Microbiological contamination of water has been a big concern to the publicity for a long time. The bacillus which causes typhoid fever was considered a major problem in the water supply in 1920’s-1960’s. After it was stumped up, new microbes edge out its place. In some parts of the United States, people concern about increasing due to outbreaks of coliform bacteria, giardiasis, cryptosporidiosis, and hepatitis A (1,2,3). Because some of these are bacteria, while others ones are viruses or protozoa. If you are using public water supply system, and you are worried about the possibility of microbial contamination, contact with your water company. If you are on a private water supply, you need to do comply water’s test. If it’s need so you have to treat your water supply.

There are some types of bacteria, viruses and microorganisms:

Coliform Bacteria

Coliform bacteria live in soil or vegetation and in the gastrointestinal tract of animals. Coliforms seep to water supplies from the direct disposal of waste into streams or lakes, or from runoff from wooded areas, pastures, feedlots, septic tanks, and sewage plants into streams or groundwater. In addition, coliforms can enter an individual house via backflow of water from a contaminated source, carbon filters, or leaking well caps that allow dirt and dead organisms to fall into the water.

Giardia Lamblia

Giardia has become more prevalent in the past few years as a waterborne disease, and a few large outbreaks that have occurred in the U.S. Giardia are famous as protozoa that is parasitic in the intestines of humans and animals. They have two stages, one of which is a cyst form that can be ingested from contaminated water. Once the cyst enters the stomach, the organism is released into the gastrointestinal tract where it will adhere to the intestinal wall. Eventually the protozoa will move into the large intestine where they encyst again and are excreted in the feces and back into the environment.


Cryptosporidium parvum is a protozoan parasite that causes cryptosporidiosis, which has gained notoriety in the past five yearsю Since outbreak 1993, there has been a greater impetus to remove the cryptosporidium from municipal water supplies.

Cryptosporidium is spread by the transmission of oocysts via drinking water which has been contaminated with infected fecal material. Oocysts from humans are infective to humans and many other mammals, and many animals act as reservoirs of oocysts which can infect humans.

Hepatitis A:

Hepatitis A is an enteric virus that is very small. It can be transferred through contaminated water, causing outbreaks. The virus is excreted by a person carrying it, and if the sewage contaminates the water supply, then the virus is carried in the water until it is consumed by a host. Symptoms such as an inflamed liver, accompanied by lassitude, anorexia, weakness, nausea, fever and jaundice are common. A mild case may only require a week or two of rest, while a severe case can result in liver damage and possible death.


Helminths are parasitic worms that grow and multiply in sewage and wet soil. They enter the body by burrowing through the skin, or by ingestion of the worm in one of its many lifecycle phases. The eggs as well as the adult and larval forms of the worms are large enough to be trapped during conventional water treatments, so they tend not be a problem in water systems. In addition, most of these helminths are not waterborne, so chances of infection are minimized.

That is why you need to care about water which you drink for awareness what you drink and avoid some diseases.