water may be contaminated, the water company will issue advice to boil water.

Boiling water

Boiling water is one of the most effective ways of sanitising and killing waterborne microbes and is recommended in situations where microbial contamination of drinking water could threaten public health. Water suppliers will send 3 kinds of water notices for different circumstances:

'Boil tap water before use': this will be for drinking and food preparation. All water for these purposes should be brought to a boil and then allowed to cool before using.
'Do not drink your tap water'.
'Do not use your tap water'.

Boiling water can carry a risk of scalding accidents. It is advisable to use a kettle rather than pots and pans. If open containers such as pots and pans must be used, then special care should be taken when young children or vulnerable people are nearby. Pan handles should be turned inwards when boiling water in pans so that children cannot reach them. Once boiled water begins to cool it is vulnerable to recontamination from kitchen utensils, so it is important that boiled water is used as soon as possible.

Mains water for showering and bathing

If the water company has advised that the domestic supply is unsafe for drinking, then it is also inadvisable to use this for bathing infants as they may ingest some during bathing. In this situation, bottled water is a safe alternative. Baby wipes can also be used for hand cleansing and washing infants.

For anyone using contact lenses, it is advised to use saline solution as the only method to clean contacts. Tap water or boiled water should not be used to wash them. Hands should be washed using warm water and soap. Contact lenses should not be touched with hands that may have been in contact with contaminated water as this could spread infection. If in doubt, residents should be advised to consult their opticians.

Private water systems

Residents whose water comes from a private supply such as a well or spring should check that it has not been affected by the floodwater. If it has been covered by floodwater, they should proceed with caution and ring their local authority for advice. While waiting for an answer or if in doubt, they should assume that the water is unsafe to drink and source an alternative supply. This is because boiling water kills pathogenic bacteria, viruses and parasites, but does not remove harmful chemicals.

Floodwater health and safety

Pets

Infections in pets during and after periods of flooding in the UK are very rare as harmful bacteria in floodwater are usually diluted and so present a low risk. However, swallowing floodwater or mud that has been brought into the garden by the floodwaters can cause stomach upsets or diarrhoea.

Residents should be made aware of the following advice to help reduce the risk of infection to pets:

avoid direct contact with floodwater and prevent pets from drinking floodwater (running or standing water)
if there is still a significant amount of water in the environment, keep pets and animals on a lead or limit access to the garden and public land as much as possible until the water has receded
keep pets out of the affected area until clean-up has been completed – make sure to remove all obvious signs of contamination and any accumulated rubbish once the floodwater has receded before allowing pets access to the garden
clean away mud and dry pets well after outdoor access, remember to wash hands thoroughly and frequently when handling pets that have been outdoors
ensure pet vaccinations and deworming are up to date

Residents should contact their local vet if they need advice and more information.

Safe play areas

Residents should be advised not to let young children play on affected grassed or paved areas until they have been cleaned down and restored to their normal condition. Sunlight and natural processes in soil help destroy harmful bacteria and any excess risk to health should disappear within a number of weeks. In the meantime, residents should be advised to wash their hands with warm water and soap as it is the best way of protecting health during the recovery phase.

Sports and recreational fields

In the course of flooding in the UK, sports playing fields and pitches can become inundated with floodwater that may be contaminated with sewage and chemicals (normally at low concentrations). Many affected sports fields have been subject to flooding regularly over recent years and as a result have deliberately been sited on land in floodplains that cannot be used for development. During the recovery phase it is important to assess whether there may be any public health implications from contamination on these pitches after the floodwater has receded and drained away.

Normal soil on playing fields and pitches will contain bacteria and fungi, some of which are usually associated with sewage. Testing the soil for contamination will not add any useful information when assessing the risk to public health. Risks cannot be completely eliminated and some pathogens may survive in low numbers in soil for some weeks. The risk of infection therefore remains low, and people using these pitches are routinely advised to take basic hygiene precautions (including washing hands after playing, before eating or drinking, thoroughly washing cuts incurred on the field with clean water, covering cuts before playing and keeping their tetanus immunisation up to date). Any additional micro-organisms deposited by the floods could be expected to decay rapidly as the pitch dries out in sunlight.

Where sports fields and pitches have been flooded, gross contamination (litter carried in by the flood) should be removed. Protective clothing such as waterproof boots, plastic aprons and gloves should be worn while cleaning up, and any open cuts should be covered with waterproof plasters. Hands should be cleaned with soap and warm water after being in contact with floodwater or items that have been contaminated and particularly before eating or preparing food. Following this, the appropriate action to return the pitch to a good playing condition should be carried out according to the local council's advice.

If a playing field has been subject to specific contamination, for example due to an overflowing septic tank or floodwater coming directly from an obvious specific chemical source, residents should be advised to contact their local council, health protection team or the Environment Agency to report an environmental incident. Appropriate remedial action (if any) will be determined on the basis of a risk assessment with professional advice from the UK Health Security Agency (UKHSA), the local authority and Environment Agency.

Chemical hazards

Flooding mobilises chemicals in the environment and may lead to increased contact between persons and industrial or agricultural chemicals (such as pesticides). For questions or concerns about any chemical hazards or pollution in homes or properties, residents should be advised to contact their local council, their local health protection team or the Environment Agency (helpline: 0800 80 70 60).

Toilets and septic tank cleaning

Infectious disease outbreaks arising from floods in the UK are rare. Despite the rarity of such events, it's important to be aware of the small risk. Contaminants can enter floodwater due to groundwater, surface water and the overtopping of rivers, which cause sewage systems to overflow and get mixed with the floodwater. This causes the floodwater to become contaminated and be harmful if exposed.

Raw or partially treated sewage may attract domestic animals, vermin and pests, which can create an unpleasant environment (odour and sight), but also could be one of the risks to public health.

The Environment Agency and UKHSA work together to reduce the risk of pollution leaks into floodwater to protect public health. This may include risk assessment of whether significant pollution has been produced by industry or from sewage treatment works and additional monitoring of watercourses.  

Toilet blockage – how to flush

The following options may be available to residents whose toilets cannot be used.

It may be possible and practicable to use the facilities of unaffected family, friends, neighbours, public toilets, rest centres, local shops, supermarkets and hotels. Chemical toilets ('portaloos') may be provided in the area.

Portable bag-in-a-bag products (for example, 'brief relief', 'wag bag') designed for solid and urine waste may be provided in your area. Once used according to manufacturers' instructions, the waste bag should be placed inside another bag, such as a bin liner, and disposed of in the usual way.

 Septic tanks

If floodwaters have affected a property with a septic tank system (also known as an onsite wastewater system), the septic tank may also be affected.

Wastewater from homes and all buildings contains sewage from toilets and grey-water from bathrooms, kitchens and laundry. Wastewater can contain human disease-causing micro-organisms such as bacteria, viruses and parasites. Diseases can be transmitted to humans from wastewater if appropriate measures are not taken, although this is very rare if safe hygiene measures are followed. The safe disposal of wastewater is an essential part of protecting your health and the health of others. Ensure children and pets are kept away from wastewater affected areas.

The advice in the Environment Agency note, 'Dealing with septic tanks during flooding', sets out information for members of the public and operators responsible for dealing with septic tanks during flooding, with suggestions for immediate action to be taken if the septic tank is waterlogged and will not drain. In addition, it sets out other options for action in the short and longer term, and highlights sources of further information.

Septic tank systems typically comprise a concrete, plastic or fibreglass tank. In a functioning system, the solids in the wastewater settle in a primary tank. The wastewater is then discharged through pipes into soil in a designated area on the property, often called a soak away or drainage field.

Failed systems are not easy to identify; however, some simple indications may include:

a pungent odour around the tank and land application area
blocked fixtures and wastewater overflowing from the relief point
high sludge levels within the primary tank
sewage flowing up through the toilet and sinks

For septic tanks affected by floodwater, there are recommended actions to be taken immediately, and in the short and long term.

Immediate actions  – just as a warning or alert is issued

If the septic tank system becomes covered with water, residents should be advised:

not to use the tank at all if possible and to avoid contact with any standing water that may contain sewage – they should continue to do this until the septic tank or drainage field is no longer covered in water and make arrangements to have their tank emptied if the situation allows (see above)
to consider hiring temporary portable toilet services
to report suspected signs of damage (such as waste blocking watercourse and damaged riverbanks) to the Environment Agency incident hotline on 0800 80 70 60 (Freephone, 24-hour service) so that a team can investigate and take the appropriate action
to eliminate all non-essential water use and flush toilets as little as possible while a flood is in progress; they should continue to do this until the ground is no longer flooded (the Waterwise website has quick tips on reducing water use in the home)
to arrange for the septic tank to be emptied and the contents removed by a contractor on a regular basis until the ground is no longer flooded following the event, though this is unsustainable in the long term
to get advice from their drainage contractor before having the tank emptied, as in some circumstances emptying the tank can cause mud or silt to be drawn into the tank or, in extreme cases, result in it lifting out of the ground

Short-term actions – soon after the flood event

Residents should be advised to:

check none of the pipes with clean water systems are connected to any affected water systems; if clean surface water needs to be disposed of, it is acceptable to do so via a drainage field or stream without treatment
keep away from the septic tank drainage area as standing water, wet ground or ponded water may contain untreated sewage – they should avoid doing work until the ground conditions are suitable
wear protective clothing, covering the eyes, skin and lungs from the fumes if caustic or toxic chemicals have been added to the septic tank in the past, and it is backing up into the cellar, basement or drainage field
clean the area and disinfect the floor if sewage has backed up into the home – a household bleach-based detergent (according to manufacturer's instructions) should be used to disinfect the area thoroughly, and the septic tank should be professionally inspected and serviced if any damage is suspected (only trained specialists should clean or repair septic tanks because tanks may contain dangerous gases)
contact the manufacturer for specific advice on how flooding or power outages may affect composting toilets or other similar approved systems if these are in place in or around the property

Long-term actions – after recovery phase to ensure future flood preparedness and protection measures

Residents should be advised to:

consider connecting to the public sewer if possible – the local sewage undertaker will be able to provide details on applications for this connection
ensure this system is well maintained, so it is better able to cope in extreme weather
consider more appropriate site of the septic tank and the soakaway, keeping it away from areas associated with flooding or waterlogging if possible
consider an improved treatment option which can be discharged directly to surface water, removing the need for an infiltration system

For further information they can contact the Environment Agency National Customer Contact Centre (NCCC) on 03708 506 506, and visit the Environment Agency website for guidance on environmental permits.

After a flooding event, residents should:

inspect the septic tank system for signs of damage and to determine if removal of silt or debris is required, then take any actions required – an appropriately qualified contractor may be needed to inspect and take action
consult a local sewage undertaker who, under s101A of the Water Industry Act (1991), should provide a public sewer – this is especially the case if there are issues with surface and ground water flooding that has become polluted from a damaged septic tank that services several properties

CO poisoning

Carbon monoxide (CO) is produced when fossil fuels such as gas, petrol, diesel, coal, coke, oil and other fuels such as wood and charcoal burn without enough air. Incorrectly installed, poorly maintained or poorly ventilated heating and cooking devices are the main sources of CO. Exposure to high indoor levels can be fatal, while exposure to lower levels can result in symptoms that resemble flu, viral infections or food poisoning.

Headache, tiredness, difficulty in thinking clearly and feeling sick are the most common symptoms. Drowsiness, dizziness, shortness of breath and chest pains may also be experienced. Prolonged exposure to low levels of CO over a long period of time can cause harm to health, often leading to lasting neurological damage in victims.

In England, CO poisoning remains a significant cause of death after a flooding. The risk of CO poisoning can occur during flooding and in the recovery phase afterwards and is often associated with inappropriate indoor use of portable generators. A literature review found that the infrequent use or improper maintenance of appliances can release CO into a room from a flood event or other disasters. For example, wood burners and rarely used chimney flues may become problematic following a flood.

To reduce the risk of CO poisoning, residents should be advised that they should not use using outdoor equipment (such as petrol- or diesel-powered tools, camping stoves and generators) inside for drying, heating, cooking, and power supply.

Petrol or diesel generators and other fuel-driven equipment (including fuel-driven DIY equipment) should never be brought indoors or other enclosed spaces. Using these devices can be fatal.

It is advisable to place equipment outdoors and at 20 feet to avoid air from entering the building, with the exhaust facing away from windows or doors to prevent exhaust gases from being drawn indoors. The exhaust gases contain carbon monoxide which can quickly build up to poisonous levels without good ventilation which involves keeping doors and windows open whenever possible.

It is important to have all appliances which use fossil fuels (and wood) installed and serviced at least annually by a qualified and registered engineer, where the appliances are operated according to the manufacturers' instructions. Residents should not turn on appliances which use fossil fuels (and wood) if they may have got wet until checked by a qualified engineer.

CO monitors can be placed in the area where there are potential sources. These monitors should be equipped with audible alarms to warn people when CO concentrations are too high. However, these alarms should not be seen as an alternative to following the above guidance or the use of caution.

Car batteries

When handling car batteries, it is advisable to use rubber gloves. This is because car batteries are usually lead-acid batteries, containing 35% sulphuric acid. Old batteries can leak this acid and may be covered by floodwater. Car batteries need to be safely handled to avoid exposure to their dangerous chemicals and potential contaminants from floodwater. They can be disposed at local civic amenity sites. Residents should be advised to let the site operator know if the batteries are leaking or contaminated from floodwater.

Household chemicals

Wear rubber gloves when handling household chemicals. Floodwater may have displaced containers of hazardous chemicals such as cleaning products, garden pesticides and domestic heating oil from their normal storage places in the home. Further information on storing domestic heating oil is available on GOV.UK and information on its safe handling is available from OFTEC.

Oil and petrol leakages

Oil in floodwater

There may be visible oil films floating on floodwat...