Preservation of Water Quality


Water pollution

1. Water pollution occurs when waste materials are thrown into water sources, making the water unsuitable for human and aquatic organisms.


2. Many humans activities either directly or indirectly pollute water sources.


3. Table below shows the main water pollutants, their effects on living things and ways to control them.


Effects on living things

Ways to control

Domestic waste

- Rubbish, garbage

- Untretaed sewage (wastewater from sinks, drains and toilets

- Rubbish chokes up rivers causing flash floods.

- Plastic wastes are non-biodegradable (cannot be broken down by microorganisms). Thus, they remain in water for a long time, killing many seabirds and aquatic animals that swallow them.

- Harmful microorganisms in faeces can cause diseases such as cholera, dysentery and hepatitis A.

- Detergents reduce dissolved oxygen in water, killing many aquatic organisms. This is because phosphates in detergents are nutrients to plants, causing algal bloom (rapid growth of algae and aquatic plants). When the plants die, large population of bacteria decompose them, using up oxygen in the water.

- Educate the public

- Reuse and recycle waste materials

- Encourage the use of degradable and non-phosphate based detergents

- Relocate residents in squatter areas as these areas lack proper sewage systems

Agricultural wastes

- Pesticides and fertilisers (these substances seeps into the ground and enter water sources)

- Animal waste (from farms)

- In high concentrations, pesticides poison fish, animals and humans that drink the polluted water.

- Non-biodegradable  pesticides remain in the water for a long time. They are passed along in food chains and become concentrated in the final consumers, causing many health problems.

- Nitrates and phosphates in fertilisers are nutrients to algae and aquatic plants. The algae bloom that occurs will eventually reduce dissolved oxygen in water, killing many aquatic organisms.

- Feeding on animal waste, the population of bacteria increases. This reduces the oxygen level in water.

- Educate farmers on the proper use of pesticides and fertilisers

- Encourage the use of biological control

- Impliment laws regarding disposal of waste from farms

Industrial waste

- Toxic wastes

- Acidic/alkaline substances

- Heavy metals (e.g. lead and mercury)

- Radioactive residues

- Toxic wastes poison aquatic life.

- Acidic and alkaline substances changes the acidity of water, causing death to sensitive aquatic organisms.

- Heavy metals accumulate and are passed along food chains. In high concentration, they are poisonous to our body.

- Radioactive residues are carcinogenic (can cause cancer).

- Impliment strict laws regarding disposal of industrial waste

- Treating wastes before they are disposed into rivers


(Mud and sand from deforestation or construction sites)

- Water becomes muddy, preventing sunlight from penetrating the water. Submerged plants cannot photosynthesise and die.

- Rivers become shallow, causing flash floods.

- Control deforestation to prevent severe soil erosion

Oil Spillage

(From oil rigs, oil tankers and illegal cleaning or vessels)

- The oil floats on the surface of the sea, killing seabirds and marine life.

- Constant surveillance of the waters


4. In short, the main steps to water pollution control are prevention, enforcement and monitoring.


5. Examples of measures in preventing water pollution include:

(a) Reusing and recycling waste materials. This would help to prevent these materials from ending up in drains and rivers.

(b) Treating industrial waste into safe effluent before being disposed of.

(c) Planning new industrial and residential areas so that they are properly sited. For example, only clean industries can be sited near water catchment areas.   


6. Strict enforcement of regulations is necessary to reduce water pollution. For example, the Environment Quality Act (EQA) 1974 is the most important legislation regarding water pollution control and the Department of Environment (DOE) was created to administer the Act. Under the EQA 1974, many sets of regulations were made to ensure safe disposal of waste water.


7. Constant monitoring is important in detecting cases of water pollution as soon as they occur. For example, constant air and sea surveillance of waters surrounding Malaysia is necessary to detect any oil spillage as early as possible. This enables corrective measures to be taken immediately.


Conservation and preservation of water quality

1. With the increase in population, we may face shortage of water supply in the near future if our rivers are heavily polluted. This is because most of the raw water for our water supply comes from rivers and streams.


2. To ensure continuous supply of clean water, we need to conserve and preserve water and its quality.


3. Some examples of measures that can be taken are as follows:

(a) Cleaning up polluted rivers. This is an expensive and tedious effort. Therefore, it requires the commitment of both the government and non-governmental organisations.

(b) Promoting public awareness through education, seminars, media campaigns, exhibitions and talks.

(c) Proper disposal of waste. For this purpose, a national centralised toxic waste treatment and disposal centre in Bukit Nanas, Negeri Sembilan has been set up.

(d) Strict enforcement of laws in pollution control. Those who dump rubbish, untreated waste and hazardous waste into rivers should be punished.

(e) Imposing higher tariffs of water. This may be done as a last resort to encourage the public to conserve water.

(f) Devising new methods or devices that is water-saving. For example, in drip or trickle irrigation, pipes with tiny holes send water directly to each plant.

(g) Resettling squatters to new residential areas where facilities for disposing domestic waste and proper sewerage are provided for.


4. To conserve and preserve water and its quality successfully, it takes tremendous effort. Therefore, everybody should play his/her part, no matter how small it is.