Water Supply Presentation PDF

WATER SUPPLY 12/05/2024 1  Introduction An adequate supply of safe drinking water is essential for human and animal health We never know the worth of water till the well is dry. Man can live nearly two months without food, but can live only three o...

WATER SUPPLY 12/05/2024 1  Introduction An adequate supply of safe drinking water is essential for human and animal health We never know the worth of water till the well is dry. Man can live nearly two months without food, but can live only three or four days without water. 12/05/2024 2  Introduction…. Many microbial (bacterial, viral, protozoan or others) and chemical contaminants of drinking water can potentially cause adverse human health effects 12/05/2024 3  Introduction…. Chemical contamination of water continues to pose a health burden; – whether natural in origin such as arsenic and fluoride, or – anthropogenic such as nitrate 12/05/2024 4  Introduction…. Key facts of Fluoride by WHO High levels of fluoride concentrations are: – associated with dental fluorosis (yellowish or brownish striations or mottling of the enamel) – if the level and period of exposure increases, it causes Crippling skeletal fluorosis (affects spinal cord) – The problem is higher in Ethiopia (rift valley regions) While low levels of fluoride, – associated with dental decay/caries (Edmunds and Smedley, 1996) 12/05/2024 5  Figure, Fluorosis causes mottling of 12/05/2024 children’s teeth (Photo: Basiro 6  Introduction…. Key facts of Fluoride by WHO Therefore, The WHO’s drinking water quality Guideline Value for fluoride is 1.5 mg/litre (WHO, 1993) In Ethiopia , around 4% of the population affected by Fluoride levels exceeding the national standard (1.5mg/L) – (Survey Drinking Water Quality in Ethiopia (2016)) 12/05/2024 7 Definition of terms – Palatable water: water that is pleasant to drink because its taste is good but it may not be safe to drink. – Raw water: water that has not been purified. – Hard water : Water which contains excessive amounts of dissolved minerals, usually salts of calcium and magnesium. 12/05/2024 8 Definition of terms Safe water (potable water) – is water which is free from disease-causing agents, chemical contaminants and radiation that constitute a danger to a person’s health – Checked by laboratory 12/05/2024 9  Adequate water supply is the minimum quantity of water available in each household should be 20 liters per person per day according to WHO Only 20% of households in Ethiopia have water on their premises, – 77% in urban areas – only 6% in rural areas (EDHS 2016) 12/05/2024 10 Basic Access to safe water supply – The distance to the water source is less than one km or – less than a 30-minute round trip and – There should be Continuous source of supply – Around half (45%) of households in Ethiopia travel more than 30 minutes to fetch their drinking water (EDHS 2016) – In urban areas, over half of households reported water being unavailable during the previous two weeks or insufficient during the preceding month 12/05/2024 Survey Drinking Water Quality in Ethiopia (2016) 11 Public water point – an example of basic access, assuming the user lives within one km distance. (Photo: Pam Furniss) 12/05/2024 12  Importance of water Drinking or physiological need: About 70% of man’s body – weight is water.  In order to maintain this level, a healthy man should drink at least 2-3 litres of water a day. Depend on climate, cost of water ,distance of water source, hygiene practice etc. 12/05/2024 13 12/05/2024 14  Cont… 2. Domestic use: personal hygiene, washing… 3. Agricultural use: irrigation 4. Industrial use 5. Hydropower generation 6. Construction 7. Transportation and recreational purpose 12/05/2024 15  Occurrence of water Water is located in all regions of the earth. The problem is that the Distribution  quality Quantity and mode of occurrence are highly variable from one locality to another. 12/05/2024 16  Occurrence of water/Earth’s Water Budget  Water is the most widely occurring substance in the earth.  Over 3/4 of the earth's surface is covered by water. Out of w/c:  97% is oceans(salty)  3% is fresh water From 3% of fresh water  2% is found in ice caps and glacier w/c is an accessible  Only 1% of fresh water is accessible for human to use for different purposes. Aquatic ecosystems of Ethiopia 17  Water and health  Contaminated water can be the vehicle of transmission of a number of disease producing organisms.  It was estimated billion people do not have access to an improved water supply and adequate sanitation.  A WHO survey has highlighted the following facts: 12/05/2024 18  Cont.…  Each day, 30,000 people die from water-associated diseases.  In developing countries, 80% of all illnesses are water associated  Safe, adequate and accessible supplies of water, combined with proper sanitation, are basic needs.  Therefore, water supply is taken as an essential component of primary health care (PHC). 12/05/2024 19 Diseases associated with water are: – Water-borne diseases – Water-washed diseases – Water-based diseases – Water-related diseases 12/05/2024 20 A. Waterborne diseases – Are those caused by drinking contaminated water – Examples are diarrhea, cholera, typhoid etc. John Snow was best known for his work tracing the source of the cholera outbreak and is considered the father of modern epidemiology 12/05/2024 21  Classical Waterborne Infection Cycle WHO,2015 12/05/2024 22 B. Water-washed diseases – They are also sometimes known as water-scarce diseases – Caused by lack of water for hygiene and sanitation – They include scabies, trachoma, relapsing fever (RF), etc 12/05/2024 23 C. Water-based diseases – Are caused by parasites that spend part of their lifecycle in water – For example, schistosomiasis (water Snails) and guinea worm (Cyclops) 12/05/2024 24  D. Water-related diseases – are caused by insect vectors, especially mosquitoes, that breed in or near water – Examples malaria, onchocerciasis… 12/05/2024 25  Water borne Water washed Water related Water based cause ingestion of lack of adequate by insect vectors caused by external contaminated water supply for that uses water as contact and ingestion water personal hygiene development and of parasites that breeding sites spend part of their life in water Example cholera, scabies malaria guinea worm s typhoid , Trachoma Sleeping Schistosomiasis bacillary Conjuctivitis sickness dysentry, Louse borne Yellow fever Poliomylethis diseases Dengue fever ameoibic Onchocerciasis dysentry, Leshmaniasis giardia, helminthiasis chemical poisoning How to water provision of an making water storage of water for prevent treatment ample amount unsuitable for 24 to 72 hrs to kill Health of water breeding of cercarie education Improve water insect Reduction of snail access Proper site by endod or lemma Personal selection of toxin hygiene house Avoidance of Health Health contact with and education education ingestion of contaminated Sources of drinking water WHO, classifications of water sources – Rain water collection – Surface water such as lakes, rivers and ponds Mainly contaminated by pathogens – Ground water from springs and wells Mainly contaminated by chemicals The well should be situated on a higher level than the source of contaminants– privies, cesspits, etc. 12/05/2024 27  Well protection Casing: should be made water proof material Cover: to prevent dust, insects, small animals, etc. from falling in to the well Diversion ditch: to divert the run-off Sanitary bucket and rope if pump is not installed Fencing: The immediate area of the well should preferably by fenced to keep animals away 12/05/2024 28 1. WHO, Improved (protected) drinking water sources include: – Piped water into dwelling, yard or plot – Public standpipes – Protected dug wells – Tube well or borehole – Protected spring and – Protected rainwater collections – In Ethiopia, 69% of households have access to an improved source of drinking water (EDHS, 2019) 12/05/2024 29 2. WHO, Unimproved water sources include – Unprotected surface water (Rivers, Lakes, pond, …) – Unprotected wells and – Unprotected springs – Tanker truck/cart with small tank 12/05/2024 30  Animals come to the river to drink at the same place as the women collect the water. (Photos: Nancy Platt, Pam Furniss) 12/05/2024 31 Global Joint Monitoring of Household Drinking Water Ladder: WHO/UNICEF JMP (2017) 12/05/2024 32  Properties of pure water  Colorless  Odorless  Tasteless  Density of one (at 4c0).  Boils at 100c0  Freezers at 0c0  universal solvent Any deviation from these characteristics should be considered as an indication of impurity of the water. 12/05/2024 33  Drinking water impurities Based on their solubility’s impurities of water are found in two forms: A) Suspended impurities, including colloids B) Dissolved impurities 12/05/2024 34  Suspended impurities Very fine Particles of insoluble matter, which float in a liquid are said to be in suspension. If they are allowed to stand undisturbed they may settle to the bottom. Causes taste, colour and turbidity E.g. Micro-organisms , algae, suspended solids etc. 12/05/2024 35  Dissolved Impurities Gases, Minerals, etc, Most common dissolved minerals in water are salts of calcium, magnesium, sodium, potassium, etc. Gases, H2S, CO2 12/05/2024 36  Treatment of Drinking Water Water treatment is the process of removing all those substances (biological, chemical or physical) which are potentially dangerous or undesirable in water supplies for human and domestic use. It is generally easier to prevent water getting dirty than it is to make it clean after wards 12/05/2024 37  Objectives of water treatment To remove pathogenic organisms & consequently to prevent waterborne disease. To remove substance which impart color, taste or odor To remove excess or undesirable chemicals or minerals To regulate essential elements or chemicals that may be in excess or lacking in a certain water supply To remove excess or undesirable dissolved gasses 12/05/2024 38 Types of water treatment levels A. Small-scale water treatment systems – At household level B. Large-scale water treatment plant – At community level 12/05/2024 39 A. Small-scale water treatment systems – (Household level water treatment) is appropriate when: – An emergency situation – Area where the municipal water treatment is not well organized – Temporary settlement – At household level 12/05/2024 40 Small-scale water treatment methods are: 1. Chemical disinfection (using chlorine) 2. Solar disinfection 3. Boiling 4. Filtration 12/05/2024 41 Chlorine is applied to water in one of three forms: – Elemental chlorine (chlorine gas), – Sodium hypochlorite solution (liquid chlorine), – Dry calcium hypochlorite (powder chlorine) Chlorination: – used at both household and large-scale levels, – is one of the most effective and widely used methods for disinfecting water 12/05/2024 42 The benefits of chlorination include: – Chlorine is proven to be effective in the reduction of most pathogens – Chlorine has residual effect The residual chlorine 0.5 ppm should stay along distribution lines up to final points It is easy to use and measurement – Chlorine is easily available at low cost 12/05/2024 43 The drawbacks of chlorine treatment include: – Chlorine doesn't kill Cysts formed by parasitic protozoa such as Entamoeba histolytica and Giardia lamblia, Cryptosporidium, can survive chlorine – Not used for chemical contamination – Potential objections to taste and odor – Chlorination has the potential of reacting with some organic compounds present in the water supply to create trihalomethanes (THM; chloroform) THMs are potentially carcinogenic 12/05/2024 44  Commonly used chlorine chemicals and the amount of water treated Available chlorine forms Amount of Amount of chlorine water to be required treated Wuha Agar (Water guard) 1 cup of the 20 liters bottle of 150ml bottle or 3 ml Aquatab (1g/tablet) 1 tablet 20 liters Bishangari (1 sachet = 2.5gm) 1 sachet 20 liters PUR (1 sachet = 4gm) 1 sachet 10 liters 12/05/2024 45  Figure, Aqua tabs tablets for household water treatment. (Photo: Abera Kumie) 12/05/2024 46  Figure, Purifier of water : International Federation of Red Cross and Red Crescent Societies, Household water treatment and safe storage in emergencies). 12/05/2024 47 A. Wuha Agar (Water guard) – Chlorine solution, also known as sodium hypochlorite solution – It is supplied in bottles and has easy instructions for use on the side of the bottle. 12/05/2024 48  – The procedure is for a 20 litre jerrycan, add one capful (3 ml) of Wuha Agar, cover and shake – After 30 minutes contact time you can use it – To avoid contamination close the water container 12/05/2024 49 B. Aquatabs – Are branded solid form of sodium dichloroisocyanurate – It is stable( a longer shelf life) and – Makes storage, handling and transport much easier than with liquid bleach – One Aquatab (1gm) treats 20 liters of water. – It is very important to mix well and leave for 30 minutes contact time before consumption 12/05/2024 50 C. PUR(Purifier of water) – Purifier of Water’ is the brand name of a combined flocculants and disinfectant product – PUR can be used to treat raw water with a wide range of turbidity and pathogen load – PUR allows flocculation to take place and helps to remove Giardia cysts that are resistant to chlorine disinfection. – PUR comes in sachets with one sachet (4gm) needed to treat 10 liters of water 12/05/2024 51 Procedures for use of PUR Prepare 10 liters of water to be treated Open the sachet and add the contents to an open bucket containing 10 liters of water Stir for 5 minutes, let the solids settle to the bottom of the bucket Strain or filter the water through a cloth into a second container and wait 20 minutes for the hypochlorite to inactivate the microorganisms. Use the water intended purposes. 12/05/2024 52 D. Bishangari (1 sachet = 2.5gm powder) Prepare 20 liters of water to be treated Open the sachet and add the contents to an open bucket containing 20 liters of water Stir for 5 minutes, let the solids settle to the bottom of the bucket Strain or filter the water through a cotton cloth into a second container, and wait 20 minutes for the hypochlorite to inactivate the microorganisms. Use the water intended purposes. 12/05/2024 53  Solar disinfection It is also known as SODIS, relies on energy from the sun to kill pathogenic organisms, especially bacteria. Ultraviolet light from the sun is an effective bactericide for water. 12/05/2024 54 Procedure of SODIS  Boiling It is one of the most reliable methods of treating water at household level. The raw water is brought to the boiling point and is kept boiling for 15 to 20 minutes. Boiling destroys pathogens such as bacteria and viruses, and any parasite ova (eggs) present in water. 12/05/2024 56  Filtration Filtration for household water supply is generally carried out by simple filtration systems, such as: Homemade sand filter Home candle filter and Clothe filtration 12/05/2024 57  Homemade Sand Filters They are simple and easy to use. It is an attractive option for household treatment because it can usually be made from locally available and inexpensive materials like clay pots or barrels. 12/05/2024 58 12/05/2024 Figure. Home made sand filter 59 Cont… The properly constructed home made sand filter can remove most of the substances that cause turbidity, taste and odor, the cysts and ova of parasites, and other relatively larger organisms. Cannot remove all forms of pathogenic micro-organisms like viruses and some of the very small-sized bacteria. It frequently gets clogged, particularly if the raw water to be filtered is turbid. 12/05/2024 60  Home Candle Filters The pore size of candle varies from a maximum radius of about 50 microns to a minimum radius of 0.3 micron. The core of the filter is a porous cylinder (shaped like a wax candle, hence the name), made from high-quality unglazed porcelain. The efficiency of filtration depends upon the pore size of the candle. 12/05/2024 61 12/05/2024 62 Cont… Limitations of candle filter The average size of a bacterium is about 1.5 microns. Thus, candle filters with a pore radius of more than 1.5 microns may not remove all the pathogenic organisms that may be present in the water. Viruses can’t removed by a candle filter 12/05/2024 63  Cloth filtration  is cheap, easy to carry out and a common water treatment technique.  pouring turbid water through a piece of fine, clean cotton cloth will remove larger contaminants and a certain amount of suspended solids.  very effective against guinea worm(dracunculiasis) 12/05/2024 64  Conventional Surface Water Treatment Steps of water treatment Raw water Screening Filtration sludge sludge sludge sludge Coagulation Cl Cl22 Disinfection Flocculation Storage Sedimentation Distribution sludge sludge 12/05/2024 65  Cont… Preliminary treatment: important to remove large materials such as:debris, rags, coarse floating matter as well as oil and grease Used To protect the main units of a treatment plant – By using d/t processes: Screening, Grit removal etc Aeration :-Addition of air, to remove substances which cause odor/taste E.g. Dissolved Methane, organic matter & H2S 12/05/2024 66  Cont… Coagulation- the process in which chemicals are added to water, causing a reduction of the forces tending to keep particles apart. Most commonly used coagulants are: A) Aluminum Sulphate B) Ferrous Sulphate C) Ferric Sulphate 12/05/2024 67  Flocculation The agglomeration of small particles and colloids to form settleable or filterable particles (flocs). Coagulant chemicals help particles stick together, make larger particles (flocs) Larger particles settle down by gravitational force is a process of floc formation 12/05/2024 68  Sedimentation  is gravitational settling of suspended particles heavier than H2O The most widely useful operation – plain sedimentation – Coagulation plain sedimentation; gravitational or natural aggregation of particles Coagulation Sedimentation- chemical or other substance are added to induce aggregation 12/05/2024 69  Filtration Filtration is a process for separating suspended impurities from water by passage through porous media. Sand is one of the most important & oldest practices of water purification because of – its wide availability, – low cost and – the satisfactory results that it has given 12/05/2024 70  Cont… Sand filtration is used to remove particles, silts and clays, flocs, larger germs such as Giardia & Cryptosporidium, Particles of organic matter Types of sand filter  Slow sand filter  Rapid sand filter 12/05/2024 71  Water Disinfection is final step before treated water is delivered to a municipal system The purpose of disinfecting water supplies is to prevent the spread of waterborne disease by destroying pathogenic Organisms Disinfection -the destruction, or at least the complete inactivation, of harmful microorganisms present in the water. Contact time - the period of disinfection in water treatment 12/05/2024 72  Cont… Chlorination - the process of adding a form of chlorine to water. Chlorine demand - is the amount of chlorine that combines with the impurities Chlorine dose - how much chlorine is added to the drinking water. It is usually expressed as milligrams per litre The chlorine that remains in the water after the chlorine demand has been satisfied is called free chlorine residual 12/05/2024 73  Factors that influence the disinfection of water The type and concentration of the disinfectant used The nature and number of the microorganisms to be destroyed. The temperature of the water to be disinfected The time of contact The nature of water to be disinfected. The pH of the water 12/05/2024 74  Surveillance of Drinking-Water Quality It can be defined as – “the continuous and vigilant public health assessment and review of the safety and acceptability of drinking water supplies” (WHO, 1976) – Water supply surveillance is therefore designed to protect public health through the identification of inadequacies and by promoting timely implementation of action to control risks 12/05/2024 75  Cont… Methods used: – Sanitary surveillance: system integrity; source of contamination – Laboratory surveillance: quality assurance (microbial, chemical, physical parameters) – Epidemiological surveillance: association of disease with drinking water 12/05/2024 76  Cont… Purpose of water surveillance is to  safeguarding the quality of drinking water  to detect potential sources of contamination  to detect system deficiencies  detect inadequacies and lack of integrity in the system that could lead to contamination 12/05/2024 77  Water quality parameters Generally, there are three main parameters of water quality. These are:- A. physical parameters B. Chemical parameters C. Biological parameters 12/05/2024 78  physical parameters in drinking water – Turbidity – Colour – Taste and odour etc 12/05/2024 79  Physical parameters…. Turbidity of water – is a measure of the cloudiness of water – It is caused by very small particles (suspended solids in water) – Turbidity not exceed of 5 NTU – NTU (nephelometric turbidity unit) – Ideally below one NTU for effective disinfection 12/05/2024 80  Physical parameters…. High levels of turbidity: – Can protect microorganisms from the effects of disinfection, – Decrease efficiency of treatment – Stimulate the growth of bacteria, and – exert a significant chlorine demand – Increases chlorine demand /dosage 12/05/2024 81  Physical parameters…. Colour in drinking-water May be due to the presence of: – metals such as iron and manganese, or – highly coloured industrial wastes etc Drinking-water should ideally be colorless, – unsafe typically exceeding 15 TCU (true colour unit) 12/05/2024 82  Physical parameters…. Taste and Odour of drinking water – Odours in water are caused mainly by the presence of organic substances – Some odours are indicative of: increased biological activity, others may result from industrial pollution – Water should be free of tastes and odours that would be objectionable to the majority of consumers 12/05/2024 83  Cont.… Temperature- it governs, to a large extent, the presence and activity rates of biological species, like  utilization of food supplies  Growth  reproduction, etc. Affect diversity of species, affect the solubility of gases etc. 12/05/2024 84  Chemical parameters of water Chloride Nitrite Nitrate Fluoride DO, Mn BOD COD Iron Lead Arsenic 12/05/2024 85 3. Biological parameter Indicator organisms are microorganisms whose presence in water indicates probable presence of pathogens It would be difficult to monitor routinely for pathogens in the water Indicator organisms are organisms used as a sign of quality or hygienic status in food, water, or the environment 12/05/2024 86  Cont.… Isolating and identifying each pathogen is beyond the capability of most water utility laboratories The number of pathogens relative to other microorganisms in water can be very small, thus requiring a large sample volume 12/05/2024 87 Testing water for individual pathogens are impossible or impractical because: – Large volume of water is needed to test, because of their small number in water – Time consuming – Most pathogens easily killed during transport (less survive) – Not grow readily on simple media (Very difficult to detect) 12/05/2024 88 But the Indicator organisms should have the following characteristics: Occurs in much greater numbers than pathogens More resistant to environmental impacts Grows readily on relatively simple media (easily detected) Survive in water longer than most pathogens Be present whenever pathogens are present 12/05/2024 89 Indicator organisms in drinking water: 1. Fecal Coliforms – Example E.coli – specific fecal indicator (only found in human& animal faeces) – Incubation temp. 44–45°C 2. Total Coliforms – Non specific indicators (found both in faeces and the environment) – Citrobacter, Enterobacter, and Klebsiella – Incubated at 35–37°C 12/05/2024 90  Ideally, drinking-water should not contain any bacteria indicative of faecal pollution 12/05/2024 91 Table, WHO, Guideline values for bacteriological quality in drinking water Organisms Guideline value In drinking water E. coli (thermo Must not be tolerant coliform detectable in any bacteria) 100-ml sample 12/05/2024 92  Food hygiene Food is any solid or liquid, when eaten & absorbed by the body, produce energy, promote growth & repair of tissue; promotes resistance against diseases It is any nutritious product whether processed, partially processed or unprocessed which is intended to be ingested by humans. 12/05/2024 93  Cont.… Food hygiene all conditions & measures necessary for ensuring the safety, wholesomeness & fitness for consumption of food at all its stages from its production(WHO/FAO) 12/05/2024 94 Cont.… Adulteration - when food composition is omitted partially, in whole or foreign substance is added Food spoilage- destruction of food as the result of the action of microorganisms Autolysis - self decomposition due to internally existing enzymes Misbranding-is the presence of any label, writing up on a food container which do not really represent 12/05/2024 95  Food Types: Based on rate of spoilage Stable/non-perishable food- not easily spoiled by the action of micro organisms. e.g. sugar, dry bean etc. Perishable food: is a food that can easily be spoiled unless properly preserved. e.g. Meat, Eggs, fish, milk etc… 12/05/2024 96  Cont.… Semi perishable food -food that remains unspoiled for a fairly long period if properly handled and stored e.g. potatoes, apples, onions, bananas etc. Potentially hazardous food: perishable food that contain in part or in whole milk products, eggs, fish , meat and other ingredients capable of supporting rapid & progressive growth of Mos 12/05/2024 97 Causes of Food Contamination 98  Growth Requirements of Microorganisms  The growth and reproduction of microbes in food can be controlled by certain factors  These controlling factors can be internal or external (Extrinsic & Intrinsic).  Understanding the factors affecting the growth of microorganisms in food help to know how to keep food safe to eat  This knowledge help us to preserve food for longer. 99  Intrinsic factors Are inherent part of food Relate to the characteristics of the substrates (food stuffs) that support or affect growth of microbes. Moisture content (Water activity) pH Nutrient contents Anti-microbial constituent Biological structures 12/05/2024 100  Extrinsic factors Are factors in the environment external to the food Are those properties of the storage environment that affect both the foods and their organisms Temperature Oxygen Relative humidity 12/05/2024 101  Food borne diseases Are diseases caused by ingesting foods that are contaminated by pathogens or toxins produced by these organisms in food or chemical poison of biotic or abiotic nature. Depending on the causative agent they are grouped into two: Food-borne poisonings/intoxications & Food-borne infections 12/05/2024 102  Food borne infections are diseases whose etiologic agents are viable pathogenic organisms ingested with foods and that can establish infection. transmitted by contaminated food via the faeco- oral route. 12/05/2024 103  Cont… The most common food-borne infections are:- 1. Bacterial infections - Cholera, salmonellosis, typhoid fever, shigellosis, Yersiniosis etc. 2. Viral infections e.g. Viral hepatitis A and E, Rota virus - cause diarrhea. 3. Parasitic infections e.g. tapeworms 4. Fungal infections:- e.g. aspergillus 12/05/2024 104  Food Poisoning/Intoxication Occurs as a result of ingestion of contaminated food by toxic chemicals, toxin produced by pathogenic MOs & plants. Categorized in to:- Intoxication : caused by eating food that contains a harmful chemical or toxin produced by bacteria or other source 12/05/2024 105  Cont… Toxin-mediated infection: caused by eating a food that contains harmful microorganisms that will produced a toxin once inside the human body  Living organisms are ingested; they then produce toxins 12/05/2024 106  Cont… The main causes of food poisoning are:  Staphylococcal food poisoning  Bacillus cereus food borne intoxication  Clostridium perfringens food borne intoxication  Clostridium botulinum food borne intoxication  Gram positive spore forming bacteria  Poisonous plants  Harmful Chemicals 12/05/2024 107  Prevention and control Methods Strictly personal hygiene Food protection from potential sources Proper excreta disposal Water safety 12/05/2024 108  Cont.… Proper storage temperature Food preservation Equipment cleaning Following proper food handling practice 12/05/2024 109  Cont.… The five key measures for safer food Keep clean Cook food thoroughly Separate cook food from raw food Keep food at safe temperature Use safe water and raw materials 12/05/2024 110