Legionella Testing Services

For Potable and Utility Water

Faster. More Accurate. More Comprehensive.

Common Questions about Legionella Testing

What is Legionella testing?

Legionella testing is the process of obtaining a water sample and analyzing it to detect the presence of the bacteria.

Why are water systems tested for Legionella?

Legionella testing done to confirm effectiveness is defined as validation. Testing for Legionella is done to confirm that a Water Management Program is effective at controlling Legionella, which is defined as a hazard. It is also done to discover the source of exposure after a disease case is reported.

What are the types of Legionella tests?

There are two general types of Legionella tests: Microbial culture tests (spread plates and field sampler “dipslides”) and molecular tests (Polymerase Chain Reaction, PCR). For microbial culture, L. pneumophila serogroup 1, serogroups 2-14 and Legionella spp. should always be determined for every isolate.

Why should my testing service be independent?

An INDEPENDENT, third-party testing service provides improved defensibility by removing real or perceived commercial conflict of interest or bias toward proprietary water treatment solutions.

Where should I test for Legionella?

Sampling locations are decided by the Water Management Team. Locations may include incoming water, showers, misters, ice machines, faucets, cooling towers and decorative water features. Phigenics recommends collecting post-flush samples from plumbing fixtures, when Legionella testing is done as part of routine validation to confirm WMP effectiveness. Call us to learn why.

When should I test for Legionella and how often?

Testing should be undertaken after a Water Management Team has confirmed that a program has been implemented as designed (verification). The frequency of testing is determined by the Water Management Team and is often monthly, quarterly or semi-annually.

How should I respond to a positive Legionella test?

Any response should be predetermined and documented as a “contingency response” in the Water Management Program. Contingency responses should include a review of the verification data and may include activities such as flushing or hyperchlorinating the water system. Call us to learn more.

What is the CDC’s guidance for laboratory selection?

The CDC has five considerations for laboratory expertise: ELITE accreditation, the performance of culture method, level of identification, willingness to save samples and experience with environmental risk assessment and sampling. Click here to see how Phigenics meets the CDC’s criteria.


PVT VIABLE (Viability Identification Assay By Legionella Enrichment) detects viable Legionella bacteria found in building water systems in as little as 72 hours. By combining traditional culture techniques with LegiPlex™, this new method results in our fastest turnaround time and highest sensitivity to date. This innovation also detects stressed Legionella bacteria that are unable to form colonies on the conventional ISO spread plate (Viable But Not Culturable; VBNC). False-negative results in the conventional culture method are now widely recognized as a serious problem because VBNC cells have been proven to be potentially infective and pathogenic.


LegiPlex Info Sheet

High-Value PCR Screening with LegiPlex™

PVT Next Day LegiPlex™ PCR delivers rapid results that confirm the serogroup of Legionella within building water systems. Polymerase Chain Reaction (PCR) analysis is a negative screening method that provides confirmation that there is no Legionella DNA in a water sample. High-Value PCR screening using PVT Next Day LegiPlex™ PCR is extremely cost-effective compared to standard culture testing and can be applied broadly across a building water system.

High-Value PCR Screening Brochure - DOWNLOAD

How are Phigenics Legionella Testing Services
More Defensible than our Competitors?

Faster. More Accurate. More Comprehensive.

PVT TimeZero™
PVt Standard ISO
PVT Premium
  • TimeZero™ test method
  • Total Heterotrophic Aerobic Bacteria (THAB)
  • PVT Next Day LegiPlex™ PCR
  • Standard Legionella 11731 ISO spread plate culture method
PVT Select
  • TimeZero™ test method
  • Total Heterotrophic Aerobic Bacteria (THAB)
  • PVT Next Day LegiPlex™ PCR

How the Phigenics Legionella Testing Services Works?

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Why Phigenics?

The CDC’s Considerations for Laboratory Expertise

Is the laboratory accredited for environmental testing and does it participate in a proficiency testing program for Legionella?

Phigenics Analytical Services Laboratory (PASL) is certified as proficient in the Environmental Legionella Isolation Techniques Evaluation (ELITE) program administered by the CDC.

Does the laboratory perform culture for Legionella?

Phigenics performs the laboratory culture method for both its Phigenics patented PVT TimeZero™ field test and ISO 11731 spread plate method.

What level of identification (species/serogroup) can the laboratory perform?

Phigenics performs comprehensive testing, including Legionella pneumophila (serogroups 1 and 2-14), non-pneumophila and Legionella species.

Is the laboratory willing to save isolates from samples and share them with public health laboratories if requested during an outbreak investigation?

Phigenics saves all isolates of Legionella from all samples and has extensive experience in helping our clients work with public health laboratories and with the CDC.

How much experience does the company have with environmental risk assessments and/or sampling for Legionella?

Phigenics has extensive experience performing environmental risk assessments and sampling for Legionella with facilities of all different types and sizes.

Other Water and Microbacterial Tests

Microbiology Testing:

Legionella Swab Test, Acinetobacter spp., Aspergillus spp., Burkholderia cepacia, Coliforms (total) & Escherichia coli, Fusarium spp., Heterotrophic Plate Count, Mycobacteria, Pseudomonas aeruginosa & Pseudomonas spp., Staphylococcus aureus, Stenotrophomonas maltophilia, LAL/Endotoxin.

Water Chemistry Testing Panels:

Cooling Tower Make Up Analysis, Cooling Tower Water Analysis, Cooling Tower Closed Loop Analysis, Boiler Make Up Analysis, Boiler Make Up Water Analysis - Softened, Boiler Feed Water Analysis, Condensate Water Analysis, Closed Loop Water Analysis - Hot, Closed Loop Water Analysis - Cold, AAMI/ Hemodialysis Water Profile.

Water Chemistry Testing:

Alkalinity "M", Alkalinity "OH", Alkalinity "P", Aluminum, Ammonia as NH3-N, Bicarbonate, Barium, Chloride, Conductivity, Conductivity - Neutralized, Copper - Dissolved, Glycols, Fluoride, Hardness - Calcium, Hardness - Magnesium, Hardness -Total, Iron - Dissolved, Manganese, Molybdenum - Molybdate, Monochloramine, Nitrate, Nitrite (as NaNO2), pH, Phosphate - Ortho, Phosphate - Total Inorganic, Phosphonate, Phosphorus - Total, Potassium, Silica - Reactive, Silicon - (as Silica), Silver, Sodium, Stronium, Sulfate, Tolyltriazole, Total Dissolved Solids, Total Organic Carbon, Turbidity, Zinc.

Safe Drinking Water Act Testing:

Coliforms - Total (SDWA), Copper (SDWA), Inorganic Chemicals (IOC's) (SDWA), Lead (SDWA), Nitrate (SDWA), Nitrite (SDWA), Synthetic Organic Chemicals (SOC's) with Glyphosate, Synthetic Organic Chemicals (SOC's) without Glyphosate, TTHM/HAA5 (Disinfection By-Products) (SDWA),  Volatile Organic Chemicals (VOC's).

Need a quote or have questions about which test is right for your facility?