Human activity is the main cause for the contamination of oceans, rivers, lakes and underground waters, a phenomenon we so well know under the name of water pollution. The safety or hazard level of contaminated waters implies potential risks for the population that cannot use the water for drinking purposes, but it also means an incapacity of the environment to support the biotic dimension of the ecosystems within these waters. There are two main sources of primary water pollution: first there are the accidental discharges from plants, factories or tanks and then there are the small amounts of contaminants that are dumped in the waters on a constant daily basis.
Water pollution experts make a clearcut distinction between what is normally considered a naturally occurring chemical in a higher concentration level and a contaminant. Chemicals and pathogens are actually the ones responsible for the waterborne diseases that affect both animals and humans. The fish living in a contaminated area will accumulate toxins in their bodies being afterwards consumed by people. This is the risk chain that the constant and over-growing water pollution has set into motion. Statistics actually indicate that 14,000 people die every day because of water pollution.
Here are some of the most frequent water pollution agents; they include detergents, insecticides and herbicides, industrial solvents, fuels, the by-products resulting from disinfection, heavy metals and fertilizers and so and so forth. The roots of water pollution go even deeper and so do the consequences, this means that on a constant basis chemicals accumulate, change and give rise to other compounds in a process that affects underground waters too. If water passes through clay layers, then much of the bacteria is filtered while other pollutants are simply diluted, but if the underground water sources pass through caves, caverns or cracks, then they are very likely to carry the pollutants to the surface.
The main prevention method of water pollution is the treatment of residual waters before they reenter the natural circuit. Urban areas in more developed countries collect the wastewater from homes in huge central treatment facilities that are connected to the sewer network throughout the cities. In some cases, industrial users are even forced to pre-treat their residual waters before sending them into the common sewers; only afterwards will such waters undergo another form of treatment that allows for the safe and secure release in the environment.