The term "pesticide" is a composite term that includes all chemicals that are used to kill or control pests. In agriculture, this includes herbicides (weeds), insecticides (insects), fungicides (fungi), nematocides (nematodes), and rodenticides (vertebrate poisons).
Drinking water is best protected by taking an approach that uses multiple barriers to prevent contamination from affecting our drinking water. Known as the 'multibarrier approach', it includes taking actions to prevent contamination of sources of our water, using adequate water treatment and distribution systems, water testing and training of water managers.
Escherichia coli, also referred to as E. coli, is a type of fecal coliform bacteria that is found in the intestines of healthy warm-blooded animals and humans. Most E. coli strains are harmless and serve a useful function in the body by stopping the growth of harmful bacteria species and by making necessary vitamins. However, some strains can be opportunistic pathogens, while others can cause gastrointestinal illness in healthy humans when ingested.