Water Pollution

Water pollution is defined as the action or effect of introducing materials or forms of energy, or inducing water conditions that result in a harmful alteration of its quality, affecting its subsequent use and ecological balance.

A. Origin and Types of Water Pollution

Based on the way pollution occurs, we distinguish between point source and diffuse pollution:

• Diffuse Pollution (Non-Point Source): Its origin is not clearly defined and it does not stem from a single, large area emitting source.
• Point Pollution (Point Source): This is produced by a particular, identifiable focus or issuer and affects a specific area.

Sources of Water Contamination

Natural Contamination

Natural contamination refers to the presence of substances in the water without human intervention. All these natural residues undergo a series of chemical and biological processes that are part of the water's self-cleaning ability, and for the most part, they are eliminated.

Anthropogenic Pollution Sources

Human activities generate several major types of pollution:

1. Urban Pollution: Results from water usage where generated wastewater, containing increased levels of waste, scrap, and chemicals, is returned to the receiving body.
2. Agricultural Pollution: Derives from the use of fertilizers and pesticides. These are carried by irrigation water, introducing salts composed of nitrogen, phosphorus, sulfur, and trace elements that can contaminate groundwater, including organochlorine compounds. The food industry also contributes a high organic load.
3. Industrial Pollution: Often produces the greatest environmental impact. Highly polluting industries include petrochemicals, energy production, paper manufacturing, steel production, food processing, textiles, and mining.

Other Anthropogenic Sources

• Waste Landfills
• Contamination from fuel remains
• Leaks in pipes and storage tanks
• Oil spills

B. Factors Influencing the Level of Contamination

Receiver Features

• Type of Receptor: Surface water or groundwater.
• Quantity and Quality of the Receptor: The volume and existing quality of the water body.
• Dynamic or Static Features: Characteristics that determine the water body's power to spread contamination and its potential for self-purification.

Characteristics of the Surrounding Area

The area's characteristics, including climate and geomorphology, influence the degree of contamination. Different contributions of contaminated water may exist, increasing the overall contamination level of the specific receptor. A high rainfall index generally decreases contaminant concentration, while pronounced relief features can affect runoff patterns.

Previous History of the Water Body

This factor relates to the type and amount of effluent the water body has received previously, and the existence (or lack) of adequate wastewater treatment systems. These elements significantly help to increase or decrease the current degree of contamination.

C. Water Pollutants and Their Effects

Water pollutants are defined as chemicals, living organisms, or forms of energy present in water at concentrations or rates higher than those considered normal or safe.

• Physical Contaminants: Include temperature changes (thermal pollution), radioactive particles, and suspended solids.
• Chemical Contaminants