Bacteria In Water
Bacteria and related single-celled organisms are increasingly recognized for their importance in decomposing organic material, processing minerals and nutrients, and in some cases converting carbon dioxide to new plant material.
From a water quality perspective, we are mostly concerned about the role bacteria play in diseases.
Unsafe drinking water from water borne pathogens have enormous impacts across the world.
According to the World Health Organization:
- Over 2 billion people today do not have access to proper sanitation,
- more than 1 million people obtain their water from contaminated sources.
- Diarrhea caused by water borne pathogens is a leading cause of illness and death in much of the world.
- Over 2 million people (mostly children) die each year from water borne bacteria such as Shigella.
Even in the U.S. water-borne pathogens are of concern. In Utah, drinking water and drinking water sources are tested regularly for E coli. This particular bacterium does not necessarily cause disease, but it is found in the intestines of warm blooded animals. Presence of E coli suggests possible fecal contamination.
WHAT ARE COLIFORM BACTERIA?
Coliform bacteria, including E. coli, are common microscopic organisms. They originate in the intestinal tract of warm blooded animals and may also be found in soil and vegetation.
WHY CARE ABOUT COLIFORM BACTERIA?
Most coliform bacteria are harmless but their presence indicate the possible presence of disease causing bacteria, viruses or parasites from sources such as raw sewage. These organisms can cause a number of diseases, such as:
- typhoid fever
- hemolytic uremic syndrome
Utah surface water standards
Drinking water sources: 668*
Contact recreation: 409*
* maximum colonies / 100 ml
NOTE: Drinking water standards vary with the size of the system. See Utah Drinking Water Standards (microbiological quality)
HUMAN FACTORS INFLUENCING COLIFORM BACTERIA AND HOW TO TREAT IT
Most coliform bacteria enter streams or rivers through direct deposition of waste in the water and runoff from areas with high concentrations of animals. Domesticated animals contribute heavily to bacterial pollution. Runoff from woodlands, septic tanks, and sewage plants may also cause an increase in coliform and other bacterial pollution. If you rely on a public water system then your water provider is responsible for the testing and treatment of your water. If they find it they will notify you within 24 hours and might issue a "Boil Order" notice.
Escherichia coli (commonly known as E. coli) is a single species in the fecal coliform group. It is a bacterium that is found in the intestines of humans and other warm blooded animals. E. coli does not occur naturally in soil nor vegetation. It will only enter water from fecal contamination.
WHY CARE ABOUT E. COLI?
According to the United States Environmental Protection Agency (USEPA) E. coli is the best indicator of health risk from water contact in recreational waters. The presence of E. coli in water is an indication of recent contamination from sewage or animal wastes, which may have many disease-causing organisms. Although most strains of E. coli are harmless, E. coli O157:H7 can infect you from water contamination and may cause severe diarrhea (sometimes bloody) and abdominal cramps. In some people (children under 5 and the elderly particularly) an infection can cause a complication referred to as hemolytic uremic syndrome. In this syndrome red blood cells are destroyed and kidneys fail. Approximately 2-7% of infections lead to this complication. It is a life-threatening condition that usually needs to be treated in an intensive care unit.
HOW IS E. COLI MONITORED
Priority recreational waters are monitored monthly in Utah from May - October by the Division of Water Quality and partner cooperators. The method used to collect this data is IDEXX. Utah Water Watch (UWW) helps with the collection of some of these samples and follow the state protocols. Consistant high levels of E. coli can lead to the closing of public beaches.
Additionally, UWW volunteers collect data through their Tier 1 monitoring using a Coliscan Easygel method. This data collection method is less rigorous, but can be used for scanning and educational purposes.
Drinking water is monitored more frequently.
If you rely on a public water system, the USEPA requires these systems to monitor for coliform bacteria. Total coliform is analyzed first because the test produces results faster. Any sample that comes back positive for total coliform must be analyzed for either fecal coliform or E. coli, which indicate contamination of animal waste or human sewage. Most water companies will send out an annual Consumer Confidence Report which discloses contaminants found, possible health effects, and the water’s source. This report is generally sent in July with your water bill. If you do not receive a report, contact your water company for this information. Private water systems are more involved. Check out this Coliform Bacteria factsheet. For more information on testing and treating public and private water systems, visit our Drinking Water page.
The Utah Division of Water Quality (UDWQ) has a monitoring program for E. coli. Unfortunately it is impossible to test all waters where people may recreate because monitoring resources are limited. Hence, E. coli monitoring is focused on places where most people recreate. In Utah there are 31 lakes and reservoirs that have been identified as highly recreated bodies of water and are currently being monitored for E. coli. Sampling of these bodies of water occurs from May through October each year. In the future UDWQ intends to sample every lake and reservoir in the state.
- Fecal Bacteria (USEPA)
- Coliform (fact sheet)
- Pathogens in Drinking Water (USEPA)
- E. coli Monitoring (UDWQ)
- Land and activity influences on water quality
- Protect your land from pollution