Kalamazoo Area Math and Science Center (KAMSC) WebQuest Practice Test

Using fertilizers in agriculture is a significant contributor to water pollution due to the runoff that can occur when it rains or when irrigation is used. Fertilizers typically contain nitrogen and phosphorus, which are essential nutrients for plant growth. However, when these chemicals enter water bodies through runoff, they can lead to the over-fertilization of aquatic ecosystems, a phenomenon known as eutrophication.

Eutrophication causes excessive growth of algae, which reduces the amount of oxygen available for fish and other aquatic organisms, leading to dead zones where life cannot be sustained. Additionally, when these algal blooms die and decompose, they further deplete oxygen levels, exacerbating the problem. Moreover, some fertilizers can also contain harmful pollutants that can directly contaminate water supplies, posing risks to both human health and the environment.

Other practices mentioned, like recycling sewage and desalination, can actually help manage and improve water quality rather than contribute to pollution. Conserving water typically functions to reduce runoff and the overall impact on water bodies, further mitigating potential pollution risks.