No, but you must Validate that your plan is effective, and the only way to know for certain is to actually test the water. Testing the water may be more important for healthcare facilities providing inpatient services to people with an increased risk for Legionnaires’ disease; or when there is difficulty maintaining control limits, such as disinfectant residuals, in the building water system.

Precept always recommends utilizing the culture method for Legionella bacteria, performed by a CDC Elite lab, which takes 7-14 days. Additionally, the CDC prefers this method for evaluating growth trends. Alternative testing methods that may promise quick results are often a waste of time and money, as they need to be validated against a standard method.

Legionella bacteria is difficult to grow and isolate in an environmental laboratory. Only a CDC Elite lab should be considered to ensure accurate results from your water samples. The prescribed culture time allows for slower growing Legionella species to be observed and avoid false negative results; therefore, faster results are not achievable without compromising accuracy.

The CDC Toolkit for Developing a Water Management Program lists two options for Validating a Water Management Program: 1) Environmental testing for Legionella, 2) Checking disinfectant residuals, such as chlorine, in the building water system. 
If a “quick result” test is offered, it often will need to be validated against the traditional culture method anyway, which can lead to ambiguity in how to respond to unfavorable results.

Precept recommends that there be a plan in place before testing is done. This enables the Water Safety Team to adequately prepare for any outcome. Corrective actions should be specific to your facility and performed according to your Water Management Plan. If you don't have a plan in place, Precept can assist with recommendations.