If a river runs through farmland, there’s a good chance it can become contaminated due to fertilizers. There are a number of obvious things that cause water contamination, such as chemicals and factory waste, but people don’t think about green pastures and corn fields as being a pollution problem. If there is enough farming activity, as well as urban waste that washes into rivers, they can be pretty dangerous down stream.
In some areas, fishing will be allowed, but it is not recommended that people eat what they catch. The chemical levels in the fish may be dangerously high. Therefore, the rivers are not safe for swimming either. This leaves seemingly beautiful natural bodies of water off limits to those who live near them. Aside from affecting the health of humans, there’s the concern to wildlife and plant life. In fact, the farming problem can come full circle as cattle drink from contaminated waters.
In small amounts of exposure, the concerns for lasting health problems are probably not high, but it is a risk that most people really don’t want to take. For a community that may rely on a river for revenue, via fishing and water recreation, fertilizers can be disastrous to the economic health of the people who live there, too. Cost is the culprit in continued contamination. Organic fertilizers are very expensive in the large quantities it would require to run a farm, so farmers purchase what they can afford. This makes the pollution problem a hard one to solve. In times of drought, water authorities may not be able to open dams and send more water down stream to dilute any lingering pollution. On the other hand, big rains wash more poison in. The solution to saving rivers is one that will ultimately rely on affordable, safe fertilizers.