Pollution in the Adaja
Pollution in the Adaja
Pollution is produced by three types of spills:
1Polluting tolerated spills, like cesspits and the spills of polluted water
sewers. These sewers don’t purify water before spilling itto the rivers.
2.Illegal spills, like sub housing, industries and constructions located out of
town-planning arrangement, because they lack sewers and connexions with
the drainage network.
3. Polluting controlled spills. Among these ones we can find:
-Urban residues: they mainly come from the water in the sewer system,
domestic rubbish, and the empty bottles that especially young people leave by
the river sides.
- Agricultural residues : agricultural residues are organic and biodegradable
compounds, and in the main they can be immediately used. Those compounds
don’t produce a lot of contamination, because, to do it, it is necessary to
accumulate lots of them in little time.
-Industrial residues, which are the most varied and each one creates
specific problems. However, we can say that industrial residues don’t suppose
a menace in Ávila, because we hardly have factories.
We can also say that the concentration of population in our town and villages
contributes to a quick pollution in the water. The main polluters are:
-Pathogen agents : bacterias, virus, “protozoos “and parasites that flow into
the water coming from organic residues.
-Residues which require oxygen: these residues can be decomposed by
bacterias which take oxygen to biodegrade them. It is necessary to control
this type of residues, because the number of bacterias could grow, taking all
the oxygen from the water , and so, killing all the aquatic living beings.
-Chemical inorganic substances : acids and toxic metal compounds
(mercury, lead) that poison the water.
-The vegetal nutrients , which can cause the excessive growth of aquatic
plants, and when these plants die, they need a lot of oxygen for their
decomposition, which could affect the aquatic life.
-Chemical organic substances: oil, plastics, pesticides and detergents
menace the living beings.
-Sediments or materials in suspension: insoluble particles of ground that
disturb the water.
-The heat: the arrival of hot water decreases the contents of oxygen and
make the aquatic organisms very vulnerable.
Violeta Zazo, Leire Díaz, Joanna Martín, Sandra Martín