Environmental sanitation disposal in flood-stricken areas
and Preventive Disinfection Guidelines (2023 Edition)
First, the basic requirements
(1) Formulate a targeted work plan according to the disaster situation and the risk of local infectious diseases, and carry out environmental sanitation cleaning and disinfection work in a timely manner. Under normal circumstances, the external environment is mainly cleaned, and the key areas are disinfected after cleaning. Do not spray and disinfect the environment, traffic roads, roads, tents, etc. in the disaster area where there is no indication for disinfection to prevent the occurrence of excessive disinfection.
(2) The key areas or objects of environmental sanitation cleaning and disinfection include drinking water, villages and places after the flood has receded, and individual residences.
(3) Sludge, animal carcasses, garbage and feces should be cleaned up in a timely manner, and harmless treatment should be done. A large amount of garbage generated by cleaning should be removed in time, and it is strictly forbidden to dump it in the river.
(4) The staff should understand the use of various disinfectants and precautions, choose disinfection methods that are reliable, simple and easy to implement, safe for humans and animals, and friendly to the environment, and correctly implement disinfection measures.
(5) Strengthen the monitoring of the symptoms of intestinal infectious diseases, and if an epidemic is discovered, the disinfection of the source of the epidemic should be done in a timely manner in accordance with the relevant standards and guidelines.
(6) Strengthen the health education of the people and staff affected by the disaster, and do a good job of personal protection in the process of environmental sanitation cleaning and disinfection.
2. Sanitation of drinking water after the disaster
(1) Repair, cleaning and disinfection of water supply facilities.
1. Flooded or damaged water supply facilities. The submerged or damaged water supply facilities can not supply water temporarily, and the sludge in the structure should be cleared out after the water recedes or repaired, and the sewage is cleaned and emptied, and the pipeline is thoroughly cleaned and disinfected. The water supply can only be activated after the indicators are checked. In the process of cleaning and disinfection of pipelines, the affected people should be reminded not to use tap water as drinking water, but as water for flushing toilets.
2. Wells that are flooded or damaged. Wells that have been flooded or damaged must be cleaned, flushed and disinfected after repair. The well is first drained, the sludge is removed, the wall and bottom of the well are flushed with clean water, and then the sewage is completely removed. After the water seeps into the normal water level of the well, it is disinfected with excess chlorine with bleach powder or other chlorine-containing disinfectants, and cleaned again before use.
3. Water storage and intake containers, as well as water pipelines, should be fully flushed and disinfected before being used or reactivated.
(2) Water quality treatment and disinfection of water plants that are in normal operation.
The water plant shall, according to the changes in the quality of the source water, use or increase the use of coagulants and disinfectants in a timely manner to ensure that the effluent quality meets the requirements of GB 5749-2022 "Sanitary Standard for Drinking Water".
(3) Methods for disinfection of household water.
1. Drinking bottled water should be preferred.
If bottled water is not available, it should be boiled and drunk.
2. Tank (barrel) water disinfection treatment.
If the water is clear, it can be directly disinfected and used. If it is very turbid, it can be disinfected after natural clarification or coagulation and precipitation with alum. Commonly used disinfectants are bleaching tablets or effervescent tablets containing chlorine. According to the amount of chlorine 4mg/L~8mg/L, first crush the bleaching tablets or chlorine-containing effervescent tablets into a bowl, add water and stir until dissolved, then take the supernatant and pour it into the tank (barrel), stir continuously to mix it with water, cover the cylinder (barrel) lid, and measure the residual chlorine content of 0.3mg/L~0.5mg/L after 30 minutes. If the amount of residual chlorine does not meet the requirements, the amount of disinfectant should be increased. The cylinder (barrel) should be cleaned frequently.
3. Disinfection of hand-pressed well water.
The disinfection method is the same as the disinfection treatment of tank (barrel) water.
(4) Disinfection methods for self-provided wells.
1. Direct addition. Measure the amount of well water and calculate the dosage before administering disinfectant, and the well is generally cylindrical, i.e.:
井水量（m3）=井水深（m）×3.14×[水井半径（m）]2
Disinfectant dosage (g) = [well water volume (m3)× chlorine dosage (mg/L)]/available chlorine content (%)
The amount of chlorine should be the sum of the chlorine demand of the well water and the residual chlorine, according to the quality of the well water, the chlorine amount of the general clean well water is 2mg/L, and the chlorine is increased to 3mg/L ~ 5mg/L when the water quality is turbid, so as to ensure that the residual chlorine of the well water is about 0.7mg/L after 30 minutes of chlorination, and the water quality microbial index test can be carried out in the conditional area.
The method of dosing is according to the required dosage, put it in a container, add water to make a concentrated solution, pour the supernatant into a bucket after clarification, dilute it with water and pour it into the well, shake the well water several times with a bucket, mix it with water, and use it after 30 minutes. The well water is disinfected at least twice a day, i.e. in the morning and in the evening before the concentrated water intake period.
2. Continuous disinfection.
Put the bleaching powder or bleaching essence into a beverage bottle (250g~300g per bottle) with a number of small holes (the pore size is 0.2cm~0.5cm, and the number of small holes can be adjusted according to the amount of residual chlorine in the water), and hang the container in the well water with a thin rope, and tie an empty bottle at the same time, so that the medicine bottle floats 10cm below the water surface. The disinfectant in the bottle is slowly released from the small hole by using the vibration when taking water, so as to achieve the purpose of continuous disinfection. It can last for about 1 week after a single dose. Using this method for disinfection, there should be a special person responsible for regularly adding drugs and measuring the residual chlorine in the water, and the amount of residual chlorine is about 0.7mg/L. If the well is large, several continuous disinfection bottles can be placed at the same time.
3. Excessive chlorine disinfection.
First dry the well water (if pathogenic bacteria are detected in the well water, it should be disinfected first and then dried), remove the dirt on the well wall and the bottom of the well, clean it with 3% ~ 5% bleach solution (half of the bleaching tablets), wait for the natural seepage of the well to the normal water level, and then add bleaching powder (or bleaching tablets) according to the chlorine amount of 10mg/L~15mg/L, that is, add 40g~60g of bleaching powder per ton of water (effective chlorine is calculated as 25%), soak for 12 hours ~ 24 hours, pump out the well water, and then wait for the natural seepage to the normal water level. After disinfection, it will be put into normal use, and water quality microbial index testing can be carried out in areas with conditions.
(5) Disinfection of temporary emergency water supply vehicles.
The equipment used for water delivery, whether it is a water truck, fire truck, sprinkler truck, water tank or polyethylene plastic bucket, must be thoroughly cleaned and disinfected before transporting water, rinsed with a chlorine-containing disinfectant solution of 500mg/L of effective chlorine, and then rinsed with water after 30 minutes. The residual chlorine of the water to be transported should be kept above 0.5mg/L to ensure the hygienic quality of the transported water and prevent the transported water from being polluted twice.
(6) Drinking water safety and health education.
1. Do not drink raw water, try to drink boiled water, bottled water, and bottled water prepared or delivered by the purification equipment on site.
2. Do not drink water from unknown sources or contaminated sources, and do not rinse your mouth or wash vegetables with water from unknown or contaminated sources.
3. Tanks, buckets, basins and other water containers should be disinfected frequently, and rinsed with clean water after disinfection.
4. Consciously protect the drinking water source and its surrounding environment, pile up domestic garbage, dump domestic sewage and feces in designated places.
3. Environmental sanitation disposal of villages and places after the disaster
(1) Sanitation and cleaning objects.
1. Manure storage structures: mainly including various toilets, septic tanks, biogas tanks, livestock and poultry farms (circles), and manure tanks (pits) used for field manure.
2. Sewage and garbage collection and treatment facilities: mainly including drainage pipes, sewage pools, sludge disposal sites, garbage temporary storage sites, landfills, and medical waste treatment plants.
3. Key places: mainly include villages and communities and other places that provide services to the public, shopping malls, supermarkets, hotels, swimming places, theaters, libraries, fitness venues and other public places, transportation, medical and health institutions work areas, veterinary stations, livestock trading places, slaughterhouses, etc.
4. Animal carcasses: mainly including domestic animals, poultry, special breeding animals and wild animals.
(2) Technical requirements for sanitation and cleaning.
1. Manure storage structures.
(1) Fecal treatment: The feces in the excavatory manure storage structure should be cleaned and removed after adding the same amount of quicklime or spreading bleaching powder with an effective chlorine content greater than 20% at 1kg/m2 and then mixed and disinfected; The feces in the non-cleaning manure storage structures are disinfected with bleaching powder at a ratio of 10:1 (volume) and removed after 2 hours of mixing. The treated feces should meet the requirements of GB 7959-2012 "Sanitary Requirements for Fecal Harmlessness".
(2) Treatment of abandoned pond pits: sprinkle and water with quicklime or bleaching powder at 1kg/m2, then fill and compact with farmland soil or construction residue.
2. Sewage and garbage collection and treatment facilities.
(1) Fixed sewage and garbage collection and treatment facilities should be disinfected after dredging, and the selection of disinfection methods can be carried out with reference to the "Disinfection Technical Specifications" according to the specific situation.
(2) Hospital waste shall be implemented in accordance with the requirements of the Regulations on the Management of Medical Waste.
3. Key places.
(1) Villages and communities that provide services to the public.
Flood villages and communities that provide services to the public are thoroughly cleaned, and disinfected after the clean-up is completed. Walls and floors can be sprayed or wiped with a chlorine-containing disinfectant solution of 500mg/L of effective chlorine for 30 minutes.
(2) Public places such as subway stations, shopping malls, and supermarkets.
Public places such as shopping malls, supermarkets, hotels, swimming places, theaters, libraries, and fitness venues that have been flooded should be cleaned and disinfected first. Indoor surfaces, walls, and floors can be sprayed or wiped with a chlorine-containing disinfectant solution of 500mg/L of effective chlorine for 30 minutes. Indoor air circulation should be strengthened, natural ventilation should be the mainstay, and mechanical ventilation can be used in poorly ventilated places.
(3) Transportation.
After the subway, bus and other means of transportation are cleaned, the surface of the internal objects of the vehicle (such as the inner wall of the body, the driver's steering wheel, the armrests in the car, tables and chairs, etc.) is sprayed or wiped with a chlorine-containing disinfectant solution of 500mg/L of effective chlorine or a 1000mg/L quaternary ammonium salt disinfectant for an action time of 30 minutes, and then wiped clean with water after disinfection.
Seat covers and other fabrics can be disposed of as general household waste; If it needs to be retained, it should be cleaned and disinfected in time. Fabrics can be disinfected using circulating steam or boiling for 30 minutes, or soaked in a chlorine-containing disinfectant solution of 500mg/L of available chlorine for 30 minutes, followed by routine cleaning.
(4) Places such as work areas of medical and health institutions.
After dredging, the floor and wall surfaces of the working areas of medical and health institutions, veterinary stations, livestock trading places, and slaughterhouses can be sprayed or wiped with a chlorine-containing disinfectant solution of 500mg/L of effective chlorine for 30 minutes.
(5) Vehicles and tools for transporting the remains of traumatically injured persons and victims.
Vehicles and tools for transporting the remains of traumatic wounded and victims can be sprayed with chlorine-containing disinfectant solution of effective chlorine 1000mg/L~2000mg/L for 30 minutes ~ 60 minutes. In case of contamination of a large amount of blood and body fluids, a chlorine-containing disinfectant solution of effective chlorine 5000mg/L~10000mg/L should be used to remove the contamination before treatment.
4. Animal carcasses.
The fresh animal carcasses cleared out in the environmental cleanup should be buried or cremated as soon as possible, and the animal carcasses that have been smelly can be sprayed with a chlorine-containing disinfectant solution of 5000mg/L~10000mg/L of effective chlorine to remove the odor and disinfect, and then buried or cremated. After the corpse is cleaned up, it needs to be disinfected, and it can be sprayed with a chlorine-containing disinfectant solution of effective chlorine 1000mg/L~2000mg/L, and the action time is 30 minutes ~ 60 minutes.
The place where the animal carcass is buried deep shall be designated by the local government, and shall not be buried indiscriminately. The location should be far away from water sources and settlements, and the downwind direction of densely populated areas should be selected. Dig the pit more than 2m deep, sprinkle bleaching powder or quicklime at the bottom of the pit, put the animal carcass into the pit, and then use bleaching powder to cover the animal carcass at 20g/m2~40g/m2, a layer of bleaching powder on the carcass, and then cover the soil and bury the compact.
The means of transportation of animal carcasses can be sprayed with chlorine-containing disinfectant solution of effective chlorine 1000mg/L~2000mg/L, or other effective disinfectant solutions, and the action time is 30 minutes ~ 60 minutes. In case of contamination of a large amount of body fluids, a chlorine-containing disinfectant solution of 5000mg/L~10000mg/L of available chlorine should be used to decontaminate and then treated with the previous method. Vehicles and tools are disinfected after each use.
4. Environmental sanitation disposal of individual residences after the disaster
(1) Check whether the structure of the house is damaged.
Before returning to your home after a flood, you should inspect the structure of your home for structural damage and make sure that it is safe before entering. Ventillate the room ahead of time and check for loose and detached power lines and gas leaks. If there is any of the above situation, contact the relevant company for maintenance in time, and then enter after the problem is solved. Also, do not enter flooded basements to prevent the risk of electric shock.
(2) Remove stagnant water in the house.
After a flood, the most critical thing to safely dispose of a room is to remove all standing water as quickly as possible. If there is a lot of water accumulation in the basement, it needs to be pumped out in batches according to the situation to avoid structural damage and wall collapse that may occur when all the water is pumped out in a short time. If there is petroleum-like substances on the surface of the stagnant water, it is necessary to contact a professional to remove it before removing the stagnant water.
(3) Do a good job of cleaning the house.
1. The principle of cleanliness in the house.
After the flood, the house needs to be thoroughly cleaned and disinfected before moving in. Before cleaning the house, you need to sort the contents of the room, which items can be cleaned and which items can be discarded. Usually some materials that do not absorb water, such as metal, glass and hard plastics, can be cleaned and dried. Highly absorbent items such as carpets are difficult to clean and dry after a flood, so consider discarding them. In addition, food, beverages, medicines, etc., which have been exposed to floods and mud and have damaged packaging, cannot be cleaned and disinfected, so it is recommended to discard them.
2. How to clean the house.
When cleaning a house, first thoroughly clean the walls, household appliances, floors, furniture, and other hard surfaces and wipe them with a solution prepared with hot water and ordinary detergents. Second, wash all soft fabrics, including bedding, clothing, children's toys, etc. If you need to use a disinfectant, you can choose a chlorine-containing disinfectant solution with 500mg/L of available chlorine, but you need to clean it before disinfecting. When using detergents and disinfectants, read carefully and follow the instructions for use on the product label and do not mix them. In order to reduce the health risks caused by microbial breeding, fans can be used to increase air circulation during and after cleaning. Clothes worn after cleaning the house should be carefully cleaned and disinfected.
3. Mold treatment.
(1) Identification of mold.
"Look": Observe whether the walls and ceilings and other material surfaces are discolored, and if so, it may be a mold growth. "Smell": If there is a persistent unpleasant musty, earthy, or foul smell in the room, there is a possibility of mold growth.
(2) Mold removal.
Level hard walls: Remove with a shovel and wipe clean with soap and water. Rough surfaces such as concrete: Remove with a stiff bristle brush and wipe clean with soap and water. If the mold growth area is too large, you can seek help from professional and technical institutions such as disease control agencies. When performing mold removal operations, it is advisable to wear gloves, masks and protective glasses, and open windows for ventilation.
4. Drinking water and hot water treatment.
(1) Turn on the faucet and release the stagnant water in the pipe until the color of the drinking water becomes colorless and odorless.
(2) It is advisable to drink boiled water or bottled water, and avoid drinking raw water directly.
(3) It is advisable to raise the water temperature of the water heater to 60°C, and open the hot water faucet to release the stagnant water in the hot water pipe for 1 hour to completely remove the pollution in the hot water pipe.
(4) Disinfection of indoor environment and items.
1. The surface, wall and ground can be sprayed or wiped with a chlorine-containing disinfectant solution of 500mg/L effective chlorine, 200mg/L chlorine dioxide or 1000mg/L peracetic acid for 30 minutes.
2. Daily necessities. After cleaning furniture, sanitary ware, office supplies, etc., rinse, wipe or soak with a chlorine-containing disinfectant solution of 500mg/L effective chlorine for 30 minutes, or use 200mg/L chlorine dioxide, 1000mg/L peracetic acid, and 1000mg/L quaternary ammonium disinfectant for disinfection, and the action time is 15 minutes ~ 30 minutes. After disinfection, wipe clean with water.
3. Disinfection of meals and drinking utensils. After cleaning meals and drinking utensils, boiling disinfection is preferred, and the boiling time should be more than 15 minutes. You can also use disinfectant for soaking and disinfection (such as soaking in a chlorine-containing disinfectant solution of effective chlorine 250mg/L~500mg/L for 30 minutes), and rinse with clean water after soaking in disinfectant.
4. Food. Food that has been soaked in flood water or spoiled should be disposed of in a timely manner, and any food soaked in flood water should not be consumed. Restorable foods should be fully heated before consumption.
5. Post-disaster personal health education and protection
(1) Personal protection of disinfection personnel.
1. Protective equipment to be equipped includes masks, disposable gloves, work clothes and insulated rubber boots.
2. After the disinfection work is completed, all the disinfection tools should be cleaned, and then the work clothes, hats, masks (or other protective equipment) should be taken off in turn, the clothes should be folded, the outer surface of the work clothes should be rolled inside, and put into a special cleaning bag for cleaning.
3. Disinfection personnel should not smoke or eat or drink during disinfection operations.
(2) Protection against accidental injuries.
1. Prevent drowning.
Try to avoid walking or driving in flood waters; If the flood water continues to rise and the evacuation site is no longer able to protect itself, make full use of the prepared life-saving equipment to escape, or quickly find some door panels, tables and chairs, large pieces of styrofoam and other floating materials to form a raft to escape; Make sure children stay away from areas where floodwaters have accumulated.
2. Prevent electric shock.
Do not climb live poles and towers, if you find that the high-voltage line tower is tilted or the wire is broken and sagging, you must quickly avoid it to prevent direct electric shock or electric shock due to the ground "stepping voltage"; Appliances that have been soaked in water should not be used until they have been repaired by a professional maintenance personnel.
(3) Personal protection of the affected people.
1. Strengthen hand hygiene.
Wash your hands before preparing food, before breastfeeding, before eating, after using the toilet, before and after caring for sick people, after touching animals or dead animals, after touching garbage, and before and after handling wounds. When washing your hands, it is best to wash them with soap and running water and dry them in time; Do not wash your hands and face or other items with water contaminated by floodwater.
2. Take good care of your wounds.
It is best to wrap the wound with waterproof material to keep the wound clean and avoid contact with floodwater; If the wound comes into contact with floodwater, rinse immediately with clean water and soap; If the wound shows signs of infection such as redness, swelling, and oozing of body fluids, you should seek professional medical attention in time, and according to the condition of the wound, medical staff should determine whether to inject tetanus vaccine.
3. Do a good job of personal health monitoring.
If you come into contact with floodwater or eat contaminated food, etc., and have symptoms such as diarrhea, vomiting, fever, or abdominal pain, you should seek medical attention promptly.
(Source: National Agency for Disease Control and Prevention)
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