Organic pollution occurs when large quantities of organic compounds from many sources
are released into the receiving running waters, lakes and also seas. Organic pollutants
originate from domestic sewage (raw or treated), or urban run off, industrial effluents and
farm water. Organic pollution could negatively affect the water quality in many ways.
During the decomposition process of organic water dissolved oxygen in the water may be
used up greater rate than it can be replenished thus, giving rise to oxygen depletion which
causes severe consequences on the aquatic biota. Organic effluents also frequently contain
large quantities of suspended solid which reduce the light available to photosynthetic
organisms mainly algae. In addition organic wastes from people and animals may also rich
in disease causing (pathogenic) organisms