• Its main source are farmland runoff, sewage farms, agro-processing sewage. Sewage contains a variety of germs, suspended solids, chemical fertilizers, pesticides, dissolved solids, and salt. Agricultural wastewater in large quantities, affect a wide range. Nitrogen and other nutrients in the sewage into rivers, lakes, inland waters can cause algae growth; pesticides, germs and other toxic substances can contaminate drinking water sources, harm to human health; cause a wide range of soil pollution miscellaneous destruction of the ecological system balance. Prevention and treatment of agricultural wastewater, mainly to reduce agricultural runoff., is needed.

Giant livestock farms, which can contain hundreds of thousands of pigs, chickens, or cows, produce lots of waste -- often equivalent of a small city. While a problem like this sounds pretty ridiculous, pollution from livestock farms seriously threatens humans, fish and ecosystems. Below are some facts and stats about the pollution:

From 1995 to 1998, 1,000 spills or pollution incidents occurred at livestock farms in 10 states. 200 manure-related fish kills resulted in the death of 13 million fish.

Manure from dairy cows is thought to have contributed to a contamination of Milwaukee's drinking water in 1993, which killed more than 100 people, made 400,000 sick and resulted in $37 million in lost wages and productivity.

Here are some more of the facts about the sewage from livestock farms!1.Nitrogen and phosphorus are key pollutants found in nutrient runoff.2.Pesticides are widely used by farmers to control plant pests, but chemical pesticides can cause water quality problems and pollution as well.3.Soil washed off fields is the largest source of agricultural pollution in the United States. They can inhibit growth of aquatic plants, clog fish gills and suffocate animal larvae.4.Washing of vegetables produces large volumes of water contaminated by soil and vegetable pieces.

Large fish farms have large discharges of excrements and excess fish food. Discharge of nutrients like nitrogen and phosphorus boosts this process by fertilizing the biomass production in the water.

Changes in water quality may also affect the living things (fishes) in the water. The fish may not adapt to the new water quality and die. But now most of the farms today are placed on deep localities with good water replacement, and the problem of overloading sea areas has been reduced in relation to the early years of the aquaculture.