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living resources and ecosystems, or that can interfere with legitimate uses of the environment.
Substances that can cause water pollution include heavy metals such as lead, sewage and pesticides. These substances are generally referred to as pollutants which can cause water to have a different taste, colour and odour.
The Environmental Management Act (CAP 20:27) Section 57, S.I 6 of 2007, Environmental Management (Effluent and Solid Waste Disposal) Regulations and Water Act CAP 20:24, regulates on water quality. The objectives are to reduce water pollution within the country.
In Zimbabwe, the Environmental Managemental Agency has the mandate to control water quality. It does this through the use of the National Environmental Laboratory, which is used to test water quality.

Regulations associated with water quality
The Environmental Management Act CAP 20:27 and S.I 6 of 2007 are used by Environmental Management Agency to advocate for the application of the “Polluter Pays” Principle in its entirety. This includes a charge for managing discharge licences and environmental charges based on volume and quality of effluent, as well as a penalty charge for any offences.
Local authorities operating a sewerage system, owner or operator of any trade or industrial undertaking is required to obtain a licence from the Environmental Management Agency to discharge any effluents or other pollutants in the environment.
The effluent is divided into four categories, namely safe, low hazard, medium hazard and high hazard. The scale of the charges for the licence is related to the quality and quantity of the effluent.
The poorer the management or quality of the effluent, the higher the charge. In addition the polluter pays for the policing of the regulations and for the monitoring of the effluent.
Sources of water pollution
The presence of pollutants in water is primarily as a result of human activities.
The sources of water pollution can be categorised as point or non-point sources.
Point sources of pollution are those where the polluting substances are emitted from an identified source directly into the waterway. A pipe spewing toxic chemicals directly into a river is an example.
Non-point sources are a result of diffuse percolation of pollutants from a large area into a waterway, for instance, pollutants from agricultural activities such as fertilisers and pesticides, leachate from landfills soil particles from erosion as well as storm water runoff.
These pollutants are carried into streams and rivers by surface run-off, leading to serious deterioration of water quality. This also affects aquatic and other organisms that may drink or be in contact with the water.

Types of Water Pollution
l Organic matter: Organic pollution occurs when excess of organic matter, such as manure or sewage, enters the water.
When organic matter increases in a pond, the number of decomposers will also increase.
These decomposers grow rapidly and use a great deal of oxygen during their growth. This leads to a depletion of oxygen and the decomposition process occurs.
A lack of oxygen can kill aquatic organisms. As the aquatic die, they are broken down by decomposer which leads to further depletion of the oxygen levels.
l Toxic Substance: A toxic substance is a chemical pollutant that is not a naturally occurring substance in aquatic ecosystems. The greatest contributors to toxic pollution are herbicides, pesticides and industrial compounds.
l Thermal Pollution: This occurs when water is used as a coolant near a power or industrial plant and then is returned to the aquatic environment at a higher temperature than it was originally. Thermal pollution can lead to a decrease in the dissolved oxygen level in the water while also increasing the biological demand of aquatic organisms for oxygen.
l Ecological Pollution: This takes place when chemical, organic or thermal pollution is caused by nature rather than by human activity.
For example, when a large animal, such as a deer drowns in flood and a large amount of organic material is added to the water as a result.

Monitoring water quality
The Water Quality Unit under the Environmental Protection Department has inspectors responsible for ambient monitoring. This helps to identify and trace point and non-point sources of water pollutants.
Each month samples are collected from the identified sampling points and taken to the National Environmental laboratory where an analytical report is produced.
Every citizen of this country is encouraged to take samples of water to the nearest EMA offices if you suspect of any pollutants from any water body elsewhere.
Majority of the point sources encompass manufacturing industries, mining and agriculture. Main sources of water pollution are found in urban areas evidenced by the presence of heavy sewage from homes and industries.
A major sign of water pollution in water bodies in major towns and cities in this country is the presence of water hyacinth.

Our clean future
Life is ultimately about choices – and so is pollution. We can live with sewage-strewn rivers, streams and fish that are poisonous to eat. Or we can work together to keep the environment clean so that plants, animals and people who depend on it remain healthy.
We can help reduce water pollution, for example, by using environmentally friendly detergents, not pouring oil down the drains, reducing pesticides, etc. Working together, we can make water pollution less of a problem and the country a better place.