Premium
A High‐Volume Sampling Method for Total Coliform and E. Coli
Author(s) -
Hargy Thomas M.,
Rosen Jeffrey,
Lechevallier Mark,
Friedman Melinda,
Clancy Jennifer L.
Publication year - 2010
Publication title -
journal ‐ american water works association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.466
H-Index - 74
eISSN - 1551-8833
pISSN - 0003-150X
DOI - 10.1002/j.1551-8833.2010.tb10074.x
Subject(s) - coliform bacteria , sample (material) , volume (thermodynamics) , fecal coliform , sampling (signal processing) , contamination , environmental science , chemistry , mathematics , chromatography , water quality , biology , bacteria , filter (signal processing) , physics , ecology , computer science , genetics , quantum mechanics , computer vision
To better define the presence of coliform bacteria and Escherichia coli in drinking water distribution systems, a capsule filter sample method was developed for collecting volumes larger than the conventional 100‐mL sample. Bench studies indicated this method was capable of consistent detection of the presence of low concentrations of seeded total coliforms and E. coli in 20‐L sample volumes. Field trials in distribution systems were performed at three utilities. In 252 sample sets, the 20‐L method detected total coliform in 18 samples, but in only two were the corresponding 100‐mL samples total coliform‐positive. E. coli was not detected by either sample method at any location. These results indicate that distribution water quality may be better characterized using this high‐volume method and suggest that the presence of total coliform positives is a function of sample volume rather than an indicator of water quality.