Dirty water tanks harm children more than anyone else in the house. Children drink more water for their size, their immune systems are still developing, and they dehydrate quickly when diarrhoea starts. A tank with sludge and bacterial film exposes them every day through drinking water, formula, bath water, brushed teeth and washed fruit. The steps that protect them are cleaning and disinfecting both tanks every 6 months, boiling or filtering what they drink, and acting early on the warning signs.
This guide is for parents. It explains the risk plainly, describes the illnesses, lists the danger signs that need a doctor, and gives a cleaning schedule for homes with children. It is general information and not a substitute for medical advice.
The Scale of the Problem: Karachi’s Children and Water Quality
- 53,000 Pakistani children under five die every year from diarrhoea due to poor water and sanitation, according to UNICEF, which also estimates that 70% of households still drink bacterially contaminated water (UNICEF Pakistan).
- Almost 44% of children in Pakistan are stunted, on the same UNICEF figures. Repeated gut infections in early childhood are one of the recognised causes, because a child who is often ill absorbs less of what it eats.
- 107 of 118 Karachi water samples were unsafe when the Pakistan Council of Research in Water Resources tested the city’s supply in 2017, and a third contained E. coli from sewage (Dialogue Earth).
- Contamination rises inside homes. Sindh’s household survey found E. coli in 79.1% of Karachi’s water at source and 85.5% at household level (Geo News).
The last figure is the one a parent can change. Part of the contamination a child drinks is added after the water reaches the house.
Why Children Are Far More Vulnerable to Contaminated Water Than Adults
- They take in more water for their body weight, so they get a larger dose of whatever is in it.
- Their immune systems are still learning. Germs an adult has met many times are new to a toddler.
- They dehydrate fast. A small body has small reserves. A few hours of diarrhoea and vomiting can make a baby seriously ill.
- They swallow bath water, suck wet hands and toys, and drink from garden taps.
- Babies on formula receive tank water in every feed unless it is boiled first.
- Illness costs them growth. Each episode means days of poor appetite and poor absorption at an age when the body and brain are growing fastest.
- They cannot tell you. A young child cannot say the water tastes odd or describe how they feel.
Waterborne Diseases From Dirty Tanks That Are Most Dangerous for Karachi’s Children
Diarrhoea
Caused by rotavirus, E. coli, Shigella and other germs. It is the most common and, through dehydration, the most dangerous for under-fives. Start oral rehydration solution (ORS) at the first loose stool and keep feeding the child. Doctors also give zinc for children with diarrhoea.
Typhoid
A sustained fever over several days, with headache, stomach pain and tiredness. Sindh has had an outbreak of extensively drug-resistant typhoid since 2016, with 69% of the early cases in Karachi (WHO). School-age children are heavily affected. The typhoid conjugate vaccine is part of the routine immunisation schedule in Sindh, and the WHO lists vaccination alongside safe water as a main recommendation.
Hepatitis A
Very common in childhood where water is unsafe. Young children often have mild illness or none, but they pass the virus to others. Older children get jaundice, nausea and weeks of tiredness.
Giardia and other parasites
Giardia causes weeks of loose, greasy stools, bloating and poor weight gain. It is a frequent hidden reason for a child who “just isn’t growing”. Its cysts survive normal chlorine levels, so boiling or filtering is the protection.
Cholera
Sudden, profuse watery diarrhoea. It appears in outbreaks, often after floods. Sindh reported 234 laboratory-confirmed cases in the first five months of 2022 (WHO). It needs urgent rehydration.
Naegleria
Rare, but nearly always fatal. The amoeba infects when warm, unchlorinated water goes up the nose, and you cannot get it by swallowing water (CDC). Children who play in tubs, splash pools and under hoses are exposed. Karachi records deaths most summers.
Skin, eye and ear infections
Bathing in dirty tank water can cause rashes, boils, conjunctivitis and ear infections. They are seldom serious, but they are a signal about the water.
Each illness is described more fully in waterborne diseases common in Karachi. Household hygiene habits are covered in the importance of water tank cleaning for health and hygiene.
Karachi-Specific Factors That Increase Your Children’s Risk
- Intermittent supply. Water is stored for days, and the first flow after a gap is the dirtiest.
- Sewage mixing in old pipes.
- Tanker water of unknown source.
- Heat. Rooftop tanks stay warm, which speeds bacterial growth and suits Naegleria.
- Monsoon flooding, which pushes sewage into underground tanks and supply lines.
- Open or broken tank lids, letting in birds, insects and dust. See bird contamination in rooftop tanks.
- School and madrasa tanks. Your child drinks and washes there too. Ask when those tanks were last cleaned.
- Shared tanks in apartment buildings, where nobody is clearly responsible. See who is responsible for tank cleaning in apartment buildings.
How Regular Professional Tank Cleaning Directly Protects Your Children
A proper cleaning removes the two things that keep a tank contaminated: the sludge on the floor and the film on the walls. Germs live in both, protected from chlorine. Once they are gone, the cleaned surfaces are disinfected and rinsed.
| What the child does | How a clean tank helps |
|---|---|
| Drinks water and formula | Fewer germs reach the kettle or filter, so the second barrier is not overloaded |
| Eats washed fruit and salad | The washing water is not adding bacteria |
| Brushes teeth | Less swallowed contamination twice a day |
| Bathes and plays in water | Lower risk of skin, eye and ear infections, and of Naegleria when the tank is chlorinated |
| Eats from washed plates and bottles | Dishes are not re-contaminated after washing |
Cleaning does not make tap water safe to drink untreated. Karachi’s supply is not reliable enough for that. It makes every other protection work better. The steps are on our service procedure page, and the disinfectants are listed under cleaning chemicals. Chlorine is rinsed from the tank before it refills.
The rest of the protection
- Boil drinking water for at least one minute, or use a well-maintained filter. See filtration and cleaning in Karachi homes.
- Make formula with boiled water. Boil it, let it cool for no more than half an hour so that it is still hot, then mix. Sterilise bottles and teats.
- Use boiled water for brushing young children’s teeth if you are unsure of the tank.
- Wash hands with soap before feeding and after nappies and the toilet.
- Keep vaccinations up to date, including rotavirus and typhoid.
- In hot months, keep the tank chlorinated, stop children snorting or jumping into tub water, and empty paddling pools after use.
- Send safe water to school in a clean bottle.
Warning Signs Your Child’s Health May Already Be Affected
Patterns that point to the water
- Loose stools or stomach aches that keep coming back
- More than one child, or the whole household, ill at the same time
- Illness that improves on a visit elsewhere and returns at home
- Poor weight gain or a child who is always tired, with no other explanation
- Repeated skin rashes or eye infections after bathing
If you see these, check the tank as well as seeing the doctor. The household signs are listed in signs your family may be drinking contaminated water.
Danger signs: take your child to a doctor or hospital now
- Not drinking or breastfeeding, or vomiting everything
- Very sleepy, floppy or hard to wake
- Sunken eyes, dry mouth, no tears, or very little urine
- Blood in the stool
- Diarrhoea lasting more than two days, or any diarrhoea in a baby under six months
- High fever, or fever lasting more than three days
- Yellow eyes or skin
- Fits, or a severe headache with fever and a stiff neck
Give ORS on the way.
Recommended Tank Cleaning Schedule for Families With Children in Karachi
| Household | Clean both tanks every |
|---|---|
| Family with children, line water, sealed tanks | 6 months |
| Family relying on tanker water | 4 months |
| Home with a newborn, or a baby on formula | 6 months, and once before the baby arrives if the last cleaning was more than 3 months ago |
| After floodwater, sewage smell or a dead animal in the tank | Immediately |
| When a child has repeated stomach illness with no other cause | Now, then back to the schedule |
Two dates suit children best: March or April, before the heat and the Naegleria season, and September or October, after the monsoon. See the best time to clean your water tank and how often to clean it.
Between cleanings
- Keep both lids closed and openings meshed.
- Look inside once a month.
- Keep children away from open tanks. An uncovered underground tank is a drowning hazard as well as a hygiene risk.
The routine is in how to maintain your water tank after cleaning.
On cleaning day
Keep children and pets away from the open tanks and equipment. A standard house takes 2 to 4 hours. Our team closes the covers before leaving, and you inspect the tank before paying. See our safety page.
Frequently Asked Questions
Can a dirty water tank make my child sick?
Yes. It stores and multiplies the germs that cause diarrhoea, typhoid and hepatitis A, and children are exposed through drinking, bathing, tooth brushing and washed food.
Is it safe to bathe a baby in tank water?
From a clean, covered tank, yes. If the tank is overdue or the water smells or looks off, use boiled and cooled water for young babies until it has been cleaned.
My child drinks only filtered water. Is the tank still a risk?
Yes. Bath water, tooth-brushing water, and water used to wash bottles, plates and fruit all come straight from the tank.
Is the chlorine used in tank cleaning safe for children?
Yes. It is the standard drinking water disinfectant, and the tank is rinsed before refilling. A faint chlorine smell in the first tankful is harmless and fades.
How often should a family with small children clean the tank?
Every 6 months, or every 4 months if you depend on tankers.
Final Thought: The Cleanest Gift You Can Give Your Children
Parents cannot fix the city’s pipes. They can decide what state the water is in when it leaves their own tank. If yours is due, call or WhatsApp 0313-2796778. We clean and disinfect home tanks across Karachi, including Gulistan-e-Johar, Gulshan-e-Iqbal, North Nazimabad and Nazimabad. Rates are on our charges page, and the calculator on the home page gives an instant rate for your house.
About the author: Ahmar Shoaib is the founder of Karachi Tank Cleaning. He holds a BS in Chemical Engineering from Karachi University and has run the company’s cleaning and disinfection work since 2007. This article follows our editorial policy.
Sources: UNICEF Pakistan, WASH programme page; PCRWR testing (2017), reported by Dialogue Earth; Sindh MICS figures reported by Geo News (May 2025); WHO Disease Outbreak News on typhoid (December 2018) and cholera (June 2022) in Pakistan; CDC, About Naegleria fowleri infection.
