electricity-basics - ITIAN Knowledge Hub

1. The Big Picture

Clean drinking water does not usually come straight from nature ready to drink. Water may look clear, but it can still contain invisible germs, chemicals, dirt, metals, or parasites.

Potable water means water that is safe enough for people to drink, cook with, brush teeth with, and use for food preparation.

A water treatment system is like a careful cleaning factory. It collects raw water, removes harmful things, kills disease-causing germs, tests the water, then sends it through pipes to homes and businesses.

2. Where Drinking Water Comes From

Water used for drinking usually starts as raw water. Raw water means untreated water from the environment.

Source	What it means	Common risks
Rivers and streams	Moving surface water	Mud, farm runoff, animal waste, bacteria, viruses
Lakes and reservoirs	Stored surface water	Algae, bird droppings, sediment, germs
Groundwater / bores	Water taken from underground	Minerals, metals, nitrates, possible contamination
Rainwater tanks	Rain collected from roofs	Bird droppings, leaves, dust, insects, roof contamination
Desalinated seawater	Salt water treated to remove salt	Salt, minerals, high treatment cost

3. What Can Make Water Unsafe?

Unsafe water can contain things we can see and things we cannot see.

Dirt and sediment
Clay, sand, silt, rust, and particles that make water cloudy.

Germs
Bacteria, viruses, and parasites that can cause illness.

Chemicals
Pesticides, fuel, solvents, cleaning products, or industrial pollution.

Natural minerals
Iron, manganese, arsenic, fluoride, or other minerals depending on the area.

Nutrients
Nitrates and phosphates from farms, septic tanks, or fertiliser.

Pipe problems
Lead, copper, rust, or contamination from old plumbing.

Important: Clear water is not always safe water. Dangerous germs can be invisible, tasteless, and odourless.

4. Waterborne Diseases

Waterborne diseases are illnesses that spread through contaminated water. They often affect the stomach and intestines.

Disease or germ	Simple explanation	Possible symptoms
E. coli	Bacteria often linked to animal or human waste	Diarrhoea, cramps, vomiting
Campylobacter	Bacteria often linked to animals, birds, or untreated water	Diarrhoea, fever, stomach pain
Giardia	A tiny parasite that can survive in water	Long-lasting diarrhoea, bloating, tiredness
Cryptosporidium	A parasite with a tough outer shell	Watery diarrhoea, cramps, nausea
Norovirus	A very contagious virus	Vomiting, diarrhoea, stomach upset
Cholera	A serious bacterial disease in badly contaminated water	Severe diarrhoea and dehydration

Care needed: Babies, older adults, pregnant people, and people with weak immune systems can become very sick from contaminated water.

5. The Treatment Process — Step by Step

Not every water supply uses exactly the same process, but many treatment plants follow these main steps.

Step 1: Collection
Water is taken from a river, lake, bore, reservoir, rain tank, or other source.

Step 2: Screening
Large objects like leaves, sticks, weeds, and rubbish are removed.

Step 3: Coagulation
A treatment chemical is added so tiny dirt particles stick together.

Step 4: Flocculation
The stuck-together particles form bigger soft clumps called floc.

Step 5: Sedimentation
The heavier floc sinks to the bottom of a tank.

Step 6: Filtration
Water passes through filters such as sand, gravel, or carbon to remove smaller particles.

Step 7: Disinfection
Germs are killed or inactivated using chlorine, ultraviolet light, ozone, or another method.

Step 8: pH correction
The water’s acidity is adjusted so it is safer for pipes and pleasant to drink.

Step 9: Storage
Clean water is stored in tanks or reservoirs.

Step 10: Distribution
Water is sent through pipes to homes, schools, farms, and businesses.

6. Key Treatment Words Made Simple

Word	Easy meaning
Raw water	Water before treatment.
Potable water	Water safe to drink.
Sediment	Dirt or particles in water.
Turbidity	Cloudiness in water.
Coagulation	Making tiny particles stick together.
Floc	Soft clumps of dirt and particles formed during treatment.
Filtration	Passing water through material that traps particles.
Disinfection	Killing or disabling germs.
Residual chlorine	A small amount of chlorine left in the water to keep it safer in pipes.
pH	A measure of how acidic or alkaline water is.

7. How Water Is Made Safe to Drink

Water becomes safe to drink when the major risks are controlled. This usually means:

Visible dirt and particles are removed.
Cloudiness is reduced so disinfection can work properly.
Harmful bacteria, viruses, and parasites are killed or removed.
Chemical levels are kept within safe limits.
The water is tested regularly.
Pipes, tanks, and treatment equipment are maintained.

Simple idea: Safe drinking water is not created by one magic step. It is made safe by using several barriers together — source protection, filtration, disinfection, testing, and careful storage.

8. Common Disinfection Methods

Method	How it works	Good points	Things to know
Chlorine	A chemical disinfectant kills many germs.	Continues protecting water in pipes.	Needs correct dose and contact time.
Ultraviolet light	UV light damages germs so they cannot multiply.	No chemical taste.	Water must be clear; no ongoing protection in pipes.
Ozone	A strong gas disinfectant treats water.	Very powerful.	More complex and usually used in treatment plants.
Boiling	Heat kills many disease-causing germs.	Useful in emergencies.	Does not remove chemicals, metals, or salt.

9. Private Water Supplies and Rain Tanks

Some homes use rainwater tanks, bores, springs, or small private systems. These need regular care because there may not be a large treatment plant protecting the supply.

Basic care checklist:

Keep roofs and gutters clean.
Fit screens to keep leaves, insects, birds, and animals out.
Check tanks for cracks, sludge, or contamination.
Keep animals away from water sources.
Test water regularly, especially after floods, storms, drought, or repairs.
Use proper filtration and disinfection if the water is for drinking.

After heavy rain or flooding: Water can become unsafe very quickly. Contaminated runoff, animal waste, septic overflow, and dirty roof water can enter tanks and waterways.

10. Boil Water Notices

A boil water notice means the water may contain germs and should be boiled before drinking or using for food preparation.

Boil water for:

Drinking
Making tea, coffee, or cold drinks
Brushing teeth
Washing fruit and vegetables
Making baby formula
Making ice
Food preparation

Important: Follow your local authority’s instructions during a boil water notice. They will say when the water is safe again.

11. What Water Testing Looks For

Testing is how operators check whether treatment is working and whether the water is safe.

Test	What it checks
E. coli	A warning sign that faecal contamination may be present.
Turbidity	How cloudy the water is.
pH	Whether water is too acidic or too alkaline.
Chlorine residual	Whether there is enough disinfectant left to protect the water.
Nitrates	Possible contamination from fertiliser, farming, or septic systems.
Metals	Lead, arsenic, copper, iron, manganese, or other metals.
Chemicals	Pesticides, solvents, fuel, or other pollutants where relevant.

12. Simple Example: From River to Tap

Imagine a town uses river water.

The river water is pumped to a treatment plant.
Leaves and sticks are screened out.
Treatment chemicals help tiny dirt particles clump together.
The clumps settle to the bottom.
The clearer water passes through filters.
Disinfection kills harmful germs.
The water is tested.
Safe water is stored in a clean reservoir.
Pipes deliver it to homes.

13. Safety Care Around Drinking Water

Do not drink water from rivers, lakes, streams, or tanks unless you know it is safe.
Do not assume water is safe just because it is clear.
Keep chemicals, fuel, sprays, and waste away from water sources.
Protect wells, bores, and tanks from animals and surface runoff.
After floods, storms, or earthquakes, check official water advice.
Maintain filters, UV lamps, pumps, tanks, and treatment equipment.
Replace filter cartridges on schedule. An old filter can become a problem.

14. Quick Beginner Quiz

1. Does clear water always mean safe water?

2. What does potable water mean?

3. Name one disease-causing germ that can be found in unsafe water.

4. What is filtration?

5. Why is disinfection important?

15. Recap

Drinking water starts as raw water from the environment. It may contain dirt, germs, chemicals, minerals, or parasites. Treatment makes it safer by removing particles, filtering the water, disinfecting it, testing it, and protecting it during storage and delivery.

Main point: Potable water is safe drinking water. It is made safe by careful treatment, testing, and protection from contamination.

16. Practical Learning Task

Look at your own water supply and answer these simple questions:

Does your water come from a town supply, rain tank, bore, or another source?
Is it filtered?
Is it disinfected?
When was it last tested?
Who is responsible for maintaining the system?

This is a learning guide only. For health or safety decisions, follow your local council, water supplier, public health authority, or qualified water treatment professional.