scholarly journals Geologic Assessment and Recommended New Well Locations to Improve the Area 25 Potable Water System, Nevada National Security Site

2021 ◽  
Author(s):  
Jennifer Larotonda ◽  
Margaret Townsend
Keyword(s):  
National Security ◽  
Potable Water ◽  
Water System

scholarly journals Legionnaires' Disease Outbreak at a Resort in Cozumel, Mexico

2016 ◽  
Vol 3 (3) ◽  
Author(s):  
Lee M. Hampton ◽  
Laurel Garrison ◽  
Jessica Kattan ◽  
Ellen Brown ◽  
Natalia A. Kozak-Muiznieks ◽  
...  
Keyword(s):  
United States ◽  
Potable Water ◽  
Water System ◽  
Disease Outbreak ◽  
Community Acquired Pneumonia ◽  
Health Departments ◽  
Medical Providers ◽  
Cozumel Island ◽  
European Working ◽  
Legionnaires Disease

Abstract Background.  A Legionnaires' disease (LD) outbreak at a resort on Cozumel Island in Mexico was investigated by a joint Mexico-United States team in 2010. This is the first reported LD outbreak in Mexico, where LD is not a reportable disease. Methods.  Reports of LD among travelers were solicited from US health departments and the European Working Group for Legionella Infections. Records from the resort and Cozumel Island health facilities were searched for possible LD cases. In April 2010, the resort was searched for possible Legionella exposure sources. The temperature and total chlorine of the water at 38 sites in the resort were measured, and samples from those sites were tested for Legionella. Results.  Nine travelers became ill with laboratory-confirmed LD within 2 weeks of staying at the resort between May 2008 and April 2010. The resort and its potable water system were the only common exposures. No possible LD cases were identified among resort workers. Legionellae were found to have extensively colonized the resort's potable water system. Legionellae matching a case isolate were found in the resort's potable water system. Conclusions.  Medical providers should test for LD when treating community-acquired pneumonia that is severe or affecting patients who traveled in the 2 weeks before the onset of symptoms. When an LD outbreak is detected, the source should be identified and then aggressively remediated. Because LD can occur in tropical and temperate areas, all countries should consider making LD a reportable disease if they have not already done so.

scholarly journals Human Health Impact of Cross-Connections in Non-Potable Reuse Systems

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1352 ◽  
Author(s):  
Mary Schoen ◽  
Michael Jahne ◽  
Jay Garland
Keyword(s):  
Potable Water ◽  
Reclaimed Water ◽  
Water System ◽  
Health Impact ◽  
Quantitative Microbial Risk Assessment ◽  
Pathogen Inactivation ◽  
Microbial Infection ◽  
Microbial Risk Assessment ◽  
Potable Reuse ◽  
Contamination Event

We used quantitative microbial risk assessment (QMRA) to estimate the microbial risks from two contamination pathways in onsite non-potable water systems (ONWS): contamination of potable water by (treated) reclaimed, non-potable water and contamination of reclaimed, non-potable water by wastewater or greywater. A range of system sizes, event durations, fraction of users exposed, and intrusion dilutions were considered (chlorine residual disinfection was not included). The predicted annual microbial infection risk from domestic, non-potable reuse remained below the selected benchmark given isolated, short-duration intrusion (i.e., 5-day) events of reclaimed water in potable water. Whereas, intrusions of wastewater into reclaimed, non-potable water resulted in unacceptable annual risk without large dilutions or pathogen inactivation. We predicted that 1 user out of 10,000 could be exposed to a 5-day contamination event of undiluted wastewater in the reclaimed, non-potable water system each year to meet the annual benchmark risk of 10−4 infections per person per year; whereas, 1 user out of 1000 could be exposed to a 5-day contamination event of undiluted reclaimed water in the potable water each year. Overall, the predicted annual risks support the use of previously derived non-potable reuse treatment requirements for a variety of ONWS sizes and support the prioritization of protective measures to prevent the intrusion of wastewater into domestic ONWS.

scholarly journals Lessons From an Outbreak of Legionnaires’ Disease on a Hematology-Oncology Unit

2016 ◽  
Vol 38 (3) ◽  
pp. 306-313 ◽  
Author(s):  
Louise K. Francois Watkins ◽  
Karrie-Ann E. Toews ◽  
Aaron M. Harris ◽  
Sherri Davidson ◽  
Stephanie Ayers-Millsap ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Potable Water ◽  
Single Case ◽  
Healthcare Providers ◽  
Water System ◽  
Positive Sequence ◽  
Environmental Isolates ◽  
Legionnaires Disease ◽  
Oncology Unit ◽  
Healthcare Associated

OBJECTIVESTo define the scope of an outbreak of Legionnaires’ disease (LD), to identify the source, and to stop transmission.DESIGN AND SETTINGEpidemiologic investigation of an LD outbreak among patients and a visitor exposed to a newly constructed hematology-oncology unit.METHODSAn LD case was defined as radiographically confirmed pneumonia in a person with positive urinary antigen testing and/or respiratory culture forLegionellaand exposure to the hematology-oncology unit after February 20, 2014. Cases were classified as definitely or probably healthcare-associated based on whether they were exposed to the unit for all or part of the incubation period (2–10 days). We conducted an environmental assessment and collected water samples for culture. Clinical and environmental isolates were compared by monoclonal antibody (MAb) and sequence-based typing.RESULTSOver a 12-week period, 10 cases were identified, including 6 definite and 4 probable cases. Environmental sampling revealedLegionella pneumophilaserogroup 1 (Lp1) in the potable water at 9 of 10 unit sites (90%), including all patient rooms tested. The 3 clinical isolates were identical to environmental isolates from the unit (MAb2-positive, sequence type ST36). No cases occurred with exposure after the implementation of water restrictions followed by point-of-use filters.CONCLUSIONSContamination of the unit’s potable water system with Lp1 strain ST36 was the likely source of this outbreak. Healthcare providers should routinely test patients who develop pneumonia at least 2 days after hospital admission for LD. A single case of LD that is definitely healthcare associated should prompt a full investigation.Infect Control Hosp Epidemiol2017;38:306–313

Interactions Between Biotic and Abiotic Factors and Viruses in a Water System

1985 ◽  
Vol 17 (10) ◽  
pp. 139-151 ◽  
Author(s):  
R. Walter ◽  
J. Dürkop ◽  
B. Friedman ◽  
H. J. Dobberkau
Keyword(s):  
River Water ◽  
Hepatitis A ◽  
Potable Water ◽  
Abiotic Factors ◽  
Water System ◽  
Industrial Effluents ◽  
Virus Content ◽  
Sampling Points ◽  
Distributed Sampling

A river intensively used along its entire course for extracting potable water and for discharging domestic and industrial effluents permanently carries a high load of viruses, including hepatitis A and rotaviruses. In the areas supplied with potable water from this river hepatitis A is endemic. The river has been investigated four times at 16 or more sampling points throughout its course in the years 1981, 1982 and 1983. Coincident with the virological investigation, biological, microbiological and chemical examinations were conducted with the same water sample. At some representatively distributed sampling points along the river course, tests for heavy metals (Cd, Ni, Cu, Cr, Pb) and selected chemical compounds were also performed. The virological quality of the river water largely depends on the virus input via domestic sewage. Statistically significant correlations have been found between virus level, pH, NH4+ and NO3−. Amoebae species are likely to counteract viruses. Knowing the dynamics of river water exploitation above the extraction sites, a model for the estimation of virus content in the raw water could be developed.

scholarly journals Introduction of Monochloramine into a Municipal Water System: Impact on Colonization of Buildings by Legionella spp

2006 ◽  
Vol 72 (1) ◽  
pp. 378-383 ◽  
Author(s):  
Matthew R. Moore ◽  
Marsha Pryor ◽  
Barry Fields ◽  
Claressa Lucas ◽  
Maureen Phelan ◽  
...  
Keyword(s):  
Potable Water ◽  
Sampling Site ◽  
Water System ◽  
Water Source ◽  
Water Systems ◽  
Hot Water ◽  
County Government ◽  
Single Family ◽  
Pinellas County ◽  
Municipal Water

ABSTRACT Legionnaires' disease (LD) outbreaks are often traced to colonized potable water systems. We collected water samples from potable water systems of 96 buildings in Pinellas County, Florida, between January and April 2002, during a time when chlorine was the primary residual disinfectant, and from the same buildings between June and September 2002, immediately after monochloramine was introduced into the municipal water system. Samples were cultured for legionellae and amoebae using standard methods. We determined predictors of Legionella colonization of individual buildings and of individual sampling sites. During the chlorine phase, 19 (19.8%) buildings were colonized with legionellae in at least one sampling site. During the monochloramine phase, six (6.2%) buildings were colonized. In the chlorine phase, predictors of Legionella colonization included water source (source B compared to all others, adjusted odds ratio [aOR], 6.7; 95% confidence interval [CI], 2.0 to 23) and the presence of a system with continuously circulating hot water (aOR, 9.8; 95% CI, 1.9 to 51). In the monochloramine phase, there were no predictors of individual building colonization, although we observed a trend toward greater effectiveness of monochloramine in hotels and single-family homes than in county government buildings. The presence of amoebae predicted Legionella colonization at individual sampling sites in both phases (OR ranged from 15 to 46, depending on the phase and sampling site). The routine introduction of monochloramine into a municipal drinking water system appears to have reduced colonization by Legionella spp. in buildings served by the system. Monochloramine may hold promise as community-wide intervention for the prevention of LD.

Comparison of two molecular methods used for subtyping of Legionella pneumophila 1 strains isolated from a hospital water supply

2008 ◽  
Vol 58 (3) ◽  
pp. 683-688 ◽  
Author(s):  
B. Casini ◽  
P. Valentini ◽  
A. Baggiani ◽  
F. Torracca ◽  
C. Lorenzini ◽  
...  
Keyword(s):  
Water Supply ◽  
Legionella Pneumophila ◽  
Potable Water ◽  
Water System ◽  
Epidemiological Studies ◽  
Molecular Methods ◽  
Pfge Analysis ◽  
Typing Method ◽  
Electrophoretic Patterns ◽  
Low Degree

The results of the pulsed-field gel electrophoresis and the sequence-based typing (using the loci flaA, pilE, asd, mip, mompS and proA) were compared for subtyping of Legionella pneumophila 1 strains isolated from a hospital water supply. Molecular typing was carried out on 61 isolates (38% of the positive samples) selected on space and temporal criteria in order to follow the evolution of the water-system colonization. For all the 61 isolates, the sequence of the amplified mip gene fragment identified Legionella pneumophila strain Wadsworth. Genotype testing by PFGE analysis showed three different patterns, correspondent to three SBT types according to the allelic profiles. Both PFGE and SBT indicated the circulation and the persistence in the hospital potable water-system of three types randomly distributed in space and time. The two molecular methods adopted showed a 100% concordance, although a low degree of genetic heterogeneity characterized the isolates. The electrophoretic patterns were sufficiently unambiguous to consider PFGE a highly discriminatory typing method, but the SBT technique besides accurately characterizing isolates, was able to identify Legionella strains through analysis of the mip gene. A typing method with this level of discriminatory power has great potential for assisting in epidemiological studies.

Point-of-Use Membrane Filtration and Hyperchlorination to Prevent Patient Exposure to Rapidly Growing Mycobacteria in the Potable Water Supply of a Skilled Nursing Facility

2011 ◽  
Vol 32 (9) ◽  
pp. 837-844 ◽  
Author(s):  
Margaret M. Williams ◽  
Tai-Ho Chen ◽  
Tim Keane ◽  
Nadege Toney ◽  
Sean Toney ◽  
...  
Keyword(s):  
Water Supply ◽  
Potable Water ◽  
Skilled Nursing Facility ◽  
Water System ◽  
Nursing Facility ◽  
Mycobacterium Chelonae ◽  
Skilled Nursing ◽  
Rapidly Growing Mycobacteria ◽  
Membrane Filters ◽  
Point Of Use

Background.Healthcare-associated outbreaks and pseudo-outbreaks of rapidly growing mycobacteria (RGM) are frequently associated with contaminated tap water. A pseudo-outbreak ofMycobacterium chelonae–M. abscessusin patients undergoing bronchoscopy was identified by 2 acute care hospitals. RGM was identified in bronchoscopy specimens of 28 patients, 25 of whom resided in the same skilled nursing facility (SNF). An investigation ruled out bronchoscopy procedures, specimen collection, and scope reprocessing at the hospitals as sources of transmission.Objective.To identify the reservoir for RGM within the SNF and evaluate 2 water system treatments, hyperchlorination and point-of-use (POU) membrane filters, to reduce RGM.Design.A comparative in situ study of 2 water system treatments to prevent RGM transmission.Setting.An SNF specializing in care of patients requiring ventilator support.Methods.RGM and heterotrophic plate count (HPC) bacteria were examined in facility water before and after hyperchlorination and in a subsequent 24-week assessment of filtered water by colony enumeration on Middlebrook and R2A media.Results.Mycobacterium chelonaewas consistently isolated from the SNF water supply. Hyperchlorination reduced RGM by 1.5 log10initially, but the population returned to original levels within 90 days. Concentration of HPC bacteria also decreased temporarily. RGM were reduced below detection level in filtered water, a 3-log10reduction. HPC bacteria were not recovered from newly installed filters, although low quantities were found in water from 2-week-old filters.Conclusion.POU membrane filters may be a feasible prevention measure for healthcare facilities to limit exposure of sensitive individuals to RGM in potable water systems.

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