| AIHA | American Industrial Hygiene Association |
| ANSI | American National Standards Institute |
| AOC | assimilable organic carbon |
| APHA | American Public Health Association |
| ASHRAE | American Society of Heating, Refrigerating and Air-Conditioning Engineers |
| ASTM | American Society for Testing and Materials |
| ATCC | American Type Culture Collection |
| ATP | adenosine triphosphate |
| AWWA | American Water Works Association |
| BAL | bronchoalveolar |
| BCYE | buffered charcoal yeast extract |
| BDOC | biodegradable dissolved organic carbon |
| BMP | best management practice |
| CAPNETZ | Competence Network for Community-Acquired Pneumonia |
| CDC | Centers for Disease Control and Prevention |
| CFR | Code of Federal Regulations |
| CFU | Colony forming units |
| CMS | Centers for Medicare & Medicaid Services |
| CSTE | Council of State and Territorial Epidemiologists |
| CT | computed tomography |
| DALY | Disability-adjusted life years |
| ddPCR | digital droplet PCR |
| DFA | direct fluorescent antibody testing |
| DNA | deoxyribonucleic acid |
| DOHMH | Department of Health and Mental Hygiene |
| DVA | Department of Veterans Affairs |
| DWSD | Detroit Water and Sewerage Department |
| ECDC | European Centers for Disease Control |
| EEA | European Economic Area |
| ELAP | NYS Environmental Laboratory Approval Program |
| ELITE | Environmental Legionella Isolation Techniques Evaluation |
| EMA | ethidium monoazide |
| EPA | Environmental Protection Agency |
| EU | European Union |
| EWGLI | European Working Group for Legionella Infections |
| FDA | Food and Drug Administration |
| FY | fiscal year |
| GAC | granular activated carbon |
| GC | gene copy |
| HIV | human immunodeficiency virus |
| HPC | heterotrophic plate count |
| HVAC | heating, ventilation, and air conditioning |
| IAPMO | International Association of Plumbing and Mechanical Officials |
| ICU | intensive care unit |
| IHC | immunohistochemistry |
| ISO | International Organization for Standardization |
| LEED | Leadership in Energy and Environmental Design |
| Lp | Legionella pneumophila |
| LPS | lipopolysaccharide |
| MCLG | maximum contaminant level goal |
| MIF | mature infectious form |
| MIP | macrophage infectivity potentiator |
| MPN | most-probable-number |
| NNDSS | National Notifiable Disease Surveillance System |
| NORS | National Outbreak Reporting System |
| NSF | National Science Foundation |
| NSFI | National Sanitation Foundation International |
| NYC | New York City |
| NYS | New York State |
| PCR | polymerase chain reaction |
| PEX | cross-linked polyethylene |
| PHB | polyhydroxybutyrate |
| PMA | propodium monoazide |
| POE | point of entry |
| POU | point of use |
| PSPC | Public Service and Procurement Canada |
| PVC | polyvinyl chloride |
| PWGSC | Public Works and Government Services Canada |
| QMRA | quantitative microbial risk assessment |
| qPCR | quantitative PCR |
| RNA | ribonucleic acid |
| SDWA | Safe Drinking Water Act |
| SLDSS | Supplemental Legionnaires’ Disease Surveillance System |
| SQI | Société Québécoise des Infrastructures |
| ST | sequence type |
| S/V | surface-to-volume |
| SWTR | Surface Water Treatment Rule |
| TDS | total dissolved solids |
| TLR | toll-like receptors |
| TNTC | too numerous to count |
| TOC | total organic carbon |
| UAT | urinary antigen test |
| UCMR | Unregulated Contaminant Monitoring Rule |
| USGBC | U.S. Green Building Council |
| UV | ultraviolet |
| VBNC | viable-but-not-culturable |
| VHA | Veterans Health Administration |
| VSP | Vessel Sanitation Program |
| WHO | World Health Organization |