Legionella Testing Services
Legionella Can’t
Hide From the
Right Test.
Culture (ISO 11731) for total Legionella species · IDEXX Legiolert for L. pneumophila · ASHRAE 188 Water Management Program support. Cooling towers, potable and hot water systems, healthcare facilities — nationwide sample submission accepted.
Legionella Thrives in Building Water Systems.
Cooling towers, hot water heaters, decorative fountains — any water system between 68–122°F is a potential reservoir.
Health Consequences
- Legionnaires’ disease: Severe pneumonia — 5–15% fatal, higher in immunocompromised patients
- Pontiac fever: Non-pneumonic, flu-like illness — rarely fatal but widespread exposure risk
- Spread by inhaling aerosolized water droplets — cooling tower drift, showers, and fixtures are the exposure routes
Where It Grows
- Cooling towers — most common outbreak source; temperature and stagnation create ideal conditions
- Hot water systems — storage tanks, recirculating loops, dead legs, and infrequently used outlets
- Decorative fountains, whirlpool spas, hospital water systems, and ice machines
Regulatory Drivers
- ASHRAE 188: Water Management Plan required for buildings meeting population risk criteria
- NYC Local Law 77: Mandatory cooling tower registration, testing, and reporting to NYC DEP
- CMS QSO-17-30: Healthcare facilities must have water management programs in place
Two Methods. Know Which One the Rule Requires.
Culture (ISO 11731) recovers total Legionella species and is the method regulations name when they require “Legionella culture.” IDEXX Legiolert detects L. pneumophila only — it suits Water Management Program verification but does not substitute for a required culture. If you are unsure which applies, call the laboratory before you sample.
Culture — ISO 11731 (Total Legionella species)
Required Where a Rule Says “Legionella Culture”IDEXX Legiolert (L. pneumophila only)
WMP Verification · Post-Remediation ChecksWhich Test Is Right for Your Situation?
Match your facility type and regulatory trigger to the correct method.
Long TATs are inherent to Legionella culture methods. Plan sampling schedules in advance for LL77 and ASHRAE deadlines. Rush options available — contact us.
When Is Legionella Testing Required?
Four situations that mandate testing — each under a different regulatory framework.
Cooling Towers
(NYC LL77)
- NYC Local Law 77: all cooling towers must register, test, and report to NYC DEP
- Requires Legionella culture by an ELAP-certified laboratory — Legiolert does not substitute
- Response thresholds (10 NYCRR Part 4): act at or above 20 CFU/mL; notify the health department above 1,000 CFU/mL
Healthcare
Facilities (CMS)
- CMS QSO-17-30 (2017): all Medicare/Medicaid facilities must have a Water Management Plan
- WMP must include routine Legionella environmental monitoring
- Positive results require corrective action and notification to CMS
ASHRAE 188
Buildings
- ASHRAE 188: WMP required for buildings meeting population risk criteria
- Sets no numeric limit — it is a process standard; control limits are written into your own WMP
- Covers cooling towers, hot water systems, ornamental fountains, and ice machines
Post-Outbreak
Investigation
- Any Legionnaires’ disease case cluster investigation requires environmental sampling
- Culture with serogroup typing enables comparison to patient clinical isolates for source attribution
- Cooperate with the local health department — report results as directed by the primacy agency
From Sample Collection to WMP Documentation.
Results are reported in CFU/mL (culture) or MPN/100 mL (Legiolert), referenced to the applicable regulatory thresholds or your Water Management Program control limits, in a format built for WMP recordkeeping.
Schedule & Confirm
Confirm your facility type, the regulatory requirement, and the method (culture, Legiolert, or both). IRIS provides the collection protocol, sterile sodium-thiosulfate bottles, and chain-of-custody forms.
Schedule Testing →Collect Water Samples
Sterile sodium-thiosulfate bottles. Cooling towers: sample the basin away from the biocide injection point. Potable and hot water: take a first draw — do not flush or remove the aerator. Leave 1–2 cm of headspace.
Ship Overnight
Ship same day as collection. Keep at 4°C — do not freeze. Pre-paid FedEx overnight label included. Analysis begins on the day of receipt at IRIS.
Report + WMP Documentation
CFU/mL with optional serogroup typing (culture) or MPN/100 mL (Legiolert). Includes threshold comparison, corrective-action trigger language, and a WMP record format.
TAT: Culture (ISO 11731) reported in 10–14 days · Legiolert reported in 8–10 days (7-day incubation). Plan sampling ahead of LL77 and ASHRAE deadlines.
Collect the Sample Right the First Time.
Download the field guide before you sample, and watch the walkthrough. Re-sampling costs more than a few minutes of preparation.
Legionella Sample Collection Field Guide
Two-page field guide: kit checklist, cooling tower and potable/hot water procedures, preservation and shipping, response thresholds, and method turnarounds.
Download PDFSchedule Your
Legionella Testing.
Culture (ISO 11731) for total Legionella species. IDEXX Legiolert for L. pneumophila. ASHRAE 188 · NYC LL77 · CMS water management program support. WMP documentation included.