Overview
ISO 7899-2:2000 is an internationally recognized standard published by the International Organization for Standardization (ISO) for assessing water quality through the detection and enumeration of intestinal enterococci using the membrane filtration method. This microbiological method plays a vital role in ensuring public health by identifying faecal contamination in various types of water, such as drinking water, swimming pool water, and other disinfected or clean waters. The approach is particularly suitable for large water volumes with low concentrations of enterococci and is integral for routine water monitoring in compliance with regulatory and safety standards.
Key Topics
- Membrane Filtration Technique: This method requires filtering a measured volume of a water sample through a membrane filter with a pore size of 0.45 μm, which retains bacteria. After filtration, the membrane is placed on a selective growth medium.
- Detection and Confirmation: Typical enterococci colonies are identified by their color on selective media, followed by confirmation on a bile-aesculin-azide agar at 44°C.
- Sampling and Preparation: Proper sample collection and handling in accordance with referenced ISO standards ensure accurate and reliable results. Prompt start of analysis after sampling is crucial.
- Quality Assurance: Laboratories must implement defined quality control protocols to validate the suitability of materials, reagents, and techniques used.
- Test Reporting: Results must include detailed sample identification, the number of confirmed enterococci colonies, and any deviations or phenomena observed during testing.
Applications
The ISO 7899-2:2000 standard is widely applied in the following areas:
- Drinking Water Monitoring: Ensures water qualifies as safe for human consumption by detecting faecal pollution indicators.
- Swimming Pool and Recreational Water Testing: Verifies the effectiveness of disinfection processes and the absence of harmful microbiological contamination in public and private pools.
- Clean and Disinfected Water: Assesses water quality in regulated environments, such as bottled water production, food processing, and pharmaceutical industries.
- Environmental Water Analysis: Used by environmental agencies and laboratories to monitor rivers, lakes, and reservoirs for public health protection.
- Regulatory Compliance: Supports adherence to national and international water quality regulations that mandate the detection of intestinal enterococci as a microbial safety indicator.
Related Standards
ISO 7899-2:2000 references several other key international standards to ensure methodological rigor and consistency:
- ISO 3696: Water for analytical laboratory use - Specification and test methods.
- ISO 5667-1, ISO 5667-2, ISO 5667-3: Guidance on sampling, sampling techniques, and handling of water samples.
- ISO 6887-1: Microbiology of food and animal feeding stuffs - Preparation of test samples.
- ISO 8199: General guide to the enumeration of micro-organisms by culture.
- ISO 7704: Evaluation of membrane filters used for microbiological analyses.
- ISO/IEC Guide 2: Standardization and related activities - General vocabulary.
These standards provide comprehensive guidance for all aspects of water sample collection, processing, and analysis, enhancing the practical value of ISO 7899-2:2000 in laboratory and field applications.
Practical Value
Implementing ISO 7899-2:2000 ensures:
- Reliable detection of waterborne pathogens
- Compliance with water quality regulations
- Public health protection through early identification of faecal contamination
- Consistent, reproducible results across laboratories and regulatory frameworks
By following ISO 7899-2:2000, laboratories, water providers, and regulatory bodies can maintain high standards of water safety and regulatory compliance in their water quality monitoring programs.
Open preview (PDF)Water quality — Detection and enumeration of intestinal enterococci — Part 2: Membrane filtration method