title: Regrowth of potential opportunistic pathogens and algae in reclaimed-water distribution systems.
abstract: A study of the quality of reclaimed water in treated effluent, after storage, and at three points in the distribution system of four plants in California, Florida, Massachusetts, and New York was conducted for 1 year. The plants had different treatment processes (conventional versus membrane bioreactor), production capacities, and methods for storage of the water, and the intended end uses of the water were different. The analysis focused on the occurrence of indicator bacteria (heterotrophic bacteria, coliforms, Escherichia coli, and enterococci) and opportunistic pathogens (Aeromonas spp., enteropathogenic E. coli O157:H7, Legionella spp., Mycobacterium spp., and Pseudomonas spp.), as well as algae. Using immunological methods, E. coli O157:H7 was detected in the effluent of only one system, but it was not detected at the sampling points, suggesting that its survival in the system was poor. Although all of the treatment systems effectively reduced the levels of bacteria in the effluent, bacteria regrew in the reservoir and distribution systems because of the loss of residual disinfectant and high assimilable organic carbon levels. In the systems with open reservoirs, algal growth reduced the water quality by increasing the turbidity and accumulating at the end of the distribution system. Opportunistic pathogens, notably Aeromonas, Legionella, Mycobacterium, and Pseudomonas, occurred more frequently than indicator bacteria (enterococci, coliforms, and E. coli). The Mycobacterium spp. were very diverse and occurred most frequently in membrane bioreactor systems, and Mycobacterium cookii was identified more often than the other species. The public health risk associated with these opportunistic pathogens in reclaimed water is unknown. Collectively, our results show the need to develop best management practices for reclaimed water to control bacterial regrowth and degradation of water before it is utilized at the point of use.
authors.affiliation: American Water Research Laboratory, 213 Carriage Lane, Delran, NJ 08075, USA. patrick.jjemba@amwater.com
authors.forename: Patrick K
authors.initials: PK
authors.lastname: Jjemba
authors.forename: Lauren A
authors.initials: LA
authors.lastname: Weinrich
authors.forename: Wei
authors.initials: W
authors.lastname: Cheng
authors.forename: Eugenio
authors.initials: E
authors.lastname: Giraldo
authors.forename: Mark W
authors.initials: MW
authors.lastname: Lechevallier
mesh_terms: D000333:Aeromonas / Q000254:growth & development; D001419:Bacteria / Q000254:growth & development*; D019149:Bioreactors; D002140:California; D056890:Eukaryota / Q000254:growth & development*; D005431:Florida; D007875:Legionella / Q000254:growth & development; D008404:Massachusetts; D009161:Mycobacterium / Q000254:growth & development; D009518:New York; D009894:Opportunistic Infections / Q000382:microbiology*; D014871:Water Microbiology; D014876:Water Pollution; D018508:Water Purification / Q000379:methods*; D014881:Water Supply
references.citation: Appl Environ Microbiol. 2001 Mar;67(3):1225-31
references.pmid: 11229914
references.citation: J Clin Microbiol. 1997 Nov;35(11):2969-73
references.pmid: 9350770
references.citation: Appl Environ Microbiol. 2005 Feb;71(2):734-40
references.pmid: 15691924
references.citation: Appl Environ Microbiol. 2005 Jun;71(6):3163-70
references.pmid: 15933017
references.citation: Appl Environ Microbiol. 2007 May;73(9):2854-9
references.pmid: 17337541
references.citation: J Appl Bacteriol. 1990 May;68(5):519-25
references.pmid: 2196257
references.citation: Infect Immun. 1999 Sep;67(9):4427-34
references.pmid: 10456883
references.citation: Am J Epidemiol. 1989 Sep;130(3):557-68
references.pmid: 2764000
references.citation: Appl Environ Microbiol. 1990 Jan;56(1):49-53
references.pmid: 1968736
references.citation: J Occup Environ Hyg. 2007 Aug;4(8):634-46
references.pmid: 17577752
references.citation: Environ Sci Technol. 2005 May 1;39(9):3289-94
references.pmid: 15926580
references.citation: Water Res. 2008 Nov;42(17):4439-48
references.pmid: 18762313
references.citation: J Microbiol Methods. 2009 Feb;76(2):128-35
references.pmid: 18950664
references.citation: J Appl Microbiol. 1998 Mar;84(3):383-92
references.pmid: 9721643
references.citation: Appl Environ Microbiol. 2002 Mar;68(3):1025-32
references.pmid: 11872446
references.citation: Environ Sci Technol. 2005 Nov 15;39(22):8600-5
references.pmid: 16323753
references.citation: Eur J Clin Microbiol Infect Dis. 1997 Dec;16(12):883-92
references.pmid: 9495668
references.citation: Appl Environ Microbiol. 2006 Sep;72(9):5974-81
references.pmid: 16957218
references.citation: Infect Immun. 1994 Aug;62(8):3254-61
references.pmid: 8039895
references.citation: Int J Syst Evol Microbiol. 2004 May;54(Pt 3):699-703
references.pmid: 15143011
references.citation: Appl Environ Microbiol. 2005 Jan;71(1):20-8
references.pmid: 15640165
references.citation: J Clin Microbiol. 1993 Feb;31(2):175-8
references.pmid: 8381805
references.citation: J Clin Microbiol. 2000 Aug;38(8):2846-52
references.pmid: 10921937
references.citation: Appl Environ Microbiol. 2000 Apr;66(4):1702-5
references.pmid: 10742264
references.citation: Lett Appl Microbiol. 1998 May;26(5):352-4
references.pmid: 9674164
references.citation: Appl Environ Microbiol. 2009 Dec;75(23):7385-90
references.pmid: 19820156
references.citation: Lett Appl Microbiol. 1999 Oct;29(4):211-5
references.pmid: 10583745