The Pollution Problem Pollution is pervasive. Few countries, whether developing or industrialized, have adequately safeguarded water quality and controlled water pollution. Many countries do not have standards to control water pollution adequately, while others cannot enforce water quality standards. Agriculture is the biggest polluter, even more so than industries and municipalities. In virtually every country where agricultural fertilizers and pesticides are used, they have contaminated groundwater aquifers and surface waters.
Animal wastes are another source of persistent pollution in some areas.
In the US, agricultural chemicals, eroded sediment, and animal wastes have fouled over 173,000 miles of waterways. The world's tremendous output of pollutants challenges the capacity of waterways to assimilate or flush away pollution. This truism is taking on frightening dimensions. Each year roughly 450 cubic kilometers of waste water are discharged into rivers, streams, and lakes. Europe and North America confront enormous water pollution problems.