MICROBIOLOGICAL WATER ANALYSIS
Microbiological water analysis is one of the most important water quality tests that deals with identification and enumeration of microorganisms in water samples. These microorganisms may be bacteria, viruses, protozoa, and fungi, which, if found in drinking water or water used for recreational purposes, can be dangerous to human health. The main goal of microbiological water analysis is to make sure that water is safe for use by humans.
Importance of Water Quality Testing
- Public Health: The identification of pathogenic microorganisms in water is crucial for the health of the population. Waterborne diseases include cholera, dysentery, and gastroenteritis, which are diseases caused by contaminated water.
- Regulatory Compliance: Water utilities and treatment facilities are bound by regulatory guidelines that demand frequent microbiological analysis to determine the quality of water.
- Environmental Protection: The presence of microorganisms in natural water bodies can be used to evaluate the state of water and the possible effects of pollution.
Key Microbiological Tests
- Total Coliform Test
- Purpose: Suggests the existence of a wide range of bacteria that are known to be present in the environment such as soil, vegetation, and water surface.
- Method: Involves the use of membrane filtration or multiple-tube fermentation to identify the presence of coliform bacteria.
- Significance: Total coliforms indicate that there could be a route through which pathogens can access the water system.
- Fecal Coliform/E. coli Test
- Purpose: Focused on coliform bacteria that are attributed to fecal pollution, including Escherichia coli (E. coli).
- Method: Some of the methods include membrane filtration, enzyme substrate tests, or multiple-tube fermentation methods.
- Significance: Presence of fecal coliforms or E. coli suggests recent fecal pollution and higher probability of pathogenic bacteria.
- Heterotrophic Plate Count (HPC)
- Purpose: Counts the total number of culturable heterotrophic bacteria in water.
- Method: This involves culturing bacteria on nutrient rich agar plates and counting the number of colonies that develop.
- Significance: HPC gives a general picture of bacterial load and water treatment efficiency.
- Legionella Test
- Purpose: Identifies Legionella bacteria, which are responsible for Legionnaires’ disease, a severe type of pneumonia.
- Method: Plating on selective media, PCR or immunoassay.
- Significance: Essential for observing water systems such as cooling towers and hot water tanks where Legionella can grow.
- Enterococci Test
- Purpose: Detects the occurrence of Enterococcus bacteria that are associated with fecal pollution in marine and fresh recreational water.
- Method: Membrane filtration, enzyme substrate tests, or multiple-tube fermentation methods.
- Significance: Therefore, enterococci are good predictors of water quality for recreational use.
Sample Collection and Handling
Proper sample collection and handling are vital to obtaining accurate microbiological results:
- Sterilized Containers: It is recommended to use sterilized and sealed containers to avoid contamination.
- Storage and Transport: Samples should be stored at low temperatures and should be taken to the laboratory as soon as possible.
- Chain of Custody: It is also important to keep a record of sample collection, handling, and analysis to avoid any loss of data.
Conclusion
Water testing for microorganisms is crucial in protecting the health of the population and water used for drinking and recreation. Through routine monitoring for coliforms, E. coli, and Legionella, water utilities and regulatory bodies can detect possible contamination and act to safeguard consumers.