Water Testing: IS 10500 Standards Covering Microbiological Parameters, Viruses, Radioactivity, Parasites, Virological Requirements
Are you in the packaged drinking water or food business and concerned about the safety and quality of your products?
The Bureau of Indian Standards (BIS) has established guidelines for drinking water quality, specifically the IS 10500:2012 standard, and IS 1602:2001. It covers comprehensive water testing for microbiological parameters, viruses, radioactivity, and parasites to ensure safe and high-quality drinking water for consumers.
By adhering to the IS 10500:2012 standard, you can ensure that your products meet the highest standards of safety and quality. This will not only protect your customers but also enhance your reputation as a trusted provider of safe drinking water and food products.
The IS 10500 standard is focused on preventing waterborne diseases through microbiological parameters. It sets limits for microbial indicators like total coliform bacteria, fecal coliform bacteria, Escherichia coli, and aerobic microbial count. To test these parameters, various methods are used, such as:
Multiple-Tube Fermentation Technique
This method involves inoculating water samples into multiple tubes containing specific culture media to detect coliform bacteria. The presence of gas and color change indicates the presence of coliforms.
Membrane Filtration Technique
To test for coliform bacteria and E. coli, water samples go through a 0.45-micron membrane filter. Next, the filter is put on a selective agar medium, which helps the bacteria grow and be counted.
MS2 phage viruses are indicators of viral contamination in drinking water. MS2 phage shall be absent per liter of water when tested in accordance with US EPA method 1602. To comply, different testing methods for viruses can be used.
Polymerase Chain Reaction (PCR)
PCR is a molecular technique that can detect viral genetic material in water samples. It is highly sensitive and can identify specific viruses like enteric viruses. This is done through amplification and analysis of target gene sequences.
Enzyme-Linked Immunosorbent Assay (ELISA)
ELISA is a method for detecting viral antigens in water samples. It uses antibodies that bind to viral proteins and creates a color change, indicating the virus’s presence. This immunological method is effective for detecting viruses in water.
The issue of radioactivity in drinking water is addressed in IS 10500. It sets limits for radioactive elements such as alpha and beta emitters, radium, and uranium.
This method measures the energy spectrum of gamma radiation emitted by radioactive isotopes in water samples. It allows for the identification and quantification of specific radionuclides present in the water.
Liquid Scintillation Counting
This technique involves mixing water samples with a scintillation cocktail that produces light when exposed to radiation. The emitted light is then detected and counted, providing information about the presence and concentration of radionuclides.
While IS 10500 does not explicitly mention testing methods for parasites such as Giardia and Cryptosporidium, it requires water to be free from pathogenic organisms. To ensure compliance and detect the presence of parasites, the following methods are employed:
Filtration and Immunofluorescence Assay (IFA)
Water samples are filtered through a specialized filter membrane, capturing parasites present in the water. The filter is then treated with fluorescent antibodies specific to the parasites, enabling their identification through microscopic examination.
Polymerase Chain Reaction (PCR)
As mentioned earlier, PCR can also be utilized for the detection of parasites in water. Specific primers are used to amplify parasite DNA or RNA, which is then analyzed to determine the presence of parasites.
IS 10500 covers various other parameters to ensure the safety and quality of drinking water. Some of these parameters include pH, turbidity, total dissolved solids (TDS), chemical contaminants (such as heavy metals, pesticides, and organic compounds), and odor and taste.
pH and Turbidity: pH measures the acidity or alkalinity of water, with the standard specifying a range of 6.5 to 8.5. Turbidity refers to the clarity of water and indicates the presence of suspended particles. Both pH and turbidity can be measured using standard testing equipment and methods.
Total Dissolved Solids (TDS)
TDS represents the total concentration of dissolved substances in water. It is determined by measuring the electrical conductivity of the water sample and calculating the TDS concentration. Excessive TDS levels can affect water taste and quality.
IS 10500 sets maximum permissible limits for various chemical contaminants in drinking water. Testing methods for chemical parameters include spectrophotometry, atomic absorption spectroscopy, and chromatography techniques, depending on the specific contaminant being analyzed.
Odor and Taste
While subjective, water should be free from objectionable odor and taste. These characteristics can be assessed through sensory evaluation by trained individuals or through specialized equipment designed to detect and measure odor and taste compounds.
Compliance and Water Testing Laboratories
To ensure compliance with the IS 10500 standard and to guarantee the safety of drinking water, it is essential to rely on accredited water testing laboratories. These laboratories employ trained personnel and follow standardized testing protocols and quality assurance measures.
Revisions and Virological Requirements in the Indian Standard for Drinking Water:
The Indian Standard for drinking water, IS 10500, originally published by the Bureau of Indian Standards (BIS) in 1983, has undergone significant revisions, with the latest one carried out in 2012.
The 2012 revision incorporated additional requirements for tests such as ammonia, chloramines, barium, molybdenum, silver, sulfide, nickel, Polychlorinated biphenyls, and trihalomethanes. It also modified the requirements for color, turbidity, total hardness, free residual chlorine, iron, magnesium, mineral oil, boron, cadmium, total arsenic, lead, polynuclear aromatic hydrocarbons, pesticides, as well as bacteriological requirements.
The standard clearly defines acceptable and permissible limits for each test parameter, with samples required to comply with the acceptable limit. Permissible limits are applicable only when an alternate source of drinking water is not available.
A significant change made in the 2012 revision was the inclusion of virological requirements. The standard now mandates that all samples taken from the distribution system, including consumer premises, should be free from viruses.
The standard highlights that viruses are resistant to disinfectants and are detected by the presence of particulate inorganic matter in water. It emphasizes that the absence of coliform organisms does not ensure the absence of active viruses, as the resistance of viruses to disinfection differs from that of coliform organisms due to the concentration of reducing components like organic matter.
To address this issue, the standard calls for testing the presence of MS2 phage as an indicator of viral contamination in drinking water. It states that 1 L of water should be free from MS2 phage when tested using the US EPA Method 1602. If MS2 phage is detected, further virological examination should be carried out using the polymerase chain reaction method.
Considering the serious health hazards associated with the presence of viruses in drinking water, the standard emphasizes that if viruses are detected, appropriate action should be taken, and immediate investigations must be conducted.
Auriga Research offers comprehensive testing services in line with the IS 10500 standards, covering a wide range of parameters including microbiological analysis, virus detection, radioactivity testing, and parasite identification. Our state-of-the-art laboratories and expert team ensure accurate and reliable results for assessing the safety and quality of water.
Our water testing laboratory has established and standardized the US EPA Method 1602 for the detection of MS2 phage. We are also accredited by the National Accreditation Board for Testing and Calibration Laboratories (NABL) for conducting this test in water, ensuring reliable and accurate results.
We employ validated methods and advanced technologies to test for microbiological contaminants, detect viruses using molecular techniques, analyze radioactivity levels, and identify parasites in water samples. With our commitment to excellence and adherence to regulatory standards, we provide trusted testing services that help safeguard public health and ensure compliance with water quality requirements.
For any query you can Contact us or fill out our Query form, call us now on +91-8588851888 or drop an e-mail to [email protected]. We will be happy to provide you with a proposal for your testing requirements.