Agricultural Practices and Water Contamination

One of the reasons that so much energy has to be expended when filtering and purifying fresh water from ground and surface water sources is because of water contamination from agricultural practices. Farming uses a great deal of water while irrigating crops, but also uses a large number of chemicals to ensure that the plants grow as well as possible without struggling with weeds and insects. But these pollutants are making fresh water worse in the long run, and we end up using money and energy to filter water so it is potable.

Fertilizers and Pesticides

The two main chemicals that are sprayed on fields grown in the agricultural industry are fertilizers and pesticides. These chemicals are not only deposited on the plants, but are sprayed on the ground during application. Irrigation and rain also wash some of this residue off the plants, but it all becomes a problem of surface runoff.

Surface runoff is the term used to describe when water flows across the surface of the ground to be deposited into a body of water. This can be in regards to surface water or ground water, but it describes the problem with spraying chemicals onto agricultural crops. The surface runoff from this spraying ends with the chemicals either soaking into the ground water and contaminating it or running into a surface body of water like a lake, river, or stream, and contaminating it.

Aside from pumping chemicals into the water supplies from which we extract fresh water, fertilizers and pesticides also damage the delicate balance of aquatic ecosystems when they are a part of surface runoff. These chemicals are poisonous to fish, and once the fish die at an alarming rate, they choke the water so that photosynthesis cannot occur for the plants below. The decomposition of corpses also affects the oxygen levels of the water and makes aquatic dead zones where no life can thrive even after the organic and chemical waste is removed.

This can be avoided though, through responsible use of chemicals. Fertilizers can be replaced by compost as an additive to crops to make them grow larger. Many farms are also going to natural methods of killing pests such as bringing in other insects, like lady bugs, to curb the populations of insects that could harm crops. Using chemicals responsibly helps to avoid many problems that can come from pesticides and fertilizers.

Organic Wastes

Organic wastes are wastes that come from agricultural practices and manufacturing that have something to do with plants or animals. Organic waste can include plant material, animal feces and body fluids, and animal carcasses and are all found in the agricultural industry. When improperly disposed of, these organic wastes can harm the water in surrounding areas and require more money and energy to be spent on more filtering to make the water potable.

Surface runoff is again a problem when it comes to organic wastes. The organic material in the wastes causes nutrient overloading in delicate aquatic ecosystems. Plants then grow and die more quickly, and algae blooms appear, choking the water in many ways. It becomes more difficult for fish to get around and see because very little light penetrates the water, and eventually, the fish and plants begin to die out. The decomposition process then uses up the oxygen, creating the aquatic dead zone again. Bacteria and pathogens are also a risk that is closely associated with organic wastes that runoff into ground water, contaminating it for human use.

The way to avoid problems from organic waste is to take responsible actions towards keeping the waste away from runoff situations. Not spreading natural fertilizer while the ground is overly wet or frozen is an excellent way to avoid the runoff problem. Using organic wastes to make compost and fertilizer is a way to dispose of the organic waste responsibly. As long as it is disposed of in a proper manor, organic wastes won�t cause problems such as eutrophication.


Eutrophication is the increase of production in an ecosystem that ends detrimentally within the ecosystem. In aquatic ecosystems, it is caused mainly by runoff that increases the nutrients in the water, and many times this runoff is from agricultural sources. The runoff from agricultural activities such as improper disposal of organic wastes and the spraying of fertilizers can contribute heavily to the source that begins eutrophication.

In this process, the excess nutrients from the surface runoff enter the water of a certain aquatic ecosystem. These nutrients promote excessive growth of aquatic vegetation, called algae blooms, which choke the water. The algae bloom eats the oxygen in the water, making it difficult for fish and shellfish to get the oxygen they need to live. They then die, and the decomposition process consumes more of the oxygen. Aside from creating aquatic dead zones, the eutrophication process also makes the water harder to filter for human consumption and just creates an aesthetically negative environment.

Natural fresh water can be protected from eutrophication though, by responsible agricultural practices. Carefully monitoring how much fertilizer agricultural crops get and how it is delivered can help in avoiding excess amounts of runoff into the ground and surface sources of water. Taking care of organic waste properly is another way of being responsible about the eutrophication process and making sure water will be easier to filter later on.

The filtering process of fresh water can be made more difficult by water contamination from agricultural sources. Chemicals and organic waste can not only destroy aquatic ecosystems, but make them harder to revive and mar the aquatic landscape. But alternatives to chemicals and responsible disposal are key factors in fighting the inevitable outcome of surface runoff, eutrophication. This responsibility will keep water cleaner, and both easier and more affordable to filter in the long run.