Significance and Use
5.1 This test provides an easy and reliable method for the detection of L. pneumophila in potable and non-potable waters in 7 days.
5.2 Routine monitoring for L. pneumophila determines whether implemented control measures are effective, such as those outlined in a water safety program (2).
5.2.1 Water system management is necessary to maintain L. pneumophila concentrations below hazardous levels. Through routine measurement of L. pneumophila levels, a monitoring program can ensure that control measures are effective and implemented when necessary in response to increasing levels. Water samples may be examined for L. pneumophila during epidemiological investigations as part of local authority, industrial, or hospital programs, or in order to validate treatment control methods. Routine sampling could also be carried out based on risk assessments or on local, state, or federal requirements or guidelines.
Scope
1.1 This test method describes a simple procedure for the detection of Legionella pneumophila (L. pneumophila) in potable water and non-potable waters (cooling towers, for example). This procedure describes a liquid culture method based on a bacterial enzyme technology. The detection of L. pneumophila is signaled through the utilization of a substrate present in the Legiolert reagent. L. pneumophila cells grow rapidly and reproduce using the rich supply of amino acids, vitamins and other nutrients present in the Legiolert reagent. Actively growing strains of L. pneumophila use the added substrate to produce a brown color indicator or produce turbid growth with or without brown coloration. Legiolert can detect this bacterial species at the following minimum concentrations based on the protocol employed:
1.1.1 Potable Water:
1.1.1.1 ≥1 organism / 100 mL at 7 days for 100 mL potable protocol.
1.1.1.2 ≥1 organism / 10 mL at 7 days for 10 mL potable protocol.
1.1.2 Non-potable Water:
1.1.2.1 ≥1 organism / 1.0 mL at 7 days for 1.0 mL non-potable protocol.
1.1.2.2 ≥1 organism / 0.1 mL at 7 days for 0.1 mL non-potable protocol.
1.1.3 This test method can be used for potable (drinking) waters and non-potable waters such as cooling tower waters (1).3 It is the user’s responsibility to ensure the validity of this test method for waters of untested matrices.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
